3D-printed bone regeneration scaffolds modulate bone metabolic homeostasis through vascularization for osteoporotic bone defects.

The treatment of osteoporotic bone defects poses a challenge due to the degradation of the skeletal vascular system and the disruption of local bone metabolism within the osteoporotic microenvironment. However, it is feasible to modulate the disrupted local bone metabolism imbalance through enhanced vascularization, a theory termed "vascularization-bone metabolic balance". This study developed a 3D-printed polycaprolactone (PCL) scaffold modified with EPLQLKM and SVVYGLR peptides (PCL-SE). The EPLQLKM peptide attracts bone marrow-derived mesenchymal stem cells (BMSCs), while the SVVYGLR peptide enhances endothelial progenitor cells (EPCs) vascular differentiation, thus regulating bone metabolism and fostering bone regeneration through the paracrine effects of EPCs. Further mechanistic research demonstrated that PCL-SE promoted the vascularization of EPCs, activating the Notch signaling pathway in BMSCs, leading to the upregulation of osteogenesis-related genes and the downregulation of osteoclast-related genes, thereby restoring bone metabolic balance. Furthermore, PCL-SE facilitated the differentiation of EPCs into "H"-type vessels and the recruitment of BMSCs to synergistically enhance osteogenesis, resulting in the regeneration of normal microvessels and bone tissues in cases of femoral condylar bone defects in osteoporotic SD rats. This study suggests that PCL-SE supports in-situ vascularization, remodels bone metabolic translational balance, and offers a promising therapeutic regimen for osteoporotic bone defects.

The Exosome-Mediated Bone Regeneration: An Advanced Horizon Toward the Isolation, Engineering, Carrying Modalities, and Mechanisms.

Exosomes, nanoparticles secreted by various cells, composed of a bilayer lipid membrane, and containing bioactive substances such as proteins, nucleic acids, metabolites, etc., have been intensively investigated in tissue engineering owing to their high biocompatibility and versatile biofunction. However, there is still a lack of a high-quality review on bone defect regeneration potentiated by exosomes. In this review, the biogenesis and isolation methods of exosomes are first introduced. More importantly, the engineered exosomes of the current state of knowledge are discussed intensively in this review. Afterward, the biomaterial carriers of exosomes and the mechanisms of bone repair elucidated by compelling evidence are presented. Thus, future perspectives and concerns are revealed to help devise advanced modalities based on exosomes to overcome the challenges of bone regeneration. It is totally believed this review will attract special attention from clinicians and provide promising ideas for their future works.

Local imperceptible adversarial attacks against human pose estimation networks.

Deep neural networks are vulnerable to attacks from adversarial inputs. Corresponding attack research on human pose estimation (HPE), particularly for body joint detection, has been largely unexplored. Transferring classification-based attack methods to body joint regression tasks is not straightforward. Another issue is that the attack effectiveness and imperceptibility contradict each other. To solve these issues, we propose local imperceptible attacks on HPE networks. In particular, we reformulate imperceptible attacks on body joint regression into a constrained maximum allowable attack. Furthermore, we approximate the solution using iterative gradient-based strength refinement and greedy-based pixel selection. Our method crafts effective perceptual adversarial attacks that consider both human perception and attack effectiveness. We conducted a series of imperceptible attacks against state-of-the-art HPE methods, including HigherHRNet, DEKR, and ViTPose. The experimental results demonstrate that the proposed method achieves excellent imperceptibility while maintaining attack effectiveness by significantly reducing the number of perturbed pixels. Approximately 4% of the pixels can achieve sufficient attacks on HPE.

[Effectiveness of bone transport with a locking plate versus conventional bone transport for tibial defects].

