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BACKGROUND:Piezo1,a mechanosensitive protein,is tightly connected to osteogenic differentiation,and it has been demonstrated that TAZ has a role in regulating osteogenic differentiation.It is unclear whether TAZ participates in the regulation of osteogenic differentiation of human bone marrow mesenchymal stem cells by Piezo1,so it is crucial to investigate its unique mechanism to prevent osteonecrosis of the femoral head. OBJECTIVE:To elucidate what function Piezo1 plays in osteogenic differentiation and TAZ expression in human bone marrow mesenchymal stem cells. METHODS:The siRNA targeting Piezo1 was constructed and transfected into 293T cells.The silencing efficiency was detected by RT-qPCR.The selected Piezo1-Home-2337 was packaged according to the silencing efficiency,and its optimal multiplicity of infection value was assayed by immunofluorescence staining.The packaged Piezo1 silencing recombinant lentivirus was transfected into human bone marrow mesenchymal stem cells,and its silencing effect was detected by RT-qPCR and western blot assay.Alizarin red staining,alkaline phosphatase activity analysis,immunofluorescence staining,RT-qPCR and western blot assay were utilized to analyze the effect of silencing Piezo1 on the osteogenic differentiation of human bone marrow mesenchymal stem cells. RESULTS AND CONCLUSION:(1)The mRNA and protein levels of Piezo1 in human bone marrow mesenchymal stem cells transfected by si-Piezo1 were decreased significantly,with a statistically significant difference compared with normal and negative control groups.(2)The alkaline phosphatase activity in the si-Piezo1 group was much lower and the calcium deposition in the si-Piezo1 group was significantly reduced compared with the negative control group.(3)The mRNA levels of osteogenesis-related genes including Runt-related transcription factor 2(Runx2),osteopontin(OPN),distal-less homeobox 5(DLX5),osteocalcin,β-catenin and Tafazzin(TAZ)in the si-Piezo1 group were significantly decreased compared with the negative control group.Afterward,the expression levels of TAZ and β-catenin protein in the si-Piezo1 group were down-regulated significantly compared with the negative control group,whereas the expression levels of p-TAZ and p-β-catenin protein in the si-Piezo1 group had the opposite condition.(4)The results of immunofluorescence staining showed that the expression of TAZ and β-catenin in human bone marrow mesenchymal stem cells in the si-Piezo1 group was less compared with the negative control group.(5)These findings indicate that Piezo1 can promote the osteogenic differentiation of human bone marrow mesenchymal stem cells.The osteogenic ability of human bone marrow mesenchymal stem cells is significantly reduced after silencing Piezo1,and the expression of TAZ is also reduced.
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BACKGROUND:Irisin,a myokine isolated from the transmembrane protein FNDC5 by muscle cells during exercise,has the function of inducing the browning of white adipose tissue,but its effect on lipotoxicity-induced osteogenic differentiation and the mechanism is unclear. OBJECTIVE:To investigate the effect of irisin on the osteogenic ability of palmitic acid-induced bone marrow mesenchymal stem cells and the mechanism of action. METHODS:CCK-8 assay was used to detect the effect of different concentrations of palmitic acid on the proliferation of mouse bone marrow mesenchymal stem cells and the effect of irisin on the proliferation of mouse bone marrow mesenchymal stem cells in the presence of palmitic acid.After pretreatment with irisin and palmitic acid for 24 hours,osteogenic differentiation of mouse bone marrow mesenchymal stem cells was induced by alkaline phosphatase staining as well as qRT-PCR was performed to detect the expression of osteogenesis-related genes on day 7 of osteogenic induction culture.The expression of proteins related to the AMPK/BMP2/SMAD signaling pathway was detected by western blot assay.Alizarin red staining was conducted on day 21 to detect osteogenic differences. RESULTS AND CONCLUSION:(1)The CCK-8 assay results suggested that the amplification of bone marrow mesenchymal stem cells was inversely proportional to the concentration of palmitic acid,but at 0.02 mmol/L concentration,palmitic acid had no significant effect on the amplification of bone marrow mesenchymal stem cells,and irisin did not affect the proliferation of bone marrow mesenchymal stem cells when its mass concentration was in the range of 0.1-20 μg/L.(2)Alkaline phosphatase staining and alizarin red staining showed that palmitic acid inhibited the osteogenic differentiation ability of bone marrow mesenchymal stem cells.Irisin improved palmitic acid-induced osteogenic inhibition of bone marrow mesenchymal stem cells.qRT-PCR results showed that palmitic acid could cause the downregulation of osteogenic-related genes,and irisin could inhibit this trend.(3)Western blot assay results showed that compared with the palmitic acid intervention group,irisin treatment enhanced AMPK/BMP2/SMAD signal transduction in bone marrow mesenchymal stem cells.It is found that irisin can improve the osteogenic differentiation ability of bone marrow mesenchymal stem cells pretreated with palmitic acid,and proposed that the specific mechanism might be mediated by AMPK/BMP/SMAD signaling pathway.
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BACKGROUND:Bone marrow mesenchymal stem cells(BMSCs)can release a large number of exosomes(Exos).The effect of Exos derived from BMSCs on hepatocyte apoptosis and the specific mechanism has not been fully clarified. OBJECTIVE:To explore the effect of miR-21-5p carried by Exos derived from BMSCs on apoptosis of rat liver cells and its mechanism. METHODS:Rat BMSCs were isolated and miR-21-5p NC or miR-21-5p inhibitor was transfected into BMSCs.The Exos were extracted by ultracentrifugation and named(BMSCs+miR-21-5p NC)-Exos and(BMSCs+miR-21-5p inhibitor)-Exos.BMSCs-derived Exos were co-cultured with rat hepatocytes to observe the effect of inhibiting miR-21-5p expression on the apoptosis of rat hepatocytes.The targeting relationship between miR-21-5p and PIK3R1 was verified by double luciferase reporter gene detection.TUNEL was used to detect the effect of miR-21-5p directly targeting PIK3R1 in Exos to activate the PI3K/AKT signaling pathway on hepatocyte apoptosis in BRL rats. RESULTS AND CONCLUSION:(1)The double luciferase reporting system confirmed that when PI3KR1 wild type vector and miR-21-5p mimics co-transfected 293T cells,the luciferase activity decreased significantly compared with the PI3KR1 mutant vector co-transfected group,indicating that miR-21-5p could target PIK3R1.(2)TUNEL test results showed that compared with(BMSCs+miR-21-5p NC)-Exos group,(BMSCs+miR-21-5p inhibitor)-Exos treatment significantly increased the apoptosis rate.Compared with the(BMSCs+miR-21-5p NC)-Exos group,after the addition of AKT inhibitor LY294002,the apoptosis rate was significantly increased.(3)The results indicate that Exos may inhibit the apoptosis of BRL rat hepatocytes through miR-21-5p,in which miR-21-5p directly targets PIK3R1 to activate PI3K/AKT signaling pathway.
