Biochemistry and Cell Biology最新文献

Increasing evidence has indicated that transforming growth factor beta 1 (TGFB1) is engaged in tumorigenesis and progression. Nevertheless, the underlying role and mechanism of TGFB1 in stomach adenocarcinoma (STAD) chemotherapy remains unknown. TGFB1 levels in various types of cancers were first analyzed by the TCGA database. Next, the degree of cellular damage, apoptosis and autophagy were detected by lactate dehydrogenase kit, flow cytometry, autophagy fluorescence analysis, and Western blot assay. The gene highly correlated with TGFB1 expression was searched by LinkedOmics and KEGG. We disclosed TGFB1 was enhanced in STAD. Besides, TGFB1 was remarkably higher in STAD patients in oxaliplatin (OXA) chemoresistant group than sensitive group. Additionally, the half maximal inhibitory concentration (IC50) values of OXA-resistant cells were markedly elevated. Furthermore, TGFB1 reduced AGS-OXA and HGC27-OXA cell injury, inhibited apoptosis and induced cellular autophagy. The addition of the autophagy inhibitor 3-methyladenine hindered this phenomenon. Further studies revealed that muscle RAS oncogene homolog (MRAS) is a downstream target gene of TGFB1. TGFB1 accelerated MRAS level in OXA cells, and MRAS knockdown reversed the effects of TGFB1 on OXA cell function. TGFB1 induces cellular autophagy via MRAS, thereby promoting STAD OXA resistance.

Osteoarthritis (OA) is a degenerative joint disorder characterized by chondrocyte dysfunction and progressive cartilage destruction, with ferroptosis emerging as a key contributor to disease pathogenesis. This study investigates the therapeutic potential of Aucubin, a natural iridoid glycoside, in OA treatment through modulation of the Keap1/NRF2 pathway and ferroptosis inhibition. Using an in vitro OA model established by IL-1β treatment of immortalized human chondrocytes, we demonstrate that Aucubin significantly improves cell viability, colony formation capacity, and migratory potential while promoting cell cycle progression. Aucubin also reduces ferroptosis-associated oxidative damage by decreasing MDA, GSSG, Fe²⁺, and ROS levels while increasing GSH content. Ferrostatin-1(Fer-1) ferroptosis inhibitor further supports this result. Molecularly, qPCR and Western blot analyses reveal that Aucubin upregulates NRF2 expression while suppressing Keap1 and modulating the levels of ferroptotic markers. These findings are further corroborated in a surgically induced OA rat model, where Aucubin administration attenuates cartilage degradation, restores Keap1/NRF2 expression, and normalizes ferroptosis-related protein expression. Our preliminary findings suggest that aucubin exerts its chondroprotective effects by inhibiting ferroptosis, at least partially through activation of the Keap1/NRF2 pathway, and may represent a potential therapeutic agent for osteoarthritis.

Our purpose was to explore the role and regulatory mechanisms of kringle containing transmembrane protein 2 (KREMEN2) in the development and progression of non-small cell lung cancer (NSCLC). KREMEN2 expression levels were higher in NSCLC tissues and cells than in normal tissues and cells. Down-regulation of KREMEN2 by siRNAs suppressed proliferation, migration, invasion, and epithelial mesenchymal transition (EMT), and accelerated apoptosis in NSCLC cells. Furthermore, KREMEN2 knockdown repressed PI3K/AKT/mTOR signaling, and KREMEN2 overexpression activated PI3K/AKT/mTOR signaling. Additionally, PI3K activator (740Y-P) treatment or PI3K overexpression reversed the inhibitory function of KREMEN2 knockdown on proliferation and metastasis, as well as the strengthened function of KREMEN2 knockdown on the apoptosis of NSCLC cells. Moreover, KREMEN2 suppressed tumor growth by inhibiting PI3K/AKT/mTOR signaling in mice. The pharmacologic inhibitor of KREMEN2 (genistein) was also demonstrated to suppress tumor growth in mice. In conclusion, our study suggested that KREMEN2 knockdown could repress the proliferative, migratory, and invasive capacity, as well as EMT, while accelerating the apoptotic capacity of NSCLC cells by inhibiting PI3K/AKT/mTOR signaling.

