Human molecular genetics最新文献

Fetal hemoglobin (HbF) modulates the clinical severity of sickle cell disease (SCD) by inhibiting the polymerization of sickle hemoglobin. Elevated HbF levels are associated with milder disease phenotypes, fewer Vaso-occlusive crises, and reduced organ damage. Understanding the molecular regulation of HbF expression is critical for the development of new therapeutic strategies, including pharmacologic agents and gene-based interventions aimed at ameliorating the course of SCD. We investigated transcriptomic expression in erythroid cells during the transition from the neonatal period to early childhood to identify genes associated with HbF regulation. Reticulocyte transcriptomes were compared between samples obtained at birth (cord blood), when HbF levels ranged from 72.6% to 90%, and at 18 months of age (whole blood), when HbF levels declined to 5.9%-10.3%. Reticulocytes were enriched, RNA extracted, and high-throughput RNA sequencing was performed, followed by differential gene expression and network analyses. Analysis of 20 346 genes revealed 1245 differentially expressed genes, of which 631 genes were upregulated in cord blood reticulocytes. The differentially expressed genes were significantly enriched in pathways related to cell signaling, proliferation, differentiation, metabolism, immune functionality, and erythropoiesis. Developmental shifts in the erythroid transcriptome uncover key biological processes that may regulate HbF expression. These findings offer a valuable panel of candidate genes for future functional studies and highlight new potential molecular targets for therapeutic modulation of HbF in sickle cell disease.

FOXP1 (Forkhead-box protein P1) is a crucial transcription factor in neural development and is associated with schizophrenia (SCZ). FOXP1-regulated genes may contribute to genetic risk of SCZ and this may vary across different stages of neurodevelopment. We analyzed RNA-seq transcriptomic data from mouse and human models of FOXP1 loss-of-function across prenatal and postnatal developmental stages, including neural stem cells from embryonic mice (E14.5) and human brain organoids (equivalent to second trimester), and cortical tissues from different mouse postnatal stages P0, P7, and P47. P0 in mice corresponds to the third trimester in humans, while P7 and P47 represent early childhood and adolescence, respectively. Linkage disequilibrium score regression assessed if FOXP1-regulated genes were enriched for SCZ heritability. Gene-set enrichment analysis investigated if FOXP1-regulated genes were enriched for SCZ-associated genes reported as differentially expressed in single cortical cell studies. SynGO analysis mapped FOXP1-regulated genes to synaptic locations and functions. FOXP1-regulated genes were enriched for SCZ heritability, with significant results for E14.5, P7 and P47 but not P0. The P7 gene-set showed the strongest enrichment for SCZ-associated genes from single cortical cell studies. FOXP1-regulated genes at both P7 and P47 were involved in multiple synaptic functions and were mainly enriched within glutamatergic excitatory neurons, with P47 also showing enrichment within GABAergic inhibitory neurons. Prenatal FOXP1-regulated genes were enriched in progenitor cells and also mapped to the synapse. Genetic risk for SCZ within FOXP1-regulated genes follows a dynamic trajectory across developmental stages, showing strongest effects at a timepoint that maps to early childhood.

The occurrence of preterm premature rupture of membranes (PPROM) significantly impacts maternal and fetal health due to its association with the cellular composition and genetic changes of the fetal membrane. However, the specific cell type responsible for triggering PPROM and the underlying mechanisms are still largely unexplored. We employed single-cell RNA sequencing (scRNA-seq) analysis on fetal membrane along with adjacent placental tissues about two centimeters from the umbilical cord obtained from women who delivered full-term in labor (FTIL), preterm premature without rupture of membrane (PPWROM), as well as PPROM，immunofluorescence were used to verify the findings. Our result s highlighted notable differences in cell type composition and interactions among these three groups. Of particular significance, we have identified a previously unrecognized subtype of trophoblast cells known as FABP7+Tb, a transitional state cell between cytotrophoblasts (CTB) and extravillous trophoblasts (EVT) cells, which appears to have some impact on PPWROM. Additionally, up-regulated expression of MMP11 in EVT-1 may serve as a promising biomarker for PPROM diagnosis. Furthermore, our study unveiled distinct interaction patterns among different trophoblast subtypes under varying pathological conditions, as well as significant variations in the interactions of trophoblast cells with other cell types, especially the pathways that are orchestrated by cell-cell cross-talk. Our study offers a comprehensive cell type and interaction map for the human fetal membrane along with adjacent placental tissues about two centimeters from the umbilical cord, providing insights into the molecular mechanisms that drive PPROM and uncovering potential targets for the early prediction of this condition.