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BACKGROUND:The repair of maxillofacial bone tissue defects is a hot and difficult point in current research and the selection of seed cells is the key.Jaw bone marrow mesenchymal stem cells are adult mesenchymal stem cells that exist in the jaw bone.They have advantages in the application of maxillofacial tissue regeneration. OBJECTIVE:To summarize the biological characteristics,osteogenic differentiation advantages of jaw bone marrow mesenchymal stem cells,and the effects of drugs,in vivo environment,and microRNAs on the osteogenic differentiation of jaw bone marrow mesenchymal stem cells. METHODS:Computers were used to perform literature retrieval in PubMed and CNKI.Chinese and English search terms were"oral,bone tissue engineering,stem cells".405 articles were retrieved and downloaded.The articles were screened according to the inclusion and exclusion criteria and 70 articles were finally included for literature review. RESULTS AND CONCLUSION:Jaw bone marrow mesenchymal stem cells were excellent seed cells for oral bone tissue engineering,and had good proliferation and osteogenic differentiation potential.Drugs,in vivo environment and microRNAs could regulate the osteogenic differentiation of jaw bone marrow mesenchymal stem cells.However,the research on jaw bone marrow mesenchymal stem cells was still in the initial stage,so more research with strong demonstration is needed to confirm that jaw bone marrow mesenchymal stem cells have more advantages in the application of maxillofacial bone tissue regeneration.
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BACKGROUND:Our previous experimental results have shown that hyaluronic acid hydrogel can act as a vehicle for bone marrow mesenchymal stem cell delivery to improve the cardiac function of rats with myocardial infarction. OBJECTIVE:To explore the molecular mechanism of bone marrow mesenchymal stem cells and hyaluronic acid hydrogel in promoting damaged heart repair. METHODS:Bone marrow mesenchymal stem cells from male Sprague-Dawley rats were isolated and cultured,and then hyaluronic acid-encapsulated bone marrow mesenchymal stem cells were cultured in vitro in a three-dimensional manner.A model of myocardial infarction was made by ligating the left anterior descending artery of female Sprague-Dawley rats.After 1 week,the model rats were screened by ultrasonic testing and then eligible ones were randomly divided into four groups:PBS group(n=12),hyaluronic acid group(n=12),bone marrow mesenchymal stem cell group(n=15),and hyaluronic acid-encapsulated bone marrow mesenchymal stem cell group(n=15).At 1 week after ligation,the model rats underwent the secondary thoracotomy followed by corresponding injections into the infarcted region and its marginal zone.The expression levels of matrix metalloproteinase-2,vascular endothelial growth factor,thymosin β4 and c-Kit were examined at post-injection day 1,week 1 and week 2 by western blot assay.At post-injection week 2,immunofluorescence staining was used to detect the differentiation of transplanted cells. RESULTS AND CONCLUSION:(1)The expression levels of matrix metalloproteinase-2 and vascular endothelial growth factor protein in the infarct zone in the bone marrow mesenchymal stem cell group were significantly up-regulated at week 1 compared with the other three groups(P<0.05).At week 2,the hyaluronic acid group had a lower expression of matrix metalloproteinase-2 and vascular endothelial growth factor protein than the other three groups(P<0.05).However,the expression of matrix metalloproteinase-2 and vascular endothelial growth factor protein in the hyaluronic acid+bone marrow mesenchymal stem cell group was not significantly different compared with the bone marrow mesenchymal stem cell group.This was primarily attributable to a prolonged paracrine effect via the controlled release of the hyaluronic acid hydrogel.This prolonged paracrine effect offsets the inhibitory effect induced by hyaluronic acid hydrogel at 2 weeks.(2)Compared with the PBS group,thymosin β4 and c-Kit expression levels in the hyaluronic acid group,bone marrow mesenchymal stem cell group and bone marrow mesenchymal stem cell+hyaluronic acid group were significantly increased(P<0.05).(3)No differentiation of transplanted cells into cardiomyocytes or blood vessels was detected 2 weeks after transplantation.(4)It is indicated that transplanted bone marrow mesenchymal stem cells promote myocardial repair through the paracrine effect,and hyaluronic acid hydrogel prolongs the paracrine effect of transplanted bone marrow mesenchymal stem cells.