Myelination is essential for the proper conduction of impulses across neuronal networks. Mature, myelinating glia differentiate from progenitor cells through distinct stages that correspond to oligodendrocyte-specific gene expression markers. Reverse transcription quantiatative PCR (RT-qPCR) is a common technique used to quantify gene expression across cell development; however, a lack of standardization and transparency in methodology may lead to irreproducible data. Here, we have designed and validated RT-qPCR assays for oligodendrocyte genes and reference genes in the developing C57BL6/J mouse brain that align with the MIQE guidelines, including quality controls for primer specificity, temperature dependence, and efficiency. A panel of eight commonly used reference genes was ranked using a series of reference gene stability methods that consistently identified Gapdh, Sdha, Hmbs, Hprt1, and Pgk1 as the top candidates for normalization across brain regions. In the cerebrum, myelin genes peaked in expression at postnatal day 21, which corresponds to the peak of developmental myelination. The gene expression patterns from the brain homogenate were in agreement with previously reported RNA-seq and microarray profiles from oligodendrocyte lineage cells. The validated RT-qPCR assays begin to build a framework for future investigation into the molecular mechanisms that regulate myelination in mouse models of brain development, aging, and disease.

The field of RNA research has provided profound insights into the basic mechanisms modulating the function and adaption of biological systems. RNA has also been at the center stage in the development of transformative biotechnological and medical applications, perhaps most notably was the advent of mRNA vaccines that were critical in helping humanity through the Covid-19 pandemic. Unbeknownst to many, Canada boasts a diverse community of RNA scientists, spanning multiple disciplines and locations, whose cutting-edge research has established a rich track record of contributions across various aspects of RNA science over many decades. Through this position paper, we seek to highlight key contributions made by Canadian investigators to the RNA field, via both thematic and historical viewpoints. We also discuss initiatives underway to organize and enhance the impact of the Canadian RNA research community, particularly focusing on the creation of the not-for-profit organization RNA Canada ARN. Considering the strategic importance of RNA research in biology and medicine, and its considerable potential to help address major challenges facing humanity, sustained support of this sector will be critical to help Canadian scientists play key roles in the ongoing RNA revolution and the many benefits this could bring about to Canada.

Over the past four decades, prion diseases have received considerable research attention owing to their potential to be transmitted within and across species as well as their consequences for human and animal health. The unprecedented nature of prions has led to the discovery of a paradigm of templated protein misfolding that underlies a diverse range of both disease-related and normal biological processes. Indeed, the "prion-like" misfolding and propagation of protein aggregates is now recognized as a common underlying disease mechanism in human neurodegenerative disorders such as Alzheimer's and Parkinson's disease, and the prion principle has led to the development of novel diagnostic and therapeutic strategies for these illnesses. Despite these advances, research into the fundamental biology of prion diseases has declined, likely due to their rarity and the absence of an acute human health crisis. Given the past translational influence, continued research on the etiology, pathogenesis, and transmission of prion disease should remain a priority. In this review, we highlight several important "unsolved mysteries" in the prion disease research field and how solving them may be crucial for the development of effective therapeutics, preventing future outbreaks of prion disease, and understanding the pathobiology of more common human neurodegenerative disorders.

Atherosclerosis (AS) is an inflammatory arterial disorder that occurs due to the deposition of the excessive lipoprotein under the artery intima, mainly including low-density lipoprotein and other apolipoprotein B-containing lipoproteins. G protein-coupled receptors (GPCRs) play a crucial role in transmitting signals in physiological and pathophysiological conditions. GPCRs recognize inflammatory mediators, thereby serving as important players during chronic inflammatory processes. It has been demonstrated that free fatty acids can function as ligands for various GPCRs, such as free fatty acid receptor (FFAR)1/GPR40, FFAR2/GPR43, FFAR3/GPR41, FFAR4/GPR120, and the lipid metabolite binding glucose-dependent insulinotropic receptor (GPR119). This review discusses GPR43 and its ligands in the pathogenesis of AS, especially focusing on its distinct role in regulating chronic vascular inflammation, inhibiting oxidative stress, ameliorating endothelial dysfunction and improving dyslipidemia. It is hoped that this review may provide guidance for further studies aimed at GPR43 as a promising target for drug development in the prevention and therapy of AS.

