DKK1 Activates the PI3K/AKT Pathway via CKAP4 to Balance the Inhibitory Effect on Wnt/ß-Catenin Signaling and Regulates Wnt3a-Induced MSC Migration.

Wnt/ß-catenin signaling plays a crucial role in the migration of mesenchymal stem cells (MSCs). However, our study has revealed an intriguing phenomenon where Dickkopf-1 (DKK1), an inhibitor of Wnt/ß-catenin signaling, promotes MSC migration at certain concentrations ranging from 25 to 100 ng/mL while inhibiting Wnt3a-induced MSC migration at a higher concentration (400 ng/mL). Interestingly, DKK1 consistently inhibited Wnt3a-induced phosphorylation of LRP6 at all concentrations. We further identified cytoskeleton-associated protein 4 (CKAP4), another DKK1 receptor, to be localized on the cell membrane of MSCs. Overexpressing the CRD2 deletion mutant of DKK1 (ΔCRD2), which selectively binds to CKAP4, promoted the accumulation of active ß-catenin (ABC), the phosphorylation of AKT (Ser473) and the migration of MSCs, suggesting that DKK1 may activate Wnt/ß-catenin signaling via the CKAP4/PI3K/AKT cascade. We also investigated the effect of the CKAP4 intracellular domain mutant (CKAP4-P/A) that failed to activate the PI3K/AKT pathway and found that CKAP4-P/A suppressed DKK1 (100 ng/mL)-induced AKT activation, ABC accumulation, and MSC migration. Moreover, CKAP4-P/A significantly weakened the inhibitory effects of DKK1 (400 ng/mL) on Wnt3a-induced MSC migration and Wnt/ß-catenin signaling. Based on these findings, we propose that DKK1 may activate the PI3K/AKT pathway via CKAP4 to balance the inhibitory effect on Wnt/ß-catenin signaling and thus regulate Wnt3a-induced migration of MSCs. Our study reveals a previously unrecognized role of DKK1 in regulating MSC migration, highlighting the importance of CKAP4 and PI3K/AKT pathways in this process.

miR-9-5p and miR-221-3p Promote Human Mesenchymal Stem Cells to Alleviate Carbon Tetrachloride-Induced Liver Injury by Enhancing Human Mesenchymal Stem Cell Engraftment and Inhibiting Hepatic Stellate Cell Activation.

Mesenchymal stem cells (MSCs) have shown great potential for the treatment of liver injuries, and the therapeutic efficacy greatly depends on their homing to the site of injury. In the present study, we detected significant upregulation of hepatocyte growth factor (HGF) in the serum and liver in mice with acute or chronic liver injury. In vitro study revealed that upregulation of miR-9-5p or miR-221-3p promoted the migration of human MSCs (hMSCs) toward HGF. Moreover, overexpression of miR-9-5p or miR-221-3p promoted hMSC homing to the injured liver and resulted in significantly higher engraftment upon peripheral infusion. hMSCs reduced hepatic necrosis and inflammatory infiltration but showed little effect on extracellular matrix (ECM) deposition. By contrast, hMSCs overexpressing miR-9-5p or miR-221-3p resulted in not only less centrilobular necrosis and venous congestion but also a significant reduction of ECM deposition, leading to obvious improvement of hepatocyte morphology and alleviation of fibrosis around central vein and portal triads. Further studies showed that hMSCs inhibited the activation of hepatic stellate cells (HSCs) but could not decrease the expression of TIMP-1 upon acute injury and the expression of MCP-1 and TIMP-1 upon chronic injury, while hMSCs overexpressing miR-9-5p or miR-221-3p led to further inactivation of HSCs and downregulation of all three fibrogenic and proinflammatory factors TGF-ß, MCP-1, and TIMP-1 upon both acute and chronic injuries. Overexpression of miR-9-5p or miR-221-3p significantly downregulated the expression of α-SMA and Col-1α1 in activated human hepatic stellate cell line LX-2, suggesting that miR-9-5p and miR-221-3p may partially contribute to the alleviation of liver injury by preventing HSC activation and collagen expression, shedding light on improving the therapeutic efficacy of hMSCs via microRNA modification.