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BACKGROUND:Medical hydrogels are new functional polymer materials with three-dimensional structural networks and excellent biocompatibility,which have been widely studied in the field of tissue engineering and drug carriers,but the research on the combination of medical hydrogels and Chinese medicine for the treatment of diseases based on tissue engineering is still in the early exploration stage.Therefore,through the analysis of the mechanism of the role of medical hydrogels,the integration of medical hydrogels and Chinese medicine in the research of the joint application of the article,can better provide ideas for scientific researchers,and the joint application of Chinese medicine and medical hydrogels is of great significance. OBJECTIVE:To explore the strategy and significance of Chinese medicine combined with medical hydrogel for disease treatment based on tissue engineering research. METHODS:PubMed and CNKI were used to retrieve articles about the application of Chinese medicine combined with medical hydrogel in tissue engineering from January 2010 to November 2022,with the Chinese and English search terms"hydrogel,traditional Chinese medicine,drug carrier,tissue engineering".After the initial screening of all articles according to the inclusion and exclusion criteria,the 61 articles with high relevance were retained for review. RESULTS AND CONCLUSION:(1)Although the application of Chinese medicine combined with medical hydrogel is involved in intra-articular,intra-tissue organ,soft tissue wounds,tissue engineering,etc.,except for the clinical application of Chinese medicine combined with hydrogel dressing for soft tissue injury,other aspects are still in the experimental stage.(2)The development of Chinese medicine combined with medical hydrogel has great potential and development prospects,but there is a certain difficulty in the manufacture of the gel with high-performance requirements,and it is difficult to master the physical and chemical properties precisely.(3)At present,the comprehensive view of injectable hydrogel with the characteristics of easy to use,its joint use of Chinese medicine can be extended to a wider range,can be used for joint,organ,tissue engineering-related disease treatment.Smart hydrogel has high sensitivity and reversible transformation can also meet the use of the special environment.During the combined use of Chinese medicine,it also needs to understand the mechanism of action of Chinese medicine components.(4)The strategy of combining Chinese medicine with medical hydrogels for disease treatment should start with matching the therapeutic effects of Chinese medicine on organs,tissues and cells combined with appropriate types of medical hydrogels to make up for the shortcomings of traditional Chinese medicine delivery methods and frequent drug delivery.In tissue engineering,hydrogels can be loaded with stem cells after Chinese medicine intervention,or with both Chinese medicine and stem cells for disease treatment.(5)In future research of combined Chinese medicine and medical hydrogel application,we also need to consider:we should ensure that the biological properties of medical hydrogel can be quantified,and grasp the characteristics of hydrogel with different manufacturing processes of different materials to produce the required medical hydrogel that meets the application conditions.In Chinese medicine,we need to comprehensively understand and analyze the therapeutic effects and application mechanisms of known Chinese medicine monomer and Chinese medicine compound extracts,so as to achieve a more perfect combination between Chinese medicine and medical hydrogel under a more clear mechanism.With the continuous improvement of medical science and technology innovation,the medical hydrogel can be innovatively combined with other traditional treatment methods of Chinese medicine,such as acupuncture,massage,cupping and so on,to be used from multiple angles.
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BACKGROUND:Currently,the dura mater is clinically repaired using autologous tissue or materials such as gelatin sponge,but all of them have their inherent defects.Therefore,there is an urgent need for a biomaterial that can promote dural repair. OBJECTIVE:The two-sided anisotropic electrospun membrane was constructed by using directional electrospinning technology and collagen self-assembly technology,and was used as a carrier for bone marrow mesenchymal stem cells to investigate various physicochemical properties and biological characteristics of the artificial dura mater. METHODS:Ordered polylactic acid electrospun fibers with double-sided(collagen protein on one side and polylactic acid on the other side)anisotropic electrospun membranes(collagen group),disordered polylactic acid electrospun membranes(disordered fiber group),and ordered oriented polylactic acid electrospun membranes(ordered fiber group)were prepared by electrospinning technique as well as collagen self-assembly technique.Scanning electron microscopy,mechanical stretching,water contact angle testing,and degradation experiments were used to characterize the physicochemical properties of the electrospun membranes.Electrospun membranes in the collagen group(bone marrow mesenchymal stem cells were inoculated on the collagen surface to obtain the stem cell-engineered electrospun membranes),disordered fiber group and ordered fiber group were cocultured with bone marrow mesenchymal stem cells.The biocompatibility of electrospun membranes was evaluated using CCK-8 assay and live/dead staining.Integrin β1 immunofluorescence staining was used to evaluate the adhesion characteristics of electrospun membranes.The stem cell-engineered electrospun membrane and the electrospun membrane in the collagen group were cocultured with bone marrow macrophages respectively.Immunomodulatory properties were assessed by detecting the expression of inflammation-related genes using inducible nitric oxide synthase(M1 type),CD206(M2 type)immunofluorescence staining,and qRT-PCR. RESULTS AND CONCLUSION:(1)The oriented electrospun fiber membrane could mimic the structure of the longitudinally aligned natural dura mater,and the addition of collagen increased the hydrophilicity of the fiber membrane by about 2-fold and the mechanical properties by 1.2-fold.(2)When cocultured with bone marrow mesenchymal stem cells,CCK-8 assay and live/dead staining suggested that the cellular bioactivity in the collagen group was significantly higher than that in the disordered fiber group and ordered fiber group.Immunofluorescence staining revealed that the expression of integrin β1 in the collagen group was about 2.6 times higher than that of the disordered and ordered fiber groups,and the cell spreading morphology was good.(3)When cocultured with bone marrow macrophages,immunofluorescence staining exhibited that the fluorescence intensity of M1 type macrophages in the stem cell-engineered electrospun membrane group was lower than that in the collagen group(P<0.01),and the fluorescence intensity of M2 type macrophages was higher than that in the collagen group(P<0.01).qRT-PCR demonstrated that proinflammatory gene tumor necrosis factor α and interleukin-1β mRNA expression in the stem cell-engineered electrospun membrane group was lower than that of the collagen group(P<0.001);anti-inflammatory genes such as interleukin-10 and transforming growth factor β mRNA expressions were higher than those in the collagen group(P<0.001).(4)The above results suggest that the stem cell-engineered amphipathic artificial dura mimics the directional structure of normal dura,with the inner surface facilitating cell growth and adhesion and the outer edge avoiding tissue adhesion,while the polarization of macrophages to the M2 subtype is promoted and the local inflammatory microenvironment is regulated through the mesenchymal stem cell paracrine component.
