Results: The fusion index and myotube surface area were higher (p
OBJECTIVE: This study investigates the cardioprotective effects of arjunolic acid (AA) via MyD88-dependant TLR4 downstream signaling marker expression.
MATERIALS AND METHODS: The MTT viability assay was used to assess the cytotoxicity of AA. LPS induced in vitro cardiovascular disease model was developed in H9C2 and C2C12 myotubes. The treatment groups were designed such as control (untreated), LPS control, positive control (LPS + pyrrolidine dithiocarbamate (PDTC)-25 µM), and treatment groups were co-treated with LPS and three concentrations of AA (50, 75, and 100 µM) for 24 h. The changes in the expression of TLR4 downstream signaling markers were evaluated through High Content Screening (HCS) and Western Blot (WB) analysis.
RESULTS: After 24 h of co-treatment, the expression of TLR4, MyD88, MAPK, JNK, and NF-κB markers were upregulated significantly (2-6 times) in the LPS-treated groups compared to the untreated control in both HCS and WB experiments. Evidently, the HCS analysis revealed that MyD88, NF-κB, p38, and JNK were significantly downregulated in the H9C2 myotube in the AA treated groups. In HCS, the expression of NF-κB was downregulated in C2C12. Additionally, TLR4 expression was downregulated in both H9C2 and C2C12 myotubes in the WB experiment.
DISCUSSION AND CONCLUSIONS: TLR4 marker expression in H9C2 and C2C12 myotubes was subsequently decreased by AA treatment, suggesting possible cardioprotective effects of AA.
RESULTS: In vitro, cultured MDSC spontaneously differentiated into insulin-expressing islet-like cell clusters as revealed using MDSC from transgenic mice expressing GFP or mCherry under the control of an insulin promoter. Differentiated clusters of beta-like cells co-expressed insulin with the transcription factors Pdx1, Nkx2.2, Nkx6.1, and MafA, and secreted significant levels of insulin in response to glucose challenges. In vivo, undifferentiated MDSC injected into streptozotocin (STZ)-treated mice engrafted within 48 h specifically to damaged pancreatic islets and were shown to differentiate and express insulin 10-12 days after injection. In addition, injection of MDSC into hyperglycemic diabetic mice reduced their blood glucose levels for 2-4 weeks.
CONCLUSION: These data show that MDSC are capable of differentiating into mature pancreatic beta islet-like cells, not only upon culture in vitro, but also in vivo after systemic injection in STZ-induced diabetic mouse models. Being nonteratogenic, MDSC can be used directly by systemic injection, and this potential reveals a promising alternative avenue in stem cell-based treatment of beta-cell deficiencies.
Methods: Myoblast cells were cultured into young and senescent state before treated with different concentrations of ginger standardised extracts containing different concentrations of 6-gingerol and 6-shogaol. Analysis on cellular morphology and myogenic purity was carried out besides determination of SA-β-galactosidase expression and cell cycle profile. Myoblast differentiation was quantitated by determining the fusion index, maturation index, and myotube size.
Results: Treatment with ginger extracts resulted in improvement of cellular morphology of senescent myoblasts which resembled the morphology of young myoblasts. Our results also showed that ginger treatment caused a significant reduction in SA-β-galactosidase expression on senescent myoblasts indicating prevention of cellular senescence, while cell cycle analysis showed a significant increase in the percentage of cells in the G0/G1 phase and reduction in the S-phase cells. Increased myoblast regenerative capacity was observed as shown by the increased number of nuclei per myotube, fusion index, and maturation index.
Conclusions: Ginger extracts exerted their potency in promoting muscle regeneration as indicated by prevention of cellular senescence and promotion of myoblast regenerative capacity.
RESULTS: Assessment of the motor performance showed that, the forelimb grip strength was significantly (P<0.0001) greater in the WT mice compared to Ts1Cje mice regardless of gender. The average survival time of the WT mice during the hanging wire test was significantly (P<0.0001) greater compared to the Ts1Cje mice. Also, the WT mice performed significantly (P<0.05) better than the Ts1Cje mice in the latency to maintain a coordinated motor movement against the rotating rod. Adult Ts1Cje mice exhibited significantly (P<0.001) lower nerve conduction velocity compared with their aged matched WT mice. Further analysis showed a significantly (P<0.001) higher population of type I fibres in WT compared to Ts1Cje mice. Also, there was significantly (P<0.01) higher population of COX deficient fibres in Ts1Cje mice. Expression of Myf5 was significantly (P<0.05) reduced in triceps of Ts1Cje mice while MyoD expression was significantly (P<0.05) increased in quadriceps of Ts1Cje mice.
CONCLUSION: Ts1Cje mice exhibited weaker muscle strength. The lower population of the type I fibres and higher population of COX deficient fibres in Ts1Cje mice may contribute to the muscle weakness seen in this mouse model for DS.
Material and methods: Human skeletal muscle myoblasts were cultured until senescence. Young and senescent cells were treated with TRF for 24 h before and after differentiation induction, followed by evaluation of cellular morphology and efficiency of differentiation. Expression of cell proliferation marker Ki67 protein and myogenic regulatory factors MyoD and myogenin were determined.
Results: Our findings showed that treatment with TRF significantly improved the morphology of senescent myoblasts. Promotion of differentiation was observed in young and senescent myoblasts with TRF treatment as shown by the increased fusion index and larger size of myotubes. Increased Ki67 and myogenin expression with TRF treatment was also observed in senescent myoblasts, suggesting amelioration of the myogenic program by TRF during replicative senescence.
Conclusions: TRF modulates the expression of regulatory factors related to proliferation and differentiation in senescent human myoblasts and could be beneficial for ameliorating the regenerative defects during aging.
Methods: Human skeletal muscle myoblast (HSMM) cells were cultured and serial passaging was carried out to obtain young and senescent cells. The cells were then treated with C. vulgaris followed by differentiation induction. The expression of Pax7, MyoD1, Myf5, MEF2C, IGF1R, MYOG, TNNT1, PTEN, and MYH2 genes and miR-133b, miR-206, and miR-486 was determined in untreated and C. vulgaris-treated myoblasts on Days 0, 1, 3, 5, and 7 of differentiation.
Results: The expression of Pax7, MyoD1, Myf5, MEF2C, IGF1R, MYOG, TNNT1, and PTEN in control senescent myoblasts was significantly decreased on Day 0 of differentiation (p<0.05). Treatment with C. vulgaris upregulated Pax7, Myf5, MEF2C, IGF1R, MYOG, and PTEN in senescent myoblasts (p<0.05) and upregulated Pax7 and MYOG in young myoblasts (p<0.05). The expression of MyoD1 and Myf5 in young myoblasts however was significantly decreased on Day 0 of differentiation (p<0.05). During differentiation, the expression of these genes was increased with C. vulgaris treatment. Further analysis on myomiRs expression showed that miR-133b, miR-206, and miR-486 were significantly downregulated in senescent myoblasts on Day 0 of differentiation which was upregulated by C. vulgaris treatment (p<0.05). During differentiation, the expression of miR-133b and miR-206 was significantly increased with C. vulgaris treatment in both young and senescent myoblasts (p<0.05). However, no significant change was observed on the expression of miR-486 with C. vulgaris treatment.
Conclusions: C. vulgaris demonstrated the modulatory effects on the expression of MRFs and myomiRs during proliferation and differentiation of myoblasts in culture. These findings may indicate the beneficial effect of C. vulgaris in muscle regeneration during ageing thus may prevent sarcopenia in the elderly.