Search Results (65)

Allergic rhinitis (AR) is characterized by persistent epithelial remodeling, yet the upstream drivers and molecular mechanisms remain poorly defined. Analysis of nasal mucosa from AR patients revealed marked epithelial remodeling, oxidative stress, and Th2 inflammation. Transcriptome analysis of nasal mucosa revealed RhoA as one of the most upregulated genes, with expression positively correlating with disease severity. Using epithelial-specific RhoA-deficient mice (RhoA^cKO) and fasudil, a RhoA/ROCK inhibitor, we found that loss of RhoA/ROCK signaling markedly attenuated nasal Th2 inflammation, oxidative stress, and epithelial remodeling following allergen challenge. Further transcriptome analysis demonstrated that elevated RhoA activation was associated with increased epithelial cellular senescence. Both in vitro and in vivo studies confirmed that epithelial RhoA activation promotes allergen- or Th2 cytokine-induced cellular senescence, whereas genetic or pharmacologic elimination of senescent cells alleviated allergic inflammation and tissue remodeling. Pathway analysis identified PRKN (parkin) as a central node within RhoA-regulated, senescence-associated networks in AR. Functional studies showed that PRKN overexpression mitigated IL-13-induced mitochondrial dysfunction, oxidative stress, and epithelial senescence in human nasal epithelial cells. Together, these findings reveal that RhoA-driven epithelial senescence contributes to allergic inflammation and epithelial remodeling in AR and identify PRKN as a potential therapeutic target to restore epithelial homeostasis. Full article

Background/Objective: Genetic factors contribute significantly to Parkinson’s disease (PD), especially in cases with early onset or positive family history. However, previous investigations of the genetic landscape in PD populations were mainly based on targeted genotyping. The aim of this study was to investigate the prevalence of pathogenic variants in known PD-associated genes in a series of Swedish PD patients. Methods: We performed whole-exome sequencing on 285 PD probands from southern Sweden. Our series was enriched for patients with early disease onset or positive family history. We focused on 44 genes previously linked to PD. Results: We identified a CHCHD2 p.(Phe84LeufsTer6) frameshift variant in two unrelated patients and report the first PD case of Swedish ancestry carrying the VPS35 p.(Asp620Asn) variant. Additionally, in one patient each, we found an SNCA duplication, an SNCA p.(Ala53Thr) variant, and a LRRK2 p.(Gly2019Ser) variant. Thus, only 2.1% (n = 6) of patients in this series had Mendelian monogenic PD forms. In addition, forty-three patients carried variants in GBA1, including T369M, which may lack disease-association in our population (n = 12); E326K (n = 22), which is classified as a PD risk variant; as well as N370S (n = 3), R329H (n = 3), S107L (n = 1), and L444P (n = 1), with one patient harboring both T369M and E326K. Pathogenic variants in ARSA, ATP7B, and PRKN genes were also detected in heterozygote form, but their role in PD remains uncertain. Conclusions: Monogenic forms of PD are rare in southern Sweden, even among the familial and early-onset PD patients that were overrepresented in our study. Our findings highlight the genetic diversity in Swedish PD patients and identify key variants for further functional and clinical studies. Full article

Background/Objectives: Suicide is a significant public health concern with a multifactorial etiology. The biological background of suicide is not sufficiently explored, which encumbers suicide prevention. Epigenetic mechanisms may mediate environmental influences on suicide risk. Recent studies have suggested that protein aggregation occurs in the brains of patients with chronic psychiatric disorders and suicidality, which may influence disease trajectory. However, the intersection between epigenetics and proteinopathy in suicide remains unexplored. Our pilot study investigated whether aggregation-related genes show epigenetic and transcriptional alterations in the post-mortem brains of individuals who had died by suicide. Methods: Brain tissue from 69 male subjects (32 suicide by hanging, 37 sudden cardiac death controls) was collected at autopsy. Genome-wide hippocampal DNA methylation data from our previous reduced representation bisulfite sequencing (RRBS) study were reanalyzed to identify differentially methylated cytosines (DMCs) in candidate aggregation-related genes. The expression of nine candidate and three reference genes in the hippocampus and Brodmann area 46 was assessed by qPCR. Statistical analyses were performed using Student’s t-test or Mann–Whitney U test (p < 0.05 was considered significant). Results: Reanalysis revealed hypomethylation in suicide cases within CRMP1, DISC1, MAPT, SOD1, PRKN, GABARAPL1, GRIN2A, and GRIN2B. In the hippocampus, suicides exhibited increased expression of CRMP1, SOD1, PRKN, GABARAPL1, and GRIN2A, and decreased MAPT expression. The GRIN2A/GRIN2B ratio was significantly elevated. In Brodmann area 46, altered expression was limited to increased GRIN2A and decreased DISC1. Conclusions: This is the first study to implicate epigenetic and transcriptional dysregulation of protein aggregation-associated genes in suicide. The findings suggest a possible role for proteostasis disturbances in suicidality, particularly within the hippocampal pathways related to stress response and synaptic signaling. Validation in larger cohorts and protein-level studies are warranted to determine the functional significance of these findings. Full article

