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Hernandez, N.

Publications and source records attributed to Hernandez, N..

17 recordsLinked to original sources

Modified 3rd Generation Synchronization Modulation Electric Field (3m-SMEF) Prevents Ischemia-Reperfusion-Induced Acute Kidney Injury via Targeting Na⁺/K⁺-ATPase

Acute kidney injury (AKI) caused by ischemia-reperfusion injury (IRI) remains a major clinical problem with limited therapeutic options. We previously demonstrated that the 3rd-generation Synchronization Modulation Electric Field (SMEF) preserves Na/K-ATPase function during ischemia and protects against kidney injury. In the present study, we substantially modified the 3rd-generation SMEF (3m-SMEF) to further improve/optimize Na/K-ATPase regulation and enhance the protective effects, which was tested both in vitro and in vivo. In HK-2 cells, hypoxia/reoxygenation reduced Na/K-ATPase expression and induced apoptotic and necroptotic signaling, whereas 3m-SMEF restored Na/K-ATPase expression and markedly reduced cell death. In vivo, male and female mice underwent unilateral renal ischemia with or without 3m-SMEF treatment during vascular clamping. At 24 h, 3m-SMEF markedly improved renal function, reducing plasma creatinine by ~90-95% and restoring glomerular filtration rate to near-control levels. Application of the 3m-SMEF also normalized kidney injury markers (KIM-1 and NGAL), preserved renal ATP, and prevented the translocation and loss of Na/K-ATPase expression. The renoprotective effects substantially exceeded those achieved with the previous SMEF platform. These findings demonstrate that 3m-SMEF provides robust protection against ischemic AKI by preserving Na/K-ATPase function and tubular integrity and represents a promising non-pharmacological therapy for ischemic kidney injury.

physiology↗

Intra-host IRES heterogeneity shapes hepatitis C virus translation through epistatic and population-level effects

Hepatitis C virus (HCV) circulates within each patient as a diverse population of closely related genomes, yet RNA functional properties are commonly inferred from a single consensus or dominant genome. The contribution of non-coding intra-host variability, particularly within the internal ribosome entry site (IRES), to translational efficiency remains poorly defined. Here we investigated how naturally occurring HCV IRES variation influences viral RNA translation. Complete IRES sequences from chronically infected patients were analyzed using molecular cloning, bicistronic reporters, full-length replication-deficient viral RNAs and reconstructed intra-host populations. We found that natural IRES mutations displayed context-dependent effects, and combinations of mutations produced translational phenotypes that could not be predicted from the corresponding single mutations, consistent with intragenic epistasis. Moreover, several variants behaved differently in bicistronic reporters and full-length viral RNAs, demonstrating that both genomic and cellular context shape IRES function. Reconstructed genotype 1a populations largely reproduced the activity of their dominant haplotypes. In contrast, reconstructed genotype 3a populations translated substantially more efficiently than their corresponding dominant sequences, showing that low-frequency variants can collectively modulate translation at the population level. These findings demonstrate that the translational phenotype of HCV cannot always be inferred from the dominant sequence alone and identify epistasis, genomic context, and intra-host population composition as interacting determinants of viral RNA translation. ImportanceHepatitis C virus (HCV) exists within each infected person as a diverse population of closely related viruses rather than as a single genetic sequence. This study shows that natural variation in a key RNA region controlling viral protein production can alter how efficiently the virus functions, and that these effects depend on combinations of mutations rather than on individual changes alone. By analyzing complete viral RNAs in addition to widely used reporter systems, we demonstrate that the full viral genome can substantially influence the activity of this regulatory region, providing a more realistic view of how translation occurs during natural infection. Our findings also reveal that rare viral variants can collectively shape the behavior of the viral population, challenging the common practice of relying on a single dominant sequence to represent an infection. These results provide new insight into how genetic diversity drives HCV evolution and adaptation.

