Tenascin-C (TNC), a non-structural extracellular matrix glycoprotein, is transiently expressed during development or after injury, playing an important role in injury and repair process. The potential role of TNC in the pathogenesis of IgA nephropathy (IgAN) remains to be clarified.Immunohistochemistry staining for TNC was conducted on paraffin-embedded slices from renal biopsies of 107 IgAN patients, and correlation analysis was made between mesangial TNC expression and clinic-pathological parameters. In situ hybridization for TNC mRNA was further performed to figure out the cells that express TNC within glomeruli. In vitro experiments were also carried out on mouse mesangial cells (SV40 MES13) to elucidate the effect of TNC on mesangial cells.TNC was expressed in the mesangial area of IgAN, as well as in fibrotic regions. Correlation analysis showed that higher mesangial TNC was associated with higher level of proteinuria, lower estimated glomerular filtration rate and more serious pathological lesions (MEST score). In situ hybridization revealed that abundant TNC mRNA expression was observed in the affected glomeruli of IgAN, but not in minimal change disease. Moreover, TNC mRNA co-localized with PDGFRβ mRNA, but not with PODXL mRNA, suggesting that TNC mRNA was expressed in the mesangial cells within glomeruli in IgAN. In vitro experiments showed that exogenous TNC promoted matrix protein production and mesangial cell proliferation, which was attenuated by an epidermal growth factor receptor inhibitor.Taken together, these results suggest that mesangial cell-derived TNC contributes to mesangial matrix expansion and mesangial cell proliferation, which is a potential therapeutic target in IgAN.

A unique set of features and characteristics of species of the Cnidaria phylum is the one reason that makes them a model for a various studies. The plasticity of a life cycle and the processes of cell differentiation and development of an integral multicellular organism associated with it are of a specific scientific interest. A new stage of development of molecular genetic methods, including methods for high-throughput genome, transcriptome, and epigenome sequencing, both at the level of the whole organism and at the level of individual cells, makes it possible to obtain a detailed picture of the development of these animals. This review examines some modern approaches and advances in the reconstruction of the processes of ontogenesis of cnidarians by studying the regulatory signal transduction pathways and their interactions.

Diabetic nephropathy (DN) is one of the most common and serious complications of diabetes, which can lead to renal failure and fatality. miRNAs are an important class of endogenous non-coding RNAs implicated in a wide range of biological processes and pathological conditions. This study aims to investigate the potential functional roles of miR-543 in DN and its underlying mechanisms.qRT-PCR was performed to detect the expression levels of miR-543 and TSPAN8 in kidney tissues of mice with DN. Western blot (WB) was used to measure the protein levels. CCK8 assay was employed to evaluate the proliferation of HK2 cells. Dual luciferase reporter assay was conducted to verify the functional interaction between miR-543 and TSpan8.The downregulation of miR-543 and upregulation of TSPAN8 were observed in kidney tissues of mice with DN. miR-543 mimic significantly decreased cell proliferation and autophagy in high-glucose (HG)-induced HK2 cells, and promoted cell fibrosis. We further identified a putative binding site between miR-543 and TSPAN8, which was validated by Dual luciferase reporter assay. The treatment of miR-543 mimic and miR-543 inhibitor could reduce or increase TSPAN8 protein level respectively. We further showed that the overexpression of TSPAN8 could attenuate HG-induced cell injury by reducing fibrosis and increase autophagy. The effects of miR-543 mimic in proliferation, fibrosis, and autophagy were rescued by TSPAN8 overexpression.Our study indicate that miR-543 mediates high-glucose induced DN via targeting TSPAN8. Interfering miR-543/TSPAN8 axis could serve as potential approach to ameliorate DN.

