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Spinal Muscular Atrophy (SMA) emerges as a prominent genetic neuromuscular disorder primarily caused by variants in the survival motor neuron (SMN) gene. However, it is noteworthy that alternative variants impacting DYNC1H1 have also been linked to a subtype known as spinal muscular atrophy lower extremity predominant (SMA-LED). This observation underscores the complexity of SMA and highlights the necessity for tailored, gene-specific management strategies. Our study elucidates how similar approaches to managing SMA can yield distinct outcomes, emphasizing the imperative for personalized gene-based interventions in effectively addressing these conditions. Two patients were referred for further management due to clinical suspicion of type-3 SMA. The definitive diagnosis was confirmed through the polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) technique, as well as whole-exome sequencing (WES). The analysis revealed deletions in exon-7 and 8 of SMN1 in the first patient and a likely pathogenic mutation (NM_001376.5(DYNC1H1):c.1867 T > C (NP_001367.2: p.Phe623Leu)) in DYNC1H1 in the second patient. Both patients presented with lower limb muscle weakness. However, while the first patient exhibited a gradual increase in severity over the years, the second patient displayed no progressive symptoms. The management was adjusted accordingly based on the genetic findings. Our observation underscores the complexity of SMA and highlights the necessity for tailored, gene-specific management strategies. Our study elucidates how similar approaches to managing SMA can yield distinct outcomes, emphasizing the imperative for personalized gene-based interventions in effectively addressing these conditions.
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Dineínas Citoplasmáticas , Atrofia Muscular Espinal , Mutación , Proteína 1 para la Supervivencia de la Neurona Motora , Humanos , Proteína 1 para la Supervivencia de la Neurona Motora/genética , Dineínas Citoplasmáticas/genética , Masculino , Atrofia Muscular Espinal/genética , Atrofia Muscular Espinal/terapia , FemeninoRESUMEN
Treacher Collins syndrome-3 (TCS-3) is a rare congenital craniofacial disorder attributed to variants in the RNA pol I subunit C (POLR1C). The pathogenesis of TCS-3 linked to polr1c involves the activation of apoptosis-dependent p53 pathways within neural crest cells (NCCs). This occurs due to disruptions in ribosome biogenesis, and the restoration of polr1c expression in early embryogenesis effectively rescues the observed craniofacial phenotype in polr1c-deficient zebrafish. Clinical variability in TCS patients suggests interactions between genes and factors like oxidative stress. Elevated production of reactive oxygen species (ROS) in epithelial cells may worsen phenotypic outcomes in TCS individuals. Our study confirmed excessive ROS production in facial regions, inducing apoptosis and altering p53 pathways. Deregulated cell-cycle and epithelial-to-mesenchymal transition (EMT) genes were also detected in the TCS-3 model. Utilizing p53 inhibitor (Pifithrin-α; PFT-α) or antioxidants (Glutathione; GSH and N-Acetyl-L-cysteine; NAC) effectively corrected migrated NCC distribution in the pharyngeal arch (PA), suppressed oxidative stress, prevented cell death, and modulated EMT inducers. Crucially, inhibiting p53 activation or applying antioxidants within a specific time window, notably within 30 h post-fertilization (hpf), successfully reversed phenotypic effects induced by polr1c MO.