Identification and characterization of two SERPINC1 mutations causing congenital antithrombin deficiency.

BACKGROUND: Antithrombin (AT) is the main physiological anticoagulant involved in hemostasis. Hereditary AT deficiency is a rare autosomal dominant thrombotic disease mainly caused by mutations in SERPINC1, which was usually manifested as venous thrombosis and pulmonary embolism. In this study, we analyzed the clinical characteristics and screened for mutant genes in two pedigrees with hereditary AT deficiency, and the functional effects of the pathogenic mutations were evaluated. METHODS: Candidate gene variants were analyzed by next-generation sequencing to screen pathogenic mutations in probands, followed by segregation analysis in families by Sanger sequencing. Mutant and wild-type plasmids were constructed and transfected into HEK293T cells to observe protein expression and cellular localization of SERPINC1. The structure and function of the mutations were analyzed by bioinformatic analyses. RESULTS: The proband of pedigree A with AT deficiency carried a heterozygous frameshift mutation c.1377delC (p.Asn460Thrfs*20) in SERPINC1 (NM000488.3), a 1377C base deletion in exon 7 resulting in a backward shift of the open reading frame, with termination after translation of 20 residues, and a different residue sequence translated after the frameshift. Bioinformatics analysis suggests that the missing amino acid sequence caused by the frameshift mutation might disrupt the disulfide bond between Cys279 and Cys462 and affect the structural function of the protein. This newly discovered variant is not currently included in the ClinVar and HGMD databases. p.Arg229* resulted in a premature stop codon in exon 4, and bioinformatics analysis suggests that the truncated protein structure lost its domain of interaction with factor IX (Ala414 site) after the deletion of nonsense mutations. However, considering the AT truncation protein resulting from the p.Arg229* variant loss a great proportion of the molecule, we speculate the variant may affect two functional domains HBS and RCL and lack of the corresponding function. The thrombophilia and decreased-AT-activity phenotypes of the two pedigrees were separated from their genetic variants. After lentiviral plasmid transfection into HEK293T cells, the expression level of AT protein decreased in the constructed c.1377delC mutant cells compared to that in the wild-type, which was not only reduced in c.685C > T mutant cells but also showed a significant band at 35 kDa, suggesting a truncated protein. Immunofluorescence localization showed no significant differences in protein localization before and after the mutation. CONCLUSIONS: The p.Asn460Thrfs*20 and p.Arg229* variants of SERPINC1 were responsible for the two hereditary AT deficiency pedigrees, which led to AT deficiency by different mechanisms. The p.Asn460Thrfs*20 variant is reported for the first time.

Han family with essential tremor caused by the P421L variant of the TENM4 gene in China.

BACKGROUND: Essential tremor (ET) is an autosomal dominant inheritance disorder. Mutations in fusion sarcoma (FUS), mitochondrial serine peptidase 2 (HTRA2), teneurin transmembrane protein 4 (TENM4), sortilin1 (SORT1), SCN11A, and notch2N-terminal-like (NOTCH2NLC) genes are associated with familial ET. METHODS: A proband with ET was tested using whole-exome sequencing and repeat-primed polymerase chain reaction. Subsequently, the family members were screened for the suspected mutation, and the results were verified using Sanger sequencing. The relationship between pedigree and phenotype was also analyzed, and structural and functional changes in the variants were predicted using bioinformatics analysis. RESULTS: In a family with ET, the proband (III4) and the proband's father (II1), grandfather (I1), uncle (II2), and cousin (III5) all presented with involuntary tremors of both upper limbs. The responsible mutation was identified as TENM4 c.1262C > T (p.P421L), which showed genetic co-segregation in the family survey. AlphaFold predicted a change in the spatial position of TENM4 after the P421L mutation, which may have affected its stability. AlphaFold also predicted P421L to be a deleterious variation, which would lead to lower degrees of freedom of the TENM4 protein, thereby affecting the protein's structure and stability. According to the bioinformatics analysis, TENM4 (p.P421L) may reduce the signal reaching the nucleus by affecting the expression of TENM4 messenger RNA (mRNA), thereby impairing the normal oligodendrocyte differentiation process and leading to impaired myelination. CONCLUSION: This study revealed that the TENM4 (p.P421L) pathogenic missense variation was responsible for ET in the proband.

