Molecular Medicine最新文献

Background: Sepsis-induced organ failure and high mortality are largely ascribed to the failure of bacterial clearance from the infected tissues. Recently, probiotic bacteria-released extracellular vesicles (BEVs) have been implicated as critical mediators of intercellular communication which are widely involved in the regulation of the inflammatory response. However, their functional role in macrophage phagocytosis during sepsis has never been explored.

Methods: BEVs were collected from three different strains of probiotics including Lactiplantibacillus plantarum WCFS1 (LP WCFS1), Lactobacillus rhamnosus Gorbach-Goldin (LGG), and Escherichia coli Nissle 1917 (EcN), or from LGG cultured under three pH conditions (pH5-acid, pH6.5-standard, pH8-akaline) through differential centrifugation, filtration, and ultracentrifugation of their culture supernatants. In vitro phagocytosis was measured in Raw264.7 cells and bone marrow-derived macrophages using pHrodo red E. coli BioParticles. The in vivo therapeutic effects of BEVs were tested using a feces-injection-in-peritoneum (FIP) model of polymicrobial sepsis.

Results: LGG-derived EVs (BEV^LGG) were the best among these three probiotics BEVs in stimulating macrophages to take up bacteria. Furthermore, BEV^LGG collected from pH8 culture condition (BEV^pH8) exhibited the strongest capacity of phagocytosis, compared with BEV^pH5 and BEV^pH6.5. Treatment of septic mice with BEV^pH8 significantly prolonged animal survival; increased bacterial clearance from the blood, peritoneal lavage fluid, and multiple organs; and decreased serum levels of pro-inflammatory cytokines/chemokines, as well as reduced multiple organ injuries, in comparison with control-treated septic mice. Mechanistically, RNA-seq and bioinformatic analysis identified that the FPR1/2 signaling was remarkably activated, along with its downstream pathways (PI3K-Akt-MARCO and NADPH-ROS) in BEV^pH8-treated macrophages, compared with control cells. Accordingly, pre-addition of Boc2, a specific antagonist of FPR1/FPR2, to macrophages significantly attenuated BEV^pH8-mediated phagocytosis, compared to controls.

Conclusions: This study demonstrates that LGG-derived BEVs may have therapeutic effects against sepsis-induced organ injury and mortality through enhancing FPR1/2-mediated macrophage phagocytosis.

The ability to heal from wounds is perhaps the most important biological function that ensures our survival and perpetuation. Cutaneous wound healing typically consists of four characteristic stages, namely hemostasis, inflammation, proliferation, and remodeling, which are carefully carried out by coordinated actions of various cells, cytokines, and hormones. Incoordination of these steps may impede complete and efficient reconstruction and functional recovery of wounds or even lead to worsened outcomes. Hormones, as powerful modulators of organ functions, participate in multiple steps of the wound healing process and play a pivotal role by choreographing the complex interplay of cellular and molecular events. Leveraging the regulatory effects of hormones to enhance the healing process, hormonal therapy has emerged as a promising approach in the clinical treatment of wounds. Current research has focused on determination of the optimal dosages, delivery methods, and combinations of hormonal therapies to maximize their therapeutic benefits while minimizing potential side effects. This review highlights the molecular mechanisms, clinical benefits and side effects of the most commonly used hormones in clinical treatment of wounds.

Background: Diffuse large B-cell lymphoma (DLBCL) is the most common type of lymphoma which possess highly aggressive and heterogeneous. Despite advances in understanding heterogeneity and development of novel targeted agents, the prognosis of DLBCL patients remains unsatisfied. Lipids are crucial components of biological membranes and signal transduction while accumulating evidence has supported the vital roles of abnormal lipid metabolism in tumorigenesis. Furthermore, some related pathways could serve as prognostic biomarkers and potential therapeutic targets. However, the clinical significance of abnormal lipid metabolism reprogramming in DLBCL has not been investigated. In the current study, we developed a prognostic risk model for DLBCL based on the abnormal expressed lipid metabolism genes and moreover based on our risk model we classified patients with DLBCL into novel subtypes and identified potential drugs for DLBCL patients with certain lipid metabolism profiles.

Methods: We utilized univariate Cox regression analysis to identify the prognosis-related lipid metabolism genes, and then performed LASSO Cox regression to identify prognostic related lipid metabolism related genes. Multivariate cox regression was used to establish the prognostic model. Patients were divided in to high and low risk groups based on the median risk score. Immune cell infiltration and GSEA were used to identify the pathways between high and low risk groups. Oncopredict algorithm was utilized to identify potential drug for high-risk patients. In vitro cell apoptosis and viability analysis were employed to verify the specific tumor inhibition effects of AZD5153.