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Antioxidantes , Benzotiazoles , Modelos Animales de Enfermedad , Disostosis Mandibulofacial , Estrés Oxidativo , Especies Reactivas de Oxígeno , Tolueno/análogos & derivados , Proteína p53 Supresora de Tumor , Proteínas de Pez Cebra , Pez Cebra , Animales , Proteína p53 Supresora de Tumor/metabolismo , Proteína p53 Supresora de Tumor/genética , Disostosis Mandibulofacial/genética , Disostosis Mandibulofacial/tratamiento farmacológico , Antioxidantes/farmacología , Benzotiazoles/farmacología , Proteínas de Pez Cebra/genética , Proteínas de Pez Cebra/metabolismo , Estrés Oxidativo/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismo , Transición Epitelial-Mesenquimal/efectos de los fármacos , Tolueno/farmacología , Cresta Neural/efectos de los fármacos , Cresta Neural/metabolismo , Apoptosis/efectos de los fármacos , ARN Polimerasa I/antagonistas & inhibidores , ARN Polimerasa I/metabolismo , ARN Polimerasa I/genéticaRESUMEN
Nager syndrome (NS) is a rare acrofacial dysostosis caused by heterozygous loss-of-function variants in the splicing factor 3B subunit 4 (SF3B4). The main clinical features of patients with NS are characterized by facial-mandibular and preaxial limb malformations. The migration and specification of neural crest cells are crucial for craniofacial development, and mitochondrial fitness appears to play a role in such processes. Here, by analyzing our previously published transcriptome dataset, we aim to investigate the potential involvement of mitochondrial components in the pathogenesis of craniofacial malformations, especially in sf3b4 mutant zebrafish. We identified that oxidative phosphorylation (OXPHOS) defects and overproduction of reactive oxygen species (ROS) due to decreased antioxidants defense activity, which leads to oxidative damage and mitochondrial dysfunction. Furthermore, our results highlight that fish lacking sf3b4 gene, primarily display defects in mitochondrial complex I. Altogether, our findings suggest that mitochondrial dysfunction may contribute to the development of the craniofacial anomalies observed in sf3b4-depleted zebrafish.
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Disostosis Mandibulofacial , Enfermedades Mitocondriales , Pez Cebra , Animales , Perfilación de la Expresión Génica , Mutación , Factores de Empalme de ARN/genética , Pez Cebra/genética , Modelos Animales de EnfermedadRESUMEN
Posterior subcapsular cataract (PSC) frequently develops as a complication in patients with retinitis pigmentosa (RP). Despite numerous scientific investigations, the intricate pathomechanisms underlying cataract formation in individuals affected by RP remain elusive. Therefore, our study aims to elucidate the potential pathogenesis of cataracts in an RP model using splicing factor subunit 3b (sf3b4) mutant zebrafish. By analyzing our previously published transcriptome dataset, we identified that, in addition to RP, cataract was listed as the second condition in our transcriptomic analysis. Furthermore, we confirmed the presence of nucleus retention in the lens fiber cells, along with abnormal cytoskeleton expression in both the lens fiber cells and lens epithelial cells in sf3b4-depleted fish. Upon closer examination, we identified 20 differentially expressed genes (DEGs) that played a role in cataract formation, with 95 % of them related to the downregulation of structural lens proteins. Additionally, we also identified that among all the DEGs, 13 % were associated with fibrotic processes. It seems that the significant upregulation of inflammatory mediators, in conjunction with TGF-ß signaling, plays a central role in the cellular biology of PSC and posterior capsular opacification (PCO) in sf3b4 mutant fish. In summary, our study provides valuable insights into cataract formation in the RP model of sf3b4 mutants, highlighting its complexity driven by changes in structural lens proteins and increased cytokines/growth factors.