VOC emission caps constrained by air quality targets based on response surface model: A case study in the Pearl River Delta Region, China.

Because of the recent growth in ground-level ozone and increased emission of volatile organic compounds (VOCs), VOC emission control has become a major concern in China. In response, emission caps to control VOC have been stipulated in recent policies, but few of them were constrained by the co-control target of PM2.5 and ozone, and discussed the factor that influence the emission cap formulation. Herein, we proposed a framework for quantification of VOC emission caps constrained by targets for PM2.5 and ozone via a new response surface modeling (RSM) technique, achieving 50% computational cost savings of the quantification. In the Pearl River Delta (PRD) region, the VOC emission caps constrained by air quality targets varied greatly with the NOx emission reduction level. If control measures in the surrounding areas of the PRD region were not considered, there could be two feasible strategies for VOC emission caps to meet air quality targets (160 µg/m3 for the maximum 8-hr-average 90th-percentile (MDA8-90%) ozone and 25 µg/m3 for the annual average of PM2.5): a moderate VOC emission cap with <20% NOx emission reductions or a notable VOC emission cap with >60% NOx emission reductions. If the ozone concentration target were reduced to 155 µg/m3, deep NOx emission reductions is the only feasible ozone control measure in PRD. Optimization of seasonal VOC emission caps based on the Monte Carlo simulation could allow us to gain higher ozone benefits or greater VOC emission reductions. If VOC emissions were further reduced in autumn, MDA8-90% ozone could be lowered by 0.3-1.5 µg/m3, equaling the ozone benefits of 10% VOC emission reduction measures. The method for VOC emission cap quantification and optimization proposed in this study could provide scientific guidance for coordinated control of regional PM2.5 and O3 pollution in China.

A novel compound heterozygous variant linked to hematuria in a family with hereditary factor VII deficiency.

BACKGROUND: Hereditary factor VII deficiency (FVIID) is a rare congenital autosomal recessive bleeding disorder. In clinical manifestations, its onset is caused by variant of the F7 gene (NM_019616) with strong heterogeneity. We identified a family with hematuria caused by a novel F7 compound heterozygous variant and investigated the FVIID-dependent mechanism impacted by these variants. METHODS: Coagulation factors in the proband were functionally verified. We located pathogenic variants in relevant genes using next-generation sequencing after target enrichment and verified them by Sanger sequencing. We examined the coagulation activity and secretion pattern of recombinant FVII variants expressed in cells and observed their location and stability by immunofluorescence. RESULTS: We found a missense variant c.1207G>A (p.Gly403Ser) and a frameshift variant c.154_155del (p.Arg53fs) in the F7 gene of the proband. FVII activity tests showed that the variants significantly decreased its presence in the cell culture supernatant. Moreover, the R53fs mutant lacked the FVII functional domain and had no detectable activity. Immunofluorescence indicated that the p.Gly403Ser variant was distributed to the cell membrane and cytoplasm, whereas the FVII R53fs variant was not detected. Deficient FVII protein function and severe coagulation disorder are the likely causes of hematuria and other bleeding symptoms in the proband. CONCLUSIONS: The newly discovered F7 gene variants enrich the spectrum of hereditary FVII deficiency and provide a new foundation for the diagnosis and treatment of this type of coagulation disorder.

Clinical and imaging features of six Han patients with SAPHO syndrome.

