PGC-1α Agonist Rescues Doxorubicin-Induced Cardiomyopathy by Mitigating the Oxidative Stress and Necroptosis.

Cardiomyopathy (particularly dilated cardiomyopathy (DCM)) significantly contributes to development and progression of heart failure (HF), and inflammatory factors further deteriorate the symptoms. Morphological and functional defects of the heart in doxorubicin (DOX)-induced cardiomyopathy (cardiotoxicity) are similar to those of DCM. We used anagonist of PGC-1α (PPAR (peroxisome proliferator-activated receptor-gamma)-γ coactivator-1α) that is considered as the 'master regulator' of mitochondrial biogenesis with an aim to rescue the DOX-induced deleterious effects on the heart. Forty male C57BL/6J mice (8 weeks old) were divided in four groups, Control, DOX, ZLN005, and ZLN005 + DOX (n = 10 each group). The DOX-induced (10 mg/kg, single dose) cardiomyopathy mimics a DCM-like phenotype with marked morphologic alteration in cardiac tissue and functional derangements. Significant increased staining was observed for Masson Trichrome/Picrosirius red and α-Smooth Muscle Actinin (α-SMA) that indicated enhanced fibrosis in the DOX group compared to the control that was attenuated by (peroxisome proliferator-activated receptor-gamma (PPAR-γ) coactivator) (PGC)-1α (alpha) agonist (four doses of 2.5 mg/kg/dose; cumulative dose = 10 mg/kg). Similarly, elevated expression of necroptosis markers along with enhanced oxidative stress in the DOX group were alleviated by PGC-1α agonist. These data collectively suggested the potent therapeutic efficacy of PGC-1α agonist in mitigating the deleterious effects of DOX-induced cardiomyopathy, and it may be targeted in developing the future therapeutics for the management of DCM/HF.

Interleukin-33 Induces Neutrophil Extracellular Trap (NET) Formation and Macrophage Necroptosis via Enhancing Oxidative Stress and Secretion of Proatherogenic Factors in Advanced Atherosclerosis.

Interleukin-33 (IL-33) acts as an 'alarmin', and its role has been demonstrated in driving immune regulation and inflammation in many human diseases. However, the precise mechanism of action of IL-33 in regulating neutrophil and macrophage functioning is not defined in advanced atherosclerosis (aAT) patients. Further, the role of IL-33 in neutrophil extracellular trap (NET) formation in aAT and its consequent effect on macrophage function is not known. In the present study, we recruited n = 52 aAT patients and n = 52 control subjects. The neutrophils were isolated from both groups via ficoll/percoll-based density gradient centrifugation. The effect of IL-33 on the NET formation ability of the neutrophils was determined in both groups. Monocytes, isolated via a positive selection method, were used to differentiate them into macrophages from each of the study subjects and were challenged by IL-33-primed NETs, followed by the measurement of oxidative stress by calorimetric assay and the expression of the proinflammatory molecules by quantitative PCR (qPCR). Transcript and protein expression was determined by qPCR and immunofluorescence/ELISA, respectively. The increased expression of IL-33R (ST-2) was observed in the neutrophils, along with an increased serum concentration of IL-33 in aAT compared to the controls. IL-33 exacerbates NET formation via specifically upregulating CD16 expression in aAT. IL-33-primed NETs/neutrophils increased the cellular oxidative stress levels in the macrophages, leading to enhanced macrophage necroptosis and the release of atherogenic factors and matrix metalloproteinases (MMPs) in aAT compared to the controls. These findings suggested a pathogenic effect of the IL-33/ST-2 pathway in aAT patients by exacerbating NET formation and macrophage necroptosis, thereby facilitating the release of inflammatory factors and the release of MMPs that may be critical for the destabilization/rupture of atherosclerotic plaques in aAT. Targeting the IL-33/ST-2-NETs axis may be a promising therapeutic target for preventing plaque instability/rupture and its adverse complications in aAT.

Participation of T cell immunoglobulin and mucin domain-3 (TIM-3) and its ligand (galectin-9) in the pathogenesis of active generalized vitiligo.

Vitiligo is a depigmentary disease where melanocytes of the basal layer of epidermis are selectively destroyed by immune-cell-mediated cytotoxicity. The T cell immunoglobulin- and mucin-domain-containing molecules (TIMs) are involved in immune regulation, and their participation is not known in vitiligo. The present study revealed significant increase in the percentage of CD3+CD4+TIM3+ T cells (P < 0.05) in peripheral blood and was positively correlated with percentage body surface area involvement in aGV group. Further, increased expression of TIM-3 and its ligand galectin-9 (Gal-9) mRNA was found in peripheral blood and lesional/perilesional skin of active generalized vitiligo (aGV) compared with controls. Characteristic migration pattern of TIM-3-positive immune cells in lesional (near/in the epidermis) and perilesional (towards epidermis) skin section suggested that TIM-3+ immune cells may be involved in melanocyte destruction. Further, investigation is required to understand the role of TIM-3/Gal-9 signalling pathways in aGV and it can be targeted in the management of vitiligo.

T helper and regulatory T cell cytokine profile in active, stable and narrow band ultraviolet B treated generalized vitiligo.

BACKGROUND: Vitiligo is a T cell mediated autoimmune depigmenting disease. Altered cytokine concentrations have been suggested in the pathogenesis of vitiligo. METHODS: T helper and regulatory T cell cytokines (IL-2, IFN-γ, IL-10, IL-13, IL-17 and TGF-ß) have been estimated by ELISA and their clinical correlation was determined. The study had 3 groups: group I with 80 vitiligo patients (60 active and 20 stable), group II with 25 narrow band ultraviolet B treated vitiligo and group III with 70 healthy controls. RESULTS: Significant difference was found in the serum interleukin (IL)-10, IL-13, IL-17A and TGF-ß1 concentrations among 3 groups (P<0.05). In group I, serum IL-2, IL-17A concentrations were significantly increased and TGF-ß1 concentrations were decreased in active vitiligo compared to stable vitiligo (P<0.05). Concentrations of IL-2, IL-10 and IL-13 (rho=-0.307, rho=-0.407, rho=-0.351 and P<0.05; respectively) were negatively- and TGF-ß1 concentrations were positively-correlated (rho=0.799, P=0.001) with disease duration. Interleukin-13 concentrations were negatively- and serum TGF-ß1 concentrations were positively-correlated (rho=-0.326, rho=0.244 and P<0.05; respectively) with percentage of body surface area involvement. CONCLUSIONS: Increased concentrations of serum IL-10, IL-13, and IL-17A and decreased concentrations of TGF-ß1 suggested altered cell-mediated immunity that may facilitate the melanocyte cytotoxicity in vitiligo.