Search Results (22)

Intramuscular fat content is a key determinant of pork quality, influencing traits such as tenderness, juiciness, and flavor. However, the molecular mechanisms regulating intramuscular fat deposition in indigenous pig breeds remain incompletely understood. This study aimed to identify genes and regulatory mechanisms associated with intramuscular fat accumulation in Hezuo pigs. Longissimus dorsi muscle samples from Hezuo pigs with extreme high and low intramuscular fat contents were subjected to chromatin accessibility profiling and transcriptome sequencing. Comparative analyses identified 2201 differentially accessible chromatin regions and 588 differentially expressed genes between the two groups. Functional enrichment analyses indicated that these genes were mainly involved in lipid metabolism, focal adhesion, extracellular matrix–receptor interaction, fatty acid metabolism, and adenosine monophosphate-activated protein kinase signaling. Integration of chromatin accessibility and gene expression datasets identified 92 co-regulated genes associated with intramuscular fat deposition, including MYLK3, PDGFC, PAK1, IGF1R, LAMA4, DIAPH1, SDC4, GADD45G, and RXRG. These findings reveal regulatory networks underlying intramuscular fat accumulation in Hezuo pigs and provide candidate genes and molecular resources for improving meat quality through genetic selection and breeding programs. Full article

Diabetic neuropathy is typically diagnosed with distal sensory and nerve conduction abnormalities. These symptoms may reflect earlier disturbances of axonal maintenance. This review examines axonal transport and cytoskeletal failure as convergent cellular mechanisms of diabetic axonopathy. Long peripheral axons are particularly vulnerable to damage because their integrity depends on continuous communication between the neuronal soma and distal terminals. This process involves the continuous renewal of cytoskeletal and functional proteins and the involvement of organelles such as mitochondria. Diabetes in experimental models disrupts this system at several levels. It slows cargo transport. The supply of neurofilaments, tubulin and retrograde signaling is reduced, and regenerative growth after injury is weakened. Carbonyl stress and AGEs cause modifications of neural proteins, the extracellular matrix, vascular barriers, and the excitability of sensory neurons. RAGE ligands, including AGEs and the proteins HMGB1 and S100, link the diabetic tissue environment to redox and inflammatory signaling. This occurs in neural and glial compartments, as well as in vascular tissue and the immune system. RAGE interacts with DIAPH1 to activate GTPase signaling and remodel the cytoskeleton. The RAGE–DIAPH1 interaction provides a plausible route from diabetic ligand accumulation to cytoskeletal remodeling. These observations provide a mechanistic context for axonal transport, although not all represent direct measurements of cargo movement. Direct evidence for transport impairment comes mainly from experimental studies showing altered slow cytoskeletal transport, impaired retrograde signaling, and weakened regenerative responses. This work highlights the possibility of developing therapies that go beyond symptomatic relief. Verifying the effectiveness of interventions in protecting axonal transport and nerve fiber integrity in diabetic neuropathy may be therapeutically beneficial. Full article

Carbonyl stress, chronic inflammation, and progressive tissue injury accompany type 2 diabetes mellitus (T2DM) and obesity. Yet, the molecular systems that connect these processes with cardiac, vascular and neuronal complications are incompletely defined. This review examines the AGE–RAGE–DIAPH1 axis as a mechanistic link between metabolic dysfunction and diabetic myocardial and neuronal injury, with emphasis on vascular and myocardial remodeling and emerging implications for autonomic neuronal vulnerability. We summarize current evidence on the formation and accumulation of advanced glycation end-products and other RAGE ligands in metabolic disease, DIAPH1’s structural and signaling role as an intracellular effector of RAGE, and the cellular consequences of pathway activation in vascular, neural, and cardiac tissues. Across experimental models, this signaling axis promotes oxidative stress and inflammatory activation, leading to endothelial dysfunction and barrier failure. Subsequent fibrotic remodeling provides a biologically plausible route through which metabolic stress may be translated into persistent organ injury. In the heart, these mechanisms are linked to coronary microvascular dysfunction, altered cardiomyocyte phenotype, calcium handling abnormalities, and myocardial fibrosis. In the autonomic nervous system, limited but emerging data connect RAGE activation to oxidative injury and mitochondrial dysfunction, abnormal neuronal excitability, and structural vulnerability. Direct evidence linking DIAPH1 to autonomic neurons is lacking. We also review biomarker candidates related to this pathway, including circulating AGEs and soluble RAGE isoforms, skin AGE measurements, imaging markers of myocardial remodeling, and autonomic functional measures. Finally, we discuss pharmacological and natural compounds that target AGE formation, ligand accumulation, RAGE signaling, or intracellular protein interactions linked to this axis. Overall, the available evidence supports the AGE–RAGE–DIAPH1 axis as a credible mechanistic concept and a potentially informative translational hypothesis in T2DM. However, the AGE–RAGE component is supported more strongly than DIAPH1-specific involvement in human diabetic myocardial disorder or cardiovascular autonomic neuropathy. The value of DIAPH1 as a biomarker or therapeutic target in these neurocardiac complications remains to be established. Full article

