Gastroesophageal tube of the Iguana iguana (Iguanidae): histological description, histochemical and immunohistochemical analysis of 5-HT and SS cells

The work aims were to describe the histological and histochemical structure of the gastroesophageal tube of Iguana iguana and verify the occurrence and distribution of immunoreactive serotonin (5-HT) and somatostatin (SS) cells. Fragments of the gastrointestinal tract (GIT) of five iguanas were which underwent standard histological and immunohistochemistry technique. Immunoreactive cells for 5-HT and SS were quantified using the STEPanizer. The oesophagus has ciliated columnar pseudostratified epithelium with staining Alcian blue (AB) + and goblet cells highly reactive to periodic acid Schiff (PAS). In the cervical oesophagus, the numerical density of 5-HT cells per unit area (QA [5-HT cells]/µm2) was 4.6x10-2 ± 2.0 and celomatic oesophagus presented QA = 4.0x10-2 ± 1.0. The epithelium of the stomach is simple columnar, PAS and AB +. The cranial and middle regions of the stomach presented (QA [5-HT cells]/µm2) = 6.18x10-2 ± 3.2 and the caudal region, QA = 0.6x10-2 ± 0.2. The SS cells were only observed in the caudal stomach, with numerical density (QA [SS cells]/µm2) = 1.4x10-2 ± 0.9 In I. iguana, variation was observed in terms of the distribution of mucus secretions and the pattern of occurrence of serotonin and somatostatin-secreting enteroendocrine cells in the TGI, which possibly will result in an interspecific adaptive response.

Brg1 Promotes Airway Mucus Hypersecretion via IL-13 and the JAK1/2-STAT6 Signaling Pathway in Asthma

Backgroud: The chromatin remodeling factor Brg1 (Brahma-related gene 1) is an important nuclear protein that promotes the transcriptional activation or inhibition of target genes by regulating ATP hydrolysis to generate energy which rearranges the position of nucleosomes and the interaction of histone DNA. In this study, we explored the effect of Brg1 on airway mucus hypersecretion in asthma.Methods: Six-to-eight-week-old female wild-type C57BL/6 mice (wild-type, WT) and type II alveolar epithelial cells (AECIIs) specifically knockout Brg1 mice (Brg1fl/fl) were selected as the experimental subjects. The asthma group was established with house dust mite (HDM), and the control group was treated with normal saline (n=10). Wright's staining was used to detect inflammatory cells in bronchoalveolar lavage fluid (BALF). Invasive lung function was used to assess the airway compliance. Hematoxylin and eosin and periodic acid-schiff staining were used to detect mucus secretion. The virus was used to knock down the Brg1 gene in the bronchial epithelial cell line (16HBE) and stimulated with HDM. Immunohistochemistry was used to measure mucin glycoprotein 5AC (MUC5AC) protein expression in the airway epithelium and 16HBE cells. Western blotting was used to detect the expression of the MUC5AC and JAK1/2-STAT6 signaling pathways in mouse lung tissue and 16HBE. Co-immunoprecipitation (Co-IP) and Chromatin Immunoprecipitation (CHIP) were used to detect whether Brg1 could regulate the JAK1/2-STAT6 signaling pathway.Results: Specifically, knocking out the Brg1 gene in AECIIs can reduce airway inflammation, airway compliance, and mucus hypersecretion in asthma. Knockdown of the Brg1 gene can simultaneously reduce Interleukin-13 (IL-13) and the expression of MUC5AC protein in airway epithelial cells and the activation of the JAK1/2-STAT6 signaling pathway. The results of Co-IP and CHIP showed that Brg1 could bind to the JAK1/2 promoter region, regulating the activity of the JAK1/2-STAT6 pathway affects airway mucus secretion in asthma.Conclusion: Brg1 gene knockout in airway epithelial cells can reduce asthmatic airway mucus hypersecretion and the expression of MUC5AC protein in airway epithelial cells partly by inhibiting the activation of the JAK1/2-STAT6 signaling pathway.

