Whole exome sequencing of patients with varicella-zoster virus and herpes simplex virus induced acute retinal necrosis reveals rare disease-associated genetic variants

Purpose: Herpes simplex virus (HSV) and varicella-zoster virus (VZV) are neurotropic human alphaherpesviruses endemic worldwide. Upon primary infection, both viruses establish lifelong latency in neurons and reactivate intermittently to cause a variety of mild to severe diseases. Acute retinal necrosis (ARN) is a rare, sight-threatening eye disease induced by ocular VZV or HSV infection. The virus and host factors involved in ARN pathogenesis remain incompletely described. We hypothesize an underlying genetic defect in at least part of ARN cases. Methods: We collected blood from 17 patients with HSV-or VZV-induced ARN, isolated DNA and performed Whole Exome Sequencing by Illumina followed by analysis in Varseq with criteria of CADD score &gt; 15 and frequency in GnomAD &lt; 0.1% combined with biological filters. Gene modifications relative to healthy control genomes were filtered according to high quality and read-depth, low frequency, high deleteriousness predictions and biological relevance. Results: We identified a total of 50 potentially disease-causing genetic variants, including missense, frameshift and splice site variants and on in-frame deletion in 16 of the 17 patients. The vast majority of these genes are involved in innate immunity, followed by adaptive immunity, autophagy, and apoptosis; in several instances variants within a given gene or pathway was identified in several patients.Discussion: We propose that the identified variants may contribute to insufficient viral control and increased necrosis ocular disease presentation in the patients and serve as a knowledge base and starting point for the development of improved diagnostic, prophylactic, and therapeutic applications.</p

Somatic insulin signaling regulates a germline starvation response in Drosophila egg chambers

AbstractEgg chambers from starved Drosophila females contain large aggregates of processing (P) bodies and cortically enriched microtubules. As this response to starvation is rapidly reversed upon re-feeding females or culturing egg chambers with exogenous bovine insulin, we examined the role of endogenous insulin signaling in mediating the starvation response. We found that systemic Drosophila insulin-like peptides (dILPs) activate the insulin pathway in follicle cells, which then regulate both microtubule and P body organization in the underlying germline cells. This organization is modulated by the motor proteins Dynein and Kinesin. Dynein activity is required for microtubule and P body organization during starvation, while Kinesin activity is required during nutrient-rich conditions. Blocking the ability of egg chambers to form P body aggregates in response to starvation correlated with reduced progeny survival. These data suggest a potential mechanism to maximize fecundity even during periods of poor nutrient availability, by mounting a protective response in immature egg chambers

Transcriptional profiling of fibroblasts from patients with mutations in MCT8 and comparative analysis with the human brain transcriptome

Thyroid hormone (TH) is crucial for normal brain development. TH transporters control TH homeostasis in brain as evidenced by the complex endocrine and neurological phenotype of patients with mutations in monocarboxylate transporter 8 (MCT8). We investigated the mechanisms of disease by analyzing gene expression profiles in fibroblasts from patients with MCT8 mutations. Studying MCT8 and its transcriptional context in different comprehensive spatial and temporal human brain transcriptome data sets revealed distinct region-specific MCT8 expression. Furthermore, MCT8 demonstrated a clear age-dependent decrease, suggesting its importance in early brain development. Performing comparative transcriptome analysis, we linked the genes differentially expressed (DE) in patient fibroblasts to the human brain transcriptome. DE genes in patient fibroblasts were strongly over-represented among genes highly correlated with MCT8 expression in brain. Furthermore, using the same approach we identified which genes in the classical TH signaling pathway are affected in patients. Finally, we provide evidence that the TRα2 receptor variant is closely connected to MCT8. The present study provides amolecular basis for understanding which pathways are likely affected in the brains of patients with mutations in MCT8. Our data regarding a functional relationship between MCT8 and TRα2 suggest an unanticipated role for TRα2 in the (patho)physiology of TH signaling in the brain. This study demonstrates how genome-wide expression data from patient-derived non-neuronal tissue related to the human brain transcriptome may be successfully employed to improve our understanding of neurological disease

Type 1 interferon-inducible gene expression in QuantiFERON Gold TB-positive uveitis: A tool to stratify a high versus low risk of active tuberculosis?