molecular biology↗

Dual Engram Architecture within a Single Striatal Cell Type Distinctly Controls Alcohol Relapse and Extinction

Relapse is a major obstacle in the treatment of alcohol and drug addiction and is thought to be driven by persistent drug-associated memories formed during their use. Behavioral therapies such as extinction training can reduce relapse and are proposed to work by creating a competing memory trace. However, where and how these opposing memories are stored in the brain is unknown. Here, we show that two anatomically and functionally distinct engram ensembles within the same genetically defined striatal cell type, direct-pathway medium spiny neurons (dMSNs), encode these opposing memories. Using engram-tagging tools in mice, we found that the acquisition of operant alcohol learning recruits a dMSN ensemble enriched in the striatal matrix compartment that stores alcohol-associated memories and whose activation selectively promotes relapse. Conversely, extinction of alcohol seeking recruits a dMSN ensemble enriched in the striosome compartment that stores extinction-related memories and whose activation suppresses relapse. Furthermore, we reveal that the physical memory trace storing the relapse-promoting memory is embedded within persistently strengthened corticostriatal synapses engaged during learning, and that artificially reproducing this plasticity is sufficient to trigger relapse-like behavior. These findings uncover a dual-engram architecture within dMSNs that governs relapse and extinction, providing a mechanistic framework for understanding how competing memories regulate drug-seeking behavior. HighlightsO_LIAcquisition and extinction of alcohol learning recruits distinct dMSN ensembles. C_LIO_LIAcquisition recruits matrix-enriched dMSN ensembles to promote relapse. C_LIO_LIExtinction recruits striosome-enriched dMSN ensembles to suppress relapse. C_LIO_LIEngram dMSNs show lasting synaptic potentiation and mimicking this potentiation triggers relapse. C_LI

neuroscience↗

Acute kidney injury disrupts cardiac remodeling via SerpinA3N

Cardiorenal syndrome type 3 (CRS-3) also known as acute reno-cardiac syndrome, refers to a condition where acute kidney injury (AKI) leads to acute cardiac dysfunction or injury. The underlying mechanisms have not been elucidated. In the current study, we examined the potential mechanisms for the development of myocardial pro-fibrotic factors and cardiac remodeling in C57BL/6J mice after AKI. The mice were subjected to bilateral pedicle clamping for 30 min followed by 24 h of reperfusion. Heart tissue was collected from control (Ctrl) and AKI mice and subjected to proteomic analysis by liquid chromatography-mass spectrometry (LC-MS) and differential mRNA expression analysis by RNA-seq. Cardiac tissue was collected to assess serine protease activity, RNA, protein and cytokine expression. The results indicate that AKI significantly upregulated SerpinA3N in the heart which was negatively correlated with serine protease (Granzyme B) activity. Further, AKI induced the development of several pro-fibrotic factors, induced mitochondrial dysfunction and increased inflammation. Finally, using H9C2 cells we demonstrated that inhibiting SerpinA3N with XAV939 increased Granzyme B activity. Thus, this study suggests that AKI leads to the development of pro-fibrotic factors in the heart and disrupts cardiac remodeling by SerpinA3N mediated inhibition of serine protease Granzyme B activity. Decreased SerpinA3N expression in the heart followed by AKI could lead to a more balanced extracellular matrix (ECM) composition in the heart with an alleviated pro-fibrotic response.

molecular biology↗

Targeting therapeutic nanoparticles to the glioblastoma resection margin by harnessing post-operative spatiotemporal blood-brain barrier disruption

