Molecular Medicine最新文献

Background: Metabolic reprogramming is a hallmark of hepatocellular carcinoma (HCC) progression, driving aberrant cellular processes in response to pathological stimuli. While dihydrolipoyl transacetylase (DLAT) has been implicated in the development of various cancers, its specific role and underlying mechanisms in HCC remain unclear. This study aimed to investigate the expression, function, and mechanistic impact of DLAT in HCC.

Methods: A comprehensive analysis was conducted using RNA sequencing data, tissue microarrays, in vitro and in vivo functional assays, and mechanistic studies to evaluate DLAT expression, its functional role in tumor progression, and associated molecular pathways in HCC.

Results: Our study revealed a significant upregulation of DLAT expression in HCC, which was linked to a poor prognosis. Furthermore, we discovered that DLAT facilitated tumor metastasis by driving metabolic reprogramming in HCC cells. Mechanistically, DLAT was found to enhance glucose transporter 1 (GLUT1) expression via H3K18 acetylation, thereby promoting aerobic glycolysis and epithelial-to-mesenchymal transition (EMT), which subsequently augmented metastasis of HCC both in vitro and in vivo. Finally, we confirmed a positive correlation between DLAT and GLUT1 expression in HCC tissues.

Conclusions: These findings establish DLAT as a key regulator in HCC progression and suggest its potential as a promising predictive biomarker and therapeutic target for improving HCC diagnosis and treatment.

Background: Acute lung injury (ALI) is distinguished by exaggerated neutrophil extracellular traps (NETs), elevated clinical mortality rates, and a paucity of targeted therapeutic interventions. The Gαq/11 protein, a member of the G protein subfamily, is an effective intervention target for a variety of diseases, but little is known about its role in ALI.

Methods: In this study, a murine model of ALI induced by lipopolysaccharide (LPS) was utilized, employing myeloid cell-specific Gna11 knockout mice. The pulmonary pathology of mice was assessed and the lung samples were collected for immunofluorescence staining and RNA-sequencing analysis to elucidate the impact and underlying mechanisms of Gαq/11 in ALI. Mouse bone marrow-derived neutrophils were isolated and cultured for live-cell imaging to investigate the in vitro effects of Gαq/11.

Results: The expression of Gαq/11 was found to be upregulated in the lung tissues of mice with ALI, coinciding with the increased expression of inflammatory genes. Myeloid cell-specific Gna11 deficience attenuated LPS-induced lung injury and the formation of NETs in mice. Mechanistically, Gαq/11 facilitates NETosis by promoting the activation of the endoplasmic reticulum (ER) stress sensor IRE1α in neutrophils and mediating the production of mitochondrial reactive oxygen species (mitoROS). Pharmacological inhibition of Gαq/11 using YM-254,890 was shown to reduce NETs formation and lung injury in mice.

Conclusions: The upregulation of Gαq/11 exacerbates ALI through the promotion of ER stress-mediated NETosis. Consequently, Gαq/11 represents a potential therapeutic target for the treatment of ALI.

Background: Osteoporosis represents a salient metabolic bone disorder. Histone demethylase plays a vital role in bone development and homeostasis. This study explored the mechanism of histone demethylase KDM5A affecting osteoporotic fracture healing via the miR-495/SKP2/Runx2 axis.

Methods: The murine model of osteoporotic fracture was established. The bone mineral density, maximum elastic stress, and maximum load were tested. The relative trabecular bone volume, bone trabecular thickness, and trabecular number at the proximal end of tibia were detected. The histopathological changes of femur tissues and bone microstructure were observed. Expressions of KDM5A and osteogenic factors were detected. The cell proliferation, alkaline phosphatase activity, and calcified nodules were measured. The binding relationships between KDM5A and miR-495 promoter, and miR-495 and SKP2 were verified. The interaction between SKP2 and Runx2 was detected. The ubiquitination level of Runx2 and the stability of Runx2 protein were detected.

