BACKGROUND:Numerous studies have shown that mechanical stimulation is essential for the lineage-specific differentiation of bone marrow mesenchymal stem cells.However,osteogenic differentiation of bone marrow mesenchymal stem cells on surfaces with different roughnesses under mechanical stretching conditions is unknown. OBJECTIVE:To investigate the effects and action mechanisms of different roughness surfaces of polydimethylsiloxane(PDMS)on osteogenic differentiation of bone marrow mesenchymal stem cells under stretching conditions. METHODS:Three morphologies with different roughnesses(PDMS-120M,PDMS-1000M,and PDMS-10000M)were constructed on PDMS surfaces by means of different grits of sandpaper(120 grits,1 000 grits and 10 000 grits),and PDMS surfaces in contact with air served as a control group.With different amplitudes of 0%,2%,4%,and 6%,osteogenesis-related gene expression of bone marrow mesenchymal stem cells on different PDMS surfaces under static and stretching conditions was detected by RT-qPCR.RT-qPCR and western blot assay were used to detect the expression of SIRT1 gene and protein as well as osteogenesis-related genes and proteins in bone marrow mesenchymal stem cells on different roughness surfaces under 2%stretching conditions.Alkaline phosphatase staining and alizarin red staining were further used to observe the osteogenic differentiation ability of bone marrow mesenchymal stem cells on different PDMS surfaces under 2%stretching conditions. RESULTS AND CONCLUSION:(1)Bone marrow mesenchymal stem cells on the PDMS-1000M surface with a roughness of(13.51±2.11)μm had better osteogenic gene expression under static conditions.(2)Bone marrow mesenchymal stem cells on the PDMS surface in contact with air had better osteogenic differentiation under 4%stretching conditions,while bone marrow mesenchymal stem cells on the PDMS-1000M surface had better osteogenic differentiation under 2%stretching conditions.(3)Bone marrow mesenchymal stem cells on the PDMS-1000M surface with a roughness of(13.51±2.11)μm had better osteogenic differentiation under 2%stretching conditions,which may be related to activation of SIRT1 signaling pathway.

Objective To study the characteristics of gait behavior in a mouse model of chronic ankle instability and provide a reference for the study of the mechanism of chronic ankle instability as well as drug screening and evaluation.Methods Thirty C57BL/6J male mice were randomly divided into a control group(n=15)and an injury group(n=15).In the control group,the ankle joint underwent sham operation,and in the injury group,the anterior talofibular ligament and calcaneofibular ligament of the left ankle joint were transected.Gait parameters were analyzed in each group using TreadScan passive gait analysis system.Results Compared with the control group,the injury group showed a 28.43％increase(P＜0.05)in average standing time and a 23.07％increase(P＜0.05)in the percentage of standing time,whereas the average swing time and the percentage of swing time were shortened by 50.63％(P＜0.001)and 19.75％(P＜0.01),respectively.The average braking time and average stride time in the injury group were also shortened by 18.37％(P＜0.01)and 37.86％(P＜0.001),respectively.The injury group exhibited a decrease in step length,anterior-posterior step width,and mediolateral step width by 36.96％,13.66％,and 8.10％,respectively.The total movement speed and instantaneous speed decreased by 8.05％and 11.12％,respectively,while the stride frequency increased by 51.41％.The average footprint area and average maximum standing area decreased by 8.8％and 13.24％,respectively,and foot pressure decreased by only 3％.The plantar pressure distribution in the injury group was uneven,with a more obvious decrease in plantar pressure in the hindfoot,especially a 13.92％decrease in plantar pressure in the right posterior quadrant.Conclusions Mice with chronic ankle instability adopt a more conservative walking pattern during the motion,reducing movement volume and amplitude to improve coordination and stability during walking.

