Cellular and Molecular Life Sciences最新文献

Background: Achieving an in-range glycated haemoglobin (HbA1c) is essential for managing diabetes mellitus (DM). However, this parameter provides an estimate of long-term blood glucose control rather than daily glycaemic variations. Glycaemic variability can be more predictive than HbA1c in terms of identifying those at risk for diabetes complications, including risk of severe respiratory virus infections and is usually measured via a continuous glucose monitor (CGM). For individuals for whom a CGM is not available, serum 1,5 anhydroglucitol (1,5-AG) level has shown potential as an alternative method for monitoring glycaemic variability. Despite this, at present 1,5-AG is not routinely used in the clinical assessment of DM. Here, we aim to determine whether assessing 1,5-AG, in addition to HbA1c, is of any potential clinical utility to the management of DM for patients.

Methods: Using machine learning and data derived from 78 patients with type I DM (for whom CGM data is available) we show that the combination of 1,5-AG and HbA1c improves the prediction of a patient's glycemia risk index (GRI) compared to HbA1c alone.

Results: The GRI is an essential tool in the management of DM as it reflects both clinical priorities and patient centred outcomes. The inclusion of 1,5-AG in this prediction was particularly important for individuals who had very high or very low GRI. Furthermore, in the context of glycaemic variability and susceptibility to severe respiratory virus infections, we show that reduced 1,5-AG in the plasma is associated with reduced ex vivo CD4 + T cell cytokine responses to influenza virus in individuals with a matched HbA1c.

Conclusions: Taken together, these data argue for an increased monitoring of 1,5-AG in the clinic for individuals without a CGM to provide additional insights for diabetes management.

Accurately imaging adult cardiac tissue in its native state is essential for regenerative medicine and understanding heart disease. Current fluorescence methods encounter challenges with tissue fixation. Here, we introduce the 3D-NaissI (3D-Native Tissue Imaging) method, which enables rapid, cost-effective imaging of fresh cardiac tissue samples in their closest native state, and has been extended to other tissues. We validated the efficacy of 3D-NaissI in preserving cardiac tissue integrity using small biopsies under hypothermic conditions in phosphate-buffered saline, offering unparalleled resolution in confocal microscopy for imaging fluorescent small molecules and antibodies. Compared to conventional histology, 3D-NaissI preserves cardiac tissue architecture and native protein epitopes, facilitating the use of a wide range of commercial antibodies without unmasking strategies. We successfully identified specific cardiac protein expression patterns in cardiomyocytes (CMs) from rodents and humans, including for the first time ACE2 localization in the lateral membrane/T-Tubules and SGTL2 in the sarcoplasmic reticulum. These findings shed light on COVID-19-related cardiac complications and suggest novel explanations for therapeutic benefits of iSGLT2 in HFpEF patients. Additionally, we challenge the notion of "connexin-43 lateralization" in heart pathology, suggesting it may be an artifact of cardiac fixation, as 3D-NaissI clearly revealed native connexin-43 expression at the lateral membrane of healthy CMs. We also discovered previously undocumented periodic ring-like 3D structures formed by pericytes that cover the lateral surfaces of CMs. These structures, positive for laminin-2, delineate a specific spatial architecture of laminin-2 receptors on the CM surface, underscoring the pivotal role of pericytes in CM function. Lastly, 3D-NaissI facilitates the mapping of native human protein expression in fresh cardiac autopsies, offering insights into both pathological and non-pathological contexts. Therefore, 3D-NaissI provides unparalleled insights into native cardiac tissue biology and holds the promise of advancing our understanding of physiology and pathophysiology, surpassing standard histology in both resolution and accuracy.

DnaJ heat shock protein family member C5 beta (DNAJC5B), also known as cysteine-string protein beta, exhibits a prominent expression in testicular tissue and plays an important role in acrosomal exocytosis in vitro. Nevertheless, the precise role and underlying mechanism of DNAJC5B in spermatogenesis and male fertility remain poorly understood. The meta-analysis of RNA-sequencing datasets from porcine and murine testes reveals that Dnajc5b could be a pivotal factor in spermatogenesis. This study illustrates that male fertility declines with an increased ratio of abnormal spermatozoa in germ-cell knockout Dnajc5b mice. DNAJC5B has been identified as a mitochondrial protein with high expression in spermatids. The absence of DNAJC5B induces a cascade of mitochondrial damages, including oxidative stress, mitochondrial stress in the testes, and lower mitochondrial membrane potential of spermatozoa. In vivo and in vitro evidence demonstrates that DNAJC5B mitigates excessive cellular autophagy and mitophagy via DNAJ domain under environmental stress conditions, such as starvation or exposure to mitochondrial uncouplers FCCP and CCCP. This study highlights the important role of DNAJC5B in safeguarding male fertility by preserving mitochondrial function and regulating autophagy during spermiogenesis.