Objective: To investigate the effectiveness difference between bone transport with a locking plate (BTLP) and conventional bone transport with Ilizarov/Orthofix fixators in treatment of tibial defect. Methods: The clinical data of 60 patients with tibial fractures who met the selection criteria between January 2016 and September 2020 were retrospectively analyzed, and patients were treated with BTLP (BTLP group, n=20), Ilizarov fixator (Ilizarov group, n=23), or Orthofix fixator (Orthofix group, n=17) for bone transport. There was no significant difference in gender, age, cause of injury, time from injury to admission, length of bone defect, tibial fracture typing, and comorbidities between groups ( P>0.05). The osteotomy time, the retention time of external fixator, the external fixation index, and the occurrence of postoperative complications were recorded and compared between groups. The bone healing and functional recovery were evaluated by the Association for the Study and Application of the Method of Ilizarov (ASAMI) criteria. Results: All patients of 3 groups were followed up 13-45 months, with a mean of 20.4 months. The osteotomy time was significantly shorter in the BTLP group than in the Ilizarov group, and the retention time of external fixator and the external fixation index were significantly lower in the BTLP group than in the Ilizarov and Orthofix groups ( P<0.05). Twenty-two fractures healed in the Ilizarov group and 1 case of delayed healing; 16 fractures healed in the Orthofix group and 1 case of delayed healing; 18 fractures healed in the BTLP group and 2 cases of delayed healing. There was no significant difference between groups in fracture healing distribution ( P=0.824). After completing bone reconstruction treatment according to ASAMI criteria, the BTLP group had better bone healing than the Orthofix group and better function than the Ilizarov groups, showing significant differences ( P<0.05). Postoperative complications occurred in 4 cases (20%) in the BLTP group, 18 cases (78%) in the Ilizarov group, and 12 cases (70%) in the Orthofix group. The incidence of complication in the BTLP group was significantly lower than that in other groups ( P<0.05). Conclusion: BTLP is safe and effective in the treatment of tibial defects. BTLP has apparent advantages over the conventional bone transport technique in osteotomy time, external fixation index, and lower limb functional recovery.

ß-Ecdysterone Enhanced Bone Regeneration Through the BMP-2/SMAD/RUNX2/Osterix Signaling Pathway.

Bone defects are a global public health problem. However, the available methods for inducing bone regeneration are limited. The application of traditional Chinese herbs for bone regeneration has gained popularity in recent years. ß-ecdysterone is a plant sterol similar to estrogen, that promotes protein synthesis in cells; however, its function in bone regeneration remains unclear. In this study, we investigated the function of ß-ecdysterone on osteoblast differentiation and bone regeneration in vitro and in vivo. MC3T3-E1 cells were used to test the function of ß-ecdysterone on osteoblast differentiation and bone regeneration in vitro. The results of the Cell Counting Kit-8 assay suggested that the proliferation of MC3T3-E1 cells was promoted by ß-ecdysterone. Furthermore, ß-ecdysterone influenced the expression of osteogenesis-related genes, and the bone regeneration capacity of MC3T3-E1 cells was detected by polymerase chain reaction, the alkaline phosphatase (ALP) test, and the alizarin red test. ß-ecdysterone could upregulate the expression of osteoblastic-related genes, and promoted ALP activity and the formation of calcium nodules. We also determined that ß-ecdysterone increased the mRNA and protein levels of components of the BMP-2/Smad/Runx2/Osterix pathway. DNA sequencing further confirmed these target effects. ß-ecdysterone promoted bone formation by enhancing gene expression of the BMP-2/Smad/Runx2/Osterix signaling pathway and by enrichment biological processes. For in vivo experiments, a femoral condyle defect model was constructed by drilling a bone defect measuring 3 mm in diameter and 4 mm in depth in the femoral condyle of 8-week-old Sprague Dawley male rats. This model was used to further assess the bone regenerative functions of ß-ecdysterone. The results of micro-computed tomography showed that ß-ecdysterone could accelerate bone regeneration, exhibiting higher bone volume, bone surface, and bone mineral density at each observation time point. Immunohistochemistry confirmed that the ß-ecdysterone also increased the expression of collagen, osteocalcin, and bone morphogenetic protein-2 in the experiment group at 4 and 8 weeks. In conclusion, ß-ecdysterone is a new bone regeneration regulator that can stimulate MC3T3-E1 cell proliferation and induce bone regeneration through the BMP-2/Smad/Runx2/Osterix pathway. This newly discovered function of ß-ecdysterone has revealed a new direction of osteogenic differentiation and has provided novel therapeutic strategies for treating bone defects.

Identification of Ferroptosis-Related Gene Prognostic Signature and HSF1 for Reversing Doxorubicin and Gemcitabine Resistance in Uterine Carcinosarcoma.

