CXCL5 inhibits excessive oxidative stress by regulating white adipocyte differentiation

The C-X-C Motif Chemokine Ligand 5, Which Exerts an Antioxidant Role by Inducing HO-1 Expression, Is C-X-C Motif Chemokine Receptor 2-Dependent in Human Prostate Stroma and Cancer Cells

While the C-X-C motif chemokine ligand 5 (CXCL5) is recognized as an inflammatory mediator and a potent attractant for immune cells, its functions within the human prostate remain unclear. This study explored the expression, functions, and regulatory mechanisms of CXCL5 in prostate stroma and cancer cells. CXCL5 secreted from prostate cancer cells enhanced neutrophil migration. CXCL5 induced cell proliferation and invasion of prostate cancer cells in vitro and tumorigenesis in a xenograft animal model. C-X-C motif chemokine receptor 2 (CXCR2) has been identified on the surface of prostate fibroblasts and cancer cells. The supernatant of LNCaP cells or CXCL5 overexpression enhanced the migration and contraction of prostate myofibroblast WPMY-1 cells; however, pretreatment with SB225002, a CXCR2 inhibitor, can reverse these effects. CXCL5 evinces antioxidant properties by upregulating heme oxygenase-1 (HO-1) to counteract H2O2-induced reactive oxygen species (ROS) in a CXCR2-dependent manner in WPMY-1 and prostate cancer cells. Our findings illustrate that CXCL5, through HO-1, plays a role in antioxidation, and determine that the CXCL5/CXCR2/HO-1 pathway facilitates antioxidative communication between fibroblasts and cancer cells in the prostate. Therefore, targeting the CXCL5/CXCR2 signaling pathway could provide a new strategy for managing oxidative stress within the prostate.

Relationship between LDL-cholesterol, small and dense LDL particles, and mRNA expression in a cohort of African Americans

Understanding the characteristics and behavior of low-density lipoprotein (LDL) particles provides insights into the atherogenic risk of elevated LDL cholesterol in hypercholesterolemia, cardiovascular disease risks. Studying LDL particles helps identify specific LDL subtypes [e.g., small dense LDL particles (sdLDL)] that may be atherogenic and, consequently, potential targets for therapeutics. This study cohort consists of African Americans (AAs), a population disproportionately affected by cardiovascular diseases, thereby accentuating the importance of the investigation. Differential expression (DE) analysis was undertaken using a dataset comprising 17,947 protein-coding mRNAs from the whole blood transcriptomes of 416 samples to identify mRNAs associated with low-density lipoprotein cholesterol (LDL-C) and sdLDL plasma levels. Subsequently, mediation analyses were used to investigate the mediating role of sdLDL particles on the relationship between LDL-C levels and mRNA expression. Finally, pathway enrichment analysis was conducted to identify pathways involving mRNAs whose relationship with LDL-C is mediated by sdLDL. DE analysis revealed 1,048 and 284 mRNA transcripts differentially expressed by LDL-C and sdLDL levels, respectively. Mediation analysis revealed that the associations between LDL-C and 33 mRNAs were mediated by sdLDL. Of the 33 mRNAs mediated by sdLDL, 18 were mediated in both males and females. Nine mRNAs were mediated only in females, and six were mediated only in males. Pathway analysis showed that 33 mRNAs are involved in pathways associated with the immune system, inflammatory response, metabolism, and cardiovascular disease (CVD) risk. In conclusion, our study provides valuable insights into the complex interplay between LDL-C, sdLDL, and mRNA expression in a large sample of AAs. The results underscore the importance of incorporating sdLDL measurement alongside LDL-C levels to improve the accuracy of managing hypercholesterolemia and effectively stratify the risk of CVD. This is essential as differences in sdLDL modulate atherogenic properties at the transcriptome level.NEW & NOTEWORTHY The study investigated the interplay between LDL-C and mRNA expression, focusing on the role of small dense LDL (sdLDL) particles and sex differences. Differential expression analysis identified 1,048 and 284 mRNAs associated with LDL-C and sdLDL levels, respectively. Mediation analysis revealed that sdLDL mediates the relationship between LDL-C and 33 mRNAs involved in immune, inflammatory, and metabolic pathways. These findings highlight the significance of sdLDL in cardiovascular disease risk assessment and underscore sex-specific differences in lipid metabolism.