Background/Objectives: Diabetic small fiber neuropathy and related sensory and epidermal problems affect up to 70% of all patients with diabetes. Long-term hyperglycemia disrupts cytoskeletal organization and axonal transport; however, molecular changes within human diabetic epidermis remain understudied. Diaph1 and its cytoskeletal ligands, including β-Actin and Profilin, are key regulators of cytoskeletal dynamics and may be associated with diabetes-related alterations in skin structure and innervation. Methods: Sixteen patients with type 2 diabetes, aged 43.3 ± 9.6 years (disease duration 18.9 ± 8.7 years), and twelve non-diabetic controls, aged 43.9 ± 8.9 years, were enrolled in the study. All participants provided informed consent. Skin punch biopsies were obtained under local anesthesia and processed for staining of PGP 9.5, Diaph1, β-Actin, and Profilin. Quantitative image analysis was performed to assess stained area fraction, signal intensity, and intraepidermal nerve fiber density. Statistical comparisons and Spearman’s rank correlation analyses were used to evaluate group differences and associations between staining parameters. Results: Diabetic skin samples exhibited a significant reduction in PGP 9.5-positive intraepidermal nerve fibers, indicating reduced cutaneous innervation. In contrast, Diaph1 and Profilin showed broader and more diffuse epidermal staining, while β-Actin displayed altered staining patterns and intensity. Significant correlations between Diaph1- and β-Actin-related staining measures indicated an association consistent with altered cytoskeletal organization under chronic hyperglycemic conditions. Conclusions: Long-standing type 2 diabetes was associated with reduced PGP 9.5-positive intraepidermal nerve fibers, together with altered epidermal staining patterns of Diaph1, Profilin and β-Actin. These findings indicate coexisting cutaneous denervation and cytoskeletal alterations in diabetic skin. Full article

Nonsyndromic hearing loss (NSHL) is a highly prevalent, genetically heterogeneous condition, yet its molecular basis in the Singaporean population remains underexplored. We performed whole-exome sequencing and integrative bioinformatics analysis in 115 patients with NSHL to define population-specific genetic biomarkers. A molecular diagnosis was achieved in 57% of cases, with 76% of identified variants classified as pathogenic or likely pathogenic and 24% exhibiting high pathogenic potential. Common East Asian NSHL genes, including GJB2, SLC26A4, and OTOF, were frequently detected alongside less prevalent genes such as ACTG1, CEACAM16, COL11A2, DIAPH1, KCQN4, MYH14, MYO6, MYO7A, MYO15A, SLC17A8, SMPX, STRC, TJP2, TMC1, TMPRSS3, highlighting extensive genetic heterogeneity. Notably, multiple novel variants, including MYO6 c.554-2A>G, and TNC p.N750Y, were identified, expanding the known mutational spectrum of NSHL. Genotype–phenotype correlations revealed that GJB2 variants were primarily associated with mild to moderate hearing loss, whereas SLC26A4 variants correlated with severe to profound phenotypes in the Singaporean populations. Collectively, our study provides important insights into the genetic architecture of NSHL in Singapore’s population. In addition, it supports improved molecular diagnosis yield and informed clinical management decisions as well as the advancement of precision medicine approaches aimed at reducing the burden of hearing loss in the region. Full article