BACKGROUND: Synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome is a rare autoimmune disease characterized by skin or osteoarticular damage. SAPHO syndrome is often misdiagnosed or missed diagnosis due to lack of overall understanding of the disease by clinicians. PURPOSE: To analyze the clinical symptoms and imaging features of six Han patients with SAPHO syndrome in order to provide reference for doctors to diagnose SAPHO syndrome. MATERIAL AND METHODS: This study retrospectively analyzed the clinical data of six Han patients with SAPHO syndrome. RESULTS: All six Han patients with SAPHO syndrome had severe acne or pustulosis of the hands and feet, and all of them had osteoarticular damage, including five cases involving the sternoclavicular joint. Some patients showed a specific and typical "bull's head" sign on 99mTc-labeled methylene diphosphonate bone imaging. Among the six patients recruited, there was one thoracic vertebra, one cervical vertebra, one sacroiliac joint, and one peripheral joint involvement. Two patients had limited activity due to severe osteoarticular damage. CONCLUSION: Due to the atypical clinical symptoms of SAPHO syndrome, most patients will experience a tortuous and long diagnostic process, while a correct understanding and timely intervention of SAPHO syndrome are essential to improve the prognosis of patients.

A thrombophilia family with protein S deficiency due to protein translation disorders caused by a Leu607Ser heterozygous mutation in PROS1.

BACKGROUND: Protein S deficiency (PSD) is an autosomal dominant hereditary disease. In 1984, familial PSD was reported to be prone to recurrent thrombosis. Follow-up studies have shown that heterozygous protein S (PROS1) mutations increase the risk of thrombosis. More than 300 PROS1 mutations have been identified; among them, only a small number of mutations have been reported its possible mechanism to reduce plasma protein S (PS) levels. However, whether PROS1 mutations affect protein structure and why it can induce PSD remains unknown. METHODS: The clinical phenotypes of the members of a family with thrombosis were collected. Their PS activity was measured using the coagulation method, whereas their protein C and antithrombin III activities were measured using methods such as the chromogenic substrate method. The proband and her parents were screened for the responsible mutation using second-generation whole exon sequencing, and the members of the family were verified for suspected mutations using Sanger sequencing. Mutant and wild type plasmids were constructed and transfected into HEK293T cells to detect the mRNA and protein expression of PROS1. RESULTS: In this family, the proband with venous thrombosis of both lower extremities, the proband's mother with pulmonary embolism and venous thrombosis of both lower extremities, and the proband's younger brother had significantly lower PS activity and carried a PROS1 c. 1820 T > C:p.Leu607Ser heterozygous mutation (NM_000313.3). However, no such mutations were found in family members with normal PS activity. The PS expression in the cell lysate and supernatant of the Leu607Ser mutant cells decreased, while mRNA expression increased. Immunofluorescence localization showed that there was no significant difference in protein localization before and after mutation. CONCLUSIONS: The analysis of family phenotype, gene association, and cell function tests suggest that the PROS1 Leu607Ser heterozygous mutation may be a pathogenic mutation. Serine substitution causes structural instability of the entire protein. These data indicate that impaired PS translation and synthesis or possible secretion impairment is the main pathogenesis of this family with hereditary PSD and thrombophilia.

Lysophosphatidic acid guides the homing of transplanted olfactory ensheathing cells to the lesion site after spinal cord injury in rats.

Olfactory ensheathing cells (OECs) are ideal candidates for cell-based therapies aimed at repairing spinal cord injury (SCI). Accurate targeting of OECs to the lesion site is critical to reconstructing the impaired nervous system. However, the key factors guiding the homing of transplanted OECs to the damaged area after SCI are still unclear. Here, we demonstrate that lysophosphatidic acid (LPA) can significantly facilitate the homing of OECs after SCI in rats. First, we found that OECs exhibited a robust chemotaxis response to LPA in vitro, with LPAR1 being predominant receptor expressed on OECs. We further found that ß-catenin signaling plays an important role in LPA-induced OEC migration. Moreover, silencing LPAR1 not only abolished the migration of OECs but also prevented ERK1/2 phosphorylation and ß-catenin activation, suggesting that LPAR1 ligation serves to activate the ERK1/2 and ß-catenin pathways in LPA-induced OEC chemotactic migration. Finally, cell transplantation experiments confirmed that endogenous LPA, which was observed to be produced at the lesion site after SCI in rat, is a key chemokine that facilitates OEC migration to the injury center. Collectively, our data provide a further description of the homing effects of LPA and a mechanism by which transplanted OECs migrate to the injured area after SCI in rats.