TRPV3 facilitates lipolysis and attenuates diet-induced obesity via activation of the NRF2/FSP1 signaling axis

Transient receptor potential vanilloid (TRPV) ion channels play a crucial role in various cellular functions by regulating intracellular Ca2+ levels and have been extensively studied in the context of several metabolic diseases. However, the regulatory effects of TRPV3 in obesity and lipolysis are not well understood. In this study, utilizing a TRPV3 gain-of-function mouse model (TRPV3G568V/G568V), we assessed the metabolic phenotype of both TRPV3G568V/G568V mice and their control littermates, which were randomly assigned to either a 12-week high-fat diet or a control diet. We investigated the potential mechanisms underlying the role of TRPV3 in restraining obesity and promoting lipolysis both in vivo and in vitro. Our findings indicate that a high-fat diet led to significant obesity, characterized by increased epididymal and inguinal white adipose tissue weight and higher fat mass. However, the gain-of-function mutation in TRPV3 appeared to counteract these adverse effects by enhancing lipolysis in visceral fat through the upregulation of the major lipolytic enzyme, adipocyte triglyceride lipase (ATGL). In vitro experiments using carvacrol, a TRPV3 agonist, demonstrated the promotion of lipolysis and antioxidation in 3T3-L1 adipocytes after TRPV3 activation. Notably, carvacrol failed to stimulate Ca2+ influx, lipolysis, and antioxidation in 3T3-L1 adipocytes treated with BAPTA-AM, a cell-permeable calcium chelator. Our results revealed that TRPV3 activation induced the action of transcriptional factor nuclear factor erythroid 2-related factor 2 (NRF2), resulting in increased expression of ferroptosis suppressor protein 1 (FSP1) and superoxide dismutase2 (SOD2). Moreover, the inhibition of NRF2 impeded carvacrol-induced lipolysis and antioxidation in 3T3-L1 adipocytes, with downregulation of ATGL, FSP1, and SOD2. In summary, our study suggests that TRPV3 promotes visceral fat lipolysis and inhibits diet-induced obesity through the activation of the NRF2/FSP1 signaling axis. We propose that TRPV3 may be a potential therapeutic target in the treatment of obesity.

ARID3C Acts as a Regulator of Monocyte-to-Macrophage Differentiation Interacting with NPM1

ARID3C is a protein located on human chromosome 9 and expressed at low levels in various organs, yet its biological function has not been elucidated. In this study, we investigated both the cellular localization and function of ARID3C. Employing a combination of LC-MS/MS and deep learning techniques, we identified NPM1 as a binding partner for ARID3C's nuclear shuttling. ARID3C was found to predominantly localize with the nucleus, where it functioned as a transcription factor for genes STAT3, STAT1, and JUNB, thereby facilitating monocyte-to-macrophage differentiation. The precise binding sites between ARID3C and NPM1 were predicted by AlphaFold2. Mutating this binding site prevented ARID3C from interacting with NPM1, resulting in its retention in the cytoplasm instead of translocation to the nucleus. Consequently, ARID3C lost its ability to bind to the promoters of target genes, leading to a loss of monocyte-to-macrophage differentiation. Collectively, our findings indicate that ARID3C forms a complex with NPM1 to translocate to the nucleus, acting as a transcription factor that promotes the expression of the genes involved in monocyte-to-macrophage differentiation.

Dipeptidyl peptidase-4 disturbs adipocyte differentiation via the negative regulation of the glucagon-like peptide-1/adiponectin-cathepsin K axis in mice under chronic stress conditions

Exposure to chronic psychosocial stress is a risk factor for metabolic disorders. Because dipeptidyl peptidase-4 (DPP4) and cysteinyl cathepsin K (CTSK) play important roles in human pathobiology, we investigated the role(s) of DPP4 in stress-related adipocyte differentiation, with a focus on the glucagon-like peptide-1 (GLP-1)/adiponectin-CTSK axis in vivo and in vitro. Plasma and inguinal adipose tissue from non-stress wild-type (DPP4+/+), DPP4-knockout (DPP4-/-) and CTSK-knockout (CTSK-/-) mice, and stressed DPP4+/+, DPP4-/-, CTSK-/-, and DPP4+/+ mice underwent stress exposure plus GLP-1 receptor agonist exenatide loading for 2 weeks and then were analyzed for stress-related biological and/or morphological alterations. On day 14 under chronic stress, stress decreased the weights of adipose tissue and resulted in harmful changes in the plasma levels of DPP4, GLP-1, CTSK, adiponectin, and tumor necrosis factor-α proteins and the adipose tissue levels of CTSK, preadipocyte factor-1, fatty acid binding protein-4, CCAAT/enhancer binding protein-α, GLP-1 receptor, peroxisome proliferator-activated receptor-γ, perilipin2, secreted frizzled-related protein-4, Wnt5α, Wnt11 and β-catenin proteins and/or mRNAs as well as macrophage infiltration in adipose tissue; these changes were rectified by DPP4 deletion. GLP-1 receptor activation and CTSK deletion mimic the adipose benefits of DPP4 deficiency. In vitro, CTSK silencing and overexpression respectively prevented and facilitated stress serum and oxidative stress-induced adipocyte differentiation accompanied with changes in the levels of pref-1, C/EBP-α, and PPAR-γ in 3T3-L1 cells. Thus, these findings indicated that increased DPP4 plays an essential role in stress-related adipocyte differentiation, possibly through a negative regulation of GLP-1/adiponectin-CTSK axis activation in mice under chronic stress conditions.