Neurodegenerative diseases (NDs) are a group of neurological disorders characterized by the progressive loss of selected neurons. Alzheimer's disease (AD) and Parkinson's disease (PD) are the most common NDs. Pathologically, NDs are characterized by progressive failure of neural interactions and aberrant protein fibril aggregation and deposition, which lead to neuron loss and cognitive and behavioral impairments. Great efforts have been made to delineate the underlying mechanism of NDs. However, the very first trigger of these disorders and the state of the illness are still vague. Existing therapeutic strategies can relieve symptoms but cannot cure these diseases. The human immune system is a complex and intricate network comprising various components that work together to protect the body against pathogens and maintain overall health. They can be broadly divided into two main types: innate immunity, the first line of defense against pathogens, which acts nonspecifically, and adaptive immunity, which follows a defense process that acts more specifically and is targeted. The significance of brain immunity in maintaining the homeostatic environment of the brain, and its direct implications in NDs, has increasingly come into focus. Some components of the immune system have beneficial regulatory effects, whereas others may have detrimental effects on neurons. The intricate interplay and underlying mechanisms remain an area of active research. This review focuses on the effects of both innate and adaptive immunity on AD and PD, offering a comprehensive understanding of the initiation and regulation of brain immunity, as well as the interplay between innate and adaptive immunity in influencing the progression of NDs.

Air pollution is a global environmental health hazard associated with elevated cardiovascular morbidity and mortality. Emerging evidence suggests that exposure to various air pollutants, specifically particulate matter (PM), ultrafine particulate matter (UFPM), and diesel exhaust particles, may exacerbate myocardial ischemia-reperfusion (I/R) injury. PM exposure can directly impair cardiomyocyte survival under ischemic conditions by inducing inflammation, oxidative stress, apoptosis, and dysregulation of non-coding RNAs. Moreover, exposure to PM, UFPM, and diesel exhaust particles can increase infarct size, worsen cardiac function, and exacerbate inflammation, oxidative stress and mitochondrial dysfunction in I/R injury. Evidence indicates that the severity of these effects depends on the specific pollutant, exposure duration, and animal model used. In clinical studies, long-term exposure to air pollution, or even high-dose exposure over a short duration, especially to PM2.5 and PM10, was found to be a risk factor for myocardial infarction. Several interventions targeting the pathways involved in air pollution-induced cardiac I/R injury have shown benefits in preclinical studies, including Cyclosporin A, vanillic acid, and β1-adrenoreceptor antagonists, TRPV1 antagonists, GSK-3β inhibitor, and indomethacin. This review comprehensively summarizes the detrimental impacts of air pollutants on cardiac I/R injury from in vitro and in vivo reports to preclinical investigations, highlighting the complex interplay between pollutant type, exposure duration, and cardiovascular outcomes. The detrimental impact of air pollution through multiple pathways, including oxidative stress, inflammation, mitochondrial dysfunction, and apoptosis on cardiac I/R injury is also discussed, emphasizing the urgence for targeted interventions and public health strategies to mitigate the cardiovascular consequences of pollutant exposure.

Ionotropic glutamate receptors (iGluRs) mediate fast excitatory neurotransmission in the nervous system. In addition to NMDA receptor co-agonists, D-serine is a ligand for glutamate delta receptors (GluDs) and interacts with the ligand-binding domain with low affinity. However, D-serine binding does not lead to typical ion channel currents in GluD1 or GluD2 but may contribute to synaptic plasticity. In the developing brain, D-serine binding to GluD2 facilitates long-term depression at parallel fiber-Purkinje cell synapses. However, the influence of D-serine on GluD1's interaction with its amino terminal domain synaptogenic ligand Cbln1 and its subsequent impact on synaptic function and behavior remains unexplored. Here, we found that D-serine inhibited the interaction between Cbln1 and GluD1 in an in vitro cell-binding assay. This effect was concentration-dependent, with an IC₅₀ value of ~ 300 µM. Furthermore, in ex vivo central amygdala (CeA) slices application of recombinant Cbln1 (rCbln1), consistent with its synaptogenic property, produced a robust increase in excitatory neurotransmission and GluD1 expression. This effect of rCbln1 was partially blocked by pre-treatment with D-serine. Finally, in behavioral experiments, we observed that the pro-nociceptive effect of intra-CeA injection of rCbln1 was inhibited by pre-treatment with D-serine. In addition, the antinociceptive effect of intra-CeA rCbln1 injection in an inflammatory pain model was blocked by D-serine. Overall, these results demonstrated that D-serine binding to GluD1 reduces its interaction with Cbln1, which may be relevant to synaptic plasticity and behavior.