Diabetic peripheral neuropathy (DPN) is a serious consequence of prolonged hyperglycemia and contributes to the morbidity associated with diabetes. Hyperglycemia enhances the non-enzymic glycation of proteins and the accumulation of Advanced Glycation End Products (AGEs). We employed a diabetic mouse model lacking both Diaph1 and RAGE to elucidate the role of RAGE-Diaph1 signaling in the pathogenesis of DPN. We demonstrate that simultaneous deletion of Diaph1 and RAGE did not change the course or the intensity of hyperglycemia-induced weight loss in mice. However, abrogating RAGE-Diaph1 signaling affects actin cytoskeleton remodeling rates in nerve axons by altering the ratio of the actin-regulating molecules cofilin and profilin. Our experimental results suggest that the loss of RAGE-Diaph1 signaling protects neurons from hyperglycemic conditions. We observed a beneficial effect of abolishing RAGE-Diaph1 signaling on the axonal structure of neuropathic nerves. In addition, we observed that abolishing RAGE-Diaph1 signaling improved motor nerve conduction velocity in the sciatic nerves of hyperglycemic mice. Our data indicate that RAGE-Diaph1 signaling is likely enhanced in chronic hyperglycemia, resulting in aberrant actin dynamics in nerve axons. These defective actin dynamics play a key role in the progression of DPN, leading to structural and functional loss in peripheral nerves. Full article

The cytoskeleton has been described as a regulator of adrenal physiology and tumour behaviour. In the adrenal cortex, both cytoskeletal filaments, by mediating cholesterol transfer to mitochondria, and their binding proteins, such as cofilin and diaphanous-related formin 1 (DIAPH1), have been implicated in modulating steroidogenic processes. Beyond hormone production, the cytoskeleton participates in oncogenic signalling and contributes to the acquisition of malignant behaviour in adrenocortical carcinoma (ACC). Cytoskeleton-associated proteins such as filamin A (FLNA), fascin-1 (FSCN1), RASSF1A, and the guanine nucleotide exchange factor VAV2 are involved in signal transduction, cell cycle regulation, and cytoskeletal remodelling. In ACC, dysregulation of the expression or activity of these proteins correlates with ACC aggressiveness, including increased proliferation, motility, and invasion as well as poor prognosis, making them attractive candidates for targeted therapeutic strategies. To date, no review has systematically addressed the role of cytoskeleton and its binding partners in both adrenal physiological regulation and pathological context. This review is the first to provide a comprehensive overview of cytoskeletal involvement in adrenal cortex function and cancer, highlighting emerging molecular players and their possible therapeutic implications. Full article

Receptor for advanced glycation end-products (RAGE) activation by hyperglycemia-induced AGE (advanced glycation end-products) accumulation is likely to play a crucial role in the development of complications such as diabetic peripheral neuropathy (DPN). RAGE signaling is mediated via its cytosolic tail. Through its cytosolic tail, RAGE recruits diaphanous-related formin 1 (Diaph1), a protein involved in actin filament organization. Disruption of RAGE–Diaph1 interactions using small molecules alleviates diabetic complications in mice; however, the role of Diaph1 in DPN progression has not been rigorously tested. In this study, we employed a Diaph1 knockout mouse (DKO) to investigate the role of Diaph1 in DPN progression. Herein, we demonstrate that, at the systemic level, CRISPR deletion of Diaph1 fails to ameliorate diabetes-induced weight loss in mice. Within the sciatic nerve (SCN), the lack of Diaph1 failed to prevent hyperglycemia-induced loss of β-actin in the nerve fibers. At a morphological level, the lack of Diaph1 leads to a partial rescue in DPN. While we observed improvements in axonal and fiber diameters in diabetic DKO mice, the g-ratio (an indicator of myelination) and myelin invaginations displayed incomplete rescue. Furthermore, the lack of Diaph1 failed to rescue motor or sensory nerve conduction defects resulting from hyperglycemia over 6 months. Overall, our data thus indicate that the complete loss of Diaph1 is insufficient to halt the progression of DPN. However, across a range of parameters including blood glucose levels, body weight measurements, axon and fiber diameters, and nerve conduction velocity, DKO diabetic mice show improvement when compared to wild-type diabetic mice. Full article

