Essential Roles of PPARs in Lipid Metabolism during Mycobacterial Infection

Abstract

The mycobacterial cell wall is composed of large amounts of lipids with varying moieties. Some mycobacteria species hijack host cells and promote lipid droplet accumulation to build the cellular environment essential for their intracellular survival. Thus, lipids are thought to be important for mycobacteria survival as well as for the invasion, parasitization, and proliferation within host cells. However, their physiological roles have not been fully elucidated. Recent studies have revealed that mycobacteria modulate the peroxisome proliferator-activated receptor (PPAR) signaling and utilize host-derived triacylglycerol (TAG) and cholesterol as both nutrient sources and evasion from the host immune system. In this review, we discuss recent findings that describe the activation of PPARs by mycobacterial infections and their role in determining the fate of bacilli by inducing lipid metabolism, anti-inflammatory function, and autophagy.

Cordyceps guangdongensis lipid-lowering formula alleviates fat and lipid accumulation by modulating gut microbiota and short-chain fatty acids in high-fat diet mice

“…The liver is very crucial for lipid metabolism and lipogenesis (43), and some antiobesonenic candidates were reported to prevent obesity and serum lipid levels by regulating fat and lipid metabolism in the liver (44). The expression levels of Pnliprp, PPARs, and Cide protein family participated in the regulation of lipid digestion and metabolism, adipogenesis and adipocyte differentiation, lipid oxidation, and lipid droplet formation (45)(46)(47)(48). Our transcriptome results showed that after CGLC administration of 14 weeks, Pnliprp1, Pnliprp2, and Ppard were markedly upregulated, whereas the expression levels of Cidea and Cidec showed an obvious downregulation (Figure 7D), being consistent with the effect of Moringa oleifera leave crude polysaccharide on the expression pattern of those genes (49).…”

Lipophilic AIEgens as the “Trojan Horse” with Discrepant Efficacy in Tracking and Treatment of Mycobacterial Infection

“…The mycobacterium's cell wall is rich in lipids, accounting for ≈30–40% of its total weight. [ 31 ] Upon invading host cells, mycobacteria promote the accumulation and redistribution of intracellular lipid droplets to create the necessary environment for their intracellular survival. They use host cell lipids as energy and carbon sources for intracellular proliferation while evading host immunity.…”

PPARs as Key Mediators in the Regulation of Metabolism and Inflammation

“…Grabacka et al [14] summarized PPARα-specific immunomodulatory functions during infections by parasites, bacteria, and viruses, as well as the modulation of processes associated with innate immunity. Tanigawa et al [29] discussed the advancement in understanding PPARs in host-mycobacteria crosstalk via their impact on the host-dependent mechanisms of lipid metabolism, anti-inflammatory processes, and autophagy during infection. PPARγ is activated in macrophages infected with Mycobacterium leprae or Mycobacterium tuberculosis and regulates some genes involved in the uptake and accumulation of lipids and in cellular metabolism.…”