Results: KDM5A was highly expressed in the murine model of osteoporotic fracture. Interference of KDM5A expression facilitated fracture healing in osteoporotic mice. KDM5A downregulated miR-495 expression by promoting the H3K4me3 methylation of the miR-495 promoter. Inhibition of miR-495 reversed the effect of KDM5A silencing on osteoblast proliferation, differentiation, and mineralization. miR-495 facilitated osteoblast proliferation, differentiation, and mineralization by targeting SKP2. SKP2 suppressed Runx2 expression through ubiquitination degradation. Inhibition of Runx2 reversed the promoting effect of SKP2 silencing on osteogenic differentiation.

Conclusion: KDM5A attenuated the inhibition of miR-495 on SKP2 and promoted the ubiquitination degradation of Runx2 protein by SKP2, thereby repressing osteoblast differentiation and retarding osteoporotic fracture healing.

Radiotherapy is one of the most effective treatments for malignant tumors. Radioresistance is a major factor that contributes to radiotherapy failure and poor prognosis. Recent studies have elucidated the pivotal role of aberrant N6-methyladenosine (m6A) modification, the predominant internal mRNA modification in eukaryotic cells, influences cancer progression by disrupting gene expression and other critical cellular processes. Furthermore, aberrant m6A methylation provides a substrate for tumor therapy; however, whether it regulates tumor radioresistance remains unclear. Methylated transferase (writer), demethylated transferase (eraser), and methylated recognition protein (reader) are the three essential proteins that regulate m6A modification via different mechanisms in different tumors. This review summarizes the latest research advances in m6A methylation and aims to provide novel perspectives on the advancement of regimens to overcome radioresistance and tumor invasion.

Background: FOLFOX is the recommended chemotherapy regimen for colorectal cancer (CRC), but its response rate remains low. Our previous studies have established a close relationship between gut microbiota and the anti-CRC effect of FOLFOX, though the underlying mechanisms remain unclear. Diet has been confirmed as a key factor influencing gut microbiota, and high-salt diets, representative of western dietary habits, has been shown to affect gut microbiota, immune function, and the risk of developing CRC. However, the impact of high-salt diets on the anti-CRC efficacy of FOLFOX remains unstudied. Therefore, we aimed to investigate the effect and mechanism of high-salt diets on the anti-CRC effect of FOLFOX.

Methods: We performed 16 S rRNA sequencing and T500 targeted metabolomics analysis on fecal samples from CRC patients and healthy adults. A CRC orthotopic xenograft mouse model was used to study the effect of a high-salt diet on FOLFOX's anti-CRC efficacy. 16 S rRNA sequencing and non-targeted metabolomics were conducted on mouse fecal samples. Flow cytometry was used to assess immune cell infiltration in tumor and paracancerous tissues. A mouse macrophage conditioned medium system, with tryptophan metabolites, was employed to annotate the functional metabolites, followed by in vivo verification using the orthotopic xenograft mouse model.

Results: The structure and metabolic profiles of gut microbiota are significantly different between 9 healthy adults and 6 CRC patients. A high-salt diet significantly reduced the efficacy of FOLFOX in mice, with notable changes in gut microbiota and related metabolites. Correlation analysis revealed a significant relationship between gut microbiota, tryptophan metabolites and FOLFOX efficacy. Flow cytometry indicated that a high-salt diet altered macrophage infiltration (CD45⁺F4/80⁺) in both the tumor and paracancerous tissues. In vitro experiments confirmed that the tryptophan metabolite SK reduced FOLFOX efficacy, while IPA enhanced it through macrophage-conditioned medium. In vivo, we verified that under a high-salt diet, SK inhibited the efficacy of FOLFOX, while IPA promoted it.

Conclusion: A high-salt diet reduces the anti-CRC efficacy of FOLFOX through gut bacterial tryptophan metabolism mediated macrophage immunomodulation.