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a chronic condition encompassing metabolic dysfunction-associated steatotic liver (MASL) and metabolic dysfunction-associated steatohepatitis (MASH), which can progress to fibrosis, cirrhosis, or hepatocellular carcinoma (HCC). The heterogeneous and complex nature of MASLD complicates optimal drug development. Ebastine, an antihistamine, exhibits antitumor activity in various types of cancer. However, its effects on MASH remain unexplored. In the present study, we identified ebastine as a potential treatment for MASH. Our results indicated that ebastine acts as a novel MKRN1 inhibitor by promoting MKRN1 destabilization through self-ubiquitination, leading to AMP-activated protein kinase (AMPK) activation. Ebastine appeared to bind to the C-terminal domain of MKRN1, particularly at residues R298 and K360. Notably, Mkrn1 knockout (KO) mice demonstrated resistance to MASH, including obesity, steatosis, inflammation, and fibrosis under high-fat-high-fructose diet (HFHFD) conditions. Additionally, liver-specific Mkrn1 knockdown using AAV8 alleviated MASH symptoms in HFHFD-fed mice, implicating MKRN1 as a potential therapeutic target. Consistent with these findings, treatment with ebastine significantly reduced the risk of MASH in HFHFD-fed mice, with a decrease in MKRN1 expression and an increase in AMPK activity. Our study suggests that ebastine binds to MKRN1, promoting its destabilization and subsequent degradation by stimulating its ubiquitination. This enhances AMPK stability and activity, suppressing lipid accumulation, inflammation, and fibrosis. Moreover, the knockout of Mkrn1 mice decreased the risk of MASH, suggesting that ebastine could be a promising therapeutic agent for the treatment of MASH.

Pancreatic β-cell damage is a critical pathological mechanism in the progression of obese type 2 diabetes mellitus (T2DM). However, the exact underlying mechanism remains unclear. We established an obese T2DM mouse model via high-fat diet feeding. The protein expression profiles of pancreatic tissues from normal and obese T2DM mice were analyzed, revealing that nuclear factor of activated T cells 5 (NFAT5) and ferroptosis are potential mediators and mechanisms of β-cell damage in obese T2DM mice. In vitro, high glucose and palmitate treatment resulted in increased NFAT5 expression and nuclear translocation in MIN6 cells. Inhibition of NFAT5 expression by shRNA significantly reduced ferroptosis and improved the reduction in insulin secretion in palmitic acid and high glucose (PG)-treated MIN6 cells. Luciferase reporter and chromatin immunoprecipitation (ChIP) assays confirmed the ability of NFAT5 to bind to the peroxiredoxin 2 (PRDX2) promoter, leading to the downregulation of PRDX2 transcription. Subsequent rescue experiments confirmed that NFAT5 is involved in PG-induced ferroptosis in MIN6 cells by inhibiting the expression of PRDX2. Finally, we demonstrated that the use of the AAV8-RIP2-miR30-shNFAT5 vector to specifically inhibit the expression of NFAT5 in β-cells significantly diminishes ferroptosis in obese T2DM mice, thereby increasing insulin secretion and improving abnormal glucose tolerance. These findings collectively highlight the therapeutic potential of targeting NFAT5 in β cells to counteract obesity-induced T2DM.

Non-small cell lung cancer (NSCLC) has emerged as one of the most prevalent malignancies worldwide. N6-methyladenosine (m⁶A) methylation, a pervasive epigenetic modification in long noncoding RNAs (lncRNAs), plays a crucial role in NSCLC progression. Here, we report that m⁶A modification and the expression of the lncRNA stem cell inhibitory RNA transcript (SCIRT) was significantly upregulated in NSCLC tissues and cells. Functional analysis revealed that SCIRT enhanced NSCLC cell proliferation, migration, invasion, and epithelial‒mesenchymal transition. The m⁶A modification of SCIRT can be installed by METTL3, which enhanced the stability of this lncRNA. Notably, SCIRT overexpression in response to DNA double-strand breaks (DSBs) sensitized cells to camptothecin (CPT) and impairs DNA homologous recombination repair. SCIRT directly interacted with SFPQ in vitro and was primarily localized in the nucleus. Furthermore, ectopic SCIRT expression upregulated SFPQ and activated the PI3K/Akt pathway following CPT treatment, suggesting an unexpected role of SCIRT in facilitating SFPQ-mediated DSB repair. In brief, our findings highlight the oncogenic role of SCIRT in NSCLC by binding SFPQ and activating PI3K/Akt signaling, presenting a promising therapeutic target for personalized NSCLC treatment.

Collagen, a major component of the extracellular matrix, is crucial for the structural integrity of the Caenorhabditis elegans cuticle. While several proteins involved in collagen biosynthesis have been identified, the complete regulatory network remains unclear. This study investigates the role of CALU-1, an ER-resident calcium-binding protein, in cuticle collagen formation and maintenance. We employed genetic analyses, including the generation of single and double mutants, scanning electron microscopy, and transcriptome profiling to characterize CALU-1 function. Our results demonstrate that CALU-1 is essential for proper cuticle structure, including annuli, furrows, and alae formation. Synthetic lethality was observed between calu-1 and dpy-18 (encoding a prolyl 4-hydroxylase subunit) mutations, while double mutants of calu-1 with peptidyl-prolyl cis-trans isomerase (PPIase) genes exhibited exacerbated phenotypes. CALU-1 deficiency led to altered collagen stability, increased cuticle permeability, and differential expression of stress response genes similar to collagen mutants. We conclude that CALU-1 plays a critical role in regulating collagen biosynthesis, possibly by modulating the ER environment to optimize the function of collagen-modifying enzymes. These findings provide new insights into the complex regulation of extracellular matrix formation in C. elegans, with potential implications for understanding related processes in other organisms.