A novel missense variant in PRKCB segregates low-frequency hearing loss in an autosomal dominant family with Meniere's disease.

Meniere's Disease (MD) is a complex disorder associated with an accumulation of endolymph in the membranous labyrinth in the inner ear. It is characterized by recurrent attacks of spontaneous vertigo associated with sensorineural hearing loss (SNHL) and tinnitus. The SNHL usually starts at low and medium frequencies with a variable progression to high frequencies. We identified a novel missense variant in the PRKCB gene in a Spanish family with MD segregating low-to-middle frequency SNHL. Confocal imaging showed strong PKCB II protein labelling in non-sensory cells, the tectal cells and inner border cells of the rat organ of Corti with a tonotopic expression gradient. The PKCB II signal was more pronounced in the apical turn of the cochlea when compared with the middle and basal turns. It was also much higher in cochlear tissue than in vestibular tissue. Taken together, our findings identify PRKCB gene as a novel candidate gene for familial MD and its expression gradient in supporting cells of the organ of Corti deserves attention, given the role of supporting cells in K+ recycling within the endolymph, and its apical turn location may explain the onset of hearing loss at low frequencies in MD.

Modulation of the inflammatory response of immune cells in human peripheral blood by oxidized arachidonoyl aminophospholipids.

Aminophospholipids (APL), phosphatidylethanolamine (PE) and phosphatidylserine (PS), can be oxidized upon oxidative stress. Oxidized PE and PS have been detected in clinical samples of different pathologies and may act as modulators of the inflammatory response. However, few studies have focused on the effects of oxidized APL (ox-APL) esterified with arachidonic acid, even though a considerable number of studies have assessed the modulation of the immune system by oxidized 1-palmitoyl-2-arachidonoyl-sn-3-glycerophosphocholine (OxPAPC). In the present study, we have used flow cytometry to evaluate the ability of oxidized PAPE (OxPAPE) and PAPS (OxPAPS) to promote or suppress an inflammatory phenotype on monocytes subsets and myeloid dendritic cells (mDCs). The results indicate that OxPAPE increases the frequency of all monocyte subpopulations expressing TNF-α, which promotes an inflammatory response. However, immune cell stimulation with OxPAPE in the presence of LPS results in a decrease of TNF-α expressed by classical monocytes. Incubation with OxPAPS and LPS induces a decrease in TNF-α produced by monocytes, and a significant decrease in IL-1ß expressed by monocytes and mDCs, indicating that OxPAPS reduces the LPS-induced pro-inflammatory expression in these populations. These results show the importance of OxPAPE and OxPAPS as modulators of the inflammatory response and demonstrate their possible contribution to the onset and resolution of human diseases related to oxidative stress and inflammation.

Identification of two novel mutations in FAM136A and DTNA genes in autosomal-dominant familial Meniere's disease.

Meniere's disease (MD) is a chronic disorder of the inner ear defined by sensorineural hearing loss, tinnitus and episodic vertigo, and familial MD is observed in 5-15% of sporadic cases. Although its pathophysiology is largely unknown, studies in human temporal bones have found an accumulation of endolymph in the scala media of the cochlea. By whole-exome sequencing, we have identified two novel heterozygous single-nucleotide variants in FAM136A and DTNA genes, both in a Spanish family with three affected cases in consecutive generations, highly suggestive of autosomal-dominant inheritance. The nonsense mutation in the FAM136A gene leads to a stop codon that disrupts the FAM136A protein product. Sequencing revealed two mRNA transcripts of FAM136A in lymphoblasts from patients, which were confirmed by immunoblotting. Carriers of the FAM136A mutation showed a significant decrease in the expression level of both transcripts in lymphoblastoid cell lines. The missense mutation in the DTNA gene produces a novel splice site which skips exon 21 and leads to a shorter alternative transcript. We also demonstrated that FAM136A and DTNA proteins are expressed in the neurosensorial epithelium of the crista ampullaris of the rat by immunohistochemistry. While FAM136A encodes a mitochondrial protein with unknown function, DTNA encodes a cytoskeleton-interacting membrane protein involved in the formation and stability of synapses with a crucial role in the permeability of the blood-brain barrier. Neither of these genes has been described in patients with hearing loss, FAM136A and DTNA being candidate gene for familiar MD.

The absence of seroconversion after exposition to hepatitis C virus is not related to KIR-HLA genotype combinations (GEHEP-012 study).