Objective To study the characteristics of gait behavior in a mouse model of chronic ankle instability and provide a reference for the study of the mechanism of chronic ankle instability as well as drug screening and evaluation.Methods Thirty C57BL/6J male mice were randomly divided into a control group(n=15)and an injury group(n=15).In the control group,the ankle joint underwent sham operation,and in the injury group,the anterior talofibular ligament and calcaneofibular ligament of the left ankle joint were transected.Gait parameters were analyzed in each group using TreadScan passive gait analysis system.Results Compared with the control group,the injury group showed a 28.43％increase(P＜0.05)in average standing time and a 23.07％increase(P＜0.05)in the percentage of standing time,whereas the average swing time and the percentage of swing time were shortened by 50.63％(P＜0.001)and 19.75％(P＜0.01),respectively.The average braking time and average stride time in the injury group were also shortened by 18.37％(P＜0.01)and 37.86％(P＜0.001),respectively.The injury group exhibited a decrease in step length,anterior-posterior step width,and mediolateral step width by 36.96％,13.66％,and 8.10％,respectively.The total movement speed and instantaneous speed decreased by 8.05％and 11.12％,respectively,while the stride frequency increased by 51.41％.The average footprint area and average maximum standing area decreased by 8.8％and 13.24％,respectively,and foot pressure decreased by only 3％.The plantar pressure distribution in the injury group was uneven,with a more obvious decrease in plantar pressure in the hindfoot,especially a 13.92％decrease in plantar pressure in the right posterior quadrant.Conclusions Mice with chronic ankle instability adopt a more conservative walking pattern during the motion,reducing movement volume and amplitude to improve coordination and stability during walking.

BACKGROUND:TD-198946 is a small molecule drug known to induce stem cells to form cartilage;however,its effect on osteogenic differentiation remains unclear.OBJECTIVE:To investigate the effects of the small molecule drug TD-198946 on promoting osteoblastic differentiation of rat bone marrow mesenchymal stem cells and its mechanism of action.METHODS:Bone marrow mesenchymal stem cells (BMSCs) were extracted from SD rats.CCK-8 assay was used to evaluate the effect of different concentrations of TD-198946 on the proliferation of bone marrow mesenchymal stem cells to determine the optimal concentration of TD-198946.Then,the optimal concentration of TD-198946 and osteogenic medium were added to induce osteogenic differentiation of bone marrow mesenchymal stem cells.On day 3,qRT-PCR was used to detect the expression of alkaline phosphatase,Runt-related transcription factor 2,osteopontin,osteocalcin,and type Ⅰ collagen genes.On day 7 of osteogenic induction,alkaline phosphatase staining and western blot assay were performed to detect the expression of Runt-related transcription factor 2,type Ⅰ collagen,AKT,p-AKT,PI3K,and p-PI3K proteins.On day 21 of osteogenic induction,Alizarin red staining was conducted.RESULTS AND CONCLUSION:(1) CCK-8 assay results revealed that 100 nmol/L TD-198946 could promote the proliferation of bone marrow mesenchymal stem cells.(2) The results of alkaline phosphatase staining and alizarin red staining showed that TD-198946 could promote osteogenic differentiation of rat bone marrow mesenchymal stem cells.(3) qRT-PCR results showed that TD-198946 could promote the expression of osteogenic genes alkaline phosphatase,Runt-related transcription factor 2,osteopontin,osteocalcin,and type Ⅰ collagen.(4) Western blot assay results showed that TD-198946 could enhance the expression of Runt-related transcription factor 2,type Ⅰ collagen,p-PI3K,and p-AKT.The results indicate that the small molecule drug TD-198946 may induce osteogenic differentiation of rat bone marrow mesenchymal stem cells by activating the PI3K/AKT signaling pathway.

Objective To establish two osteoarthritis models of destabilization of the medial meniscus(DMM)and chronic ankle instability(CAI)in mice,and compare the effects of knee osteoarthritis with varus deformity on ipsilateral ankle cartilage degeneration.Methods Thirty 6-week-old C57BL/6J male mice were randomly divided into a control group and two surgical groups(DMM group and CAI group),respectively.The progression of ankle joint degeneration was quantitatively evaluated through behavioral observation,imaging techniques and histopathology analysis in each group of mice over a 12-week period.Results A decline in gait stability and balance was observed in two surgical groups.Compared to the control group,the time required to cross the balance beam was increased by 23.20％,and the number of slips was increased by 43.26％at 12th week postoperatively in the DMM group.The bone volume fraction and bone mineral density of ankle joints also increased.Meanwhile,wear and tear of the ankle cartilage were found,with the formation of osteophytes,and OARSI score was increased by 88.89％.These changes in ankle joint were more pronounced in the CAI group.Conclusions This mouse model-based study revealed a coupling relationship between the knee and ankle motion.Knee osteoarthritis with varus deformity could lead to a significant ankle joint degeneration,while the damage was less severe than that observed in CAI.