[Preventive and Therapeutic Effects of Exogenous Apelin Regulating Autophagy on the Formation of Pulmonary Artery Hhypertension in Rats].

OBJECTIVE: To investigate the effect of exogenous Apelin on pulmonary artery hypertension (PAH) and its related mechanism. METHODS: 26 male SD rats were randomly divided into Control group ( n=6), Model group ( n=10) and Intervention group ( n=10). The rat model of PAH was established by left pneumonectomy combined with monocrotaline injection (PE+MCT) in the Model group and the Intervention group, while the Control group rats were opened chest cavity and injected the same amount of normal saline. From the 2nd week after operation, the Intervention group was intraperitoneally injected with 10 nmol/(kg·d) Apelin-13 for 3 weeks, while the Control group and Model group were injected the same volume of normal saline. The mean pulmonary arterial pressure (mPAP) was measured and the right ventricular hypertrophy index ( RVHI) was calculated in all three groups of rats at the 5th week after operation. The pulmonary tissue HE staining was performed to observe the pulmonary tissue and pulmonary vascular morphology. Protein LC3 was detected by immunofluorescence staining of lung tissues, the mRNA expression level of P62 and Beclin-1 in lung tissues was measured by RT-PCR, and the protein expressions of LC3, LC3-Ⅱ/LC3-Ⅰ, P62 and Beclin-1 in lung tissues were measured by Western blot. RESULTS: Compared with the Control group, the Model group showed increased mPAP and RVHI ( P<0.05), disordered pulmonary tissue structure and thicker pulmonary vascular wall. In Model group rats, expression of LC3 protein and LC3-Ⅱ/LC3-Ⅰ increased in lung tissues, and the expression of Beclin-1 mRNA and the Beclin-1 protein also increased in lung tissues, while the level of P62 mRNA and the expression of P62 protein decreased ( P<0.05). After Apelin-13 intervention, the above indexes were all improved ( P<0.05, compared with the Model group). CONCLUSION: Exogenous Apelin has a certain preventive and therapeutic effect on the formation of PAH, and the mechanism may be related to its inhibition effect on autophagy.

[Efficacy and safety of less invasive surfactant administration in the treatment of neonatal respiratory distress syndrome: a Meta analysis].

OBJECTIVE: To evaluate the efficacy and safety of less invasive surfactant administration (LISA) in the treatment of neonatal respiratory distress syndrome (NRDS). METHODS: PubMed, Cochrane Library, Embase, China Biology Medicine disc, China Scientific Journal Database, CNKI Database, and Wanfang Database were searched for randomized controlled trials (RCTs) on the use of LISA strategy in the treatment of NRDS. Literature screening and quality assessment were performed according to inclusion and exclusion criteria. Review Manager 5.3 software was used to perform the Meta analysis. RESULTS: A total of 9 RCTs were included, with a total of 1 212 children with NRDS. There were 611 children in the experimental group (treated with LISA strategy) and 601 children in the control group [treated with intubation-surfactant-extubation (INSURE) strategy]. The Meta analysis showed that the use of LISA strategy reduced the rate of mechanical ventilation within 72 hours after birth (OR=0.39, 95%CI: 0.29-0.51, P<0.001) and the incidence rates of bronchopulmonary dysplasia (OR=0.53, 95%CI: 0.38-0.72, P<0.001) and pneumothorax (OR=0.56, 95%CI: 0.33-0.93, P=0.02). There were no significant differences in the mortality rate and incidence rates of other neonatal diseases between the two groups (P>0.05). There was no significant difference in the rate of repeated use of pulmonary surfactant (PS) between the two groups (P>0.05), but there was a higher incidence rate of PS reflux observed by LISA strategy (OR=2.60, 95%CI: 1.64-4.12, P<0.001). CONCLUSIONS: Compared with INSURE strategy, LISA strategy has advantages in reducing the need for mechanical ventilation and the incidence rates of bronchopulmonary dysplasia and pneumothorax in children with NRDS.

Population structure of Betula albosinensis and Betula platyphylla: evidence for hybridization and a cryptic lineage.