The DNA mismatch repair protein MSH3 reversibly shifts from nucleus to the cytosol upon IL-6 signaling, abrogating the repair function of the MSH3-MSH2 heterodimer in the nucleus and increases aggressiveness and metastasis potential of colorectal cancers. A polymorphism proximate to MSH3's nuclear localization signal (NLS), Δ27bpMSH3, alters NLS function such that IL-6 triggers Δ27bpMSH3 accumulation in the cytosol. Public databases indicate Δ27bpMSH3 is rare in the germline yet we previously identified its presence in half of colon cancer cell lines tested and 19% of ulcerative colitis (UC) tissue samples. Here in examining ~ 200 each of UC, early-onset (eo)CRC, and late-onset (lo)CRC patients, biallelic MSH3 NLS germline polymorphisms were exclusively present in 15% of controls but in 18% of UC and 17% of eoCRC patients and were higher among CRC stage 3/4 patients compared to stage 2 patients; these marginal increases could potentiate inflammation-to-cancer transformation and/or metastatic disease. Using cell models we demonstrate IL-6-induced binding of wild type and Δ27bpMSH3 to the NFκB activating complex NEMO/IKKγ which stabilizes MSH3 after disengaging from its nuclear partner MSH2, linking inflammation with DNA repair protein stability. Additional NLS modifications using MSH3-FLAG mimics cytosolic Δ27bpMSH3 retention to cause loss-of-function after inflammation.

STXBP1 (Syntaxin-binding protein 1) is a presynaptic SNARE complex regulator essential for neurotransmitter release. De novo heterozygous mutations in Stxbp1 represent one of the most common genetic causes of early onset epileptic encephalopathies (STXBP1 related disorders, STXBP1-RD). STXBP1 protein is ubiquitously expressed across all neuronal populations. While impaired synaptic E/I balance is established, neuronal subtype-specific mechanisms of STXBP1-RD remain poorly defined. Here, we deployed multi-level genetic models to delineate the neuronal and behavioral consequences of STXBP1 insufficiency. In C. elegans, systemic evaluation of STXBP1 (UNC-18) deficiency revealed deficits in serotonergic neurons, manifested as progressive dendritic atrophy. In a new established Stxbp1 haploinsufficient mouse model, we confirmed serotonergic system dysfunction, characterized by reduced serotonergic neuron numbers, decreased 5-HT levels, and compensatory upregulation of serotonin receptors. Finally, mice with serotonergic neuron-specific Stxbp1 haploinsufficiency recapitulated a subset of neurological phenotypes. Together, this study reveals the underestimated serotonergic dysfunction as a pathological component of STXBP1-RD.

Heterozygous missense variants in CDK19 have been found in patients diagnosed with Developmental and Epileptic Encephalopathy-87 (DEE87) who present with global developmental delay, intellectual disability and other neuromuscular deficiencies. Two missense variants in CDK19, Y32H and T196A, were first proposed to be loss of function based on experiments in Drosophila models of DEE87. Subsequently, it was proposed that Y32H is a gain of function with elevated kinase activity. We present a detailed functional evaluation of these dominant missense variants in several contexts. We use fly models of DEE87 in which endogenous cdk8, the fly ortholog to human CDK8 and CDK19, is depleted through RNA interference (RNAi) while expressing the human genes. Depletion of Drosophila cdk8 causes thicker muscle myofibrils, fused mitochondria, and climbing defects. The expression of wild-type human CDK19 in a fly cdk8 knockdown background rescues these defects, highlighting functional conservation. In our assays, we used a cdk8 depleted background and individually expressed either the variant or wildtype CDK19 to compare the function of the variants relative to wild-type. We demonstrate that Y32H can rescue defects caused by cdk8 depletion, while T196A is unable to due to possible loss of function. Further, we find that supplementation of the fly diet with an antioxidant improves T196A phenotypes. Our Drosophila studies allowed us to assay these variants for further insight into their functional nature and to obtain translational knowledge that may be applied back to human health.

Background: Hypertension is a prevalent age-related condition with varying life risk factors. This study aimed to develop age-stratified prediction models integrating genetic risk scores (GRS) with clinical factors to improve hypertension risk stratification.

Methods: A total of 2159 Korean adults aged 20-86 years were stratified into younger (20-49 years) and older (≥50 years) cohorts. Genome-wide association analysis identified hypertension-associated single-nucleotide polymorphisms (SNPs) for constructing the GRS. Age-specific prediction models were developed and evaluated using receiver operating characteristic curve analysis.

Results: In younger adults, a GRS4 based on four SNPs with consistent effect directions and strong effects was significantly associated with hypertension after adjusting for body mass index (BMI) and sex (adjusted odds ratio [OR] = 2.79, P < 0.001). Including another SNP with a suggestive effect (GRS5) produced comparable results. In older adults, GRS1 (rs149026664) was significant in the unadjusted model (unadjusted OR = 2.72, P = 0.024), while GRS2 (including rs116861740) remained significant after adjustment for BMI and sex (adjusted OR = 2.65, P = 0.005). Predictive models combining BMI, brachial-ankle pulse wave velocity (ba-PWV), and GRS achieved strong performance, with area under the curve (AUC) = 0.821 (GRS4) and 0.809 (GRS5) in younger adults, and AUC = 0.766 (GRS1) and 0.765 (GRS2) in older adults.

