Molecular Medicine最新文献

Ulcerative colitis (UC) is a chronic inflammatory disease of the colon characterized by recurrent episodes of mucosal inflammation. During disease progression, macrophages are recruited into the intestinal lamina propria and polarized toward a pro-inflammatory phenotype, where they exacerbate tissue injury by secreting cytokines such as IL-1β, IL-6, and TNF-α. Among these, IL-1β plays a central role, exhibiting both immunomodulatory and pro-inflammatory functions that correlate with disease severity. This study revealed that glycogen metabolism critically regulates IL-1β production and secretion in inflammatory macrophages. Mechanistically, uridine diphosphate-glucose (UDPG), a metabolic intermediate of glycogen metabolism, activates the P2Y₁₄ receptor, leading to the downstream upregulation of STAT1 expression and enhanced IL-1β production. In parallel, activation of the UDPG-P2Y₁₄ axis suppresses intracellular cAMP levels, thereby facilitating inflammasome activation and caspase-1 cleavage, ultimately driving IL-1β secretion. Importantly, the glycogen phosphorylase inhibitor ameliorates dextran sulfate sodium induced UC in mice by inhibiting glycogen metabolism. These findings highlight the UDPG-P2Y₁₄ pathway as a potential therapeutic target for IL-1β-driven inflammatory diseases.

Ovarian cancer (OC) progression and metastasis are promoted by ascites, which constitutes a central part of the tumor microenvironment (TME). In this fluid, tumor-associated macrophages (TAMs) represent a prominent immune cell type. In addition to tumor and other host cells such as TAMs, ascites is highly enriched in soluble factors as well as extracellular vesicles (EVs). How TAMs contribute to the EV compartment of the OC TME remains, however, underexplored. In this work peripheral blood monocytes from healthy donors were differentiated into monocyte-derived macrophages (MDMs) and polarized into classically activated (M1-like), alternatively activated (M2-like) and TAM-like (by ascites incubation). For all subtypes, serum-free conditioned medium was collected for 24 h and EVs were isolated and characterized by nano-flow cytometry (nFC), label-free mass spectrometry-based proteomics and electron microscopy, among others. Our results demonstrated distinct traits for EV release and cargo across the different macrophage subtypes. Specifically, TAM-like macrophages exhibited impaired release of small EVs and reduced frequency of tetraspanin-positive particles. These EV subpopulations displayed sizing profiles closer to M1-like than to M2-like samples. Also, the low EV release in TAM-like MDMs was accompanied by altered expression of biogenesis-related markers like flotillin-1 (FLOT1) and a decreased N-glycosylation of CD63 protein, which was validated in patient-derived samples. Remarkably, the EV-associated proteome of TAMs displayed significant enrichment in both pro- and anti-inflammatory molecules with clinical value. Markers significantly enriched in the ascites TAM-EV signature were mostly associated with poor prognosis, whereas M1-like EV-related markers (pro-inflammatory) were mostly associated with longer survival. Our results confirmed previous data for proteins like CD163 and MRC1 to be associated to TAM-EVs, while also describing novel candidates with diagnostic (i.e., COLEC12) and/or prognostic (i.e., MSR1) value in plasma. Taken together, our data support a unique secretory profile of TAMs in OC and provide new EV-associated biomarkers with translational impact. Our results pave the way for a better understanding of the mechanisms behind TAM-EV cargo loading and function, and how these cells participate in the TME landscape.

Background: Low molecular weight protein tyrosine phosphatase (LMWPTP), encoded by the ACP1 gene, has been implicated in tumor progression across multiple malignancies. While its oncogenic functions have been reported in colorectal cancer (CRC), its role in gastric cancer (GC) remains poorly defined. This study investigated the expression patterns, functional relevance, and prognostic impact of LMWPTP in GC, with comparative analyses in CRC.

Methods: Gene expression, immune infiltration, and survival analyses were performed using data from The Cancer Genome Altas (TCGA). LMWPTP protein expression was evaluated in a gastric cancer tissue microarray. Functional assays were conducted in GC and CRC cell lines with CRISPR-Cas9-mediated LMWPTP knockout.

Results: ACP1 mRNA expression was significantly upregulated in both GC and CRC compared with adjacent normal tissues. In GC, high LMWPTP expression was associated with poor differentiation in intestinal-type tumors and reduced survival in diffuse-type cases. ACP1 overexpression correlated with an elevated tumor mutation burden but a decreased cytotoxic lymphocyte infiltration signature in GC, indicating a potential relationship between ACP1 expression, tumor mutational load, and tumor immune microenvironment. Functional assays in vitro showed that LMWPTP knockout reduced migration in both GC and CRC cells, whereas a decrease in invasion was observed only in CRC cells. These findings indicate context-dependent contributions of LMWPTP to gastrointestinal tumor biology.

Conclusion: LMWPTP is consistently upregulated in gastric and colorectal cancers and exhibits tumor-type-specific functional and immune associated features. These findings highlight its distinct oncogenic role and potential as a biomarker and therapeutic target in GC.

Background & aims: Metabolic dysfunction-associated steatohepatitis (MASH) is a multifactorial disease driven by complex molecular mechanisms. Identifying key regulators is critical for developing targeted therapies. Here, we demonstrate the impact of the loss of the apoptosis-antagonizing transcription factor (AATF) on hepatic lipid metabolism and MASH progression.

Methods: A preclinical mouse model recapitulating human MASH was established by feeding C57Bl/6 mice either a chow diet (CD) or a western diet with sugar water (WD). Hepatic AATF silencing was achieved by tail vein injection of siAATF delivered by adeno-associated virus 8 (AAV8) using a liver-specific thyroxine-binding globulin (TBG) promoter. In addition to histological, biochemical, and molecular biology evaluations, mechanistic insights were obtained through whole transcriptomic and untargeted metabolomic analyses.

Results: AAV8-mediated specific knockdown of AATF in hepatocytes significantly reduced body weight, liver weight, and insulin resistance in mice fed a western diet (WD). However, no such effects were observed in mice fed a chow diet (CD). Further analyses showed reduced liver injury, steatosis, and steatohepatitis in WDsiAATF mice. Transcriptomic analysis demonstrated that AATF loss alleviated cellular stress, inflammation, and fibrosis in WD-fed mice. Moreover, AATF silencing altered lipid metabolism, notably by decreasing hepatic lipogenesis in WD mice. Interestingly, untargeted metabolomics revealed increased glycerophospholipid biosynthesis and fatty acid β-oxidation in WDsiAATF mice.

Conclusion: Our findings reveal a previously unrecognized role of AATF as a central regulator of hepatic lipid metabolism in MASH, acting through the AKT-mTORC1 signaling pathway, and establish its inhibition as a promising therapeutic strategy for the treatment of metabolic liver disease.