Interstitial cystitis (IC), defined as a painful bladder syndrome (PBS), is a chronic condition that manifests itself as a suprapubic pain associated with an enhancing of frequency/urgency of urination, and for which there is no cure. Here, we present a retrospective pilot study on women affected from IC/PBS and treated with bovine lactoferrin (bLf). A total of 31 women, affected (20) or unaffected (11) from hereditary thrombophilia (HT), presented the median of 6 episodes of IC/PBS during the 6 months before the study. Treatment consisted of 17 weeks of orally administered Valpalf^® capsules, containing bLf plus sodium bicarbonate and citrate. Out of 31 patients, only 3 women had one episode of IC/PBS during the follow-up period, while no episode was observed in 28 women. In the HT group, a significant decrease in both serum IL-6 and D-dimers was found after Valpalf^® treatment. Moreover, in Valpalf^®-treated women, cystoscopy revealed a global improvement in the appearance of the bladder, especially in term of inflammation/irritation and presence of Hunner ulcers. Even if our results must be corroborated by randomized double-blinded controlled trials on a larger number of patients, our observations indicate that bLf treatment is efficient in relieving IC/PBS symptoms, without side effects.

We previously found that the position of matrix attachment regions (MARs) within the vector significantly affects its ability to enhance transgenic expression in the recombinant protein production. This study aims to systematically investigate the position-dependent impacts of MAR on transgene expression. We observed a significant increase in enhanced green fluorescent protein (eGFP) expression levels in stably transfected CHO-K1 cells with either MAR 1-68 or MAR X-29 when MARs located upstream of the promoter. This increase was especially evident with MAR flanked the expression cassette. Concurrently, a substantial increase was observed in the percentage of eGFP-expressing cells, with 97.8% and 96.0% in MAR-containing constructs versus 73.7% in MAR-absent constructs. Further analysis of erythropoietin (EPO) expression revealed that constructs with flanking MARs induced the highest EPO productivity. Bioinformatics analysis revealed that certain specific transcription factors are important in modulating the transcription process. In conclusion, vectors harboring both MARs around the expression cassette constitute an optimal construct for enhanced recombinant protein production in CHO-K1 cells. This insight underscores the importance of strategic MAR incorporation in vector design for optimized recombinant protein expression.

Group I and II introns are large catalytic RNAs (ribozymes) that are frequently encountered in fungal mitochondrial genomes. The discovery of respiratory mutants linked to intron splicing defects demonstrated that for the efficient removal of organellar introns there appears to be a requirement of protein splicing factors. These splicing factors can be intron-encoded proteins with maturase activities that usually promote the splicing of the introns that encode them (cis-acting) and/or nuclear-encoded factors that can promote the splicing of a range of different introns (trans-acting). Compared to plants organellar introns, fungal mitochondrial intron splicing is still poorly explored, especially in terms of the synergy of nuclear factors with intron-encoded maturases that has direct impact on splicing through their association with intron RNA. In addition, nuclear-encoded accessory factors might drive the splicing impetus through translational activation, mitoribosome assembly, and phosphorylation-mediated RNA turnover. This review explores protein-assisted splicing of introns by nuclear and mitochondrial-encoded maturases as a means of mitonuclear interplay that could respond to environmental and developmental factors promoting phenotypic adaptation and potentially speciation. It also highlights key evolutionary events that have led to changes in structure and ATP-dependence to accommodate the dual functionality of nuclear and organellar splicing factors.