Proliferation and Differentiation Potential of Bone Marrow-Derived Mesenchymal Stem Cells From Children With Polydactyly and Adults With Basal Joint Arthritis.

This study compared the proliferation and differentiation potential of bone marrow-derived mesenchymal stem cells (BMSCs) derived from infants with polydactyly and adults with basal joint arthritis. The proliferation rate of adult and infant BMSCs was determined by the cell number changes and doubling times. The γH2AX immunofluorescence staining, age-related gene expression, senescence-associated ß-galactosidase (SA-ß-gal) staining were analyzed to determine the senescence state of adult and infant BMSCs. The expression levels of superoxide dismutases (SODs) and genes associated with various types of differentiation were measured using Real-Time Quantitative Polymerase Chain Reaction (RT-qPCR). Differentiation levels were evaluated through histochemical and immunohistochemical staining. The results showed that infant BMSCs had a significantly higher increase in cell numbers and faster doubling times compared with adult BMSCs. Infant BMSCs at late stages exhibited reduced γH2AX expression and SA-ß-gal staining, indicating lower levels of senescence. The expression levels of senescence-related genes (p16, p21, and p53) in infant BMSCs were also lower than in adult BMSCs. In addition, infant BMSCs demonstrated higher antioxidative ability with elevated expression of SOD1, SOD2, and SOD3 compared with adult BMSCs. In terms of differentiation potential, infant BMSCs outperformed adult BMSCs in chondrogenesis, as indicated by higher expression levels of chondrogenic genes (SOX9, COL2, and COL10) and positive immunohistochemical staining. Moreover, differentiated cells derived from infant BMSCs exhibited significantly higher expression levels of osteogenic, tenogenic, hepatogenic, and neurogenic genes compared with those derived from adult BMSCs. Histochemical and immunofluorescence staining confirmed these findings. However, adult BMSCs showed lower adipogenic differentiation potential compared with infant BMSCs. Overall, infant BMSCs demonstrated superior characteristics, including higher proliferation rates, enhanced antioxidative activity, and greater differentiation potential into various lineages. They also exhibited reduced cellular senescence. These findings, within the context of cellular differentiation, suggest potential implications for the use of allogeneic BMSC transplantation, emphasizing the need for further in vivo investigation.

Multilineage differentiation potential in the infant adipose- and umbilical cord-derived mesenchymal stem cells.

BACKGROUND: This study aims to compare the biological properties of infant adipose-derived mesenchymal stem cells (infant ADSCs) from excised polydactyly fat tissue and umbilical cord-derived mesenchymal stem cells (UCSCs) in terms of proliferation and differentiation capabilities. The proliferation of infant ADSCs and UCSCs was analyzed by determining the fold changes of cell numbers and doubling time periods. METHODS: The state of senescence and replicative stress was compared by analyzing the expression of age-related genes, senescence-associated ß-galactosidase (SA-ß-gal) staining, and phosphorylated histone variant H2AX (γH2AX) immunofluorescence staining. The expression levels of superoxide dismutase ( SODs ) and genes related to multilineage differentiation were analyzed using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Differentiation levels were determined using histochemical staining, immunohistochemical staining, and immunofluorescence staining. RESULTS: Infant ADSCs exhibited higher proliferation rates and expression levels of SOD1 , SOD2 , and SOD3 at passages 3-5 compared with UCSCs. Senescence related genes ( p16 , p21 , and p53 ), SA-ß-gal staining, and replicative stress analysis were reduced in infant ADSCs. The expression levels of chondrogenic genes ( COL2 and COL10 ), osteogenic genes ( RUNX2 and ALP ), adipogenic genes ( LPL ), and hepatogenic genes ( ALB and TAT ) in infant ADSC-differentiated cells were significantly higher than those in UCSCs. Histochemical and immunofluorescence staining confirmed these results. Only the expression levels of tenogenic genes ( MMP3 , DCN , and COL3 ) in infant ADSC-differentiated cells were lower than those in UCSCs. CONCLUSION: Infant ADSCs exhibit higher proliferation rates, reduced cellular senescence and replicative stress, better antioxidative activity, and higher differentiation potential toward chondrogenic, osteogenic, adipogenic and hepatogenic lineages than UCSCs.

Repairing Complete Radial Tears of the Lateral Meniscus: Arthroscopic All-Inside Double Vertical Cross-Suture Technique Is Effective and Safe With 2-Year Minimum Follow-Up.

PURPOSE: To assess the failure rate and clinical outcomes of the all-inside, double-vertical, cross-suture technique in repairing complete radial tears of the lateral meniscus. METHOD: We retrospectively reviewed records of patients with this injury on whom the present technique was employed at our institution between 2011 and 2018, with at least 24 months of follow-up. Six months postoperatively, the meniscus healing and extrusion status were evaluated through magnetic resonance imaging. Preoperative and postoperative knee function, measured through IKDC, Lysholm knee, and Tegner activity scale scores, were compared. RESULTS: In total, 27 patients underwent the procedure. The preoperative mean (standard deviation) IKDC score, Lysholm knee score, and Tegner activity scale scores were 53.4 ± 5.3, 63.2 ± 9.3, and 4 ± .7, respectively. At the last follow-up (≥24 months postoperatively), these scores increased to 92.1 ± 2.6, 90.8 ± 4.2, and 6.1 ± 1.3, respectively (all P < .05). Complete healing of the meniscus was observed in 23 patients, and 4 patients had meniscus retear or nonhealing. The overall retear or nonhealing rate was 14.8%. Healing rates between those with isolated radial tears (87.5%) and those with combined anterior cruciate ligament rupture (84.2%; P = .826) were comparable. No difference was observed in the progression of coronal and sagittal meniscus extrusion (P = .133 and .797, respectively). CONCLUSION: In patients with complete radial tears of the lateral meniscus, the arthroscopic all-inside double vertical cross-suture repair technique resulted in an 85.2% healing rate, improvements in functional outcomes and activity levels, and no identifiable progression of meniscus extrusion. The all-inside double vertical cross-suture technique is effective and safe for the repair of radial tears of the meniscus. LEVEL OF EVIDENCE: Level IV, retrospective case series.