Background/Objectives: Prior studies have reported a complex interplay between Parkinson’s disease (PD) and malignancy. Although patients with PD often present a lower general risk for several types of cancer, some forms—including melanoma—show elevated frequency. The present work aimed to evaluate the occurrence of cancers other than melanoma among individuals with sporadic and genetic PD. Methods: We examined medical histories from 1888 participants with PD and 438 healthy controls (HCs) using the Parkinson’s Progression Markers Initiative (PPMI) dataset, with a focus on neoplastic disease. In cases with positive cancer history, genetic information was additionally assessed [carriers of mutations in the most prevalent PD-related genes were evaluated]. Results: Our results demonstrate that cancer incidence was antecedent to PD diagnosis for the majority of PD patients, while the most common cancer types apart from malignant melanoma were non-melanoma skin cancer and prostate cancer. Conclusions: Regarding genetic PD patients, the most common cancer types in the LRRK2 and GBA1 groups were skin cancer and lymphoma, while PRKN/PARK2 carriers appeared with an overall increased incidence of cancer. No statistically significant results were observed comparing cancer incidence in PD patients to that in healthy control individuals. Interesting results were obtained by dividing the patients by gender, showing increased cancer risk in female PD patients and female LRRK2 carriers, along with increased breast cancer risk in female PD patients compared to healthy controls. Full article

Neurodegeneration is intrinsically linked to aging through processes such as oxidative stress, mitochondrial dysfunction, and chronic inflammation. Nuclear factor erythroid 2-related factor 2 (Nrf2) emerges as a central transcription factor regulating these molecular events and promoting cytoprotective responses. In neurodegenerative diseases, notably, frontotemporal dementia (FTD) and Parkinson’s disease (PD), genetic mutations—including MAPT, LRRK2, PINK1, PRKN, and SNCA—have been reported to alter Nrf2 signaling, both in vitro and in vivo. Melatonin, a neurohormone widely known for its strong antioxidant and mitochondria-stabilizing properties, has been shown to activate Nrf2 and restore redox balance in several experimental models of neurodegeneration. Its effects include a reduction in tau hyperphosphorylation, α-synuclein aggregation, and neuroinflammation. While most data are derived from sporadic models of Alzheimer’s disease and PD, emerging evidence supports a role for melatonin in familial forms of FTD and PD as well. Thus, targeting Nrf2 through melatonin may offer a promising approach to mitigating neurodegeneration, especially in the context of mutation-driven pathologies. Further investigation is warranted to explore mutation-specific responses and optimize the therapeutic strategies. Full article

Background: Breast cancer (BC) is the most common cancer and the leading cause of cancer death in women. Hereditary BC risk accounts for 25% of all cases. Pathological variants in known BC precursor genes explain only about 30% of hereditary BC cases, while the underlying genetic factors in most families remain unknown. Identifying hereditary cancer risk factors will help improve genetic counseling, cancer prevention, and cancer care. Methods: Here, we used whole-exome sequencing (WES) to identify genetic variants in 105 Vietnamese patients with BC and 50 healthy women. BC-associated variants were screened by the Franklin software and the criteria of the American College of Medical Genetics and Genomics (ACMG) and evaluated based on in silico analysis. Results: In total, 56 variants were identified in 37 genes associated with BC, including ACVR1B, APC, AR, ARFGEF1, ATM, ATR, BARD1, BLM, BRCA1, BRCA2, CASP8, CASR, CHD8, CTNNB1, ESR1, FAN1, FGFR2, HMMR, KLLN, LZTR1, MCPH1, MLH1, MSH2, MSH3, MSH6, NF1, PMS2, PRKN, RAD54L, RB1CC1, RECQL, SLC22A18, SLX4, SPTBN1, TP53, WRN, and XRCC3 in 41 patients. Among them, 12 variants were novel, and 10 variants were assessed as pathogenic/likely pathogenic by ACMG and ClinVar. Variants of uncertain significance (VUS) were evaluated using in silico prediction software to predict whether they are likely to cause the disease in patients. Conclusions: This is the first WES study to identify BC-associated genetic variants in Vietnamese patients, providing a comprehensive database of BC susceptibility gene variants. We suggest using WES as a tool to identify genetic variants in BC patients for risk prediction and treatment guidance. Full article