QuantiFERON-Gold TB (QFT)-positive patients with undetermined cause of uveitis are problematic in terms of whether to diagnose and treat them for tuberculosis (TB). Here, we investigated whether peripheral blood expression of type 1 interferon (IFN)-inducible genes may be of use to stratify QFT-positive patients with uveitis into groups of high versus low risk of having active TB-associated uveitis. We recruited all new uveitis patients in Cipto Mangunkusumo Hospital, Jakarta, Indonesia for one year. We included 12 patients with uveitis and clinically diagnosed active pulmonary TB, 58 QFT-positive patients with uveitis of unknown cause, 10 newly diagnosed sputum-positive active pulmonary TB patients without uveitis and 23 QFT-negative healthy controls. Expression of 35 type 1 IFN-inducible genes was measured in peripheral blood cells from active pulmonary TB patients without uveitis and healthy controls. Differentially expressed genes were identified and used for further clustering analyses of the uveitis groups. A type-1 IFN gene signature score was calculated and the optimal cut-off value for this score to differentiate active pulmonary TB from healthy controls was determined and applied to QFT-positive patients with uveitis of unknown cause. Ten type 1 IFN-inducible genes were differentially expressed between active pulmonary TB and healthy controls. Expression of these 10 genes in QFT-positive patients with uveitis of unknown cause revealed three groups: 1); patients resembling active pulmonary TB, 2); patients resembling healthy controls, and 3); patients displaying an in-between gene expression pattern. A type 1 IFN gene signature score ≥5.61 displayed high sensitivity (100%) and specificity (91%) for identification of active TB. Application of this score to QFT-positive patients with uveitis of unknown cause yielded two groups with expected different likelihood (high vs. low) of having active-TB uveitis, and therefore may be useful in clinical management decisions

Sex difference in the mouse BAT transcriptome reveals a role of progesterone in BAT function: Supplementary data

Supplementary table: Selected genes from the significant functional annotation clusters and their functional descriptio

Homologous and non-homologous recombination differentially affect DNA damage repair in mice

Ionizing radiation and interstrand DNA crosslinking compounds provide important treatments against cancer due to their extreme genotoxicity for proliferating cells. Both the efficacies of such treatments and the mutagenic potential of these agents are modulated by the ability of cells to repair the inflicted DNA damage. Here we demonstrate that homologous recombination-deficient mRAD54(–/–) mice are hypersensitive to ionizing radiation at the embryonic but, unexpectedly, not at the adult stage. However, at the adult stage mRAD54 deficiency dramatically aggravates the ionizing radiation sensitivity of severe combined immune deficiency (scid) mice that are impaired in DNA double-strand break repair through DNA end-joining. In contrast, regardless of developmental stage, mRAD54(–/–) mice are hypersensitive to the interstrand DNA crosslinking compound mitomycin C. These results demonstrate that the two major DNA double-strand break repair pathways in mammals have overlapping as well as specialized roles, and that the relative contribution of these pathways towards repair of ionizing radiation-induced DNA damage changes during development of the animal

Identification of a novel variant of the ciliopathic gene FUZZY associated with craniosynostosis

Craniosynostosis is a birth defect occurring in approximately one in 2000 live births, where premature fusion of the cranial bones inhibits growth of the skull during critical periods of brain development. The resulting changes in skull shape can lead to compression of the brain, causing severe complications. While we have some understanding of the molecular pathology of craniosynostosis, a large proportion of cases are of unknown genetic aetiology. Based on studies in mouse, we previously proposed that the ciliopathy gene Fuz should be considered a candidate craniosynostosis gene. Here, we report a novel variant of FUZ (c.851 G > C, p.(Arg284Pro)) found in monozygotic twins presenting with craniosynostosis. To investigate whether Fuz has a direct role in regulating osteogenic fate and mineralisation, we cultured primary osteoblasts and mouse embryonic fibroblasts (MEFs) from Fuz mutant mice. Loss of Fuz resulted in increased osteoblastic mineralisation. This suggests that FUZ protein normally acts as a negative regulator of osteogenesis. We then used Fuz mutant MEFs, which lose functional primary cilia, to test whether the FUZ p.(Arg284Pro) variant could restore FUZ function during ciliogenesis. We found that expression of the FUZ p.(Arg284Pro) variant was sufficient to partially restore cilia numbers, but did not mediate a comparable response to Hedgehog pathway activation. Together, this suggests the osteogenic effects of FUZ p.(Arg284Pro) do not depend upon initiation of ciliogenesis

