Molecular Medicine最新文献

The incidence of obesity is increasing annually worldwide. A high-fat diet (HFD) causes intestinal barrier damage, but effective interventions are currently unavailable. Our previous work demonstrated the therapeutic effect of nobiletin on obese mice; thus, we hypothesized that nobiletin could reverse HFD-induced damage to the intestinal barrier. Male C57BL/6 J mice were orally administered nobiletin for 14 d. After identification, the obese mice were equally divided into three groups: the HFD group, the low-dose (NOL, 100 mg/kg/d) group and the high-dose nobiletin (NOH, 200 mg/kg/d) group. A normal control group (CON) was also included. Hematoxylin and eosin (HE) staining and immunofluorescence were used to observe the intestinal barrier. RT-qPCR was used to determine the transcriptomic levels of genes involved in intestinal barrier integrity and lipid metabolism. The results revealed that intestinal tight proteins, including ZO-1 and Occludin, were significantly reduced in HFD-fed mice but markedly restored after nobiletin intervention, particularly in NOH mice. Improvements in the intestinal barrier and lipid metabolism associated with major histocompatibility complex class II (MHC-II) and relevant elements were revealed after nobiletin intervention. Enrichment analysis revealed that MHC-II plays an important role in the restoration of the intestinal barrier. Taken together, nobiletin restored intestinal barrier integrity and lipid metabolism by regulating MHC-II expression.

Background: Neuropathic pain (NP) is a debilitating condition caused by lesion or dysfunction in the somatosensory nervous system. Accumulation of advanced oxidation protein products (AOPPs) is implicated in mechanical hyperalgesia. However, the effects of AOPPs on NP remain unclear.

Methods: A rat model of NP was established by chronic constriction injury (CCI) and employed to evaluate the changes of mechanical withdrawal threshold, thermal and cold withdrawal latency, as well as AOPPs levels. The effects of AOPPs on the activation of satellite glial cells (SGCs) in the dorsal root ganglion (DRG), receptor for advanced glycation end-products (RAGE) expression, and NF-κB signaling pathway activation were also investigated using western blotting, immunofluorescence, and the Fluo4-AM fluorescence probe for calcium signaling. Additionally, oxidative stress levels and inflammatory cytokine production in SGCs, triggered by AOPPs exposure, were measured through the DCFH-DA probe for ROS detection and ELISA kits for cytokine quantification.

Results: CCI significantly elevated the AOPPs levels in the plasma and sciatic nerve and caused AOPPs accumulation in the DRG. Exogenous AOPPs activated SGCs, increased reactive oxygen species and inflammatory response, upregulated the RAGE, and activated NF-κB signaling. The RAGE inhibitor FPS-ZM1 effectively inhibited AOPPs-induced SGC activation. Additionally, AOPPs intervention worsened CCI-induced hyperalgesia and neuroinflammation in vivo.

Conclusion: These results indicate that AOPPs exacerbate the SGC activation and NP following nerve injury, and AOPPs accumulation might play an important role in the pathogenesis of NP.

Background: Obesity is a significant risk factor for severe acute pancreatitis (SAP) and is typically associated with increased intestinal permeability. Understanding the role of specific molecules can help reduce the risk of developing SAP. Claudin 11 (CLDN11), a member of the Claudin family, regulates the permeability of various internal barriers. However, the role and mechanism of CLDN11 in the intestinal permeability of obesity-related SAP remain unclear.

Methods: We evaluated intestinal permeability and the expression of CLDN11 in experimental obesity-related SAP. A recombinant adeno-associated virus carrying CLDN11 was used to treat experimental obesity-related SAP. The interaction between CLDN11 mRNA and insulin-like growth factor 2 mRNA-binding protein 3 (IGF2BP3) protein was predicted through bioinformatics analysis and validated by RNA immunoprecipitation and RNA pull-down assay. Additionally, tumor necrosis factor-α (TNF-α) treatment in Caco-2 cells was conducted, and the IGF2BP3/CLDN11 axis was detected. Moreover, we conducted anti-TNFα therapy and evaluated intestinal permeability and pancreatic inflammation in experimental obesity-related SAP.