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Opacificación Capsular , Catarata , Cristalinas , Cristalino , Retinitis Pigmentosa , Humanos , Animales , Pez Cebra/genética , Transcriptoma , Catarata/etiología , Opacificación Capsular/etiología , Retinitis Pigmentosa/genética , Retinitis Pigmentosa/diagnóstico , Cristalinas/genéticaRESUMEN
Glaucoma is one of the leading causes of visual impairment and blindness worldwide, and is characterized by the progressive damage of retinal ganglion cells (RGCs) and the atrophy of the optic nerve head (ONH). The exact cause of RGC loss and optic nerve damage in glaucoma is not fully understood. The high energy demands of these cells imply a higher sensitivity to mitochondrial defects. Moreover, it has been postulated that the optic nerve is vulnerable towards damage from oxidative stress and mitochondrial dysfunction. To investigate this further, we conducted a pooled analysis of mitochondrial variants related to energy production, specifically focusing on oxidative phosphorylation (OXPHOS) and fatty acid ß-oxidation (FAO). Our findings revealed that patients carrying non-synonymous (NS) mitochondrial DNA (mtDNA) variants within the OXPHOS complexes had an almost two-fold increased risk of developing glaucoma. Regarding FAO, our results demonstrated that longer-chain acylcarnitines (AC) tended to decrease, while shorter-chain AC tended to increase in patients with glaucoma. Furthermore, we observed that the knocking down cpt1a (a key rate-limiting enzyme involved in FAO) in zebrafish induced a degenerative process in the optic nerve and RGC, which resembled the characteristics observed in glaucoma. In conclusion, our study provides evidence that genes encoding mitochondrial proteins involved in energy metabolisms, such as OXPHOS and FAO, are associated with glaucoma. These findings contribute to a better understanding of the molecular mechanisms underlying glaucoma pathogenesis and may offer potential targets for therapeutic interventions in the future.
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Glaucoma , Fosforilación Oxidativa , Animales , Humanos , Pez Cebra/genética , Pez Cebra/metabolismo , Glaucoma/genética , Glaucoma/tratamiento farmacológico , Glaucoma/patología , Mitocondrias/metabolismo , ADN Mitocondrial/genética , Ácidos Grasos/metabolismoRESUMEN
Perfluorohexanesulfonic acid (PFHxS) is a highly prevalent environmental pollutant, often considered to be less toxic than other poly- and perfluoroalkyl substances (PFASs). Despite its relatively lower environmental impact compared to other PFASs, several studies have suggested that exposure to PFHxS may be associated with disruptions of liver function in humans. Nevertheless, the precise pathomechanisms underlying PFHxS-induced non-alcoholic fatty liver disease (NAFLD) remain relatively unclear. Therefore, this study applied our previously published transcriptome dataset to explore the effects of PFHxS exposure on the susceptibility to NAFLD and to identify potential mechanisms responsible for PFHxS-induced NAFLD through transcriptomic analysis conducted on zebrafish embryos. Results showed that exposure to PFHxS markedly aggravated hepatic symptoms resembling NAFLD and other metabolic syndromes (MetS) in fish. Transcriptomic analysis unveiled 17 genes consistently observed in both NAFLD and insulin resistance (IR), along with an additional 28 genes identified in both the adipocytokine signaling pathway and IR. These shared genes were also found within the NAFLD dataset, suggesting that hepatic IR may play a prominent role in the development of PFHxS-induced NAFLD. In conclusion, our study suggests that environmental exposure to PFHxS could be a potential risk factor for the development of NAFLD, challenging the earlier notion of PFHxS being safer as previously claimed.
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Fluorocarburos , Resistencia a la Insulina , Enfermedad del Hígado Graso no Alcohólico , Ácidos Sulfónicos , Animales , Humanos , Enfermedad del Hígado Graso no Alcohólico/genética , Pez Cebra/genética , Factores de Riesgo , Resistencia a la Insulina/genéticaRESUMEN
Introduction: The COVID-19 virus spreads at a high rate, exerting many physical, mental and psychological effects on patients. Patients with COVID-19 have been reported to have high levels of interleukin 1 and interleukin 6. Therefore, this study was conducted to determine the association of physical, mental, and psychological problems with the levels of interleukin-1 and -6 in COVID-19 patients. Methodology: This is cross-sectional descriptive-analytical research on 121 COVID-19 patients selected using simple random sampling method. The patients were hospitalized in university hospitals affiliated to Ahvaz Jundishapur University of Medical Sciences and Amir al-Momenin Hospital. Data collection tools included the depression anxiety stress scale (DASS), a demographic questionnaire, and a checklist of physical problems. Blood sampling was also done to perform an ELISA test and measure the level of interleukin-1 and -6. Data were analyzed based on independent t-tests, chi-square, regression, and Pearson's correlation coefficient, using SPSS ver. 22. Results: The average age of the 121 patients participating in this study was 53.31 ± 14.09. A direct and statistically significant correlation was observed between body temperature on the first day and interleukin 1 level. A statistically significant negative correlation was observed between blood oxygen saturation level and interleukin-1 and -6 on the first, third and fifth days. Shortness of breath and coughing had a statistically significant correlation with the level of interleukin 1 on the third and fifth days. A direct and statistically significant correlation was observed between body temperature on the first, third and fifth days and interleukin 6 level. Coughing on the third and fifth days had a statistically significant relationship with interleukin 6 level. No direct and non-significant statistical correlation was found between depression and stress and the serum level of interleukin 1, but a significant correlation was observed between anxiety and serum level of interleukin 1. Finally, the results showed that depression, anxiety and stress had a direct and statistically significant correlation with the serum level of interleukin 6. Conclusion: Given the relationship between interleukin-1 and -6 and most physical and psychological problems, level of the inflammatory biomarkers interleukin-1 and -6 can be used to estimate the severity of physical and psychological symptoms in COVID-19 patients.
