Current Issues in Molecular Biology最新文献

Background: Coronary heart disease (CHD) remains a leading cause of morbidity and mortality worldwide. Mitochondria-associated endoplasmic reticulum membranes (MAMs) have recently emerged as critical mediators in cardiovascular pathophysiology; however, their specific contributions to CHD pathogenesis remain largely unexplored.

Objective: This study aimed to identify and validate MAM-related biomarkers in CHD through integrated analysis of transcriptomic sequencing data and Mendelian randomization, and to elucidate their underlying mechanisms.

Methods: We analyzed two gene expression microarray datasets (GSE113079 and GSE42148) and one genome-wide association study (GWAS) dataset (ukb-d-I9_CHD) to identify differentially expressed genes (DEGs) associated with CHD. MAM-related DEGs were filtered using weighted gene co-expression network analysis (WGCNA). Functional enrichment analysis, Mendelian randomization, and machine learning algorithms were employed to identify biomarkers with direct causal relationships to CHD. A diagnostic model was constructed to evaluate the clinical utility of the identified biomarkers. Additionally, we validated the two hub genes in peripheral blood samples from CHD patients and normal controls, as well as in aortic tissue samples from a low-density lipoprotein receptor-deficient (LDLR-/-) atherosclerosis mouse model.

Results: We identified 4174 DEGs, from which 3326 MAM-related DEGs (DE-MRGs) were further filtered. Mendelian randomization analysis coupled with machine learning identified two biomarkers, DHX36 and GPR68, demonstrating direct causal relationships with CHD. These biomarkers exhibited excellent diagnostic performance with areas under the receiver operating characteristic (ROC) curve exceeding 0.9. A molecular interaction network was constructed to reveal the biological pathways and molecular mechanisms involving these biomarkers. Furthermore, validation using peripheral blood from CHD patients and aortic tissues from the Ldlr-/- atherosclerosis mouse model corroborated these findings.

Conclusions: This study provides evidence supporting a mechanistic link between MAM dysfunction and CHD pathogenesis, identifying candidate biomarkers that have the potential to serve as diagnostic tools and therapeutic targets for CHD. While the validated biomarkers offer valuable insights into the molecular pathways underlying disease development, additional studies are needed to confirm their clinical relevance and therapeutic potential in larger, independent cohorts.

Ethylene is a multifunctional phytohormone that regulates plant growth, development, and responses to abiotic/biotic stresses. RTE1 (Reversion-To-Ethylene Sensitivity1) acts as a negative regulator of the ethylene responses in Arabidopsis by positively regulating ethylene receptor ETR1. However, the role of RTE genes in sweet potato (Ipomoea batatas), an import food crop worldwide, remains largely unknown, particularly their involvement in abiotic stress adaptation. In this study, we identified 23 RTE genes in sweet potato, distributed across 21 chromosomes and one scaffold BrgTig00017944. The phylogenetic analysis divided them into two groups, the RTE1 group and RTH (RTE1-Homolog) group. Synteny analysis revealed that whole genome duplication (WGD) was the major force of expansion of the IbRTE gene family. Multiple cis-acting elements responsive to hormones and stress were found in the promoter region of IbRTE genes. The transcriptome expression profiling showed that the majority of IbRTEs have tissue-specific and differential expression under drought and salt stresses. Meanwhile, the qRT-PCR results showed that the 14 representatives IbRTEs have differential expression profilings under salt (NaCl) and drought (PEG) treatments. These findings suggest that the IbRTE genes may be involved in sweet potato's adaptive responses to salt and drought, providing a valuable foundation for further functional studies.