Background: With fatal malignant peculiarities and poor survival rate, outcomes of pancreatic adenocarcinoma (PAAD) were frustrated by non-response and even resistance to therapy due to heterogeneity across clinical patients. Nevertheless, pharmacogenomics has been developed for individualized-treatment and still maintains obscure in PAAD.

Methods: A total of 964 samples from 10 independent multi-center cohorts were enrolled in our study. With drug response data from the profiling of relative inhibition simultaneously in mixtures (PRISM) and genomics of drug sensitivity in cancer (GDSC) databases, we established and validated multidimensionally three pharmacogenomics-classified subtypes using non-negative matrix factorization (NMF) and nearest template prediction (NTP) algorithms, separately. The heterogenous biological characteristics and precision medicine strategies among subtypes were further investigated.

Results: Three pharmacogenomics-classified subtypes after stable and reproducible validation, distinguished in six aspects of prognosis, biological peculiarities, immune landscapes, genomic variations, immunotherapy and individualized management strategies. Subtype 2 was close to immunocompetent phenotype and projected to immunotherapy; Subtype 3 held most favorable outcomes and metabolic pathways distinctively, promising to be treated with first-line agents. Subtype 1 with worst prognosis, was anticipated to chromosome instability (CIN) phenotype and resistant to chemotherapeutic agents. In addition, ITGB6 contributed to subtype 1 resistance to 5-fluorouracil, and knockdown of ITGB6 enhanced sensitivity to 5-fluorouracil in in vitro experiments. Ultimately, appropriate clinical stratified treatments were assigned to corresponding subtypes according to pharmacogenomic transcripts. Some limitations were not taken into account, thus needs to be supported by more research.

Conclusion: A span-new molecular subtype exploited for PAAD uncovered an insight into precise medication on ground of pharmacogenomics, and highly refined multiple clinical management strategies for specific patients.

Background: As an endoplasmic reticulum (ER) protein, Reticulum 3 (RTN3) has been reported to play a crucial role in neurodegenerative diseases, lipid metabolism, and chronic kidney disease. The involvement of RTN3 in idiopathic pulmonary fibrosis (IPF), a progressive and fatal interstitial lung disease, remains unexplored.

Methods: In this study, we explored the role of RTN3 in pulmonary fibrosis using public datasets, IPF patient samples, and animal models. We investigated its pathogenic mechanisms in lung fibroblasts and alveolar macrophages.

Results: We found decreased levels of RTN3 in IPF patients, bleomycin-induced mice, and TGFβ-treated cell lines. RTN3-null mice exhibited more severe pulmonary fibrosis phenotypes in old age or after bleomycin treatment. Collagen synthesis was significantly increased in RTN3-null mice lung tissues and lung fibroblasts. Mechanistic studies revealed that RTN3 deficiency reduced the ER-anchored CRTH2 in lung fibroblasts, which serves as an antifibrotic molecule via antagonizing collagen biosynthesis. Simultaneously, RTN3 deficiency reduced the autophagy degradation of CRTH2 which acts as an activator of profibrotic macrophage differentiation. Both effects of RTN3 and CRTH2 in lung fibroblasts and alveolar macrophages aggravated age-or bleomycin-induced pulmonary fibrosis. Additionally, we also identified a mutation of RTN3 in patients with ILD.

Conclusions: Our research demonstrated that RTN3 plays a significant role in the lung, and reduction of RTN3 levels may be a risk factor for IPF and related diseases.

Abnormal glucose metabolism inevitably disrupts normal neuronal function, a phenomenon widely observed in Alzheimer's disease (AD). Investigating the mechanisms of metabolic adaptation during disease progression has become a central focus of research. Considering that impaired glucose metabolism is closely related to decreased insulin signaling and insulin resistance, a new concept "type 3 diabetes mellitus (T3DM)" has been coined. T3DM specifically refers to the brain's neurons becoming unresponsive to insulin, underscoring the strong link between diabetes and AD. Recent studies reveal that during brain insulin resistance, neurons exhibit mitochondrial dysfunction, reduced glucose metabolism, and elevated lactate levels. These findings suggest that impaired insulin signaling caused by T3DM may lead to a compensatory metabolic shift in neurons toward glycolysis. Consequently, this review aims to explore the underlying causes of T3DM and elucidate how insulin resistance drives metabolic reprogramming in neurons during AD progression. Additionally, it highlights therapeutic strategies targeting insulin sensitivity and mitochondrial function as promising avenues for the successful development of AD treatments.