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BACKGROUND:Oral and maxillofacial bone tissue defects can seriously affect the physical and mental health of patients.When bone defects occur in diabetic patients,bone metabolism disorders caused by abnormal blood sugar make it more difficult to repair and treat. OBJECTIVE:To attempt to apply AOPDM1,a polypeptide with potential bioactivity to the osteogenic treatment of diabetic patients. METHODS:In normal or high-glucose environment,different concentrations of AOPDM1 were used to interfere with mouse bone marrow mesenchymal stem cells,and cell proliferation,alkaline phosphatase activity,mineralization nodules formation and osteogenic differentiation gene expression were detected.The polycaprolactone scaffold was prepared by electrospinning technology,and the scaffold was modified by polydopamine to prepare the polycaprolactone-polydopamine composite scaffold.Finally,the scaffolds were placed in AOPDM1 solution to prepare polycaprolactone-polydopamine-AOPDM1 scaffolds.The water contact angle and mechanical properties of the scaffolds were tested in the three groups.In normal or high-glucose environment,the three groups of scaffolds were co-cultured with mouse bone marrow mesenchymal stem cells,respectively,and cell adhesion,alkaline phosphatase activity and osteopontin expression were detected. RESULTS AND CONCLUSION:(1)Compared with normal environment,high-glucose environment inhibited the proliferation of bone marrow mesenchymal stem cells.In the same environment,AOPDM1 could promote the proliferation of mouse bone marrow mesenchymal stem cells.When AOPDM1 concentration was the same,alkaline phosphatase activity,mineralization ability and mRNA expression of type Ⅰ collagen,osteopontin,alkaline phosphatase,and Runx2 of bone marrow mesenchymal stem cells were decreased in high-glucose environment compared with normal environment.Under the same environment,AOPDM1 could improve the alkaline phosphatase activity,mineralization ability,and mRNA expression of type Ⅰ collagen,osteopontin,alkaline phosphatase and Runx2 of bone marrow mesenchymal stem cells.(2)The hydrophilicity of polycaprolactone-polydopamine scaffold and polycaprolactone-polydopamine-AOPDM1 scaffold was higher than that of polycaprolactone scaffold(P<0.001),and there was no significant difference in tensile strength and elastic modulus among the three groups(P>0.05).Compared with the other two groups of scaffolds,the cells on the polycaprolactone-polydopamine-AOPDM1 scaffold had better adhesion morphology.When the scaffolds were identical,compared with normal environment,high-glucose environment inhibited alkaline phosphatase activity and osteopontin expression of bone marrow mesenchymal stem cells.When the environment was the same,the alkaline phosphatase activity and osteopontin expression of bone marrow mesenchymal stem cells on the polycaprolactone-polydopamine-AOPDM1 scaffold were higher than those on the other two scaffolds.(3)The above results prove that polycaprolactone-polydopamine-AOPDM composite scaffold can promote the osteogenic properties of bone marrow mesenchymal stem cells in high-glucose environment.
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BACKGROUND:Bone marrow mesenchymal stem cells have been widely used to treat neurological diseases.However,due to limitations of the blood-brain barrier,low survival rate and differentiation rate of stem cells at damaged sites,the therapeutic effect is limited. OBJECTIVE:To investigate the effects of Shexiang Huangqi compound dripping pills on proliferation,migration and astrocyte differentiation of bone marrow mesenchymal stem cells. METHODS:Male SD rats were treated with Shexiang Huangqi compound dripping pills for 5 days after continuous gavage.Blood was collected from the abdominal aorta and serum was separated for later use.The effect of 5%,10%and 20%drug-containing serum on the proliferation of bone marrow mesenchymal stem cells was detected by CCK-8 assay.The effect of 10%drug-containing serum on lateral migration of bone marrow mesenchymal stem cells was observed by scratch test.Bone marrow mesenchymal stem cells were cultured in Transwell cells.The effects of 10%drug-containing serum on longitudinal migration of bone marrow mesenchymal stem cells were observed by crystal violet staining and DAPI nuclear staining.Differentiation of bone marrow mesenchymal stem cells into astrocytes was observed by inducing solution with 10%drug-containing serum or co-culture with astrocytes. RESULTS AND CONCLUSION:(1)10%and 20%drug-containing serum promoted cell proliferation more significantly on days 2 and 3,and there was no statistical difference between the two concentrations.(2)At 30 and 48 hours,bone marrow mesenchymal stem cell migration in 10%drug-containing serum group was significantly higher than that in the control group.(3)The number of bone marrow mesenchymal stem cells filtered through Transwell cells in 10%drug-containing serum group was higher than that in the control group.(4)10%drug-containing serum might promote the differentiation of bone marrow mesenchymal stem cells to astrocytes,but the differentiation effect was weak,and astrocytes might further promote the differentiation of bone marrow mesenchymal stem cells into astrocytes induced by drug-containing serum.(5)The results exhibited that the 10%drug-containing serum could promote the proliferation and migration of bone marrow mesenchymal stem cells in vitro.Co-culture with astrocytes may promote the differentiation of bone marrow mesenchymal stem cells towards astrocytes.
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BACKGROUND:The implant osseointegration rate of patients with diabetes is low,and the failure rate is high,which seriously affects the quality of life.It is urgent to improve the implant osseointegration of patients with diabetes by effective means to elevate the success rate.Exploring the effect of berberine on the osteogenic differentiation of bone marrow mesenchymal stem cells under a high-glucose environment and its specific mechanism will provide effective theoretical support for solving the above problems. OBJECTIVE:To explore the effect of natural extract berberine on the osteogenic differentiation of rat bone marrow mesenchymal stem cells under the high-glucose microenvironment. METHODS:Bone marrow mesenchymal stem cells of SD rats were cultured by the whole bone marrow adherence method.CCK-8 assay was used to detect the effects of different concentrations of berberine on the proliferation of bone marrow mesenchymal stem cells under the high-glucose environment and to screen out the optimal berberine concentration.The expressions of Runx2 and Osx were detected by alkaline phosphatase activity,alicarin red staining and PCR to determine the effect of berberine on osteogenic differentiation of bone marrow mesymal stem cells under the high-glucose environment.To further explore the underlying mechanism,we introduced the AMPK-specific inhibitor Dorsomorphin and used a DCFH-DA reactive oxygen species fluorescent probe to examine reactive oxygen species levels.The p-AMPK expression was also determined by western blot assay. RESULTS AND CONCLUSION:(1)10 μmol/L was the optimal concentration of berberine to promote bone marrow mesenchymal stem cell proliferation.(2)Alberberine promoted alkaline phosphatase viability of bone marrow mesenchymal stem cells and mineralized nodule formation in a high-glucose microenvironment.(3)Alberberine promoted the expression of Runx2 and OSx in a high-glucose microenvironment.(4)Alberensine effectively inhibited the reactive oxygen species level of bone marrow mesenchymal stem cells in a high-glucose environment.(5)The effects of berberine on promoting bone marrow mesenchymal stem cell osteogenesis and inhibition of reactive oxygen species were reversed by the AMPK inhibitor.(6)Berberine activated AMPK and promoted p-AMPK expression.(7)The above results indicate that berberine(10 μmol/L)promotes the osteogenic differentiation of bone marrow mesenchymal stem cells in a high-glucose environment by activating AMPK and reducing intracellular reactive oxygen species levels.