Results: Downregulation of CLDN11 was observed in the intestinal epithelial cells of experimental obesity-related SAP. When the expression of CLDN11 in intestinal epithelial cells of experimental obesity-related SAP was increased exogenously, intestinal epithelial permeability and pancreatic inflammation were relieved. Overexpression of CLDN11 reduced the paracellular permeability of Caco-2 monolayer cells, while knockdown of CLDN11 increased it. IGF2BP3 bound to and regulated the stability of CLDN11 mRNA. TNF-α treatment downregulated IGF2BP3 and CLDN11 in vitro. Anti-TNFα therapy reduced intestinal permeability, alleviated pancreatitis, and improved the expression of IGF2BP3 and CLDN11 in intestinal epithelial cells in experimental obesity-related SAP.

Conclusion: CLDN11 regulates intestinal permeability in obesity-related SAP. Mechanistically, an increase in TNF-α impaired the stability of IGF2BP3-dependent CLDN11 mRNA in obesity-related SAP.

Background: Long COVID or Post-acute sequelae of COVID-19 is an emerging syndrome, recognized in COVID-19 patients who suffer from mild to severe illness and do not recover completely. Most studies define Long COVID, through symptoms like fatigue, brain fog, joint pain, and headache prevailing four or more weeks post-initial infection. Global variations in Long COVID presentation and symptoms make it challenging to standardize features of Long COVID. Long COVID appears to be accompanied by an auto-immune multi-faceted syndrome where the virus or viral antigen persistence causes continuous stimulation of the immune response, resulting in multi-organ immune dysregulation.

Main text: This review is focused on understanding the risk factors of Long COVID with a special emphasis on the dysregulation of the gut-brain axis. Two proposed mechanisms are discussed here. The first mechanism is related to the dysfunction of angiotensin-converting enzyme 2 receptor due to Severe Acute Respiratory Syndrome Corona Virus 2 infection, leading to impaired mTOR pathway activation, reduced AMP secretion, and causing dysbiotic changes in the gut. Secondly, gut-brain axis dysregulation accompanied by decreased production of short-chain fatty acids, impaired enteroendocrine cell function, and increased leakiness of the gut, which favors translocation of pathogens or lipopolysaccharide in circulation causing the release of pro-inflammatory cytokines. The altered Hypothalamic-Pituitary-Adrenal axis is accompanied by the reduced level of neurotransmitter, and decreased stimulation of the vagus nerve, which may cause neuroinflammation and dysregulation of serum cortisol levels. The dysbiotic microbiome in Long COVID patients is characterized by a decrease in beneficial short chain fatty acid-producing bacteria (Faecalibacterium, Ruminococcus, Dorea, and Bifidobacterium) and an increase in opportunistic bacteria (Corynebacterium, Streptococcus, Enterococcus). This dysbiosis is transient and may be impacted by interventions including probiotics, and dietary supplements.

Conclusions: Further studies are required to understand the geographic variation, racial and ethnic differences in phenotypes of Long COVID, the influence of viral strains on existing and emerging phenotypes, to explore long-term effects of gut dysbiosis, and gut-brain axis dysregulation, as well as the potential role of diet and probiotics in alleviating those symptoms.

Background: Acute rejection (AR) is one of the significant factors contributing to poor prognosis in patients following kidney transplantation. Neutrophils are the main cause of early host-induced tissue injury. This paper intends to investigate the possible mechanisms of neutrophil involvement in acute rejection in renal transplantation.

Methods: Samples were analyzed for their relationship with immune cells using CIBERSORT. WGCNA was used to identify modules with high relevance to neutrophils and hub genes in the modules were extracted. The effect on neutrophil function after blocking formyl peptide receptor 1 (FPR1) was tested in vitro experiments. The effects of blocking FPR1 on neutrophil function as well as acute rejection were tested in vivo after constructing a mouse kidney transplant model.

Results: The proportion of neutrophils was higher in the AR group than in the non-rejection group, and FPR1 was identified as an important gene in the regulation of acute rejection in kidney transplantation by neutrophils. At the cellular level, blocking FPR1 inhibited the activation of the ERK1/2 pathway, decreased ferrous ion content, affected the expression of iron metabolism-related proteins, and suppressed the formation of NETs. In the acute rejection model of renal transplantation, blockade of FPR1 decreased graft neutrophil infiltration and NETs content. Meanwhile, blocking FPR1 attenuated graft injury during acute rejection.