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Perfluorohexanesulfonic acid (PFHxS) is a short-chain perfluoroalkyl substance widely used to replace the banned perfluorooctanesulfonic acid (PFOS) in various industrial and household products. It can be found in the environment and human bodies; however, its potential toxicities are not well studied. Zebrafish have been extensively used as a model for studying toxicants, and currently, two studies have reported on the toxicity of PFHxS in zebrafish from different approaches. Ulhaq and Tse (J Hazard Mater. 2023; 457: 131722) conducted general biological experiments and applied transcriptomics to demonstrate that PFHxS at a concentration of 5 µM could affect glucose and fatty acid metabolism, leading to oxidative stress, developmental defects, and cell cycle arrest. Xu et al. (Sci Total Environ. 2023; 887: 163770) employed metabolomics and showed that concentrations of various metabolites changed after exposure to 3 and 10 µM PFHxS. As we observed a match between the metabolomics data and our biochemistry experimental findings, we integrated the two studies, which enabled us to unfold the possible mechanism of the deregulated metabolites. We identified 22 differential expressed genes (DEGs) in the tricarboxylic acid (TCA) cycle, 17 DEGs in glcyolytic process, including the critical glucokinase under the carbon metabolism. Besides, genes likes aldehyde dehydrogenases, and histone-lysine N-methyltransferases that participate in lipid peroxidation and amino metabolism respectively were spotted. Lastly, we further strengthen our discoveries by undergoing the gene set enrichment analysis. This article could provide insights into the toxicity of PFHxS, as well as prospects for environmental studies.
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Ácidos Alcanesulfónicos , Fluorocarburos , Animales , Humanos , Pez Cebra , Transcriptoma , Fluorocarburos/toxicidad , Fluorocarburos/química , Ácidos Sulfónicos , Ácidos Alcanesulfónicos/toxicidad , MetabolómicaRESUMEN
Patients with breast cancer are reported to experience nausea and vomiting during neoadjuvant chemotherapy. Both remain the most troubling side effects of chemotherapy, even in the era of new antiemetic agents. Hence, our study aims to investigate the clinical outcome of acupressure in the prevention of acute chemotherapy-induced nausea (CIN) by evaluating the frequency and severity of nausea. This study was a randomized controlled trial consisting of 42 breast cancer patients, divided equally into two groups (experimental (acupressure) and control groups). Digital acupressure was performed at pericardium 6 (P6 or Neiguan) and stomach 36 (ST36 or Zusanli) points. Assessment of nausea was conducted by examining the frequency of nausea and measuring nausea-related subscores from the simulator sickness questionnaire (SSQ) and visual analog scale (VAS) within one hour after chemotherapy. Our study indicated that patients in the experimental group had significantly lower frequency and less severe nausea than those in the control group. In conclusion, acupressure effectively decreased the frequency and severity of nausea in breast cancer patients undergoing neoadjuvant chemotherapy. Acupressure could be implemented as an adjunct intervention in addition to antiemetic therapy for the prevention of CIN in breast cancer patients.