Resection surgery is the first-line therapy for glioblastoma (GBM) that is performed in >70% of patients, typically within days of suspected diagnosis. Current protocols for follow-on chemoradiotherapy have shown only modest efficacy in eliminating residual disease, leading to inevitable tumour recurrence. There remains a need for new approaches to swiftly and effectively treat post-operative residual disease to prevent the rapid early progression of recurrent GBM. Using syngeneic preclinical models of glioblastoma resection, we identified a spatially and temporally restricted window of blood brain barrier (BBB) disruption localised to the resection margin, during the immediate (15 min) and early (48-72h) postoperative periods. Intravenous administration of fluorescently labelled, clinically-used liposome nanoparticles during these periods demonstrated that selective accumulation at the postoperative resection margin, while largely being excluded from areas of the brain with an intact BBB, could be achieved. Confocal analysis confirmed the presence of extravasated nanoparticles within the margin parenchyma which largely interacted with microglial populations closely associated with residual tumour cells. Exploiting this, we performed intravenous administration of doxorubicin-loaded liposomes (DOX-Lipo) coinciding with the peak of postoperative BBB disruption and demonstrated both enhanced chemotherapy delivery and consequently complete inhibition of tumour recurrence from a single administration. Overall, this work underscores the importance of timing concomitant chemotherapy to the post-operative timeframe and demonstrates that clinically-used liposomal nanomedicines could be readily repurposed for early post-operative therapy in aggressive brain tumours.

pharmacology and toxicology↗

An endogenous GLP-1 circuit engages VTA GABA neurons to regulate mesolimbic dopamine neurons and attenuate cocaine seeking

Recent studies show that systemic administration of a glucagon-like peptide-1 receptor (GLP-1R) agonist is sufficient to attenuate the reinstatement of cocaine-seeking behavior, an animal model of relapse. However, the neural mechanisms mediating these effects and the role of endogenous central GLP-1 signaling in cocaine seeking remain unknown. Here, we show that voluntary cocaine taking decreased plasma GLP-1 levels in rats and that chemogenetic activation of GLP-1-producing neurons in the nucleus tractus solitarius (NTS) that project to the ventral tegmental area (VTA) decreased cocaine reinstatement. Single nuclei transcriptomics and FISH studies revealed GLP-1Rs are expressed primarily on GABA neurons in the VTA. Using in vivo fiber photometry, we found that the efficacy of a systemic GLP-1R agonist to attenuate cocaine seeking was associated with increased activity of VTA GABA neurons and decreased activity of VTA dopamine neurons. Together, these findings suggest that targeting central GLP-1 circuits may be an effective strategy toward reducing cocaine relapse and highlight a novel functional role of GABAergic GLP-1R-expressing midbrain neurons in drug seeking.

neuroscience↗

Tumor-derived hypoxic small extracellular vesicles promote endothelial cell migration and tube formation via ALS2/Rab5/β-catenin signaling

Tumor hypoxia has been associated with cancer progression, angiogenesis, and metastasis via modifications in the release and cargo composition of extracellular vesicles secreted by tumor cells. Indeed, hypoxic extracellular vesicles are known to trigger a variety of angiogenic responses via different mechanisms. We recently showed that hypoxia promotes endosomal signaling in tumor cells via HIF-1-dependent induction of the guanine exchange factor ALS2, which activates Rab5, leading to downstream events involved in cell migration and invasion. Since Rab5-dependent signaling is required for endothelial cell migration and angiogenesis, we explored the possibility that hypoxia promotes the release of small extracellular vesicles containing ALS2, which in turn activate Rab5 in recipient endothelial cells leading to pro-angiogenic properties. In doing so, we found that hypoxia promoted ALS2 expression and incorporation as cargo within small extracellular vesicles, leading to subsequent transfer to recipient endothelial cells, promoting cell migration, tube formation and downstream Rab5 activation. Consequently, ALS2-containing small extracellular vesicles increased early endosome size and number in recipient endothelial cells, which was followed by subsequent sequestration of components of the {beta}-catenin destruction complex within endosomal compartments, leading to stabilization and nuclear localization of {beta}-catenin. These events converged in the expression of {beta}-catenin target genes involved in angiogenesis. Knockdown of ALS2 in donor-tumor cells, which precluded its incorporation into small extracellular vesicles, prevented Rab5-downstream events and endothelial cell responses, which depended on Rab5 activity and guanine exchange factor activity of ALS2. These findings indicate that vesicular ALS2, secreted in hypoxia, promotes endothelial cell events leading to angiogenesis. Finally, these events might explain how tumor angiogenesis proceeds in hypoxic conditions.

cell biology↗

Aluminium alters excitability by inhibiting calcium, sodium and potassium currents in bovine chromaffin cells.