BACKGROUND AND AIMS: Differences in local abundance and ploidy level are predicted to impact the direction of introgression between species. Here, we tested these hypotheses on populations of Betula albosinensis (red birch) and Betula platyphylla (white birch) which were thought to differ in ploidy level, the former being tetraploid and the latter diploid. METHODS: We sampled 391 birch individuals from nine localities in China, and classified them into species based on leaf morphology. Twelve nuclear microsatellite markers were genotyped in each sample, and analysed using principal coordinates analysis and STRUCTURE software. We compared the effects of two different methods of scoring polyploid genotypes on population genetic analyses. We analysed the effect of ploidy, local species abundance and latitude on levels of introgression between the species. KEY RESULTS: Leaf morphology divided our samples into red and white birch, but genetic analyses unexpectedly revealed two groups within red birch, one of which was tetraploid, as expected, but the other of which appeared to have diploid microsatellite genotypes. Five individuals were identified as early-generation hybrids or backcrosses between white birch and red birch and five were identified between red birch and 'diploid' red birch. Cline analysis showed that levels of admixture were not significantly correlated with latitude. Estimated genetic differentiation among species was not significantly different between determined tetraploid and undetermined tetraploid genotypes. CONCLUSIONS: Limited hybridization and gene flow have occurred between red birch and white birch. Relative species abundance and ploidy level do not impact the direction of introgression between them, as genetic admixture is roughly symmetrical. We unexpectedly found populations of apparently diploid red birch and this taxon may be a progenitor of allotetraploid red birch populations. Incomplete lineage sorting may explain patterns of genetic admixture between apparently diploid and allotetraploid red birch.

Preparation and Evaluation of Antidiabetic Agents of Berberine Organic Acid Salts for Enhancing the Bioavailability.

Berberine has many pharmacological effects, such as antidiabetic, antimicrobial, anti-inflammatory, and antioxidant, but the question remains on how its low oral bioavailability has greatly limited its clinical application. As a safer hypoglycemic agent, we must evaluate the bioavailability of berberine organic acid salts (BOAs) to ensure that the bioavailability of berberine is not negatively affected. It has been proven that the bioavailability of BOAs is higher than that of BH (berberine hydrochloride); especially BF (berberine fumarate) and BS (berberine succinate), which are improved by 1.278-fold and 1.313-fold, respectively. After 1 h of oral administration, berberine mainly acted on the stomach of mice, it also influenced the liver, kidney, lungs, and intestines after 4 h. The accumulation of BF in the lung is more evident than BH. Our analysis shows that these results are closely related to the regulation of organic acids and berberine in the intestinal tract, they also indicate the influence of intestinal flora on berberine metabolism.

[The Experiment Study and Mechanism of Aspirin Enhances Cellular Sensitivity of Hepatocellular Carcinoma Cell Line to Arsenic Trioxide].

OBJECTIVE: To explore whether aspirin could sensitize arsenic trioxide on human hepatocelluar carcinoma cell line and understanding the combination mechanisms underlying co-treatment. METHODS: Cell viability was detected by MTT assay, cell apoptosis rate and reactive oxygen species (ROS) level were measured by flow cytometry, and Western blot assay was used to estimated the protein expression of heme oxygenase-1 (HO-1) in total protein and NF-E2-related factor 2 (Nrf2) in nuclear protein. RESULTS: 10 µmol/L arsenic trioxide can decreased the cell viability, while cell apoptosis rate, ROS level, HO-1 and Nrf2 protein expression was increased (P < 0.05). When compared with arsenic trioxide alone, co-treatment of arsenic trioxide with aspirin in different concentration (0, 0.1, 1.0, 2.5, 5.0 mmol/L) exhibited dual effects in intracellular ROS level, HO-1 and Nrf2 expression. Specifically, with the increasing of aspirin concentrations, the level of ROS induced by arsenic trioxide showed a rising trend after the first reduction, whereas, HO-1 and Nrf2 protein expression were decreased at first and then increased. CONCLUSION: Low concentration, less than 2.5 mmol/L, of aspirin may reduce the ROS accumulation through activating of Nrf2-HO-1 pathway, therefore decreasing the apoptotic cell death induced by arsenic trioxide. On the contrary, 5 mmol/L aspirin could increase the sensitivity of HepG2 to arsenic trioxide through enhancing the arsenic trioxide-induced apoptosis by ROS accumulation resulting in inhibiting the Nrf2-HO-1 pathway.