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Perfluorohexanesulfonic acid (PFHxS) is a short-chain perfluoroalkyl substance widely used to replace the banned perfluorooctanesulfonic acid (PFOS) in different industrial and household products. It has currently been identified in the environment and human bodies; nonetheless, the possible toxicities are not well-known. Zebrafish have been used as a toxicant screening model due to their fast and transparent developmental processes. In this study, zebrafish embryos were exposed to PFHxS for five days, and various experiments were performed to monitor the developmental and cellular processes. Liquid chromatography-mass spectrometry (LC/MS) analysis confirmed that PFHxS was absorbed and accumulated in the zebrafish embryos. We reported that 2.5 µM or higher PFHxS exposure induced phenotypic abnormalities, marked by developmental delay in the mid-hind brain boundary and yolk sac edema. Additionally, larvae exposed to PFHxS displayed facial malformation due to the reduction of neural crest cell expression. RNA sequencing analysis further identified 4643 differentiated expressed transcripts in 5 µM PFHxS-exposed 5-days post fertilization (5-dpf) larvae. Bioinformatics analysis revealed that glucose metabolism, lipid metabolism, as well as oxidative stress were enriched in the PFHxS-exposed larvae. To validate these findings, a series of biological experiments were conducted. PFHxS exposure led to a nearly 4-fold increase in reactive oxygen species, possibly due to hyperglycemia and impaired glutathione balance. The Oil Red O' staining and qPCR analysis strengthens the notions that lipid metabolism was disrupted, leading to lipid accumulation, lipid peroxidation, and malondialdehyde formation. All these alterations ultimately affected cell cycle events, resulting in S and G2/M cell cycle arrest. In conclusion, our study demonstrated that PFHxS could accumulate and induce various developmental toxicities in aquatic life, and such data might assist the government to accelerate the regulatory policy on PFHxS usage.
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Fluorocarburos , Contaminantes Químicos del Agua , Animales , Humanos , Embrión no Mamífero/metabolismo , Fluorocarburos/química , Fluorocarburos/toxicidad , Larva/metabolismo , Estrés Oxidativo , Especies Reactivas de Oxígeno/metabolismo , Ácidos Sulfónicos , Contaminantes Químicos del Agua/toxicidad , Contaminantes Químicos del Agua/metabolismo , Pez Cebra/metabolismoRESUMEN
The SF3B4 gene encodes a highly conserved protein that plays a critical role in mRNA splicing. Mutations in this gene are known to cause Nager syndrome, a rare craniofacial disorder. Although SF3B4 expression is detected in the optic vesicle before it is detected in the limb and somite, the role of SF3B4 in the eye is not well understood. This study investigated the function of sf3b4 in the retina by performing transcriptome profiles, immunostaining, and behavioral analysis of sf3b4-/- mutant zebrafish. Results from this study suggest that dysregulation of the spliceosome complex affects not only craniofacial development but also retinogenesis. Zebrafish lacking functional sf3b4 displayed characteristics similar to retinitis pigmentosa (RP), marked by severe retinal pigment epithelium defects and rod degeneration. Pathway analysis revealed altered retinol metabolism and retinoic acid signaling in the sf3b4-/- mutants. Supplementation of retinoic acid rescued key cellular phenotypes observed in the sf3b4-/- mutants, offering potential therapeutic strategies for RP in the future. In conclusion, this study sheds light on the previously unknown role of SF3B4 in retinogenesis and provides insights into the underlying mechanisms of RP.