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BACKGROUND:In recent years,some scholars in the field of tendon bone injury have attached stromal cell-derived factor 1 to tissue engineering scaffolds to promote tendon bone healing,and achieved good results.However,whether stromal cell-derived factor 1 promotes tendon bone healing mechanisms and participates in the repair of natural healing has not yet been defined. OBJECTIVE:To study the expression of stroma-cell derived factor 1 during tendon bone healing after rupture of the whole supraspinatus muscle of the rabbit rotator cuff and its migration effect and optimal in vitro migration promoting concentration on stem cells during tendon bone injury. METHODS:Totally 18 adult New Zealand rabbits were randomly selected to establish rotator cuff injury models,and an additional 3 rabbits were selected as blank controls.At 3,5,7,14,21,and 28 days after modeling,three rabbits were executed separately and the rabbits in the blank group were sacrificed.The tissues of tendon bone junction were taken and stored in a-80℃refrigerator.The expression of stromal cell-derived factor 1 was detected by ELISA at each time point after injury.Mesenchymal stem cells were isolated from the bone marrow of young rabbit femur,cultured,and identified.Transwell assay was performed to verify the migration-promoting effect of stromal cell-derived factor 1 on stem cells and the optimal migration-promoting concentration in vitro.The stem cells cultured to P3 were co-cultured with BrdU and injected into the rabbit ear marginal vein,and immunohistochemical staining was used to verify whether the stem cells migrated to the injury site. RESULTS AND CONCLUSION:(1)Stromal cell-derived factor 1 gene expression was bimodal during rotator cuff tendon bone healing.Stromal cell-derived factor 1 gene expression increased significantly at 3 days post-injury(P<0.01)and then decreased,reaching a minimum at 5 days post-injury.It increased again and reached a peak 14 days after injury(P<0.01)and then decreased.(2)Cell immunohistochemical staining displayed that stem cells labeled with BrdU did migrate to the injury site.(3)The results of the transwell experiment exhibited that 60-80 ng/mL stromal cell-derived factor 1 had the best effect on promoting migration of stem cells,while a concentration of 200 ng/mL inhibited migration.(4)Stromal cell-derived factor 1 is involved in the healing of rotator cuff tendon bone during the inflammatory response phase and the proliferation phase.The mechanism of action may be to promote the migration of stem cells to the injury and their differentiation into various types of cells to promote repair.In addition,the pro-migration effect of stromal cell-derived factor 1 exists at a range of concentrations,beyond which it may act as an inhibitor.
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BACKGROUND:As tissue engineering brings new hope to the worldwide problem of articular cartilage repair,the construction of light-curing 3D printed hydrogel scaffolds with biomimetic composition is of great significance for cartilage tissue engineering. OBJECTIVE:To construct a biomimetic methacryloylated hyaluronic acid/acellular Wharton's jelly composite hydrogel scaffold by digital light processing 3D printing technology,and to evaluate its biocompatibility. METHODS:Wharton's jelly was isolated and extracted from human umbilical cord,then decellulated,freeze-dried,ground into powder,and dissolved in PBS to prepare 50 g/L acellular Wharton's jelly solution.Methylallylated hyaluronic acid was prepared,lyophilized and dissolved in PBS to prepare 50 g/L methylallylated hyaluronic acid solution.Acellular Wharton's jelly solution was mixed with methacrylyacylated hyaluronic acid solution at a volume ratio of 1:1,and was used as bio-ink after adding photoinitiator.Methylacrylylated hyaluronic acid hydrogel scaffolds(labeled as HAMA hydrogel scaffolds)and methylacrylylated hyaluronic acid/acellular Wharton's jelly gel scaffolds(labeled as HAMA/WJ hydrogel scaffolds)were prepared by digital light processing 3D printing technology,and the microstructure,swelling performance,biocompatibility,and cartilage differentiation performance of the scaffolds were characterized. RESULTS AND CONCLUSION:(1)Under scanning electron microscope,the two groups of scaffolds showed a three-dimensional network structure,and the fiber connection of HAMA/WJ hydrogel scaffold was more uniform.Both groups achieved swelling equilibrium within 10 hours,and the equilibrium swelling ratio of HAMA/WJ hydrogel scaffold was lower than that of HAMA hydrogel scaffold(P＜0.05).(2)CCK-8 assay showed that HAMA/WJ hydrogel scaffold could promote the proliferation of bone marrow mesenchymal stem cells compared with HAMA hydrogel scaffold.Dead/live staining showed that bone marrow mesenchymal stem cells grew well on the two groups of scaffolds,and the cells on the HAMA/WJ hydrogel scaffolds were evenly distributed and more cells were found.Phalloidine staining showed better adhesion and spread of bone marrow mesenchymal stem cells in HAMA/WJ hydrogel scaffold than in HAMA.(3)Bone marrow mesenchymal stem cells were inoculated into the two groups for chondrogenic induction culture.The results of qRT-PCR showed that the mRNA expressions of agglutinoglycan,SOX9 and type Ⅱ collagen in the HAMA/WJ hydrogel scaffold group were higher than those in the HAMA hydrogel scaffold group(P＜0.05,P＜0.01).(4)These findings indicate that the digital light processing 3D bioprinting HAMA/WJ hydrogel scaffold can promote the proliferation,adhesion,and chondrogenic differentiation of bone marrow mesenchymal stem cells.