Aluminium (Al3+) has long been related to neurotoxicity and neurological diseases. This study aims to describe the specific actions of this metal on cellular excitability and neurotransmitter release. Al3+ reduced intracellular calcium concentrations around 25% and decreased catecholamine secretion in a dose-dependent manner, with an IC50 of 89.1 M. Al3+ blocked calcium currents in a time- and concentration-dependent manner with an IC50 of 560 M. This blockade was irreversible, since it did not recover after wash-out. Moreover, Al3+ produced a bigger blockade on N-, P- and Q-type calcium channels subtypes (69.5%) than on L-type channels subtypes (50.5%). Sodium currents were also inhibited by Al3+ in a time- and concentration-dependent manner, 24.3% blockade at the closest concentration to the IC50 (419 M). This inhibition was reversible. Voltage-dependent potassium currents were non-significantly affected by Al3+. Nonetheless, calcium/voltage-dependent potassium currents were inhibited in a concentration-dependent manner, with an IC50 of 447 M. This inhibition was related to the depression of calcium influx through voltage-dependent calcium channels subtypes coupled to BK channels. In summary, the blockade of these ionic conductances altered cellular excitability that reduced the action potentials firing and so, the neurotransmitter release and the synaptic transmission. These findings prove that aluminium has neurotoxic properties because it alters neuronal excitability by inhibiting the sodium currents responsible for the generation and propagation of impulse nerve, the potassium current responsible for the termination of action potentials, and the calcium current responsible for the neurotransmitters release.

neuroscience↗

Profile of the somatic mutational landscape in breast tumors from Hispanic/Latina women

Breast cancer causes the most cancer deaths among Hispanic/Latinas (H/L). However, limited tumor-sequencing data from H/L are available to guide treatment. To address this gap, we performed whole-exome sequencing of DNA from 140 HL germline and 146 matched breast tumors and RNA-seq for the tumors. We generated somatic-mutation profiles, identified copy-number alterations (CNAs), and compared results to non-Hispanic White (White) women in The Cancer Genome Atlas. Similar to Whites, PIK3CA and TP53 were the most commonly mutated genes in breast tumors from H/L. We found 4 common COSMIC mutation signatures (1, 2, 3, 13) and signature 16 not previously reported in other breast-cancer datasets. We observed recurrent amplifications in breast-cancer drivers including MYC, FGFR1, CCND1, and ERBB2, and a recurrent amplification on 17q11.2 associated with high KIAA0100 gene expression, implicated in breast-cancer aggressiveness. Expanded research is required to determine how these characteristics of H/L tumors impact treatment response and survival.

cancer biology↗

The central nucleus of the amygdala and gustatory cortex assess affective valence during CTA learning and expression in male and female rats

This study evaluated behavior (Boost(R) intake, LiCl-induced behaviors, ultrasonic vocalizations (USVs), task performance) and c-Fos activation during conditioned taste aversion (CTA), the reinforced task (Boost(R) task) and control task (cage only) to understand how male and female rats balance the relative danger or safety of a stimulus in learning and performing a task. Females drank more Boost(R) than males but showed similar aversive behaviors after LiCl treatment. Males produced 55 kHz USVs (indicating positive valence) when anticipating Boost(R) and inhibited these calls after pairing with LiCl. Females produced 55 kHz USVs based on their estrous cycle but were more likely to make 22 kHz USVs than males (indicating negative valence) after pairing with LiCl. c-Fos responses were similar in males and females after Boost(R) or LiCl. Females engaged the gustatory cortex and ventral tegmental area more than males during the Boost(R) task and males engaged the amygdala more than females in both the reinforcing and devalued tasks. Network analysis of correlated c-Fos responses across brain regions identified two unique networks characterizing the Boost(R) and LiCl (CTA) tasks, in both of which the VTA played a central role. RNAscope identified a population of D1-receptor expressing cells in the CeA that responded to Boost(R) and D2 receptor-expressing cells that responded to LiCl. The present study suggests that males and females differentially process the affective valence of a stimulus to produce the same goal-directed behavior.

