Biology subjects

Afroz, S.

Publications and source records attributed to Afroz, S..

4 recordsLinked to original sources

bioRxiv2025

ALOX12B overexpression in the skin drives inflammasome/Th17 signaling axis to promote inflammation in the mouse model and human patients

Inflammation plays a pivotal role in the etiopathogenesis of chronic inflammatory skin diseases. However, the underlying mechanism remains unclear. Here, we employed Gene expression meta-analysis and clinical validation strategy to dissect the global architecture of immune dysregulation responsible for inflammatory conditions in the skin. Using such approaches, we identified a gene signature comprising of ALOX12B, which is significantly upregulated in psoriatic and atopic dermatitis patient skin samples, and correlates with increased levels of pathological IL-1{beta} and Th17 responses. Surprisingly, ALOX12B is predominantly expressed in the skin. Furthermore, skin-specific overexpression of human ALOX12B in transgenic mice resulted in psoriasis-like inflammatory symptoms, including epidermal hyperplasia, immune cell infiltration, and elevated IL-1{beta}/Th17 responses. ALOX12B is a non-heme iron-containing enzyme that catalyses the production of 12R-HETE from polyunsaturated fatty acids such as arachidonic acid. Mechanistically, we found that ALOX12B/12R-HETE accumulation in the skin acts as an intrinsic danger signal that triggers enhanced IL-1{beta} processing and secretion via ROS generation and NLRP3 inflammasome activation. Increased IL-1{beta} levels in turn drive IL-17 producing T-cell polarization. We further designed a novel first-in-class, potent ALOX12B inhibitor, 6a, which exhibited favorable topical pharmacokinetic and safety profiles. The topical application of 6a reduced inflammation-associated pathologies in Tg-hALOX12B mice by suppressing 12R-HETE-induced IL-1{beta} production and ROS generation. These findings revealed a novel mechanism mediated by ALOX12B/12R-HETE overexpression that controls skin inflammation, thereby providing a promising therapeutic target for treating inflammatory skin diseases. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=138 SRC="FIGDIR/small/658245v1_ufig1.gif" ALT="Figure 1"> View larger version (61K): org.highwire.dtl.DTLVardef@13cdf3forg.highwire.dtl.DTLVardef@164cac3org.highwire.dtl.DTLVardef@3c0364org.highwire.dtl.DTLVardef@2ca91_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOGraphical Abstract.C_FLOATNO The proposed mechanism through which ALOX12B modulates the inflammatory pathway in psoriasiform-like inflammatory conditions in the skin. The study provides insight into the role of ALOX12B in skin inflammation. Increased levels of ALOX12B expression in the skin result in 12R-HETE accumulation, which subsequently triggers the IL-1/Th17 inflammatory cascade through ROS generation and inflammasome activation. IL-1 produced by the activated inflammasome leads to the polarization of naive T-cells to activated IL-17 producing CD4+ T-cells, which are involved in the skin-inflammation related pathologies such as keratinocyte proliferation, and cellular infiltration. Hence, we propose ALOX12B as a novel potential therapeutic target for psoriasis-like inflammatory skin disorders. Additionally, we designed a novel first-in-class ALOX12B inhibitor, 6a; which shows a substantial alleviation in ALOX12B enzymatic activity, thereby reducing cellular ROS, which in turn results in reduced levels of IL-1, as a result inhibiting IL-1/Th17 inflammatory pathway and subsequent reduction in pathological inflammatory skin conditions. A portion of the image was created using Biorender.com C_FIG HighlightsO_LIALOX12B is a key gene upregulated in the skin during psoriasis and atopic dermatitis. C_LIO_LITransgenic mice overexpressing ALOX12B in the skin developed Psoriasis-like inflammatory symptoms. C_LIO_LIMechanistically, ALOX12B, through 12R-HETE, enhanced IL-1{beta} production via ROS generation and NLRP3 inflammasome activation. Further elevated IL-1{beta} production promotes Th17 cell polarization. C_LIO_LINovel first-in-class ALOX12B inhibitor alleviates inflammatory symptoms in a transgenic mouse model. C_LIO_LIStudy reveals a crucial ALOX12B/12R-HETE-inflammasome-IL-17 axis involvement in inflammatory skin diseases. C_LI

immunology↗

bioRxiv2024

XPO1 inhibition modulates the Wnt/β-catenin signaling pathway to reduce colorectal cancer tumorigenesis.