BACKGROUND:TD-198946 is a small molecule drug known to induce stem cells to form cartilage;however,its effect on osteogenic differentiation remains unclear.OBJECTIVE:To investigate the effects of the small molecule drug TD-198946 on promoting osteoblastic differentiation of rat bone marrow mesenchymal stem cells and its mechanism of action.METHODS:Bone marrow mesenchymal stem cells (BMSCs) were extracted from SD rats.CCK-8 assay was used to evaluate the effect of different concentrations of TD-198946 on the proliferation of bone marrow mesenchymal stem cells to determine the optimal concentration of TD-198946.Then,the optimal concentration of TD-198946 and osteogenic medium were added to induce osteogenic differentiation of bone marrow mesenchymal stem cells.On day 3,qRT-PCR was used to detect the expression of alkaline phosphatase,Runt-related transcription factor 2,osteopontin,osteocalcin,and type Ⅰ collagen genes.On day 7 of osteogenic induction,alkaline phosphatase staining and western blot assay were performed to detect the expression of Runt-related transcription factor 2,type Ⅰ collagen,AKT,p-AKT,PI3K,and p-PI3K proteins.On day 21 of osteogenic induction,Alizarin red staining was conducted.RESULTS AND CONCLUSION:(1) CCK-8 assay results revealed that 100 nmol/L TD-198946 could promote the proliferation of bone marrow mesenchymal stem cells.(2) The results of alkaline phosphatase staining and alizarin red staining showed that TD-198946 could promote osteogenic differentiation of rat bone marrow mesenchymal stem cells.(3) qRT-PCR results showed that TD-198946 could promote the expression of osteogenic genes alkaline phosphatase,Runt-related transcription factor 2,osteopontin,osteocalcin,and type Ⅰ collagen.(4) Western blot assay results showed that TD-198946 could enhance the expression of Runt-related transcription factor 2,type Ⅰ collagen,p-PI3K,and p-AKT.The results indicate that the small molecule drug TD-198946 may induce osteogenic differentiation of rat bone marrow mesenchymal stem cells by activating the PI3K/AKT signaling pathway.

Objective To establish two osteoarthritis models of destabilization of the medial meniscus(DMM)and chronic ankle instability(CAI)in mice,and compare the effects of knee osteoarthritis with varus deformity on ipsilateral ankle cartilage degeneration.Methods Thirty 6-week-old C57BL/6J male mice were randomly divided into a control group and two surgical groups(DMM group and CAI group),respectively.The progression of ankle joint degeneration was quantitatively evaluated through behavioral observation,imaging techniques and histopathology analysis in each group of mice over a 12-week period.Results A decline in gait stability and balance was observed in two surgical groups.Compared to the control group,the time required to cross the balance beam was increased by 23.20％,and the number of slips was increased by 43.26％at 12th week postoperatively in the DMM group.The bone volume fraction and bone mineral density of ankle joints also increased.Meanwhile,wear and tear of the ankle cartilage were found,with the formation of osteophytes,and OARSI score was increased by 88.89％.These changes in ankle joint were more pronounced in the CAI group.Conclusions This mouse model-based study revealed a coupling relationship between the knee and ankle motion.Knee osteoarthritis with varus deformity could lead to a significant ankle joint degeneration,while the damage was less severe than that observed in CAI.

Objective To investigate the relationship between the changes of plasma thromboxane B2 (TXB2),6-keto-prostaglandin 1 α (6k-PGF1 α) and positive platelet α-granule membrane glycoprotein (CD62P) in patients with acute cerebral infarction.Methods 160 patients with acute cerebral infarction (case group) and 80 healthy subjects were enrolled in our hospital from August 2016 to August 2018.The plasma levels of 6k-PGF1α,CD62P and TXB2 were measured and analyzed.Subgroup analysis was performed on patients with cerebral infarction with different trial of org 10172 in acute stroke treatment (TOAST) classification,National Institute of Health Stroke Scale (NIHSS) score,and prognosis outcome.Results The plasma levels of 6k-PGF1α,CD62P and TXB2 in the case group were significantly higher than those in the control group (P ＜ 0.05).The plasma levels of 6k-PGF1 α,CD62P and TXB2 in mild,moderate and severe groups were gradually increased (P ＜ 0.05).The plasma levels of 6k-PGF1 α,CD62P and TXB2 in patients with small infarction,mid-infarction and large infarction were also gradually increased,with statistically significant difference (P ＜ 0.05);plasma 6k-PGF1 α,CD62P,TXB2 levels in patients with good prognosis were significantly lower than those in poor prognosis group (P ＜ 0.05).Conclusions The levels of plasma TXB2,6k-PGF1α and CD62P in patients with acute cerebral infarction are elevated,and are closely related to the patient's condition and prognosis.