animal behavior and cognition↗

Flashfm: A Flexible and Shared Information Fine-mapping Approach for Multiple Quantitative Traits

Joint fine-mapping that leverages information between quantitative traits could improve accuracy and resolution over single-trait fine-mapping. Using summary statistics, flashfm (FLexible And SHared information Fine-Mapping) fine-maps signals for multiple traits, allowing for missing trait measurements and use of related individuals. In a Bayesian framework, prior model probabilities are formulated to favour model combinations that share causal variants to capitalise on information between traits. Simulation studies demonstrate that both approaches produce broadly equivalent results when traits have no shared causal variants. When traits share at least one causal variant, flashfm reduces the number of potential causal variants by 30% compared with single-trait fine-mapping. In a Ugandan cohort with 33 cardiometabolic traits, flashfm gave a 20% reduction in the total number of potential causal variants from single-trait fine-mapping. Flashfm is computationally efficient and can easily be deployed across publicly available summary statistics for signals in up to six traits.

genetics↗

Potential impact on coagulopathy of gene variants of coagulation related proteins that interact with SARS-CoV-2

Thrombosis has been one of the complications of the Coronavirus disease of 2019 (COVID-19), often associated with poor prognosis. There is a well-recognized link between coagulation and inflammation, however, the extent of thrombotic events associated with COVID-19 warrants further investigation. Poly(A) Binding Protein Cytoplasmic 4 (PABPC4), Serine/Cysteine Proteinase Inhibitor Clade G Member 1 (SERPING1) and Vitamin K epOxide Reductase Complex subunit 1 (VKORC1), which are all proteins linked to coagulation, have been shown to interact with SARS proteins. We computationally examined the interaction of these with SARS-CoV-2 proteins and, in the case of VKORC1, we describe its binding to ORF7a in detail. We examined the occurrence of variants of each of these proteins across populations and interrogated their potential contribution to COVID-19 severity. Potential mechanisms by which some of these variants may contribute to disease are proposed. Some of these variants are prevalent in minority groups that are disproportionally affected by severe COVID-19. Therefore, we are proposing that further investigation around these variants may lead to better understanding of disease pathogenesis in minority groups and more informed therapeutic approaches. Author summaryIncreased blood clotting, especially in the lungs, is a common complication of COVID-19. Infectious diseases cause inflammation which in turn can contribute to increased blood clotting. However, the extent of clot formation that is seen in the lungs of COVID-19 patients suggests that there may be a more direct link. We identified three human proteins that are involved indirectly in the blood clotting cascade and have been shown to interact with proteins of SARS virus, which is closely related to the novel coronavirus. We examined computationally the interaction of these human proteins with the viral proteins. We looked for genetic variants of these proteins and examined how these variants are distributed across populations. We investigated whether variants of these genes could impact severity of COVID-19. Further investigation around these variants may provide clues for the pathogenesis of COVID-19 particularly in minority groups.

bioinformatics↗

Chronic repression by MAF1 supports futile RNA cycling as a mechanism for obesity resistance

