Cassiaside C Inhibits M1 Polarization of Macrophages by Downregulating Glycolysis

Dough-Kneading-Inspired Design of an Adhesive Cardiac Patch to Attenuate Cardiac Fibrosis and Improve Cardiac Function via Regulating Glycometabolism

Recently, hydrogel adhesive patches have been explored for treating myocardial infarction. However, achieving secure adhesion onto the wet beating heart and local regulation of pathological microenvironment remains challenging. Herein, a dough-kneading-inspired design of hydrogel adhesive cardiac patch is reported, aiming to improve the strength of prevalent powder-formed patch and retain wet adhesion. In mimicking the polysaccharide and protein components of natural flour, methacrylated polyglutamic acid (PGAMA) is electrostatically interacted with hydroxypropyl chitosan (HPCS) to form PGAMA/HPCS coacervate hydrogel. The PGAMA/HPCS hydrogel is freeze-dried and ground into powders, which are further rehydrated with two aqueous solutions of functional drug, 3-acrylamido phenylboronic acid (APBA)/rutin (Rt) complexes for protecting the myocardium from advanced glycation end product (AGEs) injury by reactive oxygen species (ROS) -responsive Rt release, and hypoxanthine-loaded methacrylated hyaluronic acid (HAMA) nanogels for enhancing macrophage targeting ability to regulate glycometabolism for combating inflammation. The rehydrated powders bearing APBA/Rt complexes and HAMA-hypoxanthine nanogels are repeatedly kneaded into a dough-like gel, which is further subjected to thermal-initiated crosslinking to form a stabilized and sticky patch. This biofunctional patch is applied onto the rats' infarcted myocardium, and the outcomes at 28 days post-surgery indicate efficient restoration of cardiac functions and attenuation of cardiac fibrosis.

Immunomodulatory effects of curcumin on macrophage polarization in rheumatoid arthritis

Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by synovial inflammation, cartilage destruction, pannus formation and bone erosion. Various immune cells, including macrophages, are involved in RA pathogenesis. The heterogeneity and plasticity of macrophages render them pivotal regulators of both the induction and resolution of the inflammatory response. Predominantly, two different phenotypes of macrophages have been identified: classically activated M1 macrophages exacerbate inflammation via the production of cytokines, chemokines and other inflammatory mediators, while alternatively activated M2 macrophages inhibit inflammation and facilitate tissue repair. An imbalance in the M1/M2 macrophage ratio is critical during the initiation and progression of RA. Macrophage polarization is modulated by various transcription factors, epigenetic elements and metabolic reprogramming. Curcumin, an active component of turmeric, exhibits potent immunomodulatory effects and is administered in the treatment of multiple autoimmune diseases, including RA. The regulation of macrophage polarization and subsequent cytokine production as well as macrophage migration is involved in the mechanisms underlying the therapeutic effect of curcumin on RA. In this review, we summarize the underlying mechanisms by which curcumin modulates macrophage function and polarization in the context of RA to provide evidence for the clinical application of curcumin in RA treatment.

SGLT2 inhibitors prevent LPS-induced M1 macrophage polarization and alleviate inflammatory bowel disease by downregulating NHE1 expression

BACKGROUND

Classically activated M1 macrophages, characterized by aberrant glycolysis and secretion of inflammatory cytokines, play pivotal roles in inflammatory diseases, including inflammatory bowel disease (IBD). Recently, sodium-glucose co-transporter 2 (SGLT2) inhibitors were shown to suppress Na+/H+ exchanger 1 (NHE1) and Na+/Ca2+ exchanger 1 (NCX1) activity, regulating downstream intracellular Ca2+ concentrations in cardiomyocytes. However, whether SGLT2 inhibitors regulate M1 macrophage polarization by downregulating NHE1 and NCX1 remains unknown.

METHODS

We analyzed cellular responses to SGLT2 inhibitors using mouse bone marrow-derived macrophages and peritoneal macrophages treated with lipopolysaccharide (LPS). To induce IBD, we used a dextran sulfate sodium salt-induced colitis mouse model.

RESULTS

We observed that NHE1 and NCX1 were overexpressed in LPS-treated macrophages, leading to M1 macrophage polarization. Mechanistically, NHE1 and NCX1-mediated Ca2+ accumulation in the macrophage resulted in enhanced glycolysis by promoting PI3K/AKT/mTORC1 signaling. SGLT2 inhibitors suppressed both the expression levels and activities of NHE1 and NCX1, and consequently downregulated PI3K/AKT/mTORC1 signaling and glycolysis in LPS-treated macrophages. We observed inhibition of LPS-stimulated M1 polarization and cytokine production by SGLT2 inhibitors in vitro, ex vivo, and in an IBD mouse model.

CONCLUSIONS

NHE1 promotes M1 macrophage polarization and SGLT2 inhibitors are a novel strategy to treat M1 macrophage-mediated inflammatory diseases, including IBD.

A new strategy for osteoarthritis therapy: Inhibition of glycolysis

Osteoarthritis (OA) is a common degenerative disease of the joints. It is primarily caused by age, obesity, mechanical damage, genetics, and other factors, leading to cartilage degradation, synovial inflammation, and subchondral sclerosis with osteophyte formation. Many recent studies have reported that glycolysis disorders are related lead to OA. There is a close relationship between glycolysis and OA. Because of their hypoxic environment, chondrocytes are highly dependent on glycolysis, their primary energy source for chondrocytes. Glycolysis plays a vital role in OA development. In this paper, we comprehensively summarized the abnormal expression of related glycolytic enzymes in OA, including Hexokinase 2 (HK2), Pyruvate kinase 2 (PKM2), Phosphofructokinase-2/fructose-2, 6-Bisphosphatase 3 (PFKFB3), lactate dehydrogenase A (LDHA), and discussed the potential application of glycolysis in treating OA. Finally, the natural products that can regulate the glycolytic pathway were summarized. Targeting glucose transporters and rate-limiting enzymes to glycolysis may play an essential role in treating OA.