QSOX2 Upregulated in triple-negative breast cancer exacerbates patient prognosis by stabilizing integrin β1

Breast cancer (BC) remains a significant global health threat, with triple-negative breast cancer (TNBC) standing out as a particularly aggressive subtype lacking targeted therapies. Addressing this gap, we propose Quiescin Q6 sulfhydryl oxidase 2 (QSOX2) as a potential therapeutic target, a disulfide bond-forming enzyme implicated in cancer progression. Using publicly available datasets, we conducted a comprehensive analysis of QSOX2 expression in BC tumor and non-tumor tissues, assessing its specificity across different molecular subtypes. We further explored correlations between QSOX2 expression and patient outcomes, utilizing datasets like TCGA and METABRIC. In addition, we performed in vitro experiments to evaluate QSOX2 expression in BC cell lines and investigate the effects of QSOX2 knockdown on various TNBC cellular processes, including cell proliferation, apoptosis resistance, migration, and the epithelial-to-mesenchymal transition (EMT). Our results reveal significantly elevated QSOX2 expression in BC tumor tissues, particularly in TNBC, and establish an association between high QSOX2 expression and increased patient mortality, cancer progression, and recurrence across various BC subtypes. Notably, QSOX2 knockdown in TNBC cell lines reduces cell proliferation, enhances apoptosis, and suppresses migration, potentially mediated through its influence on the EMT process. Furthermore, we identify a significant link between QSOX2 and integrin β1 (ITGB1), suggesting that QSOX2 enhances ITGB1 stability, subsequently exacerbating the malignancy of TNBC. In conclusion, elevated QSOX2 expression emerges as a key factor associated with adverse patient outcomes in BC, particularly in TNBC, contributing to disease progression through various mechanisms, including the modulation of ITGB1 stability. Our findings underscore the potential of targeting QSOX2 as a therapeutic strategy for improving patient prognoses not only in TNBC but also in other BC subtypes.

Exosome proteomes reveal glycolysis-related enzyme enrichment in primary canine mammary gland tumor compared to metastases

OBJECTIVE

Numerous evidence has highlighted the differences between primary tumors and metastases. Nonetheless, the differences in exosomal proteins derived from primary tumor and metastases remain elusive. Here, we aimed to identify differentially expressed exosomal proteins from primary canine mammary gland tumor and metastases to understand how they shape their own tumor microenvironment.

METHODS

We clearly distinguished primary canine mammary gland tumors (CHMp) from metastases (CHMm) and profiled the proteins within their secreted exosomes using LC-MS/MS. Moreover, the abundance of glycolysis enzymes (GPI, LDHA) in CHMp exosome was verified with Western blotting, To broaden the scope, we extended to human colorectal cancer-derived exosomes (SW480 vs. SW620) for comparison.

RESULTS

We identified significant differences in 87 and 65 proteins derived from CHMp and CHMm, respectively. Notably, glycolysis enzymes (GPI, LDHA, LDHB, TPI1, and ALDOA) showed specific enrichment in exosomes from the primary tumor.

CONCLUSION

We observed significant differences in the cellular proteome between primary tumors and metastases, and intriguingly, we identified a parallel heterogeneity the protein composition of exosomes. Specifically, we reported that glycolysis enzymes were significantly enriched in CHMp exosomes compared to CHMm exosomes. We further demonstrated that this quantitative difference in glycolysis enzymes persisted across primary and metastases, extending to human colorectal cancer-derived exosomes (SW480 vs. SW620). Our findings of the specific enrichment of glycolysis enzymes in primary tumor-derived exosomes contribute to a better understanding of tumor microenvironment modulation and heterogeneity between primary tumors and metastases.