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BACKGROUND:In recent years,research on the interaction mechanism between the immune system and the skeleton in postmenopausal osteoporosis has become a hot topic.However,the impact of changes in key immune-related cytokine expression on postmenopausal osteoporosis remains unclear and requires further exploration. OBJECTIVE:To investigate the differential expression of immune-related cytokines in bone marrow mesenchymal stem cells of mice with postmenopausal osteoporosis by bioinformatics methods. METHODS:Postmenopausal osteoporosis mouse model was established through ovariectomy.Bone marrow mesenchymal stem cells were obtained by the whole bone marrow adherence method and passaged to passage 2.RayBio L-Series Mouse Antibody Array 308 Glass Slide Kit immune-related factor antibody chip was used to detect the differentially expressed proteins in bone marrow mesenchymal stem cells from ovariectomy and sham-operation mice.Gene ontology,Kyoto Encyclopedia of Genes and Genomes enrichment analysis,and protein-protein interaction network analysis were performed to screen common Hub genes by MCC,EPC,and MNC algorithms. RESULTS AND CONCLUSION:This study identified a total of 68 differentially expressed genes.Gene ontology analysis revealed that the differentially expressed genes were enriched in terms including"immune system processes","extracellular regions",and"signal receptor binding".Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed that the differentially expressed genes were mainly enriched in"cytokine-cytokine receptor interactions","tumor necrosis factor signaling pathways",and"chemokine signaling pathways".Further screening was performed by constructing a protein-protein interaction network analysis of these 68 differentially expressed genes to identify 8 Hub genes.The violin plot and correlation matrix showed that the expression levels of these 8 Hub genes were significantly down-regulated in the ovariectomy group compared to the sham-operation group.These results demonstrated that there was differential expression of immune-related factors in bone marrow mesenchymal stem cells of postmenopausal osteoporosis mice,and key genes involved in cytokine-cytokine receptor interactions,immune system-related processes,and potential targeted signaling pathways and cellular biological processes were identified,providing new promising targets for the diagnosis,treatment,and prevention of postmenopausal osteoporosis.
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BACKGROUND:Numerous basic and clinical trials have confirmed that the low survival rate after bone marrow mesenchymal stem cell transplantation is a serious constraint on its long-term therapeutic effect.Previous studies have shown that apoptosis-related factors play an important role in the apoptosis of bone marrow mesenchymal stem cells,of which apoptosis-inducing factor may be a key factor. OBJECTIVE:Bone marrow mesenchymal stem cells,of which apoptosis-inducing factor was knocked down,were transplanted into infarcted myocardium of mice,aiming to certify the importance of apoptosis-inducing factor in the survival of bone marrow mesenchymal stem cells to further recover cardiac function after infarction. METHODS:Firstly,bone marrow mesenchymal stem cells were infected with LV-AIF-shRNA lentivirus to down-regulate the expression of apoptosis-inducing factor protein.Flow cytometry,western blot assay,and RT-qPCR were used to detect the infection efficiency of lentivirus.CCK-8 assay was used to detect the cell viability of bone marrow mesenchymal stem cells with apoptosis-inducing factor knockdown under hypoxic and ischemic conditions.Then,with the mouse model of acute myocardial infarction constructed,the normal bone marrow mesenchymal stem cells and bone marrow mesenchymal stem cells with apoptosis-inducing factor gene knockdown were transplanted into the model,respectively.The expression of apoptosis-inducing factor was examined by fluorescence immunoassay.Serum brain natriuretic peptide levels were detected by ELISA.Cardiac ultrasound was used to detect cardiac function.Myocardial fibrosis was observed by Masson staining.The expression of SRY gene was detected by RT-qPCR in apoptosis-inducing factor-knocked bone marrow mesenchymal stem cells after transplantation,reflecting cell survival. RESULTS AND CONCLUSION:(1)Bone marrow mesenchymal stem cells with apoptosis-inducing factor gene knockdown were successfully established by LV-AIF-shRNA lentivirus infection,following 97.7%of infection efficiency,and notably decline of the expression of apoptosis-inducing factor(P<0.001).(2)Under ischemia and hypoxia,the cell viability of apoptosis-inducing factor knockdown bone marrow mesenchymal stem cells was significantly increased compared with normal bone marrow mesenchymal stem cells.(3)Compared with normal bone marrow mesenchymal stem cells after transplantation,the survival number of bone marrow mesenchymal stem cells in the infarcted myocardium after apoptosis-inducing factor gene knockdown was significantly increased to 3.71 times(P<0.001),and the apoptosis-inducing factor protein expression and myocardial fibrosis degree in the infarcted area were significantly reduced.(4)Compared with normal bone marrow mesenchymal stem cells,the serum brain natriuretic peptide level of bone marrow stem cells with apoptosis-inducing factor gene knockdown after transplantation was significantly decreased(P<0.05),and left ventricular ejection fraction and left ventricular shortening fraction were significantly improved(P<0.05).(5)These findings confirm that apoptosis-inducing factor gene knockdown can reduce myocardial fibrosis and improve cardiac function after acute myocardial infarction via enhancing the bone marrow mesenchymal stem cell viability and increasing the bone marrow mesenchymal stem cell survival after transplantation in the donor.