BACKGROUND & AIMS: It has been reported that specific killer-cell immunoglobulin-like receptors (KIRs) and HLA genotype combinations, such as KIR2DS4/HLA-C1 with presence of KIRDL2 or KIRDL3, homozygous KIRDL3/HLA-C1 and KIR3DL1/≥2HLA-Bw4, are strongly associated with the lack of active infection and seroconversion after exposition to hepatitis C virus (HCV). OBJECTIVE: To determine whether these KIR-HLA combinations are relevant factors involved in that phenotype. PATIENTS AND METHODS: In this retrospective case-control study, genotype data from a genome-wide association study previously performed on low susceptibility to HCV-infection carried out on 27 high-risk HCV-seronegative (HRSN) individuals and 743 chronically infected (CI) subjects were used. HLA alleles were imputed using R package HIBAG v1.2223 and KIR genotypes were imputed using the online resource KIR*IMP v1.2.0. RESULTS: It was possible to successfully impute at least one KIR-HLA genotype combination previously associated with the lack of infection and seroconversion after exposition to HCV in a total of 23 (85.2%) HRSN individuals and in 650 (87.5%) CI subjects. No KIR-HLA genotype combination analyzed was related to the HRSN condition. CONCLUSIONS: Our results suggest that those KIR-HLA genotype combinations are not relevant factors involved in the lack of infection and seroconversion after exposition to HCV. More studies will be needed to completely understand this phenotype.

Hepatic Steatosis and Weight Gain During the Coronavirus Disease 2019 Pandemic Among People With Human Immunodeficiency Virus: Impact of Therapy With Tenofovir Alafenamide.

Background: Lockdown due to the coronavirus disease 2019 (COVID-19) pandemic led to increases in weight in part of the population. Weight gain leads to hepatic steatosis (HS). Antiretroviral treatment could also influence HS in people with human immunodeficiency virus (PWH). The impact of lockdown on HS in PWH is unknown. The aim of this study was to analyze the changes in HS, as measured by the controlled attenuation parameter (CAP), during the COVID-19 pandemic in PWH. Methods: This was a cohort study that included PWH who attended a tertiary care center in southern Spain from January 2018 to December 2021. The CAP was evaluated by transient elastography. Only those who had a valid CAP before and after March 2020 were included. HS was defined as CAP ≥248 dB/m. Results: Six hundred eighty PWH were attended and 488 (71.8%) were included. Two hundred and fourteen (43.9%) had HS at baseline and 239 (49%) at the end of the follow-up (P = .036). The median change in CAP among PWH taking tenofovir alafenamide (TAF) was 8.5 (interquartile range [IQR], -24 to 46.3) dB/m versus -4 (IQR, -35 to 27) dB/m among PWH receiving TAF-free regimens (P = .003). After multivariate analysis, adjusted by sex and age, weight gain (adjusted odds ratio [AOR], 1.09 [95% confidence interval {CI}, 1.05-1.14]; P < .001), TAF therapy (AOR, 1.59 [95% CI, 1.07-2.35]; P = .021), plasma triglycerides (AOR, 1.01 [95% CI, 1-1.01]; P < .001), and fasting blood glucose (AOR, 1.01 [95% CI, 1-1.02]; P = .027) were associated with HS at the end of follow-up. Conclusions: The frequency of HS increased during the COVID-19 pandemic among PWH. TAF is associated with HS development, regardless of metabolic factors.

SARS-CoV-2 viral RNA detection using the novel CoVradar device associated with the CoVreader smartphone app.

The COVID-19 pandemic has highlighted the need for innovative approaches to its diagnosis. Here we present CoVradar, a novel and simple colorimetric method that combines nucleic acid analysis with dynamic chemical labeling (DCL) technology and the Spin-Tube device to detect SARS-CoV-2 RNA in saliva samples. The assay includes a fragmentation step to increase the number of RNA templates for analysis, using abasic peptide nucleic acid probes (DGL probes) immobilized to nylon membranes in a specific dot pattern to capture RNA fragments. Duplexes are formed by labeling complementary RNA fragments with biotinylated SMART bases, which act as templates for DCL. Signals are generated by recognizing biotin with streptavidin alkaline phosphatase and incubating with a chromogenic substrate to produce a blue precipitate. CoVradar results are analysed by CoVreader, a smartphone-based image processing system that can display and interpret the blotch pattern. CoVradar and CoVreader provide a unique molecular assay capable of detecting SARS-CoV-2 viral RNA without the need for extraction, preamplification, or pre-labeling steps, offering advantages in terms of time (∼3 h/test), cost (∼€1/test manufacturing cost) and simplicity (does not require large equipment). This solution is also promising for developing assays for other infectious diseases.

Tumor Resection Induces Alterations on Serum Phospholipidome of Liver Cancer Patients.

