SIRT5 deficiency enhances the proliferative and therapeutic capacities of adipose‐derived mesenchymal stem cells via metabolic switching

Abstract

Background: Mesenchymal stem cells (MSCs) have therapeutic potential for multiple ischemic diseases. However, in vitro expansion of MSCs before clinical application leads to metabolic reprogramming from glycolysis to oxidative phosphorylation, drastically impairing their proliferative and therapeutic capacities. This study aimed to define the regulatory effects of Sirtuin 5 (SIRT5) on the proliferative and therapeutic functions of adipose-derived MSCs (ADMSCs) during in vitro expansion. Methods: ADMSCs were isolated from wild-type (WT) and Sirt5-knockout (Sirt5 −/−) mice. Cell counting assay was used to investigate the proliferative capacities of the ADMSCs. Dihydroethidium and senescence-associated βgalactosidase stainings were used to measure intracellular ROS and senescence levels. Mass spectrometry was used to analyze protein succinylation. Oxygen consumption rates and extra cellular acidification rates were measured as indicators of mitochondrial respiration and glycolysis. Metabolic-related genes expression were verified by quantitative PCR and western blot. Hind limb ischemia mouse model was used to evaluate the therapeutic potentials of WT and Sirt5 −/− ADSMCs. Results: SIRT5 protein levels were upregulated in ADMCs during in vitro expansion. Sirt5 −/− ADMSCs exhibited a higher proliferation rate, delayed senescence, and reduced ROS accumulation. Furthermore, elevated protein succinylation levels were observed in Sirt5 −/− ADMSCs, leading to the reduced activity of This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Modulation of Inherent Niches in 3D Multicellular MSC Spheroids Reconfigures Metabolism and Enhances Therapeutic Potential

“…Upon exposure to hypoxia, the 2D-cultivated MSCs showed significantly upregulated expression of PDK1 and SLC2A1 and downregulated expression of G6PD and 6PGD (Figure 4C, p < 0.01), a clear indication of MSC metabolic remodeling toward glycolysis with a reduced pentose phosphate pathway. The observed metabolic shift was consistent with the findings reported in the literature [24,25]. For 3D MSC spheroids prepared under normoxia, however, changes in the mRNA levels were rather limited, while hypoxia-cultivated 3D MSC spheroids displayed a remarkable shift in the expression level of the investigated genes (Figure 4C, p < 0.05).…”

“…Conversely, the expression of G6PD and 6PGD was upregulated as the incubation time increased, indicating the effect of other niche factors, instead of hypoxia, inherent in the spheroids on the modulation of cellular metabolism. As an enhancement of the pentose phosphate pathway is reportedly associated with MSC survival and paracrine functionality [25,45], we speculated that metabolic reconfiguration upon spheroid assembly could be an important niche factor contributing to the enhanced therapeutic potential of MSCs.…”

KAT2A Promotes Hepatitis B Virus Transcription and Replication Through Epigenetic Regulation of cccDNA Minichromosome

“…Multiple pieces of evidence have revealed the critical role of histone modification in regulating the transcription of cccDNA, particularly the acetylation and methylation of cccDNA-bound histone 3 (H3) and histone 4 (H4) ( Zhang et al, 2017 , p. 5; Ren et al, 2018 , p. 3). To investigate whether histone succinylation plays a potential role in the HBV life cycle, we used the RNA interference method to screen a series of the reported histone succinyltransferases and desuccinylases, including p300, KAT2A, CPT1A, SIRT5, and SIRT7 ( Figure 1A ), which are known to catalyse histone succinylation or desuccinylation to result in transcription activation or repression ( Zhang et al, 2011 ; Li et al, 2016 ; Wang et al, 2017 ; Kurmi et al, 2018 ; Ou et al, 2020 ). The data showed that the histone succinyltransferases and desuccinylases (including p300, KAT2A, CPT1A, SIRT5, and SIRT7) were efficiently knocked down ( Figure 1B and Supplementary Figure 1A ).…”

SIRT5 functions as a tumor suppressor in renal cell carcinoma by reversing the Warburg effect

“…SIRT5 has been previously reported as a master metabolic regulator, and its expression levels are significantly associated with the metabolic patterns and functions of various cell types [ 34 ]. SIRT5 not only maintains mitochondrial function through posttranslational modifications of mitochondrial proteins and enzymes but also modulates different pathways, including glucose oxidation, ketone body formation, fatty acid degradation, ammonia disposal, and redox homeostasis.…”