Maf1-/- mice are lean, obesity-resistant and metabolically inefficient. Their increased energy expenditure is thought to be driven by a futile RNA cycle that reprograms metabolism to meet an increased demand for nucleotides stemming from the deregulation of RNA polymerase (pol) III transcription. Metabolic changes consistent with this model have been reported in both fasted and refed mice, however the impact of the fasting-refeeding-cycle on pol III function has not been examined. Here we show that changes in pol III occupancy in the liver of fasted versus refed wild-type mice are largely confined to low and intermediate occupancy genes; high occupancy genes are unchanged. However, in Maf1-/- mice, pol III occupancy of the vast majority of active loci in liver and the levels of specific precursor tRNAs in this tissue and other organs are higher than wild-type in both fasted and refed conditions. Thus, MAF1 functions as a chronic repressor of active pol III loci and can modulate transcription under different conditions. Our findings support the futile RNA cycle hypothesis, elaborate the mechanism of pol III repression by MAF1 and demonstrate a modest effect of MAF1 on global translation via reduced mRNA levels and translation efficiencies for several ribosomal proteins.

molecular biology↗

Precision Medicine Advancements Using Whole Genome Sequencing, Noninvasive Whole Body Imaging, and Functional Diagnostics

We report the results of a three-year precision medicine study that enrolled 1190 presumed healthy participants at a single research clinic. To enable a better assessment of disease risk and improve diagnosis, a precision health platform that integrates non-invasive functional measurements and clinical tests combined with whole genome sequencing (WGS) was developed. The platform included WGS, comprehensive quantitative non-contrast whole body (WB) and brain magnetic resonance imaging/angiography (MRI/MRA), computed tomography (CT) coronary artery calcium scoring, electrocardiogram, echocardiogram, continuous cardiac monitoring, clinical laboratory tests, and metabolomics. In our cohort, 24.3% had medically significant genetic findings (MSF) which may contribute to increased risk of disease. A total of 206 unique medically significant variants in 111 genes were identified, and forty individuals (3.4%) had more than one MSF. Phenotypic testing revealed: 34.2% of our cohort had a metabolomics profile suggestive of insulin resistance, 29.2% had elevated liver fat identified by MRI, 16.4% had clinically important cardiac structure or cardiac function abnormalities on cardiac MRI or ECHO, 8.8% had a high cardiovascular risk on CT coronary artery calcium scoring (Agatston calcium score > 400, Relative Risk of 7.2), 8.0% had arrhythmia found on continuous rhythm monitoring, 6.5% had cardiac conduction disorders found on EKG, 2% had previously undetected tumors detected by WB MRI, and 2.5% had previously undetected aneurysms detected by non-contrast MRI/MRA. Using family histories, personal histories, and test results, clinical and phenotypic findings were correlated with genomic findings in 130 study participants (63.1%) with high to moderate penetrance variants, suggesting the precision health platform improves the diagnostic process in asymptomatic individuals who were at risk. Cardiovascular and endocrine diseases achieved considerable clinical associations between MSFs and clinical phenotypes (89% and 72%, respectively). These findings demonstrate the value of integrating WGS and noninvasive clinical assessments for a rapid and integrated point-of-care clinical diagnosis of age-related diseases that contribute to premature mortality.

genomics↗

Cycles of gene expression and genome response during mammalian tissue regeneration

BackgroundCompensatory liver hyperplasia -- or regeneration -- induced by two-thirds partial hepatectomy (PH) permits the study of synchronized activation of mammalian gene expression, particularly in relation to cell proliferation. Here, we measured genomic transcriptional responses and mRNA accumulation changes after PH and sham surgeries.\n\nResultsDuring the first 10-20 hours, the PH- and sham-surgery responses were very similar, including parallel early activation of cell-division-cycle genes. After 20 hours, however, whereas post-PH livers continued with a robust and coordinate cell-division-cycle gene-expression response before returning to the resting state by one week, sham-surgery livers returned directly to a resting gene-expression state. Localization of RNA polymerase II (Pol II), and trimethylated histone H3 lysine 4 (H3K4me3) and 36 (H3K36me3) on genes dormant in the resting liver and activated during the PH response revealed a general de novo promoter Pol II recruitment and H3K4me3 increase during the early 10-20 hour phase followed by Pol II elongation and H3K36me3 accumulation in gene bodies during the later proliferation phase. H3K36me3, generally appearing at the first-internal exon, was preceded 5' by H3K36me2; 3' of the first-internal exon, in about half of genes H3K36me3 predominated and in the other half H3K36me2 and H3K36me3 co-existed. Further, we observed some unusual gene profiles with abundant Pol II but little evident H3K4me3 or H3K36me3 modification, indicating that these modifications are neither universal nor essential partners to Pol II transcription.\n\nConclusionsPH and sham surgical procedures on mice reveal striking early post-operatory gene expression similarities followed by synchronized mRNA accumulation and epigenetic histone mark changes specific to PH.