VEGF Enhances the Migration of MSCs in Neural Differentiation by Regulating Focal Adhesion Turnover.

Mesenchymal stem cells (MSCs) hold great promise in neural regeneration, due to their intrinsic neuronal potential and migratory tropism to damaged nervous tissues. However, the chemotactic signals mediating the migration of MSCs remain poorly understood. Here, we investigated the regulatory roles for focal adhesion kinase (FAK) and Rac1 in vascular endothelial growth factor (VEGF)-stimulated migration of MSCs in neural differentiation. We found that MSCs in various differentiation states show significant different chemotactic responses to VEGF and cells in 24-h preinduction state possess the highest migration speed and efficiency. FAK, as the downstream signaling molecule, is involved in the VEGF-induced migration by regulating the assembly and distribution of focal adhesions (FAs) and reorganization of F-actin. The features of FAs and cytoskeletons and the ability of lamellipodia formation are closely related to the neural differentiation states of MSCs. VEGF promotes FA formation with an asymmetric distribution of FAs and induces the activation of Y397-FAK and Y31/118-paxillin of undifferentiated and 24-h preinduced MSCs in a time-dependent manner. Inhibition of FAK by PF-228 or expressing FAK-Y397F mutant impairs the dynamics of FAs in MSCs during VEGF-induced migration. Furthermore, Rac1 regulates FA formation in a FAK-dependent manner. Overexpression of constitutive activated mutants of Rac1 increases the number of FAs in undifferentiated and 24-h preinduced MSCs, while VEGF-induced increase of FA formation is decreased by inhibiting FAK by PF-228. Collectively, these results demonstrate that FAK and Rac1 signalings coordinately regulate the dynamics of FAs during VEGF-induced migration of MSCs in varying neural differentiation states.

Neural differentiation of mesenchymal stem cells influences their chemotactic responses to stromal cell-derived factor-1α.

Mesenchymal stem cells (MSCs) are proposed as a promising source for cell-based therapies in neural disease. Although increasing numbers of studies have been devoted to the delineation of factors involved in the migration of MSCs, the relationship between the chemotactic response and the differentiation status of these cells is still unclear. In the present study, we demonstrated that MSCs in varying neural differentiation states display various chemotactic responses to stromal cell-derived factor-1α (SDF-1α). The chemotactic responses of MSCs under different differentiation stages in response to SDF-1α were analyzed by Boyden chamber, and the results showed that cells of undifferentiation, 24-h preinduction, 5-h induction, and 18-h maintenance states displayed a stronger chemotactic response to SDF-1α, while 48-h maintenance did not. Further, we found that the phosphorylation levels of PI3K/Akt, ERK1/2, SAPK/JNK, and p38MAPK are closely related to the differentiation states of MSCs subjected to SDF-1α, and finally, inhibition of SAPK/JNK signaling significantly attenuates SDF-1α-stimulated transfilter migration of MSCs of undifferentiation, 24-h preinduction, 18-h maintenance, and 48-h maintenance, but not MSCs of 5-h induction. Meanwhile, interference with PI3K/Akt, p38MAPK, or ERK1/2 signaling prevents only cells at certain differentiation state from migrating in response to SDF-1α. Collectively, these results demonstrate that MSCs in varying neural differentiation states have different migratory capacities, thereby illuminating optimization of the therapeutic potential of MSCs to be used for neural regeneration after injury.

[Research on the sodium arsenite and arsenic trioxide induced proliferation and apoptosis effects on human hepatocyte].