Neurodegenerative diseases are a group of disorders characterized by the progressive deterioration of the structure and function of central nervous system neurons and include, among others, amyotrophic lateral sclerosis (ALS), multiple sclerosis (MS), Parkinson’s (PD), Alzheimer’s (AD), and Huntington’s (HD) diseases. And while all these diseases seem to have different genetic and environmental components, growing evidence shows that they share common underlying pathological features such as increased neuroinflammation and excessive oxidative stress. RAGE, the receptor for advanced glycation end-products, is a signal transduction receptor, and its activation triggers an increase in proinflammatory molecules, oxidative stressors, and cytokines. Diaph1, protein diaphanous homolog 1, is an actin modulator and an intracellular ligand of RAGE. Studies demonstrated that RAGE and Diaph1 act together, and their downstream signaling pathways play a role in neurodegeneration. Here, based on current evidence and our own research, we provide an overview of the RAGE–Diaph1 signaling and discuss the therapeutic potential of targeted therapy aimed at RAGE–Diaph1 signaling inhibition in the prevention and treatment of neurodegenerative diseases. Full article

Background: Uniparental disomy (UPD) is the inheritance of both copies of a chromosome from a single parent, leading to distinct genetic conditions. Maternal UPD of chromosome 6 (UPD(6)mat) is extremely rare, with few molecularly confirmed cases reported. Methods: We report a prematurely born female with isodisomic UPD(6)mat, presenting with intrauterine growth restriction (IUGR), developmental delay, autism spectrum disorder, dysmorphic features, and a sacrococcygeal teratoma. In addition, we reviewed 24 confirmed UPD(6)mat cases to assess clinical patterns in prenatal findings, birth outcomes, and postnatal features. Results: Trio whole-exome sequencing revealed complete isodisomy of chromosome 6 and a de novo heterozygous DIAPH2 variant of uncertain significance. In the literature review, IUGR was present in 87% of cases, with most individuals born small for gestational age and preterm. Failure to thrive and neurodevelopmental issues were also frequent. While the exact molecular basis remains unknown, imprinting disturbances—similar to those in UPD(6)pat—and cryptic trisomy 6 mosaicism, particularly in heterodisomy, are the most likely mechanisms. No specific gene or consistent epigenetic abnormality has been identified. Conclusions: This study aims to enhance the understanding of the genetic and phenotypic spectrum of UPD(6)mat, improving diagnostic and management approaches for this ultra-rare genetic disorder. We propose a detailed list of clinical assessments and tests to be performed following the detection of maternal uniparental disomy of chromosome 6. Full article

Copy number variation (CNV) serves as a crucial source of genomic variation and significantly aids in the mining of genomic information in cattle. This study aims to analyze re–sequencing data from Chinese Hainan yellow cattle, to uncover breed CNV information, and to elucidate the resources of population genetic variation. We conducted whole–genome sequencing on 30 Chinese Hainan yellow cattle, thus generating 814.50 Gb of raw data. CNVs were called using CNVnator software, and subsequent filtering with Plink and HandyCNV yielded 197,434 high–quality CNVs and 5852 CNV regions (CNVRs). Notably, the proportion of deleted sequences (81.98%) exceeded that of duplicated sequences (18.02%), with the lengths of CNVs predominantly ranging between 20 and 500 Kb This distribution demonstrated a decrease in CNVR count with increasing fragment length. Furthermore, an analysis of the population genetic structure using CNVR databases from Chinese, Indian, and European commercial cattle breeds revealed differences between Chinese Bos indicus and Indian Bos indicus. Significant differences were also observed between Hainan yellow cattle and European commercial breeds. We conducted gene annotation for both Hainan yellow cattle and European commercial cattle, as well as for Chinese Bos indicus and Indian Bos indicus, identifying 206 genes that are expressed in both Chinese and Indian Bos indicus. These findings may provide valuable references for future research on Bos indicus. Additionally, selection signatures analysis based on Hainan yellow cattle and three European commercial cattle breeds identified putative pathways related to heat tolerance, disease resistance, fat metabolism, environmental adaptation, candidate genes associated with reproduction and the development of sperm and oocytes (CABS1, DLD, FSHR, HSD17B2, KDM2A), environmental adaptation (CNGB3, FAM161A, DIAPH3, EYA4, AAK1, ERBB4, ERC2), oxidative stress anti–inflammatory response (COMMD1, OXR1), disease resistance (CNTN5, HRH4, NAALADL2), and meat quality (EHHADH, RHOD, GFPT1, SULT1B1). This study provides a comprehensive exploration of CNVs at the molecular level in Chinese Hainan yellow cattle, offering theoretical support for future breeding and selection programs aimed at enhancing qualities of this breed. Full article