SARS-CoV-2 has evolved into a panel of variants of concern (VOCs) and constituted a sustained threat to global health. The wildtype (WT) SARS-CoV-2 isolates fail to infect mice, while the Beta variant, one of the VOCs, has acquired the capability to infect standard laboratory mice, raising a spreading risk of SARS-CoV-2 from humans to mice. However, the infectivity and pathogenicity of other VOCs in mice remain not fully understood. In this study, we systematically investigated the infectivity and pathogenicity of three VOCs, Alpha, Beta, and Delta, in mice in comparison with two well-understood SARS-CoV-2 mouse-adapted strains, MASCp6 and MASCp36, sharing key mutations in the receptor-binding domain (RBD) with Alpha or Beta, respectively. Our results showed that the Beta variant had the strongest infectivity and pathogenicity among the three VOCs, while the Delta variant only caused limited replication and mild pathogenic changes in the mouse lung, which is much weaker than what the Alpha variant did. Meanwhile, Alpha showed comparable infectivity in lungs in comparison with MASCp6, and Beta only showed slightly lower infectivity in lungs when compared with MASCp36. These results indicated that all three VOCs have acquired the capability to infect mice, highlighting the ongoing spillover risk of SARS-CoV-2 from humans to mice during the continued evolution of SARS-CoV-2, and that the key amino acid mutations in the RBD of mouse-adapted strains may be referenced as an early-warning indicator for predicting the spillover risk of newly emerging SARS-CoV-2 variants.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes respiratory disease in mink similar to human COVID-19. We characterized the pathological findings in 72 mink from US farms with SARS-CoV-2 outbreaks, localized SARS-CoV-2 and its host cellular receptor angiotensin-converting enzyme 2 (ACE2) in mink respiratory tissues, and evaluated the utility of various test methods and specimens for SARS-CoV-2 detection in necropsy tissues. Of SARS-CoV-2-positive animals found dead, 74% had bronchiolitis and diffuse alveolar damage (DAD). Of euthanized SARS-CoV-2-positive animals, 72% had only mild interstitial pneumonia or minimal nonspecific lung changes (congestion, edema, macrophages); similar findings were seen in SARS-CoV-2-negative animals. Suppurative rhinitis, lymphocytic perivascular inflammation in the lungs, and lymphocytic infiltrates in other tissues were common in both SARS-CoV-2-positive and SARS-CoV-2-negative animals. In formalin-fixed paraffin-embedded (FFPE) upper respiratory tract (URT) specimens, conventional reverse transcription-polymerase chain reaction (cRT-PCR) was more sensitive than in situ hybridization (ISH) or immunohistochemistry (IHC) for detection of SARS-CoV-2. FFPE lung specimens yielded less detection of virus than FFPE URT specimens by all test methods. By IHC and ISH, virus localized extensively to epithelial cells in the nasal turbinates, and prominently within intact epithelium; olfactory mucosa was mostly spared. The SARS-CoV-2 receptor ACE2 was extensively detected by IHC within turbinate epithelium, with decreased detection in lower respiratory tract epithelium and alveolar macrophages. This study expands on the knowledge of the pathology and pathogenesis of natural SARS-CoV-2 infection in mink and supports their further investigation as a potential animal model of SARS-CoV-2 infection in humans.

Ranaviruses are large double-stranded DNA viruses within the genus Ranavirus (family Iridoviridae) that are being detected with increasing frequency among aquacultured and wild fishes. In the USA, multiple sturgeon hatcheries have experienced ranavirus epizootics resulting in significant morbidity and mortality in young-of-year (YOY). Significant economic losses have resulted from repeated outbreaks of frog virus 3 (FV3), the type species for the genus Ranavirus, in YOY pallid sturgeon Scaphirhynchus albus reared at a hatchery within the Missouri River Basin. Water temperature and stocking density are known to influence the severity of ranavirus disease in ectothermic vertebrates. To determine the effect of water temperature on ranavirus disease in hatchery-raised S. albus, we conducted FV3 challenges at 2 temperatures (17 and 23°C) and compared cumulative survival over a 28 d study period. A mean (±SE) survival rate of 57.5 ± 13.2% was observed in replicate tanks of sturgeon maintained at 23°C, whereas no mortality was observed among sturgeon maintained at 17°C. In a second challenge study, we compared the effect of water temperature on disease progression by regularly sampling fish over the study period and evaluating lesions by histopathology and in situ hybridization, and by assessing viral titer and load in external and internal tissues using virus isolation and qPCR, respectively. Results suggest that temperature manipulation may be an effective mitigation strategy that sturgeon hatcheries can employ to minimize ranavirus-associated disease.