OBJECTIVE: To explore the proliferation and apoptosis effects induced by sodium arsenite and arsenic trioxide on human hepatocyte L02 and provide evidence for the paradox effects of arsenic. METHODS: Human hepatocyte L02 was treated by a series of concentration of sodium arsenite or arsenic trioxide, respectively. Cytotoxicity were tested by MTT assay and colony formation assay, cellular apoptosis and cell cycle were detected by flow cytometry, chromosomal breakage were measured by micronucleus test and reactive oxygen species level and GSH contents were detected with commercial kits. RESULTS: With the increase of sodium arsenite or arsenic trioxide concentrations, cellular viability, colony formation rate and GSH contents decreased; inhibition of colony formation, cellular apoptotic rate, reactive oxygen species level and frequency of micronuclei increased, and dosed cells were both arrested in G2/M phase of cell cycle. CONCLUSION: Both sodium arsenite and arsenic trioxide could induce oxidative stress in human hepatocyte L02 and result in chromosomal damage, apoptosis, cell cycle arrest and cellular proliferation inhibition, suggesting that oxidative stress induction might be the common molecular mechanism of malignant transformation induced by sodium arsenite and therapeutic effects exhibited by arsenic trioxide.

[The apoptotic mechanism of hepatocellular carcinoma cell line (HepG2) induced by arsenic trioxide].

OBJECTIVE: To explore the apoptotic mechanism of human hepatic carcinoma cell line HepG2 induced by arsenic trioxide (As2O3). METHODS: The human hepatoma cell line HepG2 was treated with 0, 2.5, 5 and 10 micromol/L arsenic trioxide for 24 h. Cytotoxicity was tested by MTT assay (additional 25 and 50 micromol/L arsenic trioxide treatment groups), cellular apoptosis were detected by flow cytometry, reactive oxygen species (ROS) level were quantified by DCFH-DA fluorescent probe staining and glutathione content were measured by DTNB method with commercial kits. Western blot assay was used to detect the protein expression of gamma-glutamylcysteine synthetase (gamma-GCS, GCLC and GCLM subunits) and nuclear factor erythroid 2-related factor 2 (Nrf2). RESULTS: With the increase of arsenic trioxide concentration, cellular survival, glutathione content and gamma-GCS (GCLC and GCLM subunits) protein expression level decreased (P < 0.05); while cellular apoptotic rate, reactive oxygen species level and Nrf2 protein expression increased (P < 0.05). CONCLUSION: Arsenic trioxide induces the apoptosis of human hepatoma cell line HepG2 through ROS induction, gamma-GCS expression inhibition and cellular glutathione content depletion.

[Predictive study on properties of traditional Chinese medicine components based on pharmacological effects].

OBJECTIVE: To study the relationship between pharmacological effects and properties of traditional Chinese medicine by the decision tree algorithm. METHOD: Based on of pharmacological effects of traditional Chinese medicine, the decision tree algorithm was applied in the study on the relationship between pharmacological effects and properties of traditional Chinese medicines. A model was established with the decision tree algorithm for the purpose of predicting the properties of traditional Chinese medicine components. RESULT: The established model was reliable and stable, and could be used to predict the properties of traditional Chinese medicine components. CONCLUSION: The prediction for the properties of traditional Chinese medicine components with a decision tree model could reflect the theoretical connotation of the properties of traditional Chinese medicine components to some extent and provide a new method for studying the properties of traditional Chinese medicine components.

[Study on self-similarity relationship between decoction pieces property and component property].

OBJECTIVE: To predict part of medicinal properties of traditional Chinese medicine components and traditional Chinese medicine decoction pieces by using the traditional Chinese medicinal property data prediction platform, in order to establish the relationship between properties of traditional Chinese medicine components and traditional Chinese medicine decoction pieces. METHOD: The properties of traditional Chinese medicine components were predicted by using the medicinal property data prediction platform based on the pharmacological effects of the components. RESULT: The total sum of identical or similar results of the prediction for the properties of traditional Chinese medicine components and traditional Chinese medicine decoction pieces accounted for over 75%. CONCLUSION: The self-similarity exists between properties of traditional Chinese medicine components and traditional Chinese medicine decoction pieces, which reflects the inheritance, additivity and emergence among different properties of traditional Chinese medicines.