Conclusion: This study found that FPR1 might be an important molecule involved in neutrophils during acute rejection of kidney transplantation, explored the relationship between kidney transplantation and neutrophils, and provided potential treatment methods for clinical practice.

Hepatocellular carcinoma is one of the most common malignant tumors, and radiotherapy plays a pivotal role in its therapeutic regimen. However, radiotherapy resistance is the main cause of therapeutic failure in patients. Our previous study revealed that Adiponectin Receptor 1 (AdipoR1) is involved in regulating radiation resistance in liver cancer patients treated with stereotactic body radiotherapy. To explore the mechanism, we performed high-throughput transcriptome sequencing of hepatocellular carcinoma cells with stable knockdown of AdipoR1. KEGG enrichment analysis indicated that the cell cycle and ubiquitination degradation pathways may be involved in the regulation of radiation resistance by AdipoR1.The knockdown of AdipoR1 can attenuate the radiation-induced G2/M phase arrest through cyclin B1.By the ubiquitination IP assay and a rescue experiment, we confirmed that CCNB1IP1 regulated the ubiquitination and degradation of cyclin B1. Combined with information from transcription factor database and AdipoR1 transcriptome sequencing, these results showed that estrogen receptor 1 (ESR1) may be a transcription factor of CCNB1IP1. We found that AdipoR1 promoted the translocation of ESR1 from the cytoplasm to the nucleus, and ESR1 inhibited the transcription of CCNB1IP1.Therefore, we propose that AdipoR1 regulates the ubiquitination level, cell cycle progression, and radiation resistance of HCC cells through the "AdipoR1 /ESR1/CCNB1IP1/cyclin B1" axis. This study will promote the development of novel targeted radiosensitizing drugs.

Background: Uremia (UR) is caused by increased UR-related toxins in the bloodstream. We explored the mechanism of enterogenous toxin methylmalonic acid (MMA) in calcium-phosphorus metabolic disorder in UR rats via the Wnt/β-catenin pathway.

Methods: The UR rat model was established by 5/6 nephrectomy. The fecal bacteria of UR rats were transplanted into Sham rats. Sham rats were injected with exogenous MMA or Salinomycin (SAL). Pathological changes in renal/colon tissues were analyzed. MMA concentration, levels of renal function indicators, serum inflammatory factors, Ca²⁺/P³⁺, and parathyroid hormone, intestinal flora structure, fecal metabolic profile, intestinal permeability, and glomerular filtration rate (GFR) were assessed. Additionally, rat glomerular podocytes were cultured, with cell viability and apoptosis measured.

Results: Intestinal flora richness and diversity in UR rats were decreased, along with unbalanced flora structure. Among the screened 133 secondary differential metabolites, the MMA concentration rose, showing the most significant difference. UR rat fecal transplantation caused elevated MMA concentration in the serum and renal tissues of Sham rats. The intestinal flora metabolite MMA or exogenous MMA promoted intestinal barrier impairment, increased intestinal permeability, induced glomerular podocyte loss, and reduced GFR, causing calcium-phosphorus metabolic disorder. The intestinal flora metabolite MMA or exogenous MMA induced inflammatory responses and facilitated glomerular podocyte apoptosis by activating the Wnt/β-catenin pathway, which could be counteracted by repressing the Wnt/β-catenin pathway.

Conclusions: Enterogenous toxin MMA impelled intestinal barrier impairment in UR rats, enhanced intestinal permeability, and activated the Wnt/β-catenin pathway to induce glomerular podocyte loss and reduce GFR, thus aggravating calcium-phosphorus metabolic disorder.

Background: Double-strand breaks (DSBs) are primarily repaired through non-homologous end joining (NHEJ) and homologous recombination (HR). Given that DSBs are highly cytotoxic, PARP inhibitors (PARPi), a prominent class of anticancer drugs, are designed to target tumors with HR deficiency (HRD), such as those harboring BRCA mutations. However, many tumor cells acquire resistance to PARPi, often by restoring HR in HRD cells through the inactivation of NHEJ. Therefore, identifying novel regulators of NHEJ could provide valuable insights into the mechanisms underlying PARPi resistance.