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Retinitis Pigmentosa , Empalmosomas , Animales , Empalmosomas/genética , Empalmosomas/metabolismo , Pez Cebra/genética , Pez Cebra/metabolismo , Factores de Empalme de ARN/genética , Mutación , Retinitis Pigmentosa/genética , Retinitis Pigmentosa/metabolismo , Tretinoina/metabolismoRESUMEN
Purpose: Diabetic retinopathy (DR) is a leading cause of irreversible blindness worldwide. Identifying risk factors associated with DR development and progression is crucial for improving treatment efficacy. Although proteomic changes in DR have been extensively studied, the results remain equivocal. Hence, this study aims to summarize and identify potential diagnostic or prognostic markers for DR. In addition, the upstream regulator responsible for protein deregulation of this disease was also validated. Methods: We systematically analyzed the current literature on proteomic profile changes in DR, followed by pathway analysis identification. To validate the protein level changes, ELISA was performed from serum samples collected from 27 patients with DR and 25 healthy controls. Results: Our analysis revealed that 1 candidate marker (afamin [AFM]) distinguished non-proliferative diabetic retinopathy (NPDR) from type 2 diabetic patients with no diabetic retinopathy/controls, 65 candidate markers distinguished proliferative diabetic retinopathy (PDR) from NPDR, 1 candidate marker (thyroid receptor-interacting protein 11 [TRIP11]) distinguished PDR from PDR-DME/DME, and 3 candidate markers for therapeutic evaluation of PDR. Our results pinpoint that inflammatory response, which IL-6 mainly modulated, is responsible for the changes of proteomic profiles identified in DR. This was also validated by ELISA analysis, indicating that IL-6 could be potentially useful for diagnosing DR. Conclusion: We report a comprehensive patient-based proteomic approach to identify potential biomarkers for DR diagnosis, prognosis, and treatment evaluation. Supplementary information: The online version contains supplementary material available at 10.1007/s40200-023-01204-6.
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Fatty acid oxidation disorders (FAODs) are a group of rare genetic metabolic disorders caused by mutations in genes responsible for transporting and metabolizing fatty acids in the mitochondria. One crucial enzyme involved in this process is carnitine palmitoyltransferase I (CPT1), which transports long-chain fatty acids to the mitochondrial matrix for beta-oxidation. Defects in beta-oxidation enzymes often lead to pigmentary retinopathy; however, the underlying mechanisms are not entirely understood. To investigate FAOD and its impact on the retina, we employed zebrafish as a model organism. Specifically, we used antisense-mediated knockdown strategies to target the cpt1a gene and examined the resulting retinal phenotypes. We demonstrated that the cpt1a MO-injected fish significantly reduced the length of connecting cilia and severely affected photoreceptor cell development. Moreover, our findings highlight that the loss of functional cpt1a disrupted energy homeostasis in the retina, leading to lipid droplet deposition and promoting ferroptosis, which is likely attributed to the photoreceptor degeneration and visual impairments observed in the cpt1a morphants.
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Enfermedades de la Retina , Pez Cebra , Animales , Pez Cebra/metabolismo , Carnitina O-Palmitoiltransferasa/genética , Carnitina O-Palmitoiltransferasa/metabolismo , Enfermedades de la Retina/etiología , Oxidación-Reducción , Ácidos Grasos/metabolismo , Carnitina/metabolismoRESUMEN
BACKGROUND: Brain arteriovenous malformations (bAVMs) remains one of the most prevalent causes of intracranial hemorrhage and stroke-like syndromes in the young adult population. Although it has been agreed upon that definitive treatment using either single or multi-modal approach is warranted for successful bAVM management, much debate still revolves regarding the optimal timing of definitive treatment. CASE SUMMARY: In this report, we present a case of delayed, definitive endovascular treatment for ruptured bAVM in a 21-year-old female, 3 mo post-ictus. The bAVM, with a left pericallosal feeding artery and cortical draining veins, was successfully obliterated through embolization using the Onyx 18. On follow-up the patient has recommenced her daily activities and experiences only mild occasional headaches with mild motor deficits. The report leads to our review on an important issue regarding the optimal timing of ruptured bAVM definitive management and bring forward the current evidence available on delayed vs immediate definitive bAVM intervention. We also highlight current issues that need to be addressed for clearer guidelines on definitive therapy initiation. CONCLUSION: Current treatment paradigms of ruptured bAVM remains elusive, with substantial heterogeneity in the current literature. A consensus on the definition of "acute" vs "delayed", management goal, follow-up length and outcome parameters are required to support formation of a clear paradigm.