Background/Objectives: Major Depression (MD) is a common disorder that has significant social and economic impacts. Approximately 30% of all MD patients are refractory to common treatments, representing a major obstacle to managing the impacts of depression. One potential explanation for the incomplete treatment efficacy in MD is a substantial divergence in the mechanisms and brain networks involved in different subtypes of the disorder. The aim of this study was to identify novel brain regional targets for MD clinical screening using a gene-informed approach. Methods: A new analysis pipeline, called “Analysis Tool for Local Association of Neuronal Transcript Expression” (ATLANTE), was generated and validated. The pipeline identifies brain regions based on the shared high expression of user-generated gene lists; in this study, the pipeline was applied to discover brain regions that may be significant to MD. Results: Nine discrete brain regions of interest to MD were identified, including the temporal pole, anterior transverse temporal gyrus (Heschl’s gyrus), olfactory tubercle, ventral tegmental area, postcentral gyrus, CA1 of the hippocampus, olfactory area, perirhinal gyrus, and posterior insular cortex. The application of network and clustering analyses identified genes of special importance, including, most notably, PRKN. Conclusions: This study provides two major insights. The first is that several brain regions have unique MD-associated genetic architectures, indicating a potential explanation for subtype-specific dysfunction. The second insight is that the PRKN gene, which is strongly associated with Parkinson’s disease, is a key player amongst the MD-associated genes. These findings reveal novel targets for the clinical screening of depression and reinforce a mechanistic connection between MD and Parkinson’s disease. Full article

Hyperechogenicity of the substantia nigra (SN) is observed using transcranial ultrasonography in patients with Parkinson’s Disease. In this study, we investigated whether monogenic forms of PD are more prevalent in these patients and clinically defined their characteristics. Eighty-eight PD patients were part of the analysis. All patients received clinical diagnoses from experienced movement disorder specialists. Each patient underwent transcranial ultrasonography and genetic testing for mutations in the SNCA, PRKN, LRRK2, DJ1, and PINK1 genes. SN hyperechogenicity was identified in 48 patients. Compared to the non-hyperechogenicity group, these patients did not have monogenic forms of PD more frequently, but they did have REM sleep behavior disorder significantly more often, lived in rural areas, and experienced a later age of disease onset. Our study indicated no association between substantia nigra echogenicity and the presence of mutations in the SNCA, LRRK2, DJ1, PRKN, and PINK1 genes. Hyperechogenicity of the substantia nigra, however, remains a common finding in patients with Parkinson’s Disease, correlating with certain features of the disease. Full article

Background: Autosomal recessive juvenile Parkinson disease (ARJP) is an early-onset neurodegenerative disorder characterized by Parkinsonian motor symptoms with slow progression and preserved cognition. Biallelic pathogenic variants within the PRKN gene are associated with ARJP. Among PRKN pathogenic variants, deletions are a frequent occurrence and may be identified through chromosomal microarray testing. Methods: Here we present a case with two intragenic PRKN deletions initially identified as a secondary finding using chromosomal microarray. One deletion was paternally inherited and the second initially appeared to be de novo. In addition to microarray which initially identified the two deletions, long-range GAP-PCR and Sanger sequencing were used to further characterize the de novo deletion and phase of the deletions. Results: Molecular characterization of the apparently de novo deletion demonstrated low-level maternal mosaicism of this deletion, thus proving that these deletions are in trans in the proband, yielding a diagnosis of autosomal recessive juvenile Parkinson disease. Conclusions: This case highlights the utility of a diagnostic approach combining microarray, long-range PCR, and Sanger sequencing to establish the phase and confirm biallelic PRKN deletions in a patient with ARJP. Furthermore, these findings highlight the importance of investigating the possibility of parental mosaicism to determine the phase of autosomal recessive variants and establish accurate recurrence risks. Full article

