Correlation between Mitochondria-Associated Endoplasmic Reticulum Membrane-Related Genes and Cellular Senescence-Related Genes in Osteoarthritis.

BACKGROUND: The role of mitochondria-associated endoplasmic reticulum membrane (MAM) formation in the development of osteoarthritis (OA) is yet unclear. METHODS: A mix of bioinformatics methods and in vitro experimental methodologies was used to study and corroborate the role of MAM-related genes and cellular senescence-related genes in the development of OA. The Gene Expression Omnibus database was used to obtain the microarray information that is relevant to the OA. Several bioinformatic methods were employed to carry out function enrichment analysis and protein-protein correlation analysis, build the correlation regulatory network, and investigate potential relationships between MAM-related genes and cellular senescence-related genes in OA. These methods also served to identify the MAM-related and OA-related genes (MAM-OARGs). RESULTS: For the additional functional enrichment analysis, a total of 13 MAM-OARGs were detected. The correlation regulatory network was also created. Hub MAM-OARGs were shown to have a strong correlation with genes relevant to cellular senescence in OA. Results of in vitro experiments further demonstrated a positive correlation between MAM-OARGs (PTPN1 and ITPR1) and cellular senescence-related and OA-related genes. CONCLUSIONS: As a result, our findings can offer new insights into the investigations of MAM-related genes and cellular senescence-related genes, which could be linked to the OA as well as brand-new potential treatment targets.

Chondroitin Sulfate Improves Mechanical Properties of Gelatin Hydrogel for Cartilage Regeneration in Rats.

Cartilage injury is a common disease in daily life. Especially in aging populations, the incidence of osteoarthritis is increasing. However, due to the poor regeneration ability of cartilage, most cartilage injuries cannot be effectively repaired. Even cartilage tissue engineering still faces many problems such as complex composition and poor integration of scaffolds and host tissues. In this study, chondroitin sulfate, one of the main components of extracellular matrix (ECM), is chosen as the main natural component of the material, which can protect cartilage in a variety of ways. Moreover, the results show that the addition of chondroitin sulfate improves the mechanical properties of gelatin methacrylate (GelMA) hydrogel, making it able to effectively bear mechanical loads in vivo. Further, chondroitin sulfate is modified to obtain the oxidized chondroitin sulfate (OCS) containing aldehyde groups via sodium periodate. This special group improves the interface integration and adhesion ability of the hydrogel to host cartilage tissue through schiff base reactions. In summary, GelMA/OCS hydrogel is a promising candidate for cartilage regeneration with good biocompatibility, mechanical properties, tissue integration ability, and excellent cartilage repair ability.

[Imageology and significances of rotational axes of distal femur on Chinese adults with total knee arthroplasty].

OBJECTIVE: To explore clinical significance of rotational axis of distal femur on Chinese adults in total knee arthroplasty (TKA). METHODS: There were 86 Chinese adults (106 normal knees) including 47 males (53 knees) and 39 females (53 knees), 54 knees were on left and 52 on right. The CT scan was employed in the distal femur. The scan direction was aligned to be on the plane perpendicular to the mechanical axis of the femoral. The CT images of cross sections across lateral and medial femoral epicondyle were moved to personal computer,lateral angle between anterior posterior line (APL) and surgical transepicondylar axis (STEA) (ATA),lateral angle between posterior condylar line (PCL) and APL (APA), angle between perpendicularity of APL and PCL (A-PA), posterior condylar angle (PCA), condylar twist angle (CTA), angle between clinical transepicondylar axis (CTEA) and STEA (CSA) were measured. These values were divided into different groups according to gender and side, the values of CTA, PCA, A-PA, angle PT (varus of tibia plateau), constant 3, ATA, APA and constant 90° were compared by statistically. A-PA and PCA, and CTA were analysed statistically with the liner regression, the relationship among CTEA, STEA ,PCL, APL and PLP were performed to assess by liner regression. RESULTS: ATA was (89.79 ± 1.22)°, APA was (84.84 ± 1.83)°, A-PA was (5.16 ± 1.83)°, PCA was (4.80 ± 1.23)°, CTA was (8.23 ± 1.40), CSA was (3.45 ± 0.68)°. All the parameters had no differences on sex and side,but CSA had difference on male and female. There was no difference among angle PT, PCA, A-PA. There was significant difference in CAT, constant 30 and angle PT, PCA,A-PA. There was no difference between ATA and constant 90°, but there was difference between APA and constant 90°. There was relativity between PCA and CTA, and also PCA and A-PA, CTA and A-PA. There was significant relativity between STEA and CTEA, between STEA and APL, between STEA and PCL, and also between APLP, APL and PCL, but there was no significant relativity between PCL and CTEA. CONCLUSION: TKA for Chinese, the section of femoral posterior condyle should be external 5° to obtain the optimum rotational orientation. The property is different entirely between STEA and CTEA, the rotational alignment is not performed according to parallel to the CTEA in distal femur. Among STEA, APL, PCL, the STEA is the most reliable mark ofrotational alignment of the distal femur, and the PCL is the less reliable mark.