We have previously reported that Cystatin C (CysC) is a pivotal mediator in the neuroprotection induced by hyperbaric oxygen (HBO) preconditioning; however, the underlying mechanism and how CysC changes after stroke are not clear. In the present study, we demonstrated that CysC expression was elevated as early as 3 h after reperfusion, and this was further enhanced by HBO preconditioning. Concurrently, LC3-II and Beclin-1, two positive-markers for autophagy induction, exhibited increases similar to CysC, while knockdown of CysC blocked these elevations. As a marker of autophagy inhibition, p62 was downregulated by HBO preconditioning and this was blocked by CysC knockdown. Besides, the beneficial effects of preserving lysosomal membrane integrity and enhancing autolysosome formation induced by HBO preconditioning were abolished in CysC rats. Furthermore, we demonstrated that exogenous CysC reduced the neurological deficits and infarct volume after brain ischemic injury, while 3-methyladenine partially reversed this neuroprotection. In the present study, we showed that CysC is biochemically and morphologically essential for promoting autophagic flux, and highlighted the translational potential of HBO preconditioning and CysC for stroke treatment.
Animals ; Autophagy ; physiology ; Beclin-1 ; metabolism ; Brain ; metabolism ; pathology ; Brain Ischemia ; metabolism ; pathology ; therapy ; Cystatin C ; genetics ; metabolism ; Disease Models, Animal ; Gene Expression ; Gene Knockdown Techniques ; Hyperbaric Oxygenation ; Lysosomes ; metabolism ; pathology ; Male ; Microtubule-Associated Proteins ; metabolism ; Neurons ; metabolism ; pathology ; Neuroprotection ; physiology ; Oxygen ; therapeutic use ; Random Allocation ; Rats, Sprague-Dawley ; Rats, Transgenic ; Reperfusion Injury ; metabolism ; pathology ; therapy

Objective To investigate the surgical methods and experience of laparoscopic radical cystectomy and orthotopic ileal neobladder for invasive bladder cancer. Methods The clinical data of 14 patients with invasive bladder cancer underwent laparoscopic radical cystectomy and orthotopic ileal neobladder were collected retrospectively during March 2011 and October 2014. Results The 13 patients with invasive bladder cancer were successfully completed laparoscopic radical cystectomy and orthotopic ileal neobladder. 1 case was treated with laparotomy because of unsatisfactory surgery ifeld caused by excessive tumor bleeding. Twelve cases of the urethra-neobaldder anastomosis were completed through the abdominal incision, while for the other 2 cases, the anastomosis was done under the laparoscope, 2 cases were performed neovesicourethral anastomosis using single-needle running sutures through laparoscopy. The median operative time was 444 minutes, the mean intraoperative blood loss was 490 ml. Postoperative pathologic results conifrmed that 12 cases were bladder transitional cell carcinoma (1 case with partial squamous cell carcinoma) and 2 cases with bladder adenocarcinoma. No severe complication occurred except for 2 cases of urinary leakage and 1 case of urinary incontinence. Patients were followed up for 6-56 months,within which 3 patients were died of distant metastasis, 1 case was detected with intracranial metastasis, 1 case was found with urethra-vesical anastomotic stenosis while cured after urethrotomy. Ten cases were well recovered and the mean volume of the neobladder was 300 ml. Conclusions Laparoscopic radical cystectomy and orthotopic ileal neobladder have the advantage of better therapeutic effects, safety, minimal invasion and rapid recovery, which are the preferred therapeutic methods for invasive bladder cancer.