Evaluation of immunohistochemical markers, CK17 and SOX2, as adjuncts to P53 for the diagnosis of differentiated vulvar intraepithelial neoplasia (dVIN)

Histological diagnosis of differentiated vulvar intraepithelial neoplasia (dVIN), the precursor of human papillomavirus (HPV)-independent vulvar squamous cell carcinoma (VSCC), can be challenging, as features of dVIN may mimic those of non-dysplastic dermatoses. To aid the diagnosis, p53-immunohistochemistry (IHC) is commonly used, and mutant expression patterns are used to support a histological diagnosis of dVIN. However, a proportion of dVIN can show wild-type p53-expression, which is characteristic of non-dysplastic dermatoses. Furthermore, recent research has identified a novel precursor of HPV-independent VSCC—the p53-wild-type differentiated exophytic vulvar intraepithelial lesion (de-VIL). Currently, there are no established diagnostic IHC-markers for p53-wild-type dVIN or de-VIL. We evaluated IHC-markers, cytokeratin 17 (CK17), and SRY-box 2 (SOX2), as diagnostic adjuncts for dVIN. For this, IHC-expression of CK17, SOX2, and p53 was studied in dVIN (n = 56), de-VIL (n = 8), and non-dysplastic vulvar tissues (n = 46). For CK17 and SOX2, the percentage of cells showing expression, and the intensity and distribution of expression were recorded. We also performed next generation targeted sequencing (NGTS) on a subset of dVIN (n = 8) and de-VIL (n = 8). With p53-IHC, 74% of dVIN showed mutant patterns and 26% showed wild-type expression. Median percentage of cells expressing CK17 or SOX2 was significantly higher in dVIN (p53-mutant or p53-wild-type) and de-VIL than in non-dysplastic tissues (p < 0.01). Diffuse, moderate-to-strong, full epithelial expression of CK17 or SOX2 was highly specific for dVIN and de-VIL. With NGTS, TP53 mutations were detected in both dVIN and de-VIL. We infer that immunohistochemical markers CK17 and SOX2, when used along with p53, may help support the histological diagnosis of dVIN

Nuclear factor IB is downregulated in vulvar squamous cell carcinoma (VSCC): Unravelling differentially expressed genes in VSCC through gene expression dataset analysis

Vulvar squamous cell carcinoma (VSCC) comprises two distinct etiopathological subtypes: i) Human papilloma virus (HPV)-related VSCC, which arises via the precursor high grade squamous intraepithelial lesion (HSIL); and ii) HPV-independent VSCC, which arises via precursor, differentiated vulvar intraepithelial neoplasia (dVIN), driven by TP53 mutations. However, the mechanism of carcinogen- esis of VSCC is poorly understood. The current study aimed to gain insight into VSCC carcinogenesis by identifying differentially expressed genes (DEGs) for each VSCC subtype. The expression of certain DEGs was then further assessed by performing immunohistochemistry (IHC) on whole tissue sections of VSCC and its precursors. Statistical analysis of microarrays was performed on two independent gene expres- sion datasets (GSE38228 and a study from Erasmus MC) on VSCC and normal vulva. DEGs were identified that were similarly (up/down) regulated with statistical significance in both datasets. For HPV-related VSCCs, this constituted 88 DEGs, and for HPV-independent VSCCs, this comprised 46 DEGs. IHC was performed on VSCC (n=11), dVIN (n=6), HSIL (n=6) and normal vulvar tissue (n=7) with i) signal trans- ducer and activator of transcription 1 (STAT1; an upregulated DEGs); ii) nuclear factor IB (NFIB; a downregulated DEG); iii) p16 (to determine the HPV status of tissues); and iv) p53 (to confirm the histological diagnoses). Strong and diffuse NFIB expression was observed in the basal and para-basal layers of normal vulvar tissue, whereas NFIB expression was minimal or completely negative in dVIN and in both subtypes of VSCC. In contrast, no discernable difference was observed in STAT1 expression among normal vulvar tissue, dVIN, HSIL or VSCC. By leveraging bioinformatics, the current study identified DEGs that can facilitate research into VSCC carcinogenesis. The results suggested that NFIB is down- regulated in VSCC and its relevance as a diagnostic/prognostic biomarker deserves further exploration