PURPOSE: Iron metabolism and ferroptosis play crucial roles in the pathogenesis of cancer. In this study, we aim to study the role of ferroptosis-related genes (FRGs) in uterine carcinosarcoma (UCS) and identify potential target for UCS. METHODS: Prognostic differentially expressed FRGs were identified of in the TCGA cohort. Integrated analysis, cox regression, and the least absolute shrinkage and selection operator (LASSO) methods of FRGs were performed to construct a multigene signature prognostic model. Moreover, a dataset from Gene Expression Omnibus (GEO) served as an external validation. HSF1 was knockdown in MES-SA and FU-MMT-1 cells, and cell viability, lipid ROS, and intracellular iron level were detected when combined with doxorubicin or gemcitabine. RESULT: Five FRGs were selected to construct a prognostic model of UCS. The group with high-risk signature score exhibited obviously lower overall survival (OS) than the group with low risk signature score in both TCGA and validated GEO cohorts. Multivariate Cox regression analysis further indicated that the risk score was an independent factor for the prognosis of UCS patients. The high-risk group of UCS has a higher sensitivity in the treatment of doxorubicin and gemcitabine. Knocking down of HSF1 in MES-SA and FU-MMT-1 cells was more sensitive to doxorubicin and gemcitabine via increasing ferroptosis. CONCLUSIONS: The five FRGs risk signature prognostic model having a superior and drug sensitivity predictive performance for OS in UCS, and HSF1 is a potential marker sensitive to doxorubicin and gemcitabine in UCS patients.

Marein Prevented LPS-Induced Osteoclastogenesis by Regulating the NF-κB Pathway In Vitro.

Many bone diseases such as osteolysis, osteomyelitis, and septic arthritis are caused by gram-negative bacterial infection, and lipopolysaccharide (LPS), a bacterial product, plays an essential role in this process. Drugs that inhibit LPS-induced osteoclastogenesis are urgently needed to prevent bone destruction in infective bone diseases. Marein, a major bioactive compound of Coreopsis tinctoria, possesses anti-oxidative, anti-inflammatory, anti-hypertensive, anti-hyperlipidemic, and anti-diabetic effects. In this study, we measured the effect of marein on RAW264.7 cells by CCK-8 assay and used TRAP staining to determine osteoclastogenesis. The levels of osteoclast-related genes and NF-κB-related proteins were then analyzed by western blot, and the levels of pro-inflammatory cytokines were quantified by ELISA. Our results showed that marein inhibited LPS-induced osteoclast formation by osteoclast precursor RAW264.7 cells. The effect of marein was related to its inhibitory function on expressions of pro-inflammatory cytokines and osteoclast-related genes containing RANK, TRAF6, MMP-9, CK, and CAII. Additionally, marein leads to markedly inhibited NF-κB signaling pathway activation in LPS-induced RAW264.7 cells. Concurrently, when the NF-κB signaling pathway was inhibited, osteoclast formation and pro-inflammatory cytokine expression were decreased. Collectively, marein could inhibit LPS-induced osteoclast formation in RAW264.7 cells via regulating the NF-κB signaling pathway. Our data demonstrate that marein might be a potential drug for bacteria-induced bone destruction disease. Our findings provide new insights into LPS-induced bone disease.

Sympathetic nerve infiltration promotes stomach adenocarcinoma progression via norepinephrine/ß2-adrenoceptor/YKL-40 signaling pathway.