Results: Nineteen survival related lipid metabolism genes TMEM176B, LAYN, RAB6B, MMP9, ATAD3B, SLC2A11, CD3E, SLIT2, SLC2A13, SLC43A3, CD6, SIRPG, NEK6, LCP2, CTTN, CXCL2, SNX22, BCL6 and FABP4 were identified and subjected to build the prognostic model which was further verified in four external microarray cohorts and one RNA seq cohorts. Tumor immune microenvironment analysis and GSEA results showed that the activation of MYC targets genes rather than immunosuppression contribute to the poor survival outcome of patients in the high-risk group. AZD5153, a novel bivalent BET bromodomain inhibitor which could inhibit the transcription of MYC and E2F exhibited specific antitumor function for cells with high-risk score.

Conclusions: Our results provide the first lipid metabolism-based gene signature for predicting the survival of patients with DLBCL. Furthermore, by determining novel subtypes with our lipid metabolism prognostic model we illustrated that drugs that compromising MYC target genes rather than immune checkpoint inhibitors may be beneficial to DLBCL patients with certain lipid metabolism profiles.

Background: Cardiac fibrosis is common in myocardial infarction (MI), leading to progressive cardiac dysfunction. Studies suggested that the abnormal N⁶-methyladenosine (m⁶A) modification induced by fat mass and obesity protein (FTO) is vital in MI. However, the effects of FTO on post-infarction cardiac fibrosis have not been detected.

Methods: Western blot and quantitative real-time PCR were performed to detect the expression of FTO in the fibrotic tissue of rats. The functions of FTO on collagen biosynthesis were analyzed in vitro and in vivo. The underlying targets of FTO were selected through RNA-seq with m⁶A-seq. The following dual luciferase reporter assay and RNA stability assay were conducted to investigate the mechanisms of FTO-mediated m⁶A regulation.

Results: The expression of FTO was decreased in the fibrotic tissue of post-infarction rats. The HIF-1 signal pathway was enriched after MI. HIF-1α could bind to the promoter of FTO and inhibit its expression. Functionally, FTO inhibited collagen synthesis after MI in vitro and in vivo. Mechanistically, EPRS was selected as the underlying target of FTO-induced m⁶A regulation. IGF2BP3 recognized and bound to the m⁶A sites of EPRS mRNA, which improved its stability. EPRS was required for cardiac fibrosis induced by FTO silencing.

Conclusions: FTO, identified as a cardioprotective factor, suppressed collagen synthesis in post-infarction cardiac fibrosis via m⁶A modification, which provided a new therapeutic strategy for cardiac fibrosis.

The overexpression of MYC genes is frequently found in many human cancers, including adult and pediatric malignant brain tumors. Targeting MYC genes continues to be challenging due to their undruggable nature. Using our prediction algorithm, the nine-amino-acid activation domain (9aaTAD) has been identified in all four Yamanaka factors, including c-Myc. The predicted activation function was experimentally demonstrated for all these short peptides in transactivation assay. We generated a set of c-Myc constructs (1-108, 69-108 and 98-108) in the N-terminal regions and tested their ability to initiate transcription in one hybrid assay. The presence and absence of 9aaTAD (region 100-108) in the constructs strongly correlated with their activation functions (5-, 3- and 67-times respectively). Surprisingly, we observed co-activation function of the myc region 69-103, called here acetyl-TAD, previously described by Faiola et al. (Mol Cell Biol 25:10220-10234, 2005) and characterized in this study as a new domain collaborating with the 9aaTAD. We discovered strong interactions on a nanomolar scale between the Myc-9aaTAD activation domains and the KIX domain of CBP coactivator. We showed conservation of the 9aaTADs in the MYC family. In summary for the c-Myc oncogene, the acetyl-TAD and the 9aaTAD domains jointly mediated activation function. The c-Myc protein is largely intrinsically disordered and therefore difficult to target with small-molecule inhibitors. For the c-Myc driven tumors, the strong c-Myc interaction with the KIX domain represents a promising druggable target.

Pelvic organ prolapse (POP) and urinary incontinence (UI) are common disorders that significantly impact women's quality of life. Studies have demonstrated that cytokines, including pro- and anti-inflammatory immune mediators, play a role in illness genesis and progression. Research on the inflammatory milieu of the pelvic floor has shown that POP patients have increased inflammation in vaginal tissues. This evidence revealed that significant changes in the inflammatory milieu of the pelvic floor are an aspect of the pathogenesis of POP. POP patients exhibit increased levels of inflammatory cytokines (IL-1, TNF, IFN, and others) in the front vaginal wall, which may alter collagen metabolism and contribute to POP. Studies indicate that cytokines such as IL-6, IL-10, and TGF, which are involved in inflammation, remodelling, and repair, have dual effects on POP and UI. They can promote tissue healing and regeneration but also exacerbate inflammation and fibrosis, contributing to the progression of these conditions. Understanding the dual roles of these cytokines could help us improve the vaginal microenvironment of women and treat POP and UI. Given the considerable changes in these cytokines, this review addresses studies published between 2000 and 2024 on the molecular mechanisms by which pro- and anti-inflammatory cytokines affect women with POP and UI. Furthermore, we explain novel therapeutic strategies for cytokine regulation, emphasizing the possibility of personalized treatments that address the underlying inflammatory milieu of the vagina in POP and UI patients. This thorough analysis aims to establish a foundation for future research and clinical applications, ultimately improving patient outcomes via designed cytokine-based therapies.