Endometrial cancer (EC) is the most common gynecological malignancy. EC is associated with metabolic disorders that may promote non-enzymatic glycation and activate the receptor for advanced glycation end-products (RAGE) signaling pathways. Thus, we assumed that RAGE and its ligands may contribute to EC. Of particular interest is the interaction between diaphanous-related formin 1 (Diaph1) and RAGE during the progression of human cancers. Diaph1 is engaged in the proper organization of actin cytoskeletal dynamics, which is crucial in cancer invasion, metastasis, angiogenesis, and axonogenesis. However, the detailed molecular role of RAGE in EC remains uncertain. In this review, we discuss epigenetic factors that may play a key role in the RAGE-dependent endometrial pathology. We propose that DNA methylation may regulate the activity of the RAGE pathway in the uterus. The accumulation of negative external factors, such as hyperglycemia, inflammation, and oxidative stress, may interfere with the DNA methylation process. Therefore, further research should take into account the role of epigenetic mechanisms in EC progression. Full article

Autosomal dominant non-syndromic hearing loss (HL) typically occurs when only one dominant allele within the disease gene is sufficient to express the phenotype. Therefore, most patients diagnosed with autosomal dominant non-syndromic HL have a hearing-impaired parent, although de novo mutations should be considered in all cases of negative family history. To date, more than 50 genes and 80 loci have been identified for autosomal dominant non-syndromic HL. DFNA22 (MYO6 gene), DFNA8/12 (TECTA gene), DFNA20/26 (ACTG1 gene), DFNA6/14/38 (WFS1 gene), DFNA15 (POU4F3 gene), DFNA2A (KCNQ4 gene), and DFNA10 (EYA4 gene) are some of the most common forms of autosomal dominant non-syndromic HL. The characteristics of autosomal dominant non-syndromic HL are heterogenous. However, in most cases, HL tends to be bilateral, post-lingual in onset (childhood to early adulthood), high-frequency (sloping audiometric configuration), progressive, and variable in severity (mild to profound degree). DFNA1 (DIAPH1 gene) and DFNA6/14/38 (WFS1 gene) are the most common forms of autosomal dominant non-syndromic HL affecting low frequencies, while DFNA16 (unknown gene) is characterized by fluctuating HL. A long audiological follow-up is of paramount importance to identify hearing threshold deteriorations early and ensure prompt treatment with hearing aids or cochlear implants. Full article

Hearing relies on the proper functioning of auditory hair cells and on actin-based cytoskeletal structures. Diaphanous-related formins (DRFs) are evolutionarily conserved cytoskeletal proteins that regulate the nucleation of linear unbranched actin filaments. They play key roles during metazoan development, and they seem particularly pivotal for the correct physiology of the reproductive and auditory systems. Indeed, in Drosophila melanogaster, a single diaphanous (dia) gene is present, and mutants show sterility and impaired response to sound. Vertebrates, instead, have three orthologs of the diaphanous gene: DIAPH1, DIAPH2, and DIAPH3. In humans, defects in DIAPH1 and DIAPH3 have been associated with different types of hearing loss. In particular, heterozygous mutations in DIAPH1 are responsible for autosomal dominant deafness with or without thrombocytopenia (DFNA1, MIM #124900), whereas regulatory mutations inducing the overexpression of DIAPH3 cause autosomal dominant auditory neuropathy 1 (AUNA1, MIM #609129). Here, we provide an overview of the expression and function of DRFs in normal hearing and deafness. Full article

Increasing evidence links the RAGE (receptor for advanced glycation end products)/DIAPH1 (Diaphanous 1) signaling axis to the pathogenesis of diabetic complications. RAGE is a multi-ligand receptor and through these ligand–receptor interactions, extensive maladaptive effects are exerted on cell types and tissues targeted for dysfunction in hyperglycemia observed in both type 1 and type 2 diabetes. Recent evidence indicates that RAGE ligands, acting as damage-associated molecular patterns molecules, or DAMPs, through RAGE may impact interferon signaling pathways, specifically through upregulation of IRF7 (interferon regulatory factor 7), thereby heralding and evoking pro-inflammatory effects on vulnerable tissues. Although successful targeting of RAGE in the clinical milieu has, to date, not been met with success, recent approaches to target RAGE intracellular signaling may hold promise to fill this critical gap. This review focuses on recent examples of highlights and updates to the pathobiology of RAGE and DIAPH1 in diabetic complications. Full article