CD163 protein inhibits lipopolysaccharide-induced macrophage transformation from M2 to M1 involved in disruption of the TWEAK-Fn14 interaction

Construction of pH-Sensitive Multifunctional Hydrogel with Synergistic Anti-Inflammatory Effect for Treatment of Diabetic Wounds

Background/Objectives: A sustainable inflammatory response is a significant obstacle for diabetic wound care. In this study, the pH-sensitive multifunctional hydrogel ODex/BSA-Zn was fabricated via a Schiff base and coordination force for the first time. Methods: The hydrogel consisted of oxidized dextran (ODex), bovine serum albumin (BSA), and zinc ions (Zn2+) in the absence of an additional crosslinking agent. Results: The hydrogel showed excellent mechanical stability, fast self-healing ability, and significant anti-inflammatory effects, as demonstrated by the formation of dynamic covalent bonds between the aldehyde group (-CHO) of ODex and the amino group (-NH2) of BSA via the Schiff base reaction, as well as the metal-ion coordination reaction of Zn2+ with the imidazole ring of BSA. In a diabetic mouse full-thickness cutaneous defect wound model, the ODex/BSA-Zn hydrogel could effectively inhibit the inflammatory response and increase collagen deposition, thereby accelerating the transition of macrophage M1 to M2 and promoting wound closure. This study offers a promising therapeutic approach for managing long-term diabetic ulcers.

CD163+ macrophages attenuate pressure overload-induced left ventricular systolic dysfunction and cardiac mitochondrial dysfunction via interleukin-10

Macrophage depletion exacerbates pressure overload-induced heart failure, but therapeutic translation is hindered by macrophage subset heterogeneity. The functional role of CD163+ macrophages in heart failure remains unclear. Transverse aortic constriction (TAC) was employed to induce pressure overload. Cd163-/- mice exhibited significantly aggravated TAC-induced left ventricular systolic dysfunction, as demonstrated by reduced ejection fraction, fractional shortening, and global longitudinal strain, compared to wild-type (WT) controls. RNA sequencing of cardiac tissues revealed significant differential gene expression between TAC-treated WT and Cd163-/- mice, especially in pathways governing mitochondrial bioenergetics and homeostasis. Transmission electron microscopy confirmed greater accumulation of dysfunctional mitochondria in cardiomyocytes of Cd163-/- mice relative to WT following TAC. Additionally, the proportion of CD163+ macrophages among cardiac macrophages increased post-TAC. Serum IL-10 levels and cardiac macrophage IL-10 expression were significantly diminished in Cd163-/- mice compared to WT after TAC. IL-10 supplementation effectively reversed the TAC-induced impairment in left ventricular systolic function in both WT and Cd163-/- mice, and reduced NADH/NAD+ ratios, reduced mitochondrial dysfunction, and improved mitochondrial membrane potential in Cd163-/- mice. Cross-sectional clinical data supported these findings, showing decreased IL-10 levels as a significant risk factor for heart failure in hypertensive patients (odds ratio: 0.397; 95% CI 0.203-0.775; p = 0.007). Collectively, these results highlight the protective role of CD163+ macrophages against pressure overload-induced left ventricular dysfunction and mitochondrial dysfunction through IL-10-dependent pathways.

