Resveratrol: Mechanistic and therapeutic perspectives in pulmonary arterial hypertension

T cells expressing chimeric antigen receptors (CAR) targeting human CD19 (huCD19) have exhibited impressive clinical efficacy against B cell malignancies 1,2 . CAR-T cells have been less effective against solid tumors 3–5 , in part because they enter a hyporesponsive (“exhausted” or “dysfunctional”) state 6–9 triggered by chronic antigen stimulation and characterized by upregulation of inhibitory receptors and loss of effector function. To investigate the function of CAR-T cells in solid tumors, we transferred huCD19-reactive CAR-T cells into huCD19+ tumor-bearing mice. CD8+ CAR+ tumor-infiltrating lymphocytes (TILs) and endogenous TILs expressing inhibitory receptors PD-1 and TIM3 exhibited similar profiles of gene expression and chromatin accessibility, associated with secondary activation of nuclear receptor transcription factors (TFs) Nr4a1 (Nur77), Nr4a2 (Nurr1) and Nr4a3 (Nor1) by the initiating TF NFAT (nuclear factor of activated T cells) 10–12 . CD8+ T cells from humans with cancer or chronic viral infections 13,14,15 expressed high levels of Nr4a TFs and displayed enrichment of Nr4a binding motifs in accessible chromatin regions. CAR-T cells lacking all three Nr4a TFs (Nr4aTKO) promoted tumor regression and prolonged the survival of tumor-bearing mice. Nr4aTKO CAR-TILs displayed phenotypes and gene expression profiles characteristic of CD8+ effector T cells, and chromatin regions uniquely accessible in Nr4aTKO CAR-TILs compared to WT were enriched for binding motifs for NFκB and AP-1, TFs involved in T cell activation. Our data identify Nr4a TFs as major players in the cell-intrinsic program of T cell hyporesponsiveness and point to Nr4a inhibition as a promising strategy for cancer immunotherapy.

Resveratrol (3,5,4′-trihydroxy-trans-stilbene) belongs to polyphenols’ stilbenoids group, possessing two phenol rings linked to each other by an ethylene bridge. This natural polyphenol has been detected in more than 70 plant species, especially in grapes’ skin and seeds, and was found in discrete amounts in red wines and various human foods. It is a phytoalexin that acts against pathogens, including bacteria and fungi. As a natural food ingredient, numerous studies have demonstrated that resveratrol possesses a very high antioxidant potential. Resveratrol also exhibit antitumor activity, and is considered a potential candidate for prevention and treatment of several types of cancer. Indeed, resveratrol anticancer properties have been confirmed by many in vitro and in vivo studies, which shows that resveratrol is able to inhibit all carcinogenesis stages (e.g., initiation, promotion and progression). Even more, other bioactive effects, namely as anti-inflammatory, anticarcinogenic, cardioprotective, vasorelaxant, phytoestrogenic and neuroprotective have also been reported. Nonetheless, resveratrol application is still being a major challenge for pharmaceutical industry, due to its poor solubility and bioavailability, as well as adverse effects. In this sense, this review summarized current data on resveratrol pharmacological effects.

Chronic hypoxic exposure induces changes in the structure of pulmonary arteries, as well as in the biochemical and functional phenotypes of each of the vascular cell types, from the hilum of the lung to the most peripheral vessels in the alveolar wall. The magnitude and the specific profile of the changes depend on the species, sex, and the developmental stage at which the exposure to hypoxia occurred. Further, hypoxia-induced changes are site specific, such that the remodeling process in the large vessels differs from that in the smallest vessels. The cellular and molecular mechanisms vary and depend on the cellular composition of vessels at particular sites along the longitudinal axis of the pulmonary vasculature, as well as on local environmental factors. Each of the resident vascular cell types (ie, endothelial, smooth muscle, adventitial fibroblast) undergo site- and time-dependent alterations in proliferation, matrix protein production, expression of growth factors, cytokines, and receptors, and each resident cell type plays a specific role in the overall remodeling response. In addition, hypoxic exposure induces an inflammatory response within the vessel wall, and the recruited circulating progenitor cells contribute significantly to the structural remodeling and persistent vasoconstriction of the pulmonary circulation. The possibility exists that the lung or lung vessels also contain resident progenitor cells that participate in the remodeling process. Thus the hypoxia-induced remodeling of the pulmonary circulation is a highly complex process where numerous interactive events must be taken into account as we search for newer, more effective therapeutic interventions. This review provides perspectives on each of the aforementioned areas.