Background: Patients with higher-risk (HR) myelodysplastic syndrome (MDS), ineligible for allogeneic hematopoietic stem cell transplantation (alloHSCT), require prompt therapeutic interventions, such as treatment with hypomethylating agents (HMAs) to restore normal DNA methylation patterns, mainly of oncosuppressor genes, and consequently to delay disease progression and increase overall survival (OS). However, response assessment to HMA treatment relies on conventional methods with limited capacity to uncover a wide spectrum of underlying molecular events.

Methods: We implemented liquid chromatography-tandem mass spectrometry (LC-MS/MS) to assess 5' methyl-2' deoxycytidine (5mdC), 5' hydroxy-methyl-2'-deoxycytidine (5hmdC) levels and global adenosine/thymidine ([dA]/[T]) ratio in bone marrow aspirates from twenty-one HR MDS patients, pre- and post-HMA treatment. Additionally, targeted methylation analysis was performed by interpretation of NGS-methylation (MeD-seq) data obtained from the same patient cohort.

Results: LC/MS-MS analysis revealed a significant hypomethylation status in responders (Rs), already established at baseline and a trend for further DNA methylation reduction post-HMA treatment. Non-responders (NRs) reached statistical significance for DNA hypomethylation only post-HMA treatment. The 5hmdC epigenetic mark was approximately detected at 37.5-40% among NRs and Rs, implying the impairment of the natural active demethylation pathway, mediated by the ten-eleven (TET) 5mdC dioxygenases. R and NR subgroups displayed a [dA]/[T] ratio < 1 (0.727 - 0.633), supporting high frequences of 5mdC transition to thymidine. Response to treatment, according to whole genome MeD-seq data analysis, was associated with specific, scattered hypomethylated DMRs, rather than presenting a global effect across genome. MeD-seq analysis identified divergent epigenetic effects along chromosomes 7, 9, 12, 16, 18, 21, 22, X and Y. Within statistically significant selected chromosomal bins, genes encoding for proteins and non-coding RNAs with reversed methylation profiles between Rs and NRs, were highlighted.

Conclusions: Implementation of powerful analytical tools to identify the dynamic DNA methylation changes in HR MDS patients undergoing HMA therapy demonstrated that LC-MS/MS exerts high efficiency as a broad-based but rapid and cost-effective methodology (compared to MeD-seq) to decode different perspectives of the epigenetic background of HR MDS patients and possess discriminative efficacy of the response phenotype to HMA treatment.

Cell death can terminate in plasma membrane rupture to release potent pro-inflammatory intracellular contents thereby contributing to inflammatory diseases. Cell rupture is an active process, mediated by the membrane protein ninjurin-1 (NINJ1) in pyroptosis, post-apoptosis lysis, ferroptosis, and forms of necrosis. Once activated, NINJ1 clusters into large oligomers within the membrane to initiate cellular lysis. Recent preclinical studies have demonstrated that inhibiting NINJ1 is a new strategy for treating immune-mediated diseases. Indeed, both small molecule inhibitors and neutralizing antibodies can target NINJ1 clustering to preserve plasma membrane integrity and mitigate disease pathogenesis. In this Perspective, we provide a summary of the current state of knowledge and recent developments in targeting cellular integrity during cell death through NINJ1 inhibition to treat inflammatory disease, with a focus on liver injury. As these NINJ1-mediated cell death pathways are pivotal in maintaining health and contribute to disease pathogenesis when dysregulated, the studies discussed within have broad implications across the immunologic basis of molecular medicine.