Background: Growing evidence suggests that the prevalence of sarcopenic obesity (SOB) is on the rise across the globe. However, the key molecular mechanisms behind this disease have not been clarified. Methods: In this experiment, we fed zebrafish a high-fat diet (HFD) for 16 weeks to induce sarcopenic obesity. Results: After a dietary trial, HFD zebrafish exhibited an obese phenotype with skeletal muscle atrophy and decreased swimming capacity. We demonstrated that mitochondrial content and function were abnormal in SOB zebrafish skeletal muscle. These results may be associated with the impairment of mitophagy regulated by the PTEN-induced putative kinase 1 (PINK1)/Parkin (PRKN) pathway. In addition, we also found that NOD-like receptor protein 3 (NLRP3)/gasdermin D (GSDMD) signaling was activated with the upregulation of NLRP3, GSDMD-NT, and mature-IL1β, which indicated that pyroptosis was induced in SOB zebrafish skeletal muscle. Conclusions: Our study identified that impaired mitophagy and pyroptosis were associated with the pathogenesis of SOB. These results could potentially offer novel therapeutic objectives for the treatment of sarcopenic obesity. Full article

Parkinson’s disease (PD) is a neurodegenerative disease with a high prevalence among the middle-aged and elderly population. The pathogenesis of PD is closely linked to the misfolding and aggregation of α-synuclein, which contributes to the formation of Lewy bodies. These processes are associated with the degeneration of dopaminergic neurons, a key neuropathological change that underlies the motor symptoms of PD. In addition, genetic susceptibility, mitochondrial dysfunction, oxidative stress and neuroinflammation are involved in the progress of the disease. Previous studies indicated that the dysregulation of epigenetic modifications, including DNA methylation and histone acetylation, may be the key pathophysiological factors in PD. N6-methyladenosine (m6A) is a dynamically reversible modification in eukaryotes RNA, and could regulate mRNA degradation, stability, maturation, and translation. Recently, clinical research has shown that the global m6A level is significantly reduced in PD patients as well as the expression changes in m6A-associated proteins. Moreover, the dysregulation of m6A modification was shown to impact dopamine metabolism and damage dopaminergic neurons, indicating that m6A RNA modification may play a critical role in the pathogenesis of PD. In this review, we summarize recent clinical studies on m6A RNA modification in PD patients and discuss the regulatory role of m6A modification in dopamine metabolism and dopaminergic neurons death. Furthermore, based on the different m6A modification databases and prediction websites, we analyzed the potential m6A modification sites on the mRNA of key PD pathogenic genes (SNCA, PRKN, PINK1, and LRRK2) for the first time, aiming to offer new gene targets and perspectives understanding the pathogenesis of PD. Full article

Background: Parkinson’s disease (PD) is a genetically complex neurodegenerative disorder. Up to 15% of cases are considered monogenic. However, research on monogenic PD has largely focused on populations of European ancestry, leaving gaps in our understanding of genetic variability in other populations. This study addresses this gap by analysing the allele frequencies of pathogenic and likely pathogenic variants in known monogenic PD genes across eight global populations, using data from the gnomAD database. Methods: We compiled a list of 27 genes associated with Mendelian PD from the Online Mendelian Inheritance in Man (OMIM) database, and identified pathogenic and likely pathogenic variants using ClinVar. We then performed pairwise comparisons of allele frequencies across populations included in the gnomAD database. Variants with significant frequency differences were further assessed using in silico pathogenicity predictions. Results: We identified 81 variants across 17 genes with statistically significant allele frequency differences between at least two populations. Variants in GBA1 were the most prevalent among monogenic PD-related genes, followed by PLA2G6, ATP13A2, VPS13C, and PRKN. GBA1 exhibited the greatest variability in allele frequencies, particularly the NM_000157.4:c.1226A>G (p.Asn409Ser) variant. Additionally, we observed significant population-specific differences in PD-related variants, such as the NM_032409.3:c.1040T>C (p.Leu347Pro) variant in PINK1, which was most prevalent in East Asian populations. Conclusions: Our findings reveal substantial population-specific differences in the allele frequencies of pathogenic variants linked to monogenic PD, emphasising the need for broader genetic studies beyond European populations. These insights have important implications for PD research, genetic screening, and understanding the pathogenesis of PD in diverse populations. Full article