Objective: This study aimed to address the status, role, and mechanism of sympathetic nerve infiltration in the progression of stomach adenocarcinoma (STAD). Methods: Sympathetic nerve and its neurotransmitter NE, ß-ARs, and associated signaling molecules in the STAD tissues and the adjacent tissues from 46 STAD patients were examined using immunostaining, HPLC, and western blotting. The effects and mechanisms of ß2-AR activation on the proliferation, migration and invasion of AGS and SGC-7901 gastric cancer (GC) cell lines were examined using CCK-8, transwell, and western blotting assays. Correlations between genes and STAD survival were analyzed using bioinformatics. Results: Striking sympathetic nerve infiltration, elevations of NGF, TrkA, GAP43, TH, S100, NE, ß2-AR, YKL-40, syndecan-1, MMP9, CD206, and CD31 were observed in the STAD tissues compared to the adjacent tissues. Activation of ß2-AR in the two GC cell lines significantly amplified the expressions of NGF, YKL-40, MMP9, syndecan-1, p-STAT3 and p-ERK, and increased GC cell proliferation, migration and invasion. Bioinformatic analyses revealed positive correlations of NGF, ß2-AR, syndecan-1, and macrophage infiltration, respectively, with low survival of STAD, of ß2-AR respectively with STAT3, ERK1/2 (MAPK1/3), YKL-40, MMP9, and syndecan-1, and of YKL-40 with MMP9. Conclusion: Sympathetic nerves significantly infiltrated into human STAD tissues as a result of high NGF and TrkA expressions; elevated NE led to overactivation of ß2-AR-STAT3/ERK-YKL-40 signaling pathway, and finally caused cancer cell growth and invasion, M2 macrophage infiltration, angiogenesis, matrix degradation and STAD metastasis and progression.

[Comparison of effectiveness of femoral neck system and cannulate compression screw in treatment of femoral neck fracture in young and middle-aged patients].

OBJECTIVE: To compare the effectiveness of femoral neck system (FNS) and cannulate compression screw (CCS) in the treatment of femoral neck fractures in young and middle-aged patients. METHODS: The clinical data of 82 young and middle-aged patients with femoral neck fracture treated between January 2018 and September 2020 were retrospectively analyzed. They were divided into FNS group (24 cases) and CCS group (58 cases) according to different surgical methods. There was no significant difference between the two groups ( P>0.05) in general data such as gender, age, height, body mass, cause of injury, complications, fracture location, and fracture classification (Garden classification and Pauwells classification). The operation time, intraoperative blood loss, complications (nonunion, osteonecrosis of the femoral head, shortening of femoral neck, etc.), visual analogue scale (VAS) score at 2 days after operation, clinical healing time of fracture, and Harris score of hip joint after operation were recorded and compared between the two groups. RESULTS: The operation time and VAS score at 2 days after operation in FNS group were significantly lower than those in CCS group ( P<0.05); there was no significant difference in intraoperative blood loss between the two groups ( t=0.263, P=0.796). The patients in CCS group were followed up 6-18 months, with an average of 13.6 months; and the follow-up time in FNS group was 3-12 months, with an average of 7.3 months. There was no complication of internal fixator loosening in both groups. There were 2 cases of osteonecrosis of the femoral head, 1 case of bone nonunion, and 13 cases of femoral neck shortening in CCS group and only 2 cases of femoral neck shortening in FNS group. The difference in the incidence of complications between the two groups (27.6% vs. 8.3%) was significant ( χ 2=36.670, P=0.015). In CCS group, 3 cases underwent secondary artificial hip arthroplasty due to bone nonunion and osteonecrosis of the femoral head, and the remaining 55 cases achieved clinical healing; in FNS group, 6 patients excluded in the statistics because the follow-up time was less than 6 months, and the remaining 18 fractures healed clinically; there was significant difference in fracture healing time between the two groups ( t=4.481, P=0.000). The difference of Harris score of hip joint between 9 months and 6 months after operation in FNS group was significantly higher than that in CCS group ( P<0.05), and the Harris score at 9 months after operation was significantly higher than that at 6 months after operation in both groups ( P<0.05). CONCLUSION: FNS can accelerate the healing of femoral neck fractures in young and middle-aged patients, so that patients can start functional exercise as soon as possible, thereby reducing the incidence of related complications.

Applications of Functionalized Hydrogels in the Regeneration of the Intervertebral Disc.

Intervertebral disc degeneration (IDD) is caused by genetics, aging, and environmental factors and is one of the leading causes of low back pain. The treatment of IDD presents many challenges. Hydrogels are biomaterials that possess properties similar to those of the natural extracellular matrix and have significant potential in the field of regenerative medicine. Hydrogels with various functional qualities have recently been used to repair and regenerate diseased intervertebral discs. Here, we review the mechanisms of intervertebral disc homeostasis and degeneration and then discuss the applications of hydrogel-mediated repair and intervertebral disc regeneration. The classification of artificial hydrogels and natural hydrogels is then briefly introduced, followed by an update on the development of functional hydrogels, which include noncellular therapeutic hydrogels, cellular therapeutic hydrogel scaffolds, responsive hydrogels, and multifunctional hydrogels. The challenges faced and future developments of the hydrogels used in IDD are discussed as they further promote their clinical translation.

