A nitroalkene derivative of salicylate alleviates diet-induced obesity by activating creatine metabolism and non-shivering thermogenesis.

Obesity-related type II diabetes (diabesity) has increased global morbidity and mortality dramatically. Previously, the ancient drug salicylate demonstrated promise for the treatment of type II diabetes, but its clinical use was precluded due to high dose requirements. In this study, we present a nitroalkene derivative of salicylate, 5-(2-nitroethenyl)salicylic acid (SANA), a molecule with unprecedented beneficial effects in diet-induced obesity (DIO). SANA reduces DIO, liver steatosis and insulin resistance at doses up to 40 times lower than salicylate. Mechanistically, SANA stimulated mitochondrial respiration and increased creatine-dependent energy expenditure in adipose tissue. Indeed, depletion of creatine resulted in the loss of SANA action. Moreover, we found that SANA binds to creatine kinases CKMT1/2, and downregulation CKMT1 interferes with the effect of SANA in vivo. Together, these data demonstrate that SANA is a first-in-class activator of creatine-dependent energy expenditure and thermogenesis in adipose tissue and emerges as a candidate for the treatment of diabesity.

The intracellular cation channel TMEM176B as a dual immunoregulator.

Characterizing immune regulatory pathways is critical to understand physiological and pathophysiological processes as well as to identify novel immunotherapeutic targets. The cation channel TMEM176B has emerged in the last years as a potential new immunoregulatory player and pharmacological target. Here, we review how expression data, clinical associations of genetic variants and functional studies support a dual role for TMEM176B in regulating immune responses. Thus, TMEM176B can inhibit effector immune responses in some settings whereas it may also promote immunity by supporting antigen presentation in others. We also discuss a potential role for TMEM176B in regulating type 2 and 3 immunity and comment recent data on modulation of DC biology and inflammasome activation as well as CD8+ T cell responses. Understanding the role of TMEM176B in immunity is critical to propose rational pharmacological approaches targeting this channel.

PD-1/PD-L1 blockade abrogates a dysfunctional innate-adaptive immune axis in critical ß-coronavirus disease.

Severe COVID-19 is associated with hyperinflammation and weak T cell responses against SARS-CoV-2. However, the links between those processes remain partially characterized. Moreover, whether and how therapeutically manipulating T cells may benefit patients are unknown. Our genetic and pharmacological evidence demonstrates that the ion channel TMEM176B inhibited inflammasome activation triggered by SARS-CoV-2 and SARS-CoV-2-related murine ß-coronavirus. Tmem176b-/- mice infected with murine ß-coronavirus developed inflammasome-dependent T cell dysfunction and critical disease, which was controlled by modulating dysfunctional T cells with PD-1 blockers. In critical COVID-19, inflammasome activation correlated with dysfunctional T cells and low monocytic TMEM176B expression, whereas PD-L1 blockade rescued T cell functionality. Here, we mechanistically link T cell dysfunction and inflammation, supporting a cancer immunotherapy to reinforce T cell immunity in critical ß-coronavirus disease.

A novel nitroalkene vitamin E analogue inhibits the NLRP3 inflammasome and protects against inflammation and glucose intolerance triggered by obesity.

Chronic metabolic diseases, like obesity, type II diabetes and atherosclerosis often involve a low-grade and sterile systemic inflammatory state, in which activation of the pro-inflammatory transcription factor NF-kB and the NLRP3 inflammasome play a major role. It is well established that genetic inhibition of the NLRP3 inflammasome ameliorates acute and chronic inflammation. Indeed, accumulating experimental evidences in murine models and also in humans suggest that inhibition of the NLRP3 inflammasome might be a suitable approach to tackle the deleterious effects of chronic metabolic diseases. In this work, we explored our previously synthesized nitroalkene-Trolox™ derivative named NATx0, as a non-conventional anti-inflammatory strategy to treat chronic inflammatory diseases, such as obesity-induced glucose intolerance. We found that NATx0 inhibited NF-kB nuclear translocation and pro-inflammatory gene expression in macrophages in vitro. In addition, treatment with NATx0 prevented NLRP3 inflammasome activation after LPS/ATP stimulation in macrophages in vitro. When tested acutely in vivo, NATx0 inhibited neutrophil recruitment in zebrafish larvae, and also diminished IL-1ß production after LPS challenge in mice. Finally, when NATx0 was administered chronically to diet-induced obese mice, it decreased muscle tissue inflammation and glucose intolerance, leading to improved glucose homeostasis. In conclusion, we propose that this novel nitroalkene-Trolox derivative is a suitable tool to tackle acute and chronic inflammation in vitro and in vivo mainly due to inhibition of NF-kB/NLRP3 activation.