genomics↗

Stimulus-responsive self-assembly of enzymatic fractal structures by computational design

Fractal topologies, which are statistically self-similar over multiple length scales, are pervasive in nature. The recurrence of patterns at increasing length scales in fractal-shaped branched objects, e.g., trees, lungs, and sponges, results in high effective surface areas, and provides key functional advantages, e.g., for molecular trapping and exchange. Mimicking these topologies in designed protein-based assemblies will provide access to novel classes of functional biomaterials for wide ranging applications. Here, we describe a modular, multi-scale computational design method for the reversible self-assembly of proteins into tunable supramolecular fractal-like topologies in response to phosphorylation. Computationally-guided atomic-resolution modeling of fusions of symmetric, oligomeric proteins with Src homology 2 (SH2) binding domain and its phosphorylatable ligand peptide was used to design iterative branching leading to fractal-like assembly formation by enzymes of the atrazine degradation pathway. Structural characterization using various microscopy techniques and Cryo-electron tomography revealed a variety of dendritic, hyperbranched, and sponge-like topologies which are self-similar over three decades ([~]10nm-10m) of length scale, in agreement with models from multi-scale computational simulations. We demonstrate control over mesoscale topology (by linker design), formation dynamics, and functional enhancements due to dynamic multi-component assemblies constructed with three atrazine degradation pathway enzymes. The described design method should enable the construction of a variety of novel, spatiotemporally responsive catalytic biomaterials featuring fractal topologies.

biophysics↗

Whole Genome Sequencing and Rare Variant Analysis in Essential Tremor Families

Essential tremor (ET) is one of the most common movement disorders. The etiology of ET remains largely unexplained. Whole genome sequencing (WGS) is likely to be of value in understanding a large proportion of ET with Mendelian and complex disease inheritance patterns. In ET families with Mendelian inheritance patterns, WGS may lead to gene identification where WES analysis failed to identify the causative variant due to incomplete coverage of the entire coding region of the genome. Alternatively, in ET families with complex disease inheritance patterns with gene x gene and gene x environment interactions enrichment of functional rare coding and non-coding variants may explain the heritability of ET. We performed WGS in eight ET families (n=40 individuals) enrolled in the Family Study of Essential Tremor. The analysis included filtering WGS data based on allele frequency in population databases, rare variant classification and association testing using the Mixed-Model Kernel Based Adaptive Cluster (MM-KBAC) test and prioritization of candidate genes identified within families using phenolyzer. WGS analysis identified candidate genes for ET in 5/8 (62.5%) of the families analyzed. WES analysis in a subset of these families in our previously published study failed to identify candidate genes. In one family, we identified a deleterious and damaging variant (c.1367G>A, p.(Arg456Gln)) in the candidate gene, CACNA1G, which encodes the pore forming subunit of T-type Ca(2+) channels, CaV3.1, and is expressed in various motor pathways and has been previously implicated in neuronal autorhythmicity and ET. Other candidate genes identified include SLIT3 (family D), which encodes an axon guidance molecule and in three families, phenolyzer prioritized genes that are associated with hereditary neuropathies (family A, KARS, family B, KIF5A and family F, NTRK1). This work has identified candidate genes and pathways for ET that can now be prioritized for functional studies.

genetics↗