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Variants in the gene encoding trafficking protein particle complex 11 (TRAPPC11) cause limb-girdle muscular dystrophy R18 (LGMD R18). Although recently several genes related to myopathies have been identified, correlations between genetic causes and signaling events that lead from mutation to the disease phenotype are still mostly unclear. Here, we utilized zebrafish to model LGMD R18 by specifically inactivating trappc11 using antisense-mediated knockdown strategies and evaluated the resulting muscular phenotypes. Targeted ablation of trappc11 showed compromised skeletal muscle function due to muscle disorganization and myofibrosis. Our findings pinpoint that fish lacking functional trappc11 suppressed FGF8, which resulted in the aberrant activation of Notch signaling and eventually stimulated epithelial-mesenchymal transition (EMT) and fibrotic changes in the skeletal muscle. In summary, our study provides the role of FGF8 in the pathogenesis and its therapeutic potential of LGMD R18.
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Enfermedades Musculares , Distrofia Muscular de Cinturas , Animales , Pez Cebra , Distrofia Muscular de Cinturas/genética , Enfermedades Musculares/metabolismo , Músculo Esquelético/metabolismo , MutaciónRESUMEN
Nager syndrome (NS) is a rare disease marked with craniofacial and preaxial limb anomalies. In this report, we summarized the current evidence to determine a possible genotype-phenotype association among NS individuals. Twenty-four articles comprising of 84 NS (including 9 patients with a severe form of NS [Rodriguez syndrome]) patients were examined, of which 76% were caused by variants in SF3B4 (OMIM *605593, Splicing Factor 3B, Subunit 4). Within the SF3B4 gene, variants located in exon 3 commonly occurred (20%) from a total identified variant, while hotspot location was identified in exon 1 (12%), and primarily occurred as frameshift variants (64%). Thirty-five distinct pathogenic variants within SF3B4 gene were identified with two common sites, c.1A > G and c.1060dupC in exons 1 and 5, respectively. Although no significant genotype-phenotype association was found, it is notable that patients with frameshift SF3B4 variants and predicted to lead to nonsense-mediated RNA decay (NMD) of the transcripts tended to have a more severe clinical manifestation. Additionally, patients harboring variants in exons 2 and 3 displayed a higher proportion of cardiac malformations. Taken together, this article summarizes the pathogenic variants observed in SF3B4 and provides a possible genotype-phenotype relationship in this disease.
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Mutación del Sistema de Lectura , Disostosis Mandibulofacial , Humanos , Mutación , Disostosis Mandibulofacial/genética , Factores de Empalme de ARN/genéticaRESUMEN
Treacher Collins syndrome (TCS, OMIM: 154500) is a rare congenital craniofacial disorder that is caused by variants in the genes TCOF1, POLR1D, POLR1C, and POLR1B. Studies on the association between phenotypic variability and their relative variants are very limited. This systematic review summarized the 53 literatures from PubMed and Scopus to explore the potential TCS genotype-phenotype correlations with statistical analysis. Studies reporting both complete molecular genetics and clinical data were included. We identified that the molecular anomaly within TCOF1 (88.71%) accounted for most TCS cases. The only true hot spot for TCOF1 was detected in exon 24, with recurrent c.4369_4373delAAGAA variant is identified. While the hot spot for POLR1D, POLR1C, and POLR1B were identified in exons 3, 8, and 15, respectively. Our result suggested that the higher severity level was likely to be observed in Asian patients harboring TCOF1 variants rather than POLR1. Moreover, common 5-bp deletions tended to have a higher severity degree in comparison to any variants within exon 24 of TCOF1. In summary, this report suggested the relationship between genetic and clinical data in TCS. Our findings could be used as a reference for clinical diagnosis and further biological studies.