Methods: Cellular DSBs were assessed using neutral comet assays and phospho-H2AX immunoblotting. Fluorescence-based reporter assays quantified repair via NHEJ or HR. The recruitment of proteins that promote NHEJ and HR to DSBs was analyzed using immunostaining, live-cell imaging following laser-induced microirradiation, and FokI-inducible single DSB generation. Loss-of-function experiments were performed in multiple human cancer cell lines using siRNA-mediated knockdown or CRISPR-Cas9 gene knockout. Cell viability assays were conducted to evaluate resistance to PARP inhibitors. Additionally, bioinformatic analyses of public databases were performed to investigate the association between TLK expression and BRCA1 status.

Results: We demonstrate that human tousled-like kinase (TLK) orthologs are essential for NHEJ-mediated repair of DSBs and for PARPi sensitivity in cells with BRCA1 mutation. TLK1 and TLK2 exhibit redundant roles in promoting NHEJ, and their deficiency results in a significant accumulation of DSBs. TLKs are required for the proper localization of 53BP1, a key factor in promoting the NHEJ pathway. Consequently, TLK deficiency induces PARPi resistance in triple-negative breast cancer (TNBC) and ovarian cancer (OVCA) cell lines with BRCA1 deficiency, as TLK deficiency in BRCA1-depleted cells, impairs 53BP1 recruitment to DSBs and reduces NHEJ efficiency, while restoring HR.

Conclusions: We have identified TLK proteins as novel regulators of NHEJ repair and PARPi sensitivity in BRCA1-depleted cells, suggesting that TLK repression may represent a previously unrecognized mechanism by which BRCA1 mutant cancers acquire PARPi resistance.

Background: Inflammation is a critical protective response in the body, essential for combating infections and healing injuries. However, chronic inflammation can be harmful and significantly contribute to the development and progression of chronic diseases, with macrophage-mediated responses being central to these processes. This study presents "SBR-Pel," a new therapeutic blend of Shinbaro tab (SBR), a traditional herbal formula, and pelubiprofen (Pel), a non-steroidal anti-inflammatory drug, and investigated their combined anti-inflammatory effects to create a treatment that both improves efficacy and reduces side effects.

Methods: To this end, we performed both in vitro and in vivo analyses, utilizing a mouse model of inflammation. Viability and cytotoxicity assays, immunohistochemistry, enzyme-linked immunosorbent assays, real-time polymerase chain reaction assays, nociception assays, writhing tests, and blood biochemical analyses were performed.

Results: In vitro, SBR-Pel synergistically reduced the production of nitric oxide and reactive oxygen species and the expression of pro-inflammatory cytokines. SBR-Pel also significantly attenuated paw edema in vivo in a Complete Freund's adjuvant-induced inflammation model in adult mice. Furthermore, immunohistochemical analyses showed that treatment with SBR-Pel reduced both the infiltration of CD68⁺ macrophages and the expression of pro-inflammatory cytokines in inflamed tissues. Additionally, compared with individual treatment alone, SBR-Pel enhanced the expression of anti-inflammatory cytokines CD206, TGF-β, and IL-10, indicating a synergistic effect. Our research demonstrates that SBR-Pel effectively diminishes inflammatory pain by reducing macrophage infiltration and pro-inflammatory cytokine secretion. Additionally, while 1.5 mg/kg of Pel alone increases levels of liver and kidney toxicity markers, such as aspartate aminotransferase, alanine aminotransferase, and creatinine, combining it with SBR at a reduced dosage of 0.5 mg/kg maintains these markers at normal levels.

Conclusions: This combined effect highlights SBR-Pel's potential as an effective treatment for inflammatory diseases driven by heightened macrophage activity, while also minimizing side effects by reducing the Pel dosage.

Severe sepsis is cognate with life threatening multi-organ dysfunction. There is a disturbance in endocrine functions with alterations in several hormonal pathways. It has frequently been linked with dysfunction in the hypothalamic pituitary-adrenal axis (HPA). Increased cortisol or cortisolemia is evident throughout the acute phase, along with changes in the hypothalamic pituitary thyroid (HPT) axis, growth hormone-IGF-1 axis, insulin-glucose axis, leptin, catecholamines, renin angiotensin aldosterone axis, ghrelin, glucagon, hypothalamic pituitary gonadal (HGA) axis, and fibroblast growth factor-21. These changes and metabolic alterations constitute the overall response to infection in sepsis. Further research is essential to look into the hormonal changes that occur during sepsis, not only to understand their potential relevance in therapy but also because they may serve as prognostic indicators.