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BACKGROUND:Stem cell therapy is an alternative treatment strategy for restoring damaged myocardial tissue after acute myocardial infarction.Exercise preconditioning can induce endogenous cardioprotective effects in the body.However,the efficacy and mechanism of the combined application are still unclear. OBJECTIVE:To explore the effect and possible mechanism of exercise preconditioning combined with bone marrow mesenchymal stem cells on the therapeutic effect in rats with acute myocardial infarction. METHODS:Seventy male SD rats were randomly divided into sham operation group,model group,stem cell therapy group,exercise preconditioning group,and combined intervention group.Rats in the exercise preconditioning group and combined intervention group underwent 8-week aerobic exercise on the treadmill before modeling.The animal model of acute myocardial infarction was made by ligating the anterior descending coronary artery.The stem cell therapy group and the combined intervention group were injected with bone marrow mesenchymal stem cells(1×109 L-1,1 mL)through the tail vein the next day after modeling.After 4 weeks of treatment,the exercise performance was evaluated by a graded treadmill exercise test.The cardiac structure and function were detected by echocardiography.The left ventricle was isolated.2,3,5-Triphenyltetrazolium chloride staining was used to evaluate myocardial infarct size.Masson staining was used to obtain collagen volume fraction.CD31 immunohistochemical staining was used to detect myocardial capillary density.TUNEL staining was used to detect myocardial cell apoptosis.Immunoblotting was used to detect protein expression levels of stromal cell-derived factor 1,CXC chemokine receptor protein 4,tumor necrosis factor-α,interleukin-10,and vascular endothelial growth factor. RESULTS AND CONCLUSION:(1)Intervention efficacy:Compared with the sham operation group,exercise performance,left ventricular ejection fraction,left ventricular fractional shortening,and CD31 positive cell rate decreased(P<0.05);myocardial infarct size,collagen volume fraction,and myocardial apoptotic rate increased(P<0.05)in the model group.Compared with the model group,exercise performance was not statistically significant(P>0.05)in the stem cell therapy group,and the exercise performance improved(P<0.05)in the exercise preconditioning and combined intervention groups;left ventricular ejection fraction,left ventricular fractional shortening,and CD31 positive cell rate increased(P<0.05),and the myocardial infarct size,collagen volume fraction,and cardiomyocyte apoptosis rate decreased(P<0.05)in the stem cell therapy,exercise preconditioning,and combined intervention groups.Compared with the stem cell therapy group,exercise performance,left ventricular ejection fraction,left ventricular shortening fraction,and CD31 positive cell rate increased(P<0.05),myocardial infarct size,collagen volume fraction,and myocardial cell apoptosis rate decreased(P<0.05)in the combined intervention group.(2)Protein expression:Compared with the sham operation group,the expression of tumor necrosis factor-α increased(P<0.05),while interleukin-10 and vascular endothelial growth factor expression decreased(P<0.05)in the model group.Compared with the model group,the expression of CXC chemokine receptor protein 4 increased(P<0.05)in the stem cell therapy group and combined intervention group,and the expression of tumor necrosis factor-α decreased(P<0.05)while interleukin-10 and vascular endothelial growth factor increased(P<0.05)in the stem cell therapy group,exercise preconditioning group,and combined intervention group.Compared with the stem cell therapy group,the expression of tumor necrosis factor-α decreased(P<0.05),while CXC chemokine receptor protein 4,interleukin-10,and vascular endothelial growth factor increased(P<0.05)in the combined intervention group.To conclude,exercise preconditioning can enhance the therapeutic effect of bone marrow mesenchymal stem cells in rats with acute myocardial infarction,which can inhibit cardiac remodeling,improve cardiac function,and delay the progress of heart failure.Its mechanism is related to the promotion of stem cell homing,inhibition of inflammatory response,and promotion of angiogenesis.
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BACKGROUND:Recent studies have shown that the occurrence and prevention of osteoporosis often focus on the cellular molecular level,and the mechanism of related signaling pathways is an important way to further understand osteoporosis.At present,traditional Chinese medicine has been proved to play a significant role in alleviating osteoporosis.Kaempferol as an emerging Chinese herbal extract has become the focus of clinical and basic research due to its anti-osteoporosis effectiveness and mechanism of action. OBJECTIVE:To further understand the mechanism underlying the anti-osteoporosis effect of kaempferol active monomer through regulation of related signaling pathways by analyzing and collating domestic and foreign literature. METHODS:"Kaempferol,osteoporosis,osteoblasts,osteoclasts,bone marrow mesenchymal stem cells,signaling pathways"were used as Chinese and English search terms to search CNKI,WanFang,VIP,PubMed,Web of Science and Embase databases for relevant literature published from database inception to February 2023. RESULTS AND CONCLUSION:Kaempferol affects the occurrence and progression of osteoporosis to varying degrees by participating in the regulation of differentiation,proliferation and apoptosis of bone marrow mesenchymal stem cells,osteoblasts and osteoclasts.Kaempferol can prevent and treat osteoporosis by regulating various signaling pathways.Kaempferol can promote the proliferation and differentiation of osteoblasts and inhibit the formation of osteoclasts by interfering with the Wnt/β-catenin signaling pathway to regulate β-catenin protein counting and the formation of β-catenin-TCf/LEF complex.Kaempferol interferes with the RANK/RANKL pathway to maintain the dynamic balance of osteoclasts and bone homeostasis.Kaempferol can promote bone formation by intervening with the PI3K/Akt signaling pathway to upregulate the levels of related osteogenic factors Runx2 and Osterix and promote bone cell calcification.Kaempferol interferes with osteoclast differentiation and inhibits reactive oxygen species activity by regulating the ER/ERK pathway.Kaempferol inhibits the expression of ERK,JNK,p38/MAPK and decreases reactive oxygen species production by interfering with the MAPK pathway,thus protecting osteogenesis.Kaempferol enhances the expression of osteogenic factors,bone morphogenetic protein-2,p-Smad1/5/8,β-catenin and Runx2,inhibits the expression of Peroxisome proliferation-activated receptor,and promotes the differentiation and proliferation of osteoblasts through the BMP/Smad pathway.
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BACKGROUND:The pathogenesis of osteoporosis is complex,and its essence is the weakening of bone formation and the enhancement of bone absorption caused by various reasons,resulting in the imbalance of bone metabolism.In recent years,N6-methyladenosine has been found(N6-methyladenosine,m6A)methylation can prevent and treat osteoporosis by regulating bone metabolism. OBJECTIVE:Taking the regulation of bone metabolism by m6A methylation as an entry point,to systematically sort out and summarize the research progress of m6A methylation in osteoporosis,so as to provide certain theoretical reference bases for the search of new therapeutic targets for osteoporosis. METHODS:CNKI,WanFang,VIP,PubMed,MEDLINE,Nature,and Cochrane databases were retrieved for relevant literature published from database inception to 2023.The keywords were"osteoporosis,m6A methylation,bone metabolism,bone marrow mesenchymal stem cells,osteoblasts,osteoclasts"in Chinese and English.Duplicates and obsolete non-referenced documents were excluded,and a total of 73 standard papers were included for further review. RESULTS AND CONCLUSION:m6A methylation can affect the activity and differentiation of bone marrow mesenchymal stem cells,osteoblasts,and osteoclasts through various pathways to regulate bone metabolism and prevent osteoporosis.The regulatory process of m6A methylation is extremely complex,and its related proteins play different roles in different cells.Even in the same kind of cells,the same type of proteins may have radically different roles,regulating different physiological and pathological processes.