Glucagon-Like Peptide-1 Analog Liraglutide Attenuates Pressure-Overload Induced Cardiac Hypertrophy and Apoptosis through Activating ATP Sensitive Potassium Channels.

PURPOSE: This study aimed to investigate whether inhibition of glucagon-like peptide-1 (GLP-1) on pressure overload induced cardiac hypertrophy and apoptosis is related to activation of ATP sensitive potassium (KATP) channels. METHODS: Male SD rats were randomly divided into five groups: sham, control (abdominal aortic constriction), GLP-1 analog liraglutide (0.3 mg/kg/twice day), KATP channel blocker glibenclamide (5 mg/kg/day), and liraglutide plus glibenclamide. RESULTS: Relative to the control on week 16, liraglutide upregulated protein and mRNA levels of KATP channel subunits Kir6.2/SUR2 and their expression in the myocardium, vascular smooth muscle, aortic endothelium, and cardiac microvasculature. Consistent with a reduction in aortic wall thickness (61.4 ± 7.6 vs. 75.0 ± 7.6 µm, p < 0.05), liraglutide enhanced maximal aortic endothelium-dependent relaxation in response to acetylcholine (71.9 ± 8.7 vs. 38.6 ± 4.8%, p < 0.05). Along with a reduction in heart to body weight ratio (2.6 ± 0.1 vs. 3.4 ± 0.4, mg/g, p < 0.05) by liraglutide, hypertrophied cardiomyocytes (371.0 ± 34.4 vs. 933.6 ± 156.6 µm2, p < 0.05) and apoptotic cells (17.5 ± 8.2 vs. 44.7 ± 7.9%, p < 0.05) were reduced. Expression of anti-apoptotic protein BCL-2 and contents of myocardial ATP were augmented, and expression of cleaved-caspase 3 and levels of serum Tn-I/-T were reduced. Echocardiography and hemodynamic measurement showed that cardiac systolic function was enhanced as evidenced by increased ejection fraction (88.4 ± 4.8 vs. 73.8 ± 5.1%, p < 0.05) and left ventricular systolic pressure (105.2 ± 10.8 vs. 82.7 ± 7.9 mmHg, p < 0.05), and diastolic function was preserved as shown by a reduction of ventricular end-diastolic pressure (-3.1 ± 2.9 vs. 6.7 ± 2.8 mmHg, p < 0.05). Furthermore, left ventricular internal diameter at end-diastole (5.8 ± 0.5 vs. 7.7 ± 0.6 mm, p < 0.05) and left ventricular internal diameter at end-systole (3.0 ± 0.6 vs. 4.7 ± 0.4 mm, p < 0.05) were improved. Dietary administration of glibenclamide alone did not alter all the parameters measured but significantly blocked liraglutide-exerted cardioprotection. CONCLUSION: Liraglutide ameliorates cardiac hypertrophy and apoptosis, potentially via activating KATP channel-mediated signaling pathway. These data suggest that liraglutide might be considered as an adjuvant therapy to treat patients with heart failure.

Exogenous supplement of glucagon like peptide-1 protects the heart against aortic banding induced myocardial fibrosis and dysfunction through inhibiting mTOR/p70S6K signaling and promoting autophagy.