A novel nitroalkene-α-tocopherol analogue inhibits inflammation and ameliorates atherosclerosis in Apo E knockout mice.

BACKGROUND AND PURPOSE: Atherosclerosis is characterized by chronic low-grade inflammation with concomitant lipid accumulation in the arterial wall. Anti-inflammatory and anti-atherogenic properties have been described for a novel class of endogenous nitroalkenes (nitrated-unsaturated fatty acids), formed during inflammation and digestion/absorption processes. The lipid-associated antioxidant α-tocopherol is transported systemically by LDL particles including to the atheroma lesions. To capitalize on the overlapping and complementary salutary properties of endogenous nitroalkenes and α-tocopherol, we designed and synthesized a novel nitroalkene-α-tocopherol analogue (NATOH) to address chronic inflammation and atherosclerosis, particularly at the lesion sites. EXPERIMENTAL APPROACH: We synthesized NATOH, determined its electrophilicity and antioxidant capacity and studied its effects over pro-inflammatory and cytoprotective pathways in macrophages in vitro. Moreover, we demonstrated its incorporation into lipoproteins and tissue both in vitro and in vivo, and determined its effect on atherosclerosis and inflammatory responses in vivo using the Apo E knockout mice model. KEY RESULTS: NATOH exhibited similar antioxidant capacity to α-tocopherol and, due to the presence of the nitroalkenyl group, like endogenous nitroalkenes, it exerted electrophilic reactivity. NATOH was incorporated in vivo into the VLDL/LDL lipoproteins particles to reach the atheroma lesions. Furthermore, oral administration of NATOH down-regulated NF-κB-dependent expression of pro-inflammatory markers (including IL-1ß and adhesion molecules) and ameliorated atherosclerosis in Apo E knockout mice. CONCLUSIONS AND IMPLICATIONS: In toto, the data demonstrate a novel pharmacological strategy for the prevention of atherosclerosis based on a creative, natural and safe drug delivery system of a non-conventional anti-inflammatory compound (NATOH) with significant potential for clinical application.

Electrophilic nitroalkene-tocopherol derivatives: synthesis, physicochemical characterization and evaluation of anti-inflammatory signaling responses.

Inflammation plays a major role in the onset and development of chronic non-communicable diseases like obesity, cardiovascular diseases and cancer. Combined, these diseases represent the most common causes of death worldwide, thus development of novel pharmacological approaches is crucial. Electrophilic nitroalkenes derived from fatty acids are formed endogenously and exert anti-inflammatory actions by the modification of proteins involved in inflammation signaling cascades. We have developed novel nitroalkenes derived from α-tocopherol aiming to increase its salutary actions by adding anti-inflammatory properties to a well-known nutraceutical. We synthesized and characterized an α-tocopherol-nitroalkene (NATOH) and two hydrosoluble analogues derived from Trolox (NATxME and NATx0). We analyzed the kinetics of the Michael addition reaction of these compounds with thiols in micellar systems aiming to understand the effect of hydrophobic partition on the reactivity of nitroalkenes. We studied NATxME in vitro showing it exerts non-conventional anti-inflammatory responses by inducing Nrf2-Keap1-dependent gene expression and inhibiting the secretion of NF-κB dependent pro-inflammatory cytokines. NATxME was also effective in vivo, inhibiting neutrophil recruitment in a zebrafish model of inflammation. This work lays the foundation for the rational design of a new therapeutic strategy for the prevention and treatment of metabolic and inflammation-related diseases.