Notch, Numb and Numb‐like responses to exercise‐induced muscle damage in human skeletal muscle

Abstract

Introduction: Notch proteins are a single-pass type 1 transmembrane protein that regulates cellular proliferation and inhibits myogenic differentiation. Numb and Numb-Like are adaptor proteins. Among their functions is control of cell fate determination and progression of cell differentiation via inhibition of Notch. While no role for Numb-Like has been found in cells of the myogenic lineage, Numb promotes myogenic differentiation of satellite cells. The roles these proteins in human skeletal muscle in response to exercise-induced muscle damage have yet to be examined. Purpose: The purpose of this investigation is to examine changes in the expression of Notch, Numb and Numb-Like in human skeletal muscle after a bout of muscle damage via eccentric exercise. Methods: Seventeen, recreationally trained, male subjects signed an informed consent approved by The University of Kansas's Institutional Review Board and were randomly assigned to one of two groups: a control group (n = 5) or a damage group (n = 12). Subjects completed a one repetition maximum (1RM) in leg extension followed by seven sets of ten repetitions of eccentric leg extension at %120 of 1RM with a two minutes of rest period between sets. Four muscle biopsies of the vastus lateralis were collected at baseline, 3-hours post-two days post-, and five days post-muscle damage and analyzed utilizing Western blot and quantitative reverse transcription polymerase chain reaction analyses. The results were analyzed using two separate analyses. The first being a 2X3 (Group X Time) Two-Way Repeated Measures ANOVA for the baseline measures, two days post-and five days post-muscle damage time points with the exclusion of the 3-hour post damage time point. The second being a One-Way Repeated Measures ANOVA with only the experimental group. Results: There were no significant main effects of time for the damage group with the inclusion of the three hour time point from baseline for Numb (p > 0.05: 3-Hour p = 0.22, Day 2 p = 0.89, and Day 5 p = 0.17) and Numb-Like (3-Hour p = 0.63, iv Day 2 p = 0.30, and Day 5 p = 0.77). Additionally, no significant differences in mRNA expression were observed for Numb between groups two days post-and five days post-muscle damage for Numb (p = 0.13 and p = 0.74, respectively) and Numb-Like (p = 0.28 and p = 0.60, respectively).There was no significant main effect of time for Notch1 among the damage group with the inclusion of the three-hour time point from baseline (3-Hour p = 0.84, Day 2 p = 0.28, and Day 5 p = 0.20). Additionally, no significant differences in mRNA expression were observed for Notch1 between groups at two days post-muscle damage (p = 0.56). However, there was a significant increase in Notch1 at five days post-muscle damage between the exercise group (1.91 ± 1.29 fold change) and the control group (0.52 ± 0.38 fold change) from baseline measures (p = 0.04). Conclusion:Numb and Numb-Like expression was unaltered post-muscle damage, while Notch mRNA expression was increased after exercise-induced muscle damage. These resu...

Methylome and proteome integration in human skeletal muscle uncover group and individual responses to high‐intensity interval training

“…For instance, we found proteins positively correlated with CpGs located in genes related to fatty acid metabolism, such as COMMD9 (involved in LDL regulation), 100 ARHGAP42 (associated with hypertension), 101 APOBEC1 (linked to weight loss and muscle development), 102 PTPRT, PTPRN2 (implicated in obesity), [103][104][105][106] and DACT1, DIO2, RPTOR, and PLEKHM3 (involved in muscle myogenesis and hypertrophy). [107][108][109][110][111] Conversely, these proteins were negatively correlated with CpG sites located in genes such as KCNMA1, NOTCH1, CAMKK2 (related to skeletal muscle regeneration, proliferation, and differentiation), [112][113][114][115][116][117] DHRS3, DGKG, LPIN1, WNT5A (associated with obesity, metabolic syndrome, and lipid regulation), [118][119][120] LRRC2 (a mediator of mitochondrial and cardiac function), 121 and PDE4A (linked to diabetes). 122,123 These associations provide valuable insights into the intricate relationships between specific genes, proteins, and exercise response.…”

DNA methylation and proteomics integration uncover dose-dependent group and individual responses to exercise in human skeletal muscle

“…The integration analysis highlighted proteins both positively and negatively associated with specific CpGs, worthy following up in future replication/mechanistic studies. Interestingly of the 261 proteins highlighted in the results, we found proteins positively correlated with CpGs located in genes involved in fatty acid metabolism such as COMMD9, (involved in LDL regulation) [88]; hypertension (ARHGAP42) [89]; weight loss and muscle development (APOBEC1) [90]; obesity (PTPRT and PTPRN2) [91][92][93][94], and muscle myogenesis and hyperthrophy (DACT1, DIO2, RPTOR, and PLEKHM3) [95][96][97][98][99] These proteins were also negatively correlated with CpGs located in genes such as KCNMA1, NOTCH1, and CAMKK2 which are involved in skeletal muscle regeneration, proliferation and differentiation [100][101][102][103][104][105], DHRS3, DGKG, LPIN1, WNT5A which have been associated with obesity, metabolic syndrome and lipid regulation [106][107][108], LRRC2 which is a mediator of mitochondrial and cardiac function [109], and PDE4A which has been associated with diabetes [110; 111]. Based on results of this integration, we suggest that future work studying the relationship between such genes/proteins should be prioritized as this may reveal important mechanisms associated with exercise response across multiple OMIC layers.…”

Septin 7 interacts with Numb to preserve sarcomere structural organization and muscle contractile function

“…Numb expression was evaluated by western blotting ( De Gasperi et al, 2022 ; Bubak et al, 2022 ). Tibialis anterior (TA) and EDL were homogenized using an MP homogenizer in RIPA buffer (#9806, Cell Signaling Technologies Inc, Danvers, MA) supplemented with a protease and phosphatase inhibitor cocktail (Halt, Thermo Fisher Scientific).…”