Mammalian target of rapamycin (mTOR) and a ribosomal protein S6 kinase (p70S6K) mediate tissue fibrosis and negatively regulate autophagy. This study aims to investigate whether glucagon-like peptide-1 (GLP-1) analog liraglutide protects the heart against aortic banding-induced cardiac fibrosis and dysfunction through inhibiting mTOR/p70S6K signaling and promoting autophagy activity. Male SD rats were randomly divided into four groups (n = 6/each group): sham operated control; abdominal aortic constriction (AAC); liraglutide treatment during AAC (0.3 mg/kg, injected subcutaneously twice daily); rapamycin treatment during AAC (0.2 mg/kg/day, administered by gastric gavage). Relative to the animals with AAC on week 16, liraglutide treatment significantly reduced heart/body weight ratio, inhibited cardiomyocyte hypertrophy, and augmented plasma GLP-1 level and tissue GLP-1 receptor expression. Phosphorylation of mTOR/p70S6K, populations of myofibroblasts and synthesis of collagen I/III in the myocardium were simultaneously inhibited. Furthermore, autophagy regulating proteins: LC3-II/LC3-I ratio and Beclin-1 were upregulated, and p62 was downregulated by liraglutide. Compared with liraglutide group, treatment with rapamycin, a specific inhibitor of mTOR, compatibly augmented GLP-1 receptor level, inhibited phosphorylation of mTOR/p70S6K and expression of p62 as well as increased level of LC3-II/LC3-I ratio and Beclin-1, suggesting that there is an interaction between GLP-1 and mTOR/p70S6K signaling in the regulation of autophagy. In line with these modifications, treatment with liraglutide and rapamycin significantly reduced perivascular/interstitial fibrosis, and preserved systolic/diastolic function. These results suggest that the inhibitory effects of liraglutide on cardiac fibrosis and dysfunction are potentially mediated by inhibiting mTOR/p70S6K signaling and enhancing autophagy activity.

Silica nanomaterials induce organ injuries by Ca2+-ROS-initiated disruption of the endothelial barrier and triggering intravascular coagulation.

BACKGROUND: The growing use of silica nanoparticles (SiNPs) in many fields raises human toxicity concerns. We studied the toxicity of SiNP-20 (particle diameter 20 nm) and SiNP-100 (100 nm) and the underlying mechanisms with a focus on the endothelium both in vitro and in vivo. METHODS: The study was conducted in cultured human umbilical vein endothelial cells (HUVECs) and adult female Balb/c mice using several techniques. RESULTS: In vitro, both SiNP-20 and SiNP-100 decreased the viability and damaged the plasma membrane of cultured HUVECs. The nanoparticles also inhibited HUVECs migration and tube formation in a concentration-dependent manner. Both SiNPs induced significant calcium mobilization and generation of reactive oxygen species (ROS), increased the phosphorylation of vascular endothelial (VE)-cadherin at the site of tyrosine 731 residue (pY731-VEC), decreased the expression of VE-cadherin expression, disrupted the junctional VE-cadherin continuity and induced F-actin re-assembly in HUVECs. The injuries were reversed by blocking Ca2+ release activated Ca2+ (CRAC) channels with YM58483 or by eliminating ROS with N-acetyl cysteine (NAC). In vivo, both SiNP-20 and SiNP-100 (i.v.) induced multiple organ injuries of Balb/c mice in a dose (range 7-35 mg/kg), particle size, and exposure time (4-72 h)-dependent manner. Heart injuries included coronary endothelial damage, erythrocyte adhesion to coronary intima and coronary coagulation. Abdominal aorta injury exhibited intimal neoplasm formation. Lung injuries were smaller pulmonary vein coagulation, bronchiolar epithelial edema and lumen oozing and narrowing. Liver injuries included multifocal necrosis and smaller hepatic vein congestion and coagulation. Kidney injuries involved glomerular congestion and swelling. Macrophage infiltration occurred in all of the observed organ tissues after SiNPs exposure. SiNPs also decreased VE-cadherin expression and altered VE-cadherin spatial distribution in multiple organ tissues in vivo. The largest SiNP (SiNP-100) and longest exposure time exerted the greatest toxicity both in vitro and in vivo. CONCLUSIONS: SiNPs, administrated in vivo, induced multiple organ injuries, including endothelial damage, intravascular coagulation, and secondary inflammation. The injuries are likely caused by upstream Ca2+-ROS signaling and downstream VE-cadherin phosphorylation and destruction and F-actin remodeling. These changes led to endothelial barrier disruption and triggering of the contact coagulation pathway.

In vitro and in vivo evaluations of nano-hydroxyapatite/polyamide 66/yttria-stabilized zirconia as a novel bioactive material for bone screws: Biocompatibility and bioactivity.