Sub-Chronic Difenoconazole Exposure Induced Gut Microbiota Dysbiosis in Mice

Difenoconazole (DIF) is a widely separated triazole fungicide in many countries. The excessive usage of DIF increases the high volume of residues in agriculture production and water bodies. Some previous studies demonstrated the toxic effects of DIF on non-target animals, however, there were still some gaps in the knowledge of the potential hazards of DIF to mammals and human health. Herein, 7-week-old male mice were exposed to 30 and 100 mg/kg/day DIF for 14 and 56 days. We observed that 56 days of DIF exposure decreased the colonic mucus expression of alcin blue-periodic acid-schiff (AB-PAS) stain and the immunochemical stain of muc2 protein. The transcript levels of mucin protein (muc1, muc2 and muc3) decreased significantly in the gut of mice followed 56 days of 100 mg/kg/day DIF exposure. In addition, the gut microbiota composition was also affected after 14 or 56 days of DIF exposure. Although the mucus expression after 14 days of DIF exposure only decreased slightly, the gut microbiota composition compared with the control group was changed significantly. Moreover, the DIF-30 and DIF-100 caused respectively different changes on the gut microbiota. The relative abundance of Bacteroidetes decreased significantly after 14 days and 56 days of DIF exposure. After 14 days of DIF exposure, there were 35 and 18 differential genera in the DIF-30 and DIF-100 group, respectively. There were 25 and 32 differential genera in the DIF-30 and DIF-100 group after 56 days of exposure, respectively. Meanwhile, the alpha diversity indexes, including observed species, Shannon, Simpson, Chao1 and ACE, in gut microbiota decreased significantly after 56 days of DIF exposure. Interestingly, the relative abundance of Akkermansia increased significantly after 56 days of 100 mg/kg/d DIF exposure. Although Akkermansia was considered as one probiotic, the phenomenon of dramatic Akkermansia increase with the decrease in gut microbiota diversity needed further discussion. These results provided some new insights on how DIF exposure impacts the mucus barrier and induces gut microbiota dysbiosis.

Dexrazoxane Alleviated Doxorubicin-Induced Nephropathy in Rats

<b><i>Introduction:</i></b> Doxorubicin (DOX), an anthracycline antitumor agent, has been widely used against various solid tumors and hematological malignancies. However, the clinical application of DOX is restricted by its multiple organ toxicity including nephrotoxicity. This study investigated the protective effects and mechanisms of dexrazoxane (DZR) against DOX-induced nephropathy in rats. <b><i>Methods:</i></b> Male Sprague Dawley rats received 2.5 mg/kg DOX once a week for 5 consecutive weeks. 24-h urinary protein and renal function injury biomarkers were determined to evaluate the renal function. Histopathological changes and glomerulosclerosis were examined by hematoxylin and eosin and periodic acid-Schiff staining. The change of renal ultrastructure in the DOX-induced rats was observed by the electron microscopy. The renal apoptosis was detected by TUNEL staining and measured the protein expression of Caspase-3, Bcl-2, and Bax. Renal interstitial fibrosis was determined by Masson staining and immunohistochemistry examination. The levels of vimentin, alpha-smooth muscle actin (α-SMA), and transforming growth factor β (TGF-β) in kidney tissue were detected by Western blot. <b><i>Results:</i></b> DZR pretreatment markedly raised the survival rate and improved the renal dysfunction in DOX-treated rats. DZR ameliorated DOX-induced histopathological lesion of glomerular and tubular and apoptosis. DZR restored the oxidant/antioxidant balance via regulating the levels of MDA, SOD, and TAC. DZR reduced DOX-induced collagen IV deposition and renal interstitial fibrosis and downregulated the fibrosis-related protein expressions of vimentin, α-SMA, and TGF-β1. <b><i>Conclusion:</i></b> Our results suggest DZR exerted its protective effects against DOX-induced nephropathy through inhibition of lipid peroxidation, apoptosis, and fibrosis.

Histological and Immunohistochemical Characterization of Vascular Alterations in Meninges of Cats Infected with Gurltia paralysans

Gurltia paralysans, a metastrongyloid nematode, parasitizes in meningeal vessels in the thoracolumbar spinal cord of cats in South America and causes progressive paraparesis. Recently, the first report outside of South America described gurltiosis in a cat in Spain. As this parasitic disease has so far been largely neglected, especially outside of South America, the aim of the present case study was to add knowledge to the histologic and immunohistochemical characterization of central nervous lesions. To this purpose, formalin-fixed and paraffin-embedded (FFPE) tissue samples from the spinal cord and brain of five cats affected by clinical signs caused by Gurltia paralysans and of three control cats without CNS lesions were histopathologically examined using hematoxylin and eosin stain (HE), Elastica van Gieson stain, as well as periodic acid–Schiff (PAS) reaction. Moreover, immuno- histochemistry for alpha smooth muscle actin and Factor VIII-related antigen were performed to characterize vascular lesions. Lesions were consistent with previous descriptions and were mainly located in the spinal cord and consisted of chronic suppurative or lymphoplasmahistiocytic meningi tis as well as suppurative vasculitis, congestion and varicosis of meningeal veins. In view of the recent detection of this parasite in Europe and the increasing