Background: Mesenchymal stem cells (MSCs) are widely dispersed in vivo and are isolated from several tissues, including bone marrow, heart, body fluids, skin, and perinatal tissues. Bone marrow MSCs have a multidirectional differentiation potential, which can be induced to differentiate the medium in a specific direction or by adding specific regulatory factors. MSCs repair damaged tissues through lineage differentiation, and the ex vivo transplantation of bone marrow MSCs can heal injured sites. MSCs have different propensities for lineage differentiation and pathological evolution for different diseases, which are crucial in disease progression. In this study, we describe various lineage analysis methods to explore lineage ontology in vitro and in vivo, elucidate the impact of MSC lineage differentiation on diseases, advance our understanding of the role of MSC differentiation in physiological and pathological states, and explore new targets and ideas associated with disease diagnosis and treatment.

Background: Patient-derived xenograft (PDX) is currently considered a preferred preclinical model to evaluate drug sensitivity, explore drug resistance mechanisms, and select individualized treatment regimens.

Methods: Histopathological examination, immunohistochemistry and whole-exome sequencing confirmed similarity between our PDX tumors and primary tumors in terms of morphology and genetic characteristics. The drug reactivity of the PDX tumor was validated in vivo. The mechanisms of acquired resistance to Osimertinib PDX tumors were investigated by WES and WB.

Results: We successfully established 13 NSCLC-PDXs derived from 62 patients, including eight adenocarcinomas, four squamous-cell carcinoma, and one large-cell neuroendocrine carcinoma. Histological subtype and clinical stage were significant factors affecting the successful PDXs establishment. The treatment responses to conventional chemotherapy in PDXs were entirely consistent with that of their corresponding patients. According to the genetic status of tumors, more appropriate targeted agents were selected in PDXs for their corresponding patients as alternative treatment options. In addition, a PDX model with acquired resistance to osimertinib was induced, and the overactivation of RAS mitogen-activated protein kinase (MAPK)-extracellular signal-regulated kinase (ERK) signaling pathway caused by the dual-specificity phosphatase 6 (DUSP6) M62I mutation was found to play a key role in the development of osimertinib resistance. Trametinib, a specific inhibitor of the MAPK-ERK pathway significantly slowed down the tumor growth in osimertinib-resistant PDX models, providing an alternative treatment in patients after osimertinib failure.

Background: Pulmonary arterial hypertension (PAH) is characterized by lipid accumulation and mitochondrial dysfunction. This study was designed to investigate the effects of hypoxia-inducible factor-1α (HIF-1α) on fatty acid uptake and mitophagy in PAH.

Methods: Peripheral blood samples were obtained from PAH patients. Human pulmonary arterial smooth muscle cells and rat cardiac myoblasts H9c2 were subjected to hypoxia treatment. Male Sprague-Dawley rats were treated with monocrotaline (MCT). Right ventricular systolic pressure (RVSP), right ventricular hypertrophy index (RVHI), pulmonary artery remodeling, and lipid accumulation were measured. Cell proliferation and ROS accumulation were assessed. Mitochondrial damage and autophagosome formation were observed. Co-immunoprecipitation was performed to verify the interaction between HIF-1α and CD36/PI3K p85α.

Results: HIF-1α, CD36, Parkin, and PINK1 were upregulated in PAH samples. HIF-1α knockdown or PI3K p85α knockdown restricted the expression of HIF-1α, PI3K p85α, Parkin, PINK1, and CD36, inhibited hPASMC proliferation, promoted H9c2 cell proliferation, reduced ROS accumulation, and suppressed mitophagy. CD36 knockdown showed opposite effects to HIF-1α knockdown, which were reversed by palmitic acid. The HIF-1α activator dimethyloxalylglycine reversed the inhibitory effect of Parkin knockdown on mitophagy. In MCT-induced rats, the HIF-1α antagonist 2-methoxyestradiol (2ME) reduced RVSP, RVHI, pulmonary artery remodeling, lipid accumulation, and mitophagy. Recombinant CD36 abolished the therapeutic effect of 2ME but inhibited mitophagy. Activation of Parkin/PINK1 by salidroside (Sal) promoted mitophagy to ameliorate the pathological features of PAH-like rats, and 2ME further enhanced the therapeutic outcome of Sal.

Conclusion: PI3K p85α/HIF-1α induced CD36-mediated fatty acid uptake and Parkin/PINK1-dependent mitophagy to accelerate the progression of experimental PAH.