In humans, basaloid follicular hamartomas are benign follicular tumours, that can be solitary or multiple, in which case they show autosomal dominant inheritance.This study describes clinical and histopathological findings observed in a young cat, which could be consistent with basaloid follicular hamartomas.Multiple follicular abnormalities, consistent with cutaneous diffuse basaloid follicular hamartomas, were observed in skin samples from a one-year old neutered domestic short hair cat. Clinical signs were diffuse symmetrical alopecia with exaggerated skin markings (ventral abdomen, thorax and medial aspects of the limbs) and intense follicular-centred thickening (face and feet). Microscopic lesions were characterised by multiple proliferative follicular abnormalities in all samples. The epidermis showed a very irregular surface with the follicles filled with variably pigmented keratin. The epithelial walls of the follicles had multiple small hyperplastic basaloid cells foci. In the superficial dermis under the epidermis and around the follicles, fibroblastic spindle-shaped mesenchymal cells with a homogeneous moderate density were present in the collagenous connective tissue. The interfollicular epidermis was also abnormal with multiple small proliferating trichoblastic foci originating from the basal layer. RNAscope testing for feline papillomavirus was negative.This case report provides the first evidence of clinical and histopathological findings of multiple follicular abnormalities, consistent with cutaneous diffuse basaloid follicular hamartomas in a cat.

Introduction: Avian influenza (AI) is a highly contagious disease that, during the last few years, has been occurring with increased frequency in Europe. Immunohistochemistry (IHC) is commonly used to demonstrate AI virus (AIV) antigens in affected tissues. Recent studies suggest that RNAscope in-situ hybridization outperforms IHC for viral detection in human tissues. This study aims to validate and compare RNAscope with IHC routinely used for the detection of AIV. Materials and Methods: RNAscope targeting the Influenza M gene and anti-influenza A virus nucleoprotein IHC were first performed on AIV positive (n=7) and negative tissues (n=6) collected between 2009 and 2021, including seven avian species (chicken, duck, guinea fowl, quail, turkey, goose and houbara bustard) and three different AIVs (H5N8, H5N9, H6N1). A Tissue Micro-Array (TMA) with 132 cores, including 44 triplicated organs (brain, lung, heart, spleen, pancreas) originating from nine mule ducks naturally infected with H5N8 (2020) was then used to compare techniques through computer-assisted quantitative analysis. Results: AIV nucleoprotein and M gene were detected in all positive tissues of all species and for all AIVs. All uninfected birds were negative. While IHC appeared affected by autolysis, the quality of the RNAscope signal remained unchanged. On the TMA, viral detection efficacy measurements revealed higher sensitivity with RNAscope compared with IHC, in particular for brain and heart tissues. Conclusions: These preliminary results indicate that RNAscope is a suitable and sensitive tool for the detection of AIV and encourage the development of additional probes for the detection of AIV subtypes.

Introduction: OvHV-2 and other gamma-herpesviruses of the Rhadinovirus genus are responsible for malignant catarrhal fever (MCF) in cattle. Sheep are considered asymptomatic carriers and shedders of OvHV-2. A 1-year-old sheep died following several days of malaise and wasting. The cause of death was attributed to multisystemic vasculitis due to ovine herpesvirus-2 (OvHV-2) as supported by pathological and virological findings. Materials and Methods: The investigation involved post-mortem examination, histopathological evaluation, real-time polymerase chain reaction (RT-PCR) on spleen for the detection of OvHV-2 and in-situ hybridization (ISH) using RNAScope^® on sections of brain and lung. Results: A marked lymphohistiocytic polyarteritis with segmental to circumferential expansion of all mural layers in medium and small arteries was present in multiple organs. The low cycle threshold value (19.84) for OvHV2 DNA on splenic material was highly suggestive of active viral replication in which ISH further demonstrated co-localisation of OvHV-2 nucleic acids within the vascular lesions. Conclusions: The pathogenesis of OvHV-2 in this case is not fully understood. The authors speculate that immune insufficiency might have enabled this otherwise endogenous, persistent and clinically innocuous virus to cause clinical disease in this sheep. It is important to consider OvHV-2 amongst the differential diagnoses in sheep presented with polyarteritis.