MicroRNAs (miRNAs) play important roles in the regulation of melanogenesis and coat color in mammals. Short tandem target mimics (STTMs) have been used to block the functions of small RNA in animals and plants. To investigate the role of miR-5110 in melanogenesis, STTM was used to block the expression of miR-5110 (STTM-miR-5110). Luciferase reporter assay data indicated the miR-5110 regulates SOX10 expression by targeting its 3'-UTR. Overexpression of STTM-miR-5110 in alpaca melanocytes downregulated the expression of miR-5110 (decreased by about 38%, p < 0.05) and upregulated SOX10 mRNA (2.2-fold, p < 0.001) and protein (1.3-fold, p < 0.05) levels. Overexpression of STTM-miR-5110 in alpaca melanocytes increased the mRNA expression of melanogenic genes, including microphthalmia transcription factor (2.0-fold, p < 0.01), tyrosinase (1.6-fold, p < 0.01), tyrosinase-related protein 1 (approximately 3.9-fold, p < 0.001) and tyrosinase-related protein 2 (1.9-fold, p < 0.01). Overexpression of STTM-miR-5110 in alpaca melanocytes increased the protein expression of melanogenic genes, including microphthalmia transcription factor (1.9-fold, p < 0.05), tyrosinase (1.3-fold, p < 0.05), tyrosinase-related protein 1 (1.8-fold, p < 0.001) and tyrosinase-related protein 2 (1.6-fold, p < 0.05). The overexpression of pGL0-STTM-miR-5110 in alpaca melanocytes increased melanin production by approximately 26% (p < 0.05), pheomelanin production by approximately 38% (p < 0.05) and eumelanin production by approximately 56% (p < 0.001). In addition, overexpression of STTM-miR-5110 in alpaca melanocytes increased the TYR activity by 37% (p < 0.01). We also identified melanin granules in alpaca melanocytes transfected with STTM-miR-5110 under Fontana-Masson staining. These results suggest that STTM-miR-5110 upregulates melanogenesis by effectively blocking miR-5110 expression.

Radiotherapy is an effective treatment for cancer; however, radioresistant cancer cells result in recurrence. Therefore, elucidating the mechanisms of radioresistance is urgently needed. Super-enhancers (SEs) are clusters of enhancers occupied by a high density of master transcription factors, mediators, and bromodomain protein BRD4. Recently, we reported that ΔNp63, an oncogenic transcription factor, promotes radioresistance in human head and neck squamous cell carcinoma (HNSCC) cells. As ΔNp63 establishes SEs in HNSCC cells, SEs may be involved in radioresistance. Here, we investigated the role of the SE component BRD4 in the radiation responses of HNSCC cells using a BRD4 degrader ARV-771 or BRD4 knockdown. First, Western blotting confirmed that ARV-771 decreased BRD4 protein expression. ARV-771 treatment resulted in reduced cell proliferation and enhanced apoptosis in irradiated HNSCC cells. Moreover, colony formation assays revealed that both ARV-771 and BRD4 knockdown enhanced the radiosensitivity of HNSCC cells, suggesting BRD4 contributes to the radioresistance of HNSCC cells. Furthermore, fluorescence immunostaining revealed distinct localization patterns of γH2AX, a marker of DNA double-strand breaks, compared with BRD4 and ΔNp63 in irradiated cells. Notably, ARV-771 and BRD4 knockdown decreased ΔNp63 and BRD4 protein expression, whereas ΔNp63 knockdown had minimal impact on BRD4 expression. Taken together, these findings suggest that BRD4-dependent maintenance of ΔNp63 expression may contribute, at least in part, to the regulation of radioresistance in HNSCC cells.

