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.

Comparison of the Infant and Adult Adipose-Derived Mesenchymal Stem Cells in Proliferation, Senescence, Anti-oxidative Ability and Differentiation Potential.

BACKGROUND: Infant adipose-derived mesenchymal stem cells (ADSCs) collected from excised polydactyly fat tissue, which was surgical waste, could be cultured and expanded in vitro in this study. In addition, the collecting process would not cause pain in the host. In this study, the proliferation, reduction of senescence, anti-oxidative ability, and differentiation potential in the infant ADSCs were compared with those in the adult ADSCs harvested from thigh liposuction to determine the availability of infant ADSCs. METHODS: Proliferation was determined by detecting the fold changes in cell numbers and doubling time periods. Senescence was analyzed by investigating the age-related gene expression levels and the replicative stress. The superoxide dismutase (SOD) gene expression, adipogenic, neurogenic, osteogenic, and tenogenic differentiation were compared by RT-qPCR. The chondrogenic differentiation efficiency was also determined using RT-qPCR and immunohistochemical staining. RESULTS: The proliferation, SOD (SOD1, SOD2 and SOD3) gene expression, the stemness-related gene (c-MYC) and telomerase reverse transcriptase of the infant ADSCs at early passages were enhanced compared with those of the adults'. Cellular senescence related genes, including p16, p21 and p53, and replicative stress were reduced in the infant ADSCs. The adipogenic genes (PPARγ and LPL) and neurogenic genes (MAP2 and NEFH) of the infant ADSC differentiated cells were significantly higher than those of the adults' while the expression of the osteogenic genes (OCN and RUNX) and tenogenic genes (TNC and COL3A1) of both demonstrated opposite results. The chondrogenic markers (SOX9, COL2 and COL10) were enhanced in the infant ADSC differentiated chondrogenic pellets, and the expression levels of SODs were decreased during the differentiation process. CONCLUSION: Cultured infant ADSCs demonstrate less cellular senescence and replicative stress, higher proliferation rates, better antioxidant defense activity, and higher potential of chondrogenic, adipogenic and neurogenic differentiation.

Tendon repair with intercalated partial extensor carpi radialis longus tendon graft for chronic extensor pollicis longus tendon rupture.

BACKGROUND: The main treatment choices for chronic extensor pollicis longus (EPL) tendon rupture consists of tendon transfer and tendon repair with tendon graft. Tendon transfer with extensor indicis proprius (EIP) is currently considered the gold standard treatment which yields predictable and satisfactory results, but potentially compromises the strength of independent extension of the index finger. We propose our method of using a partial extensor carpi radialis longus (ECRL) tendon graft to repair chronic EPL tendon tears. METHODS: The distal stump of the EPL was located through an incision at the basal joint level. The proximal stump was located through a curved incision at the dorsoradial wrist where the partial ECRL tendon graft was harvested. The tendon graft was subcutaneously transposed, sutured at both ends, and tensioned at full thumb extension with a neutral wrist position. RESULTS: From March 2016 to June 2019, 23 patients (mean age: 59.7 years; mean follow-up: 29.6 months) were retrospectively reviewed. All the patients were followed for a minimum of 12 months. The final total active motion was 93.2% of the contralateral thumb. The mean Quick Disabilities of the Arm, Shoulder and Hand score was 6.0. There was one complication possibly due to poor EPL muscle quality, and the patient was subsequently treated with EIP tendon transfer. CONCLUSION: Our study showed that using a partial ECRL tendon graft to repair chronic EPL tendon rupture results in satisfactory functional outcomes. The advantages of this method include preservation of EIP function and using the same incision for graft harvesting and tendon repair. This method can be considered an alternative to EIP tendon transfer in patients with high demand for their index finger function.