The multilayered meninges surrounding the brain and spinal cord harbor distinct immune cell populations with prominent roles in health and diseases. Here we present an optimized protocol for RNA fluorescence in situ hybridization (RNA FISH) in meningeal whole mounts, allowing the visualization of gene expression. We also describe the combination of this protocol with immunohistochemistry for simultaneous visualization of mRNA and proteins. This protocol can be used for assessing spatial gene expression within the meninges.

The SARS-CoV-2 Omicron (B.1.1.529) variant has proven highly transmissible and has outcompeted the Delta variant in many regions of the world. Early reports have also suggested that Omicron may result in less severe clinical disease in humans. Here we show that Omicron is less pathogenic than prior SARS-CoV-2 variants in Syrian golden hamsters.Hamsters were inoculated with either SARS-CoV-2 Omicron or other SARS-CoV-2 variants. Animals were followed for weight loss, and upper and lower respiratory tract tissues were assessed for viral loads and histopathology.Infection of hamsters with the SARS-CoV-2 WA1/2020, Alpha, Beta, or Delta strains led to 4-10% weight loss by day 4 and 10-17% weight loss by day 6. In contrast, infection of hamsters with two different Omicron challenge stocks did not result in any detectable weight loss, even at high challenge doses. Omicron infection led to substantial viral replication in both the upper and lower respiratory tracts but demonstrated lower viral loads in lung parenchyma and reduced pulmonary pathology compared with WA1/2020 infection.These data suggest that the SARS-CoV-2 Omicron variant may result in robust upper respiratory tract infection but less severe lower respiratory tract clinical disease compared with prior SARS-CoV-2 variants.Funding for this study was provided by NIH grant CA260476, the Massachusetts Consortium for Pathogen Readiness, the Ragon Institute, and the Musk Foundation.

Multiple myeloma (MM) is an incurable plasma cell malignancy in the bone marrow (BM), while immunoglobulin D type of MM (IgD MM) is a very rare but most severe subtype in all MM cases. Therefore, systemic study on IgD MM is purposeful to disclose the recurrent and refractory features in both IgD and other types of MM, and beneficial to the development of potent therapeutic strategy on MM.Agilent SBC-ceRNA microarray chips were employed to examine 3 normal plasma cell samples (NPCs), 5 lgD MM samples and 5 lgG MM samples, respectively. Sanger sequencing, RNase R digestion and qPCR assays were used to detect the existence and expression of circHNRNPU. BaseScope RNA ISH assay was performed to test circHNRNPU levels in paraffin-embedded MM tissues. The protein encoded by circHNRNPU was identified by LC-MS/MS, which was named as circHNRNPU_603aa. The function of circHNRNPU_603aa on cellular proliferation and cell cycle was assessed by MTT test, colony formation assay, flow cytometry and MM xenograft mouse model in vivo. RIP-seq, RIP-PCR and WB analysis for ubiquitination were performed to explore the potential mechanism of circHNRNPU_603aa in MM. Exosomes were isolated from the culture supernatant of MM cells by ultracentrifugation and characterized by Transmission Electron Microscope and WB confirmation of exosomes markers Alix and CD9.CircHNRNPU was one of the top most abundant and differentially expressed circRNA in IgD MM relative to lgG and NPCs samples. Increased circHNRNPU was associated with poor outcomes in four independent MM patient cohorts. Intriguingly, MM cells secreted circHNRNPU, which encoded a protein named as circHNRNPU_603aa. Overexpressed circHNRNPU_603aa promoted MM cell proliferation in vitro and in vivo, in contrast knockdown of circHNRNPU_603aa by siRNA abrogated these effects. Due to circHNRNPU_603aa including RNA-binding RGG-box region, it regulated SKP2 exon skipping, thereby competitively inhibited c-Myc ubiquitin so as to stabilize c-Myc in MM. MM cells secreted circHNRNPU through exosomes to interfere with various cells in the BM microenvironment.Our findings demonstrate that circHNRNPU_603aa is a promising diagnostic and therapeutic marker in both MM cells and BM niche.