Parkinson’s Disease (PD) is the most frequent movement disorder and is second only to Alzheimer’s Disease as the most frequent neurodegenerative pathology. Early onset Parkinson’s disease (EOPD) is less common and may be characterized by genetic predisposition. NGS testing might be useful in the diagnostic assessment of these patients. A panel of eight genes (SNCA, PRKN, PINK1, DJ1, LRRK2, FBXO7, GBA1 and HFE) was validated and used as a diagnostic tool. A total of 38 in sequence EOPD patients of the Parkinson’s Disease Unit of our Hospital Institution were tested. In addition, the number of the hexanucleotide repeats of the C9ORF72 gene and the frequency of main HFE mutations were evaluated. Six patients were carriers of likely pathogenic mutations in heterozygosity in the analyzed genes, one of them presented mutations in association and another had a complex genetic background. Their clinical symptoms were correlated with their genotypes. In the cohort of patients, only the p.Cys282Tyr of HFE was significantly decreased in the dominant model and allele contrast comparison. Only one patient with one allele of C9ORF72 containing 10 repeats was identified and clinically described. The clinical signs of sporadic and monogenic PD are often very similar; for this reason, it is fundamental to correlate genotypes and phenotypes, as we tried to describe here, to better classify PD patients with the aim to deepen our knowledge in the molecular mechanisms involved and collaborate in reaching a personalized management and treatment. Full article

Neonatal encephalopathy suspected to be due to hypoxic ischaemic encephalopathy (NESHIE) carries the risk of death or severe disability (cognitive defects and cerebral palsy). Previous genetic studies on NESHIE have predominantly focused on exomes or targeted genes. The objective of this study was to identify genetic variants associated with moderate–severe NESHIE through whole-genome, unbiased analysis. Variant filtering and prioritization were performed, followed by association testing both on a case–control basis and to compare the grades of severity and/or progression. Association testing on neonates with NESHIE (N = 172) and ancestry-matched controls (N = 288) produced 71 significant genetic variants (false discovery rate corrected p-value < 6.2 × 10⁻⁴), all located in non-coding regions and not previously implicated in NESHIE. Disease-associated variants in non-coding regions are considered to affect regulatory functions, possibly by modifying gene expression, promoters, enhancers, or DNA structure. The most significant variant was at position 6:162010973 in the Parkin RBR E3 ubiquitin protein ligase (PRKN) intron. Intronic variants were also identified in genes involved in inflammatory processes (SLCO3A1), DNA repair (ZGRF1), synaptogenesis (CNTN5), haematopoiesis (ASXL2), and the transcriptional response to hypoxia (PADI4). Ten variants were associated with a higher severity or lack of improvement in NESHIE, including one in ADAMTS3, which encodes a procollagen amino protease with a role in angiogenesis and lymphangiogenesis. This analysis represents one of the first efforts to analyze whole-genome data to investigate the genetic complexity of NESHIE in diverse ethnolinguistic groups of African origin and provides direction for further study. Full article

Neurotrophic keratopathy (NK) is a degenerative corneal disease characterized by impaired corneal sensitivity and epithelial repair that is often linked to sensory nerve dysfunction. To establish a clinically relevant model and explore the mechanisms underlying NK pathogenesis, we developed a novel mouse model through partial transection of the ciliary nerve. This approach mimics the progressive nature of NK, reproducing key clinical features such as corneal epithelial defects, reduced sensitivity, diminished tear secretion, and delayed wound healing. Using this model, we investigated how disruptions in mitochondrial dynamics contribute to corneal epithelial dysfunction and impaired repair in NK. Our findings revealed substantial disruptions in mitochondrial dynamics, including reduced expression of fusion proteins (OPA1), downregulation of fission regulators (FIS1 and MFF), and impaired mitochondrial transport, as evidenced by decreased expression of Rhot1 and Kif5b. Additionally, the downregulation of mitophagy-related genes (Pink1 and Prkn) contributed to the accumulation of dysfunctional mitochondria, leading to DNA damage and impaired corneal epithelial repair. These mitochondrial abnormalities were accompanied by increased γH2AX staining, indicative of DNA double-strand breaks and cellular stress. This study highlights the pivotal role of mitochondrial dynamics in corneal epithelial health and repair, suggesting that therapeutic strategies aimed at restoring mitochondrial function, enhancing mitophagy, and mitigating oxidative stress may offer promising avenues for treating NK. Full article