Conclusion: Age-specific integration of GRS with clinical markers such as BMI and ba-PWV significantly improves hypertension prediction, offering actionable thresholds for precision prevention across age groups. These models provide clinically actionable tools for precision prevention.

ADSS1 myopathy is an ultrarare congenital myopathy characterized by progressive cardiac and skeletal muscle degeneration with childhood to adolescent onset. This autosomal recessive disease is caused by mutations in the ADSS1 gene, encoding the enzyme adenylosuccinate synthetase (AdSS1). AdSS1 plays a critical role in the adenine nucleotide cycle, which is important for energy metabolism in muscle cells. Enzymatic defects, engendered by loss-of-function mutations in ADSS1, lead to a bottleneck in the adenine nucleotide cycle, causing metabolic dysfunction that ultimately results in progressive muscle weakness, mobility impairment, and respiratory and cardiac dysfunction, often requiring the use of a ventilator. Despite its debilitating nature, there are currently no cures or targeted treatments available, and little research into possible therapeutic strategies has been done. With a limited patient profile encompassing fewer than 200 known patients worldwide, establishing a mouse model for ADSS1 myopathy is critical to understanding its pathogenesis and for developing future therapies. Here, we present and characterize the first mouse model of ADSS1 myopathy-a constitutive Adss1 knockout model-by (1) defining its natural history, (2) exploring its metabolic pathomechanisms, and (3) characterizing its histopathological features. We find that Adss1KO/KO mice have subtle motor deficits and present with histopathological features consistent with patient phenotypes. Overall, we show that despite a relatively mild phenotype, this novel mouse model has quantifiable pathological features that can be used to develop therapies for, and further probe pathophysiology of, ADSS1 myopathy.

The small heat shock protein HSPB6 (a.k.a. Hsp20) is highly expressed in striated and smooth muscles. It modulates the oligomerization of its paralogs HSPB1 and CRYAB (HSPB5) and is involved e.g. in cytoskeletal regulation and autophagy. While HSPB6 variants have been implicated in cardiomyopathy, they have not been previously linked to neuromuscular disease. We report here a patient with late-onset myopathy and cataract, carrying in cis the novel HSPB6 variant c.464delC and the common polymorphism c.488G > C, together resulting in the extended protein p.Pro155Argfs*25;p.Gly163Arg. The family history was consistent with dominant inheritance. The mutant protein showed decreased solubility due to phase separation propensity, and caused mislocalization of CRYAB and BAG3, and a decrease of HSPB1 in transfected cells. The patient's muscle biopsy showed rimmed vacuoles and, in line with the functional studies, accumulation of HSPB6 and its interaction partners. The identified HSPB6 variants are most likely the cause of the muscle disease in this family, thus identifying HSPB6 mutations as a novel cause of vacuolar myopathy. Other reported HSPB6 variants causing a late frameshift or extension may cause disease in a similar fashion.

Objective: To describe the genetic, phenotypic, and pathologic manifestations of patients presenting with inherited kidney cancer and germline variants of the Tuberous Sclerosis Complex (TSC) genes.

Materials and methods: Inherited kidney cancer patients were screened for germline RCC susceptibility gene variants and patient histories and clinical evaluations were performed. Renal tumors were evaluated for somatic genetic alterations by DNA sequencing and mRNA expression analysis by RNAseq and immunohistochemical analyses were performed.

Results: Nine distinct germline TSC1/TSC2 variants were identified in 13 patients, including seven known or likely pathogenic alterations. Five patients presented with a clinical diagnosis of TSC, and eleven patients had a genetic diagnosis of TSC. Nine patients had bilateral RCC and nine had multifocal RCC. The average initial age at diagnosis of RCC was 47 years old. The TSC-associated tumors demonstrated a variety of histologies including ccRCC, RCC with clear cell and papillary features, chromophobe RCC, and oncocytoma; with ccRCC being the most prevalent. Loss of heterozygosity or secondary somatic alteration of TSC1/TSC2 was observed in ~ 37% of tumors. RNAseq analysis demonstrated specific expression patterns associated within histologically defined tumor clusters and increased expression of CLEAR genes activated by the TFE3/TFEB transcription factors, including GPNMB and NPC1 which were confirmed with immunohistochemistry.

Conclusion: This study confirms the importance of screening individuals with a family history of kidney cancer for TSC1/TSC2 germline variants, even in the absence of canonical TSC manifestations, and indicates a critical role of TFE3 and TFEB as drivers of human TSC-deficient renal cell carcinoma.