Cognitive impairment is a frequent but heterogeneous consequence of SARS-CoV-2 infection, with objective cognitive deficits not always aligning with subjective cognitive complaints. Age, nutritional status, and stress-related biological pathways may contribute to this variability. The corticotropin-releasing hormone receptor 1 (CRHR1), a key regulator of stress and neuroendocrine responses, represents a biologically plausible candidate for post-infection cognitive vulnerability. In this pilot case-control study, we investigated associations between CRHR1 copy number variations (CNVs), prior viral exposures, and cognitive outcomes in adults following SARS-CoV-2 infection. Objective cognitive performance was assessed using the Montreal Cognitive Assessment (MoCA) and RBANS, alongside evaluation of subjective cognitive complaints and depressive symptoms. Analyses accounted for age and circulating levels of vitamins B12, B9, and vitamin D. CRHR1 CNVs affecting specific exons (Exon 1 [210 nucleotides] and Exon 11) were associated with objective cognitive impairment, whereas subjective cognitive complaints were more closely related to depressive symptoms than measurable cognitive deficits. Associations with age and certain viral seropositivities (HSV-1, HSV-2, and Hepatitis A) were also observed with objective cognitive outcomes; however, these findings should be interpreted cautiously given their exploratory nature. This study highlights CRHR1 CNVs as potential modifiers of objectively measured post-COVID-19 cognitive impairment and underscores the importance of distinguishing subjective cognitive complaints from objective cognitive dysfunction, providing a framework for future mechanistic and longitudinal studies.

Vascular endothelial growth factor receptor 3 (VEGFR3) assumes a pivotal role in regulating the development and maintaining the structural integrity of the lymphatic system. Decreased activity of VEGFR3 can precipitate aplasia or hypoplasia of lymphatic system components, culminating in primary lymphedema. To date, numerous genetic variants have been identified within the FLT4 gene, which encodes VEGFR3; however, the majority of these remain uncharacterised and are classified as 'variants of uncertain significance'. In preceding investigations involving FLT4 sequence analysis conducted on individuals presenting with primary lymphedema, we identified several rare genetic variants that possess the potential to modulate the functional activity of VEGFR3, including the heterozygous variant c.3175G>C (p.A1059P). Preliminary assessments encompassing clinical characteristics, family history, and predictive computational algorithms indicated that this variant was likely pathogenic. Consequently, this study presents the results of functional evaluation of the mutant VEGFR3 activity in cell models overexpressing the FLT4 variant c.3175G>C. VEGFC-dependent VEGFR3 phosphorylation and FLT4 expression were reduced in cells with c.3175G>C FLT4 variant compared to wild-type, confirming the pathogenic role of c.3175G>C in primary lymphedema.

Nazarloo et al [...].

Replication stress (RS) is a hallmark of cancer, largely driven by oncogene activation. Due to high levels of RS, cancer cells depend heavily on the RS response mechanisms to avoid DNA damage. This dependency creates a therapeutic opportunity that can be exploited for more effective cancer treatment. This review synthesizes current mechanistic understanding of RS and RS response and further describes how targeted disruption of RS response proteins (ATR, Chk1, Wee1, PARP, RPA) has been used in preclinical and clinical studies. We summarize preclinical and emerging clinical evidence for exploiting RS for radiosensitization, and outline candidate biomarkers and functional assays for patient selection. We also highlight the links between RS, therapy-induced senescence and innate immune activation via the cGAS-STING (cyclic GMP-AMP synthase-Stimulator of Interferon Genes) pathway, and address current challenges and future directions.

Sepsis is a life-threatening condition driven by a dysregulated host response to infection and remains a leading cause of mortality and morbidity worldwide. Among the many mechanisms implicated in its pathophysiology, the contribution of eryptosis-programmed red blood cell (RBC) death-has been suggested but remains insufficiently investigated. In this hypothesis paper, we propose that eryptosis may represent an underrecognized driver of sepsis-induced anemia and a potential contributor to subsequent organ dysfunction. This hypothesis is supported only by fragmented, predominantly preclinical evidence, which is currently too limited to allow firm conclusions. In this context, we critically revisit the sparse data linking sepsis, endotoxemia, and eryptosis, and outline a testable framework for understanding their possible interaction. We emphasize the substantial gaps in current knowledge, including the absence of robust clinical studies, the heterogeneity of existing experimental models, and persistent uncertainty regarding causality versus mere association. We also explore the theoretical implications of modulating eryptosis as a potential therapeutic approach. Our aim is to stimulate scientific discussion and promote targeted research efforts that may help determine whether addressing eryptosis could ultimately contribute to mitigating anemia, reducing organ injury, and improving outcomes in critically ill patients affected by sepsis.