Hepatocellular carcinoma and cholangiocarcinoma are the most common primary malignant liver tumors. Since the liver plays a key role in lipid metabolism, the study of serum phospholipid (PL) profiles may provide a better understanding of alterations in hepatic lipid metabolism. In this study, we used a high-resolution HILIC-LC-MS lipidomic approach to establish the serum phospholipidome profile of patients with liver cancer before (T0) and after tumor resection (T1) and a control group (CT) of healthy individuals. After the analysis of PL profiles, we observed that the phospholipidome of patients with liver cancer was significantly modified after the tumor resection procedure. We observed an upregulation of some phosphatidylcholine (PtdCho) species, namely, PtdCho(36:6), PtdCho(42:6), PtdCho(38:5), PtdCho(36:5), PtdCho(38:6) and choline plasmalogens (PlsCho), and/or 1-O-alkyl-2-acyl-glycerophosphocholine (PakCho) in patients with liver cancer at T0 compared to the CT group, and a downregulation after tumor resection (T1) when compared to T0. These results show that LC-MS can detect different serum PL profiles in patients with liver cancer, before and after tumor resection, by defining a specific PL fingerprint that was used to determine the effect of tumor and tumor resection on lipid metabolism.

Functional Impairment of Circulating FcεRI+ Monocytes and Myeloid Dendritic Cells in Hepatocellular Carcinoma and Cholangiocarcinoma Patients.

BACKGROUND: Hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA) represent the most common primary liver malignancies whose outcome is influenced by the immune response. METHODS: In this study, we have functionally characterized, by flow cytometry, circulating myeloid dendritic cells (mDCs) and FcεRI+ monocytes in a group of healthy individuals (n = 10) and in a group of patients with HCC (n = 19) and CCA (n = 8), at the time point of the surgical resection (T0) and once the patient had recovered from surgery (T1). Moreover, we proceeded to a more in depth phenotypic characterization of the FcεRI+ monocyte subpopulation. RESULTS: A significant decrease in the frequency of TNFα producing FcεRI+ monocytes and mDCs in HCC and CCA patients when compared to the group of healthy individuals was observed, and a close association between FcεRI+ monocytes and mDCs dysfunction was identified. In addition, the phenotypic characteristics of FcεRI+ monocytes from healthy individuals strongly suggest that this population drives to mDCs, which matches with the fact that both populations are functionally affected. CONCLUSIONS: The frequency and the function of circulating mDCs and FcεRI+ monocytes are affected in both HCC and CCA patients, and FcεRI+ monocytes could represent those fated to become mDCs. © 2019 International Clinical Cytometry Society.

Subcutaneous immunotherapy induces alterations in monocytes and dendritic cells homeostasis in allergic rhinitis patients.

BACKGROUND: Specific subcutaneous immunotherapy (SCIT) can achieve long-term remission in patients with allergic rhinitis (AR) through complex and still unknown mechanisms. The aim of this study is to evaluate the effect of SCIT over CD16+ and CD16- monocytes, myeloid (mDCs) and plasmacytoid dendritic cells (pDCs) in patients with AR, comparatively to pharmacological standard treatment (non-SIT). METHODS: The relative frequency and absolute number of monocytes and DC subsets, the frequency of these cells producing TNFα after in vitro stimulation with Dermatophagoides pteronyssinus (Dpt) extract, and the expression levels of receptor-bound IgE or IgG were assessed by flow cytometry, in peripheral blood samples from 23 healthy individuals (HG) and 43 participants with AR mono-sensitized to Dpt; 10 with non-SIT treatment and 33 under SCIT, just before (SCIT-T0) and 4 h after administration (SCIT-T4). Moreover, IFNα mRNA expression was evaluated in purified pDCs, by qRT-PCR. RESULTS: After SCIT administration we observed a strong decrease of circulating pDCs, although accompanied by higher levels of IFNα mRNA expression, and an increase of circulating CD16+ monocytes. AR participants under SCIT exhibited a higher expression of receptor-bound IgE in all cell populations that expressed the high affinity receptor for IgE (FcεRI) and a higher frequency of CD16+ monocytes producing TNFα. Conversely, we observed a decrease in the frequency of mDCs producing TNFα in AR under SCIT, similar to the observed in the control group. CONCLUSIONS: SCIT seems to induce numeric, phenotypic, and functional changes in circulating monocytes and dendritic cells, contributing at least in part to the well described immunological alterations induced by this type of immunotherapy.

Variable expressivity and genetic heterogeneity involving DPT and SEMA3D genes in autosomal dominant familial Meniere's disease.

Autosomal dominant (AD) familial Meniere's disease (FMD) is a rare disorder involving the inner ear defined by sensorineural hearing loss, tinnitus and episodic vertigo. Here, we have identified two novel and rare heterozygous variants in the SEMA3D and DPT genes segregating with the complete phenotype that have variable expressivity in two pedigrees with AD-FMD. A detailed characterization of the phenotype within each family illustrates the clinical heterogeneity in the onset and progression of the disease. We also showed the expression of both genes in the human cochlea and performed in silico analyses of these variants. Three-dimensional protein modelling showed changes in the structure of the protein indicating potential physical interactions. These results confirm a genetic heterogeneity in FMD with incomplete penetrance and variable expressivity.