Zirconia and its derivatives have been receiving increased levels of attention with regard to their potential application in bone tissue engineering. These materials are of particular interest because of their excellent characteristics, such as superior biological and mechanical properties. In this study, yttria-stabilized tetragonal zirconia (YTZ)-reinforced nanohydroxyapatite/polyamide 66 (nHA/PA66) bone screws were prepared. The biocompatibility and bioactivity of nHA/PA66/YTZ were evaluated in vitro using MC3T3-E1 cells. Biocompatibility and bioactivity experiments (cell counting kit-8 tests, cell immunofluorescence analysis, and polymerase chain reaction) showed that nHA/PA66/YTZ could facilitate the biological functions of MC3T3-E1 cells. The attachment, proliferation, spreading, and expression of genes associated with osteogenesis (collagen 1, osteopontin, and osteocalcin) in cells cultured with the nHA/PA66/YTZ composite were all superior compared with the control groups (P < 0.05). In addition, nHA/PA66/YTZ bone screws were implanted into the femoral condyles of rabbits, and titanium screws were employed as a control group; postoperative histology and blood analysis revealed no obvious damage to the liver, kidneys, or any other major organs in either of the experimental groups. Moreover, nHA/PA66/YTZ screws resulted in significantly better bone-implant contact interfaces and enhanced formation of trabecular bone (P < 0.05); these characteristics were markedly better than those in the group that received titanium screws. These observations indicate that YTZ-reinforced nHA/PA66 composites have significant potential for applications in bone tissue engineering.

Liraglutide attenuates cardiac remodeling and improves heart function after abdominal aortic constriction through blocking angiotensin II type 1 receptor in rats.

OBJECTIVE: Angiotensin II (Ang II) is known to contribute to the pathogenesis of heart failure by eliciting cardiac remodeling and dysfunction. The glucagon-like peptide-1 (GLP-1) has been shown to exert cardioprotective effects in animals and patients. This study investigates whether GLP-1 receptor agonist liraglutide inhibits abdominal aortic constriction (AAC)-induced cardiac fibrosis and dysfunction through blocking Ang II type 1 receptor (AT1R) signaling. METHODS: Sprague-Dawley rats were subjected to sham operation and abdominal aortic banding procedure for 16 weeks. In treated rats, liraglutide (0.3 mg/kg) was subcutaneously injected twice daily or telmisartan (10 mg/kg/day), the AT1R blocker, was administered by gastric gavage. RESULTS: Relative to the animals with AAC, liraglutide reduced protein level of the AT1R and upregulated the AT2R, as evidenced by reduced ratio of AT1R/AT2R (0.59±0.04 vs. 0.91±0.06, p<0.05). Furthermore, the expression of angiotensin converting enzyme 2 was upregulated, tissue levels of malondialdehyde and B-type natriuretic peptide were reduced, and superoxide dismutase activity was increased. Along with a reduction in HW/BW ratio, cardiomyocyte hypertrophy was inhibited. In coincidence with these changes, liraglutide significantly decreased the populations of macrophages and myofibroblasts in the myocardium, which were accompanied by reduced protein levels of transforming growth factor beta1, Smad2/3/4, and upregulated smad7. The synthesis of collagen I and III was inhibited and collagen-rich fibrosis was attenuated. Consistent with these findings, cardiac systolic function was preserved, as shown by increased left ventricular systolic pressure (110±5 vs. 99±2 mmHg, p<0.05), ejection fraction (83%±2% vs. 69%±4%, p<0.05) and fraction shortening (49%±2% vs. 35%±3%, p<0.05). Treatment with telmisartan provided a comparable level of protection as compared with liraglutide in all the parameters measured. CONCLUSION: Taken together, liraglutide ameliorates cardiac fibrosis and dysfunction, potentially via suppressing the AT1R-mediated events. These data indicate that liraglutide might be selected as an add-on drug to prevent the progression of heart failure.

A false alarm of narcolepsy: obstructive sleep apnea masquerading as narcolepsy and depression.