Colorectal Cancer (CRC) is the second leading cause of cancer-related death in the U.S. and high-risk individuals face a notably higher likelihood of developing CRC based on their genetic background. Hence, there is a compelling need for innovative chemopreventive treatments aimed at minimizing CRC tumorigenesis. Exportin 1 (XPO1; also referred to as CRM1) plays a pivotal role in transporting proteins from the nucleus to the cytoplasm. Various cancers overexpress XPO1, including CRC, and Selective Inhibitors of Nuclear Export (SINE) compounds, such as Eltanexor (KPT-8602), have been developed to target XPO1. Eltanexor demonstrates fewer adverse effects than its precursors and is currently under evaluation in Phase I/II clinical trials. This research evaluates Eltanexor as a chemopreventive agent for CRC. Our findings indicate Eltanexor treatment inhibits expression of the common chemoprevention target in CRC, cyclooxygenase-2 (COX-2). This occurs by Eltanexor-dependent reduction of Wnt/{beta}-catenin signaling. Furthermore, XPO1 inhibition leads to forkhead transcription factor O subfamily member 3a (FoxO3a) nuclear retention, which can modulate {beta}-catenin/TCF transcriptional activity. In vivo oral treatment of Eltanexor to Apcmin/+ mice (a mouse model for Familial Adenomatosis Polyposis) was well-tolerated and reduced tumor burden by approximately 3-fold, along with decreased tumor size. Drug sensitivity assays using organoids from Apcmin/+ mice tumors show increased sensitivity to Eltanexor compared to wild-type organoids. Collectively, these findings highlight XPO1 as a potent target for CRC chemoprevention. SIGNIFICANCEIn this study, we show the XPO1 inhibitor, Eltanexor, reduces COX-2 by modulating the Wnt/{beta}-catenin signaling pathway and acts as an effective chemopreventive agent in the Familial Adenomatous Polyposis (FAP) mouse model, Apcmin/+ mice.

cancer biology↗

bioRxiv2024

Characterization of novel role for Rab27B in autophagy regulation in colorectal cancer

IntroductionAutophagy is a dynamic, multi-step process that cells use to degrade damaged, abnormal, and potentially harmful cellular substances. While autophagy is maintained at a basal level in all cells, it is activated at a higher level in many cancer cells and promotes tumor growth, anti-tumor immune response, and resistance to cancer therapy. As a result, autophagy is increasingly being recognized to have an important role in cancer progression and emerging as a potential target for cancer therapy. We recently discovered that small GTPase Rab27B, a known regulator of vesicle trafficking and exosome secretion, is also involved in the autophagy process. MethodsRab27B was knocked out using CRISPR/Cas9 in CRC cell line HCT116. Western blotting, Immunofluorescence, MTT assay, spheroid formation assay, soft agar assay and xenograft studies were performed to analyze the effects of Rab27B deletion on CRC cells. ResultsCRISPR/Cas9 deletion or siRNA knockdown of Rab27B in colorectal cancer cells (CRC) showed an abnormal accumulation of autophagy vesicles. Additionally, we observed a significant increase in the autophagy markers LC3-II and p62 by immunocytochemistry and western blot analysis, suggesting a defect in the autophagy flux process. Lysotracker and mCherry-EGFP-LC3 fusion construct indicate an impairment in autophagosome and lysosome fusion when Rab27B is silenced. This defect was rescued by full-length and constitutively active GTP mutant of Rab27B. As autophagy has been shown to have a pro-survival role in tumor growth and stress response, we hypothesized that the observed defects in autophagy flux resulting from Rab27B loss would cause reduced stress response and tumor growth. Indeed, Rab27B knockout reduced cell viability in response to starvation and a 94% reduction in soft agar colony formation. Rab27B deletion also prevented spheroid formation in vitro. Finally, to analyze the effect of Rab27B deletion in tumor formation in vivo, we performed a xenograft study with wildtype and Rab27B knockout CRC cells, resulting in a dramatic loss of tumor growth (p<0.0001) in the KO cells. ConclusionsTogether, our results demonstrate a new role of Rab27B in the autophagy trafficking process in CRC. Future studies will focus on investigating the mechanism of how Rab27B functions in the autophagy pathway and whether Rab27B can be targeted as a potential therapeutic strategy for CRC.

cancer biology↗

bioRxiv2021

SARS-CoV-2-specific T cells in unexposed adults display broad trafficking potential and cross-react with commensal antigens

The baseline composition of T cells directly impacts later response to a pathogen, but the complexity of precursor states remains poorly defined. Here we examined the baseline state of SARS-CoV-2 specific T cells in unexposed individuals. SARS-CoV-2 specific CD4+ T cells were identified in pre-pandemic blood samples by class II peptide-MHC tetramer staining and enrichment. Our data revealed a substantial number of SARS-CoV-2 specific T cells that expressed memory phenotype markers, including memory cells with gut homing receptors. T cell clones generated from tetramer-labeled cells cross-reacted with bacterial peptides and responded to stool lysates in a MHC-dependent manner. Integrated phenotypic analyses revealed additional precursor diversity that included T cells with distinct polarized states and trafficking potential to other barrier tissues. Our findings illustrate a complex pre-existing memory pool poised for immunologic challenges and implicate non-infectious stimuli from commensal colonization as a factor that shapes pre-existing immunity. One Sentence SummaryPre-existing immunity to SARS-CoV-2 contains a complex pool of precursor lymphocytes that include differentiated cells with broad tissue tropism and the potential to cross-react with commensal antigens.

immunology↗