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BACKGROUND:The occurrence and development of various ophthalmic diseases are closely related to excessive oxidative stress,and the inhibition of oxidative stress response may produce preventive and therapeutic effects. OBJECTIVE:To explore the role of Pax6 gene expression on hydrogen peroxide-induced aging of mouse bone marrow mesenchymal stem cells(BM-MSCs). METHODS:Resuscitated BM-MSCs,Pax6/BM-MSCs,and shPax6/BM-MSCs were treated with hydrogen peroxide for 24 hours,and then β-galactosidase staining was performed.The proliferation index Ki67 expression and apoptosis were detected by flow cytometry.The expression of senescence-associated molecules(Wnt7a,p21,and p53)was detected by RT-PCR. RESULTS AND CONCLUSION:(1)After hydrogen peroxide treatment,the cells of the three groups showed senescence phenotype and β-galactosidase staining was positive.Compared with BM-MSCs group,the expression of positive cells in Pax6/BM-MSCs group was less and that in the shPax6/BM-MSCs group was more,and the difference was statistically significant(P<0.05).(2)The results of flow cytometry showed that compared with BM-MSCs group,the positive expression of Ki67 in the Pax6/BM-MSCs group increased and the level of apoptosis decreased,while the positive expression of Ki67 decreased and the level of apoptosis increased in the shPax6/BM-MSCs group;the difference was significantly different(P<0.05).(3)RT-PCR showed that compared with the BM-MSCs group,the expression of Wnt7a,p53,and p21 decreased in the Pax6/BM-MSCs group,while the expression of Wnt7a,p53,and p21 increased in the shPax6/BM-MSCs group;the difference was significantly different(P<0.05).(4)These findings indicate that overexpression of Pax6 can antagonize the aging progression of BM-MSCs induced by hydrogen peroxide,which may be related to Wnt signaling pathway.
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BACKGROUND:There is still controversy whether human bone marrow mesenchymal stem cells can maintain their biological characteristics,energy metabolism patterns,and multidirectional differentiation potential after long-term expression in vitro.Further comprehensive and systematic research is needed. OBJECTIVE:To evaluate the effects of long-term expansion in vitro on the biological characteristics of mesenchymal stem cells. METHODS:Human bone marrow mesenchymal stem cells cultured to passage 5,10,and 15 in vitro.MTT assay was used to detect cell proliferation ability.Flow cytometry was used to detect cell cycle.The multi-differentiation potential of mesenchymal stem cells was detected by inducing to adipogenic,osteogenic and chondrogenic differentiation.Cell migration and invasion abilities were detected by scratch test and Transwell assay.The mitochondrial oxidative phosphorylation and glycolysis function were analyzed using energy metabolism analyzer.The cell senescence was detected by senescence-associated β-galactosidase staining.The expression levels of p21,p16,and p53 proteins were detected by western blot assay. RESULTS AND CONCLUSION:Bone marrow mesenchymal stem cells at passages 5,10,and 15 grew adherently;the volume of passage 15 mesenchymal stem cells increased and its proliferation ability decreased;the percentage of S-phase cells decreased(P<0.05).With the increase of culture passages,the migration and invasion abilities decreased gradually(P<0.05).There was no significant difference in the differentiation potential,demonstrated by adipogenic,osteogenic and chondrogenesis induction.The ability of oxidative phosphorylation of mitochondria and glycolysis decreased gradually(P<0.05).The number of senescence-associated β-galactosidase-positive cells increased with the increase of passages(P<0.05),and the expression of senescence protein p21,p16,and p53 increased gradually(P<0.05).The results indicated that the biological characterization of mesenchymal stem cells changed after long-term in vitro expansion.Mesenchymal stem cells cultured over 10 passages may have a reduced activity due to increasing senescence.Therefore,bone marrow mesenchymal stem cells cultured less than 10 passages are suitable for clinical research/therapy.
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BACKGROUND:Quercetin plays an important role in the proliferation and differentiation of bone marrow mesenchymal stem cells,but less research has been done on its mechanism of promoting the migration of bone marrow mesenchymal stem cells. OBJECTIVE:To study the effect of quercetin on the migration of human bone marrow mesenchymal stem cells through in vitro experiments,and to explore the regulatory role of CCR1 and CXCR4. METHODS:Human bone marrow mesenchymal stem cells were selected as experimental subjects.CCK8 assay was used to detect the effect of quercetin on the proliferative activity of human bone marrow mesenchymal stem cells.Cell scratch assay and Transwell assay were used to detect the in vitro invasive and migratory abilities of human bone marrow mesenchymal stem cells after quercetin treatment,respectively.The role of quercetin in relation to CCR1 and CXCR4 was demonstrated with the help of molecular docking technology.Western blot assay and real-time fluorescence quantitative PCR were used to detect the migration-related chemokine expression after quercetin treatment. RESULTS AND CONCLUSION:(1)5 and 10 μmol/L quercetin could significantly promote the proliferation of human bone marrow mesenchymal stem cells,and the drug concentration of 10 μmol/L resulted in the highest cell proliferation efficiency.(2)To better explore the dose-effect relationship of quercetin affecting the migration of human bone marrow mesenchymal stem cells,5 and 10 μmol/L quercetin were selected for the subsequent experiments,and ligustrazine was used as the positive control drug,and the experiments were divided into blank control group,5 μmol/L quercetin group,10 μmol/L quercetin group,and 100 μmol/L ligustrazine group.(3)In vitro migration and invasion ability of human bone marrow mesenchymal stem cells were elevated in a concentration-dependent manner after quercetin treatment,and the migration effect of 10 μmol/L quercetin group was better than that of ligustrazine group.(4)The molecular docking results suggested that there was a strong interaction between quercetin and CCR1 and CXCR4.(5)Quercetin could up-regulate the expression of CCR1 and CXCR4 proteins and mRNA.(6)This study confirmed at the cellular level that quercetin could promote the migration of human bone marrow mesenchymal stem cells by targeting CCR1 and CXCR4.