TAMing Gliomas: Unraveling the Roles of Iba1 and CD163 in Glioblastoma

Gliomas, the most common type of primary brain tumor, are a significant cause of morbidity and mortality worldwide. Glioblastoma, a highly malignant subtype, is particularly common, aggressive, and resistant to treatment. The tumor microenvironment (TME) of gliomas, especially glioblastomas, is characterized by a distinct presence of tumor-associated macrophages (TAMs), which densely infiltrate glioblastomas, a hallmark of these tumors. This macrophage population comprises both tissue-resident microglia as well as macrophages derived from the walls of blood vessels and the blood stream. Ionized calcium-binding adapter molecule 1 (Iba1) and CD163 are established cellular markers that enable the identification and functional characterization of these cells within the TME. This review provides an in-depth examination of the roles of Iba1 and CD163 in malignant gliomas, with a focus on TAM activation, migration, and immunomodulatory functions. Additionally, we will discuss how recent advances in AI-enhanced cell identification and visualization techniques have begun to transform the analysis of TAMs, promising unprecedented precision in their characterization and providing new insights into their roles within the TME. Iba1 and CD163 appear to have both unique and shared roles in glioma pathobiology, and both have the potential to be targeted through different molecular and cellular mechanisms. We discuss the therapeutic potential of Iba1 and CD163 based on available preclinical (experimental) and clinical (human tissue-based) evidence.

CD163 detection in immune check-point inhibitors-related acute interstitial nephritis

Background

Acute interstitial nephritis (AIN) is the most common renal immune-related adverse event after immune check-point inhibitors (ICI). We hypothesized that alternatively activated macrophages (CD163-M) could be involved in ICI-AIN and wished to evaluate the use of their soluble urinary form (us)CD163 as a non-invasive diagnostic marker.

Methods

CD163-M infiltrates were evaluated by both immune-histochemistry and multiplex immunofluorescence and imaging. usCD163 was detected with ELLA technology and evaluated together with urinary creatinine to be expressed as a ratio to creatinuria in ng/mmol. Clinical data were collected to perform correlations with renal function assessed by estimated glomerular filtration rate (eGFR).

Results

A retrospective cohort of 63 ICI-exposed patients with tubular acute kidney injury profile requiring a biopsy were selected. AIN patients (n = 44) were compared to acute tubular necrosis (ATN) patients (n = 19). CD163-M staining was detectable in all ICI-AIN patients, which was significantly higher than in ATN patients (18.4% vs 3.6% of area, P  = .005). CD163-M staining was restricted to the interstitial compartment. CD163-M infiltrate inversely correlated with initial eGFR (r = -0.6, P  = .003), and was positively correlated with delta eGFR, reflecting a renal improvement outcome (r = 0.48; P  = .02). usCD163 was well detected in urines of patients, but did not allow us to distinguish ATN from AIN patients at diagnosis. No correlation was observed, neither between usCD163 and CD163-M staining nor with renal response after 3 months of glucocorticoid tapering.

Conclusion

CD163-M are detected in ICI-AIN and correlate both with severity at diagnosis and better prognosis at 3 months. CD163-M may help us to distinguish AIN from ATN but, it does not allow us to assess ICI imputability. Although detected in urine, usCD163 is clearly not a surrogate biomarker for AIN diagnosis.

Homocysteine affects macrophage polarization by altering m6A methylation of scavenger receptors CD209 and CD163L1

Atherosclerosis is a chronic inflammatory disease characterized by fatty plaque deposits on artery walls. Elevated plasma homocysteine (Hcy) levels are an independent risk factor for atherosclerosis. Research on the mechanism by which Hcy promotes atherosclerosis has gradually turned to epigenetic inheritance, but the correlation between Hcy and m6A (N6-methyladenosine) modification has not been reported. In this study, MeRIP-seq was performed on macrophages and Hcy-treated macrophages. GO and KEGG analyses were used to perform functional analysis of differentially methylated genes. qRT-PCR and western blot were taken to determine the expression of CD209, CD163L1, proinflammatory, and anti-inflammatory factors. Flow cytometry was used to detect the proportion of M2 macrophages. The results showed that after Hcy treatment, the overall m6A methylation of macrophages was down-regulated, and 856 differential methylation peaks were annotated to 781 genes. These included CD209 and CD163L1, whose m6A methylation was inhibited after treatment with Hcy. In addition, mRNA and protein expressions of CD209 and CD163L1 were also inhibited after Hcy treatment. Overexpression of CD209 or CD163L1 prevents the Hcy-induced decrease in the proportion of M2 macrophages. This article identified changes in the modification level of m6A in macrophages by Hcy and revealed the possible mechanism by which Hcy induces macrophage polarization.