Lung cancer progression relies on angiogenesis, which is a response to hypoxia typically coordinated by hypoxia-inducible transcription factors (HIFs), but growing evidence indicates that transcriptional programs beyond HIFs control tumor angiogenesis. Here, we show that the redox-sensitive transcription factor BTB and CNC homology 1 (BACH1) controls the transcription of a broad range of angiogenesis genes. BACH1 is stabilized by lowering ROS levels; consequently, angiogenesis gene expression in lung cancer cells, tumor organoids, and xenograft tumors increased substantially following administration of vitamins C and E and N-acetylcysteine in a BACH1-dependent fashion under normoxia. Moreover, angiogenesis gene expression increased in endogenous BACH1–overexpressing cells and decreased in BACH1-knockout cells in the absence of antioxidants. BACH1 levels also increased upon hypoxia and following administration of prolyl hydroxylase inhibitors in both HIF1A-knockout and WT cells. BACH1 was found to be a transcriptional target of HIF1α, but BACH1’s ability to stimulate angiogenesis gene expression was HIF1α independent. Antioxidants increased tumor vascularity in vivo in a BACH1-dependent fashion, and overexpressing BACH1 rendered tumors sensitive to antiangiogenesis therapy. BACH1 expression in tumor sections from patients with lung cancer correlated with angiogenesis gene and protein expression. We conclude that BACH1 is an oxygen- and redox-sensitive angiogenesis transcription factor.

Psoriasis is a chronic inflammatory skin disorder characterized by hyperproliferation of keratinocytes and persistent inflammation. Although persistent activation of signal transducer and activator of transcription 3 (STAT3) is implicated in its pathogenesis, the mechanisms underlying the sustained STAT3 activation remain poorly understood. Here, we identify sphingosine-1-phosphate receptor 3 (S1PR3) as a critical regulator of STAT3 activation and psoriasis pathogenesis, orchestrating a self-amplifying circuit that sustains keratinocyte hyperproliferation and chronic inflammation. S1PR3 expression is markedly elevated in psoriatic lesions and correlates with disease severity. Using genetic and pharmacological approaches, we reveal a novel S1PR3–Src–STAT3 signaling axis that drives both early and prolonged STAT3 activation in keratinocytes. Mechanistically, S1PR3 operates through Gαi/PKA-mediated Src activation, enhancing STAT3 phosphorylation and subsequent transcriptional activity. Importantly, we reveal a previously unrecognized positive feedback loop wherein activated STAT3 directly upregulates S1PR3 expression, perpetuating inflammation and hyperproliferation. Genetic deletion of S1pr3 in mice or pharmacological inhibition of S1PR3 significantly attenuates psoriasis-like skin inflammation, decreasing epidermal hyperplasia, dermal angiogenesis, and inflammatory mediator production. These findings provide new insights into the molecular mechanisms underlying psoriasis and identify S1PR3 as a promising therapeutic target. Our study suggests that disrupting the S1PR3–STAT3 feedback loop may offer a novel strategy for treating psoriasis and potentially other chronic inflammatory diseases driven by persistent STAT3 activation.

Background: Understanding the processes behind carotid plaque instability is necessary to develop methods for identification of patients and lesions with stroke risk. Here, we investigated molecular signatures in human plaques stratified by echogenicity as assessed by duplex ultrasound. Methods: Lesion echogenicity was correlated to microarray gene expression profiles from carotid endarterectomies (n=96). The findings were extended into studies of human and mouse atherosclerotic lesions in situ, followed by functional investigations in vitro in human carotid smooth muscle cells (SMCs). Results: Pathway analyses highlighted muscle differentiation, iron homeostasis, calcification, matrix organization, cell survival balance, and BCLAF1 (BCL2 [B-cell lymphoma 2]-associated transcription factor 1) as the most significant signatures. BCLAF1 was downregulated in echolucent plaques, positively correlated to proliferation and negatively to apoptosis. By immunohistochemistry, BCLAF1 was found in normal medial SMCs. It was repressed early during atherogenesis but reappeared in CD68+ cells in advanced plaques and interacted with BCL2 by proximity ligation assay. In cultured SMCs, BCLAF1 was induced by differentiation factors and mitogens and suppressed by macrophage-conditioned medium. BCLAF1 silencing led to downregulation of BCL2 and SMC markers, reduced proliferation, and increased apoptosis. Transdifferentiation of SMCs by oxLDL (oxidized low-denisty lipoprotein) was accompanied by upregulation of BCLAF1, CD36, and CD68, while oxLDL exposure with BCLAF1 silencing preserved MYH (myosin heavy chain) 11 expression and prevented transdifferentiation. BCLAF1 was associated with expression of cell differentiation, contractility, viability, and inflammatory genes, as well as the scavenger receptors CD36 and CD68 . BCLAF1 expression in CD68+/BCL2+ cells of SMC origin was verified in plaques from MYH11 lineage-tracing atherosclerotic mice. Moreover, BCLAF1 downregulation associated with vulnerability parameters and cardiovascular risk in patients with carotid atherosclerosis. Conclusions: Plaque echogenicity correlated with enrichment of distinct molecular pathways and identified BCLAF1 , previously not described in atherosclerosis, as the most significant gene. Functionally, BCLAF1 seems necessary for survival and transdifferentiation of SMCs into a macrophage-like phenotype. The role of BCLAF1 in plaque vulnerability should be further evaluated.