PURPOSE: We report a case with symptoms and signs of obstructive sleep apnea (OSA), depression, and narcolepsy. Polysomnographic (PSG) and multiple sleep latency test (MSLT) findings, clinical characteristics, and diagnostic challenges in this case are discussed. METHODS: A 23-year-old single male presented with excessive daytime sleepiness, low mood, lack of energy, and snoring for 3 years. In addition, he reported excessive weight gain, lack of interest in work, partial loss of muscle tone during excitations, and sleep attacks during work and driving. He had experienced three episodes of sleep paralysis. The patient underwent a sleep study including PSG and MSLT. RESULTS: On baseline PSG, he had an apnea/hypopnea index (AHI) of 72.8/h. The MSLT showed a mean sleep latency of 3.8 min and two sleep-onset rapid eye movement periods (SOREMPs). On admission, he had an Epworth Sleepiness Scale (ESS) score of 21, and positive findings for depression in the clinical interview and psychometric scales. He was treated with continuous positive airway pressure without any medication. Follow-up PSG and MSLT were performed after 1 week, which showed an AHI of 0/h without SOREMPs. After 1 month, there was no sign of depression. CONCLUSIONS: This study reflects that OSA can present with cataplexy-like features and false positive MSLT results for narcolepsy, as well as depressive symptoms. The case highlights the complexity in which OSA can present to physicians, and emphasizes that clinicians should be aware that OSA can mimic narcolepsy and present with depressive symptoms.

Curcumin inhibits cardiac hypertrophy and improves cardiovascular function via enhanced Na+/Ca2+ exchanger expression after transverse abdominal aortic constriction in rats.

BACKGROUND: This study tested the hypothesis that inhibition of cardiac hypertrophy and preservation of cardiac/endothelial function by the natural yellow pigment curcumin are associated with upregulated expression of Na+/Ca2+ exchanger (NCX) after transverse aortic constriction (TAC). METHODS: Male Wistar rats were subjected to TAC for 10 weeks and curcumin (50 mg/kg/day) was fed by gastric gavage during TAC. Expression of NCX and endothelial nitric oxide synthase (eNOS) was analyzed by Western blot and immunohistochemistry. RESULTS: Compared with the animals in the TAC group, curcumin significantly increased the survival rate and reduced the ratio of heart or left ventricle (LV) to body weight and the cross sectional area of cardiomyocytes. In coincidence with improved LV systolic pressure and reduced LV end-diastolic pressure, curcumin significantly reduced LV end-systolic and diastolic diameter/dimension, and enhanced LV ejection fraction and LV fractional shortening as measured by echocardiography. Furthermore, endothelium-dependent relaxation of aortic rings in response to acetylcholine was significantly improved by curcumin. Along with these modifications, the expression and localization of NCX and eNOS in the myocardium and vascular endothelium were significantly upregulated by curcumin. The protective effect of curcumin on endothelium-dependent relaxation was partly blocked by pretreatment with the NCX inhibitor, KB-R7943. CONCLUSIONS: These results demonstrate that inhibition of cardiac hypertrophy, improvement of cardiac systolic/diastolic function and preservation of vascular endothelium by curcumin might be associated with upregulated NCX expression level in response to increased afterload.

Methotrexate, combined with cyclophosphamide attenuates murine collagen induced arthritis by modulating the expression level of Breg and DCs.

To explore the mechanism of methotrexate (MTX) and its combination with cyclophosphamide (CTX) in collagen-induced arthritis (CIA), we investigated the levels of several immune cells and cytokines in mice with different treatments. CIA was induced in DBA/1 mice at the age of 7 weeks by primary immunization with 100µl emulsion containing 2mg/ml bovine type II collagen which was mixed with complete Freund's adjuvant (CFA). The booster immunization was performed with 50-100µl emulsion containing 2mg/ml bovine type II collagen (CII) mixed with incomplete Freund's adjuvant (IFA). MTX, CTX or both were administrated after the booster immunization. Therapeutic effect was evaluated by arthritic scores, X-rays and assessment of histopathological joint destruction. The expression of TNF-α, IL-6, IL-23, IL-10 were also measured. The frequencies of different immune cell subsets in the lymph node, spleen and bone marrow were determined by flow cytometry analysis. Our results showed that CTX and MTX treatment attenuated the severity of arthritis of CIA mice and reduced the levels of several cytokines. CTX and MTX treated mice showed a lower frequency of B cells in bone marrow. Also, when treated the CIA mice with MTX, alone or together with CTX, the lymph nodes and spleen exhibited a decrease in regulatory B cells (Breg) and dendritic cells (DCs). Notably, the combination of MTX and CTX had a more pronounced effect. By measuring the levels of different immune cells those participated in the development of rheumatoid arthritis (RA), our experiment may help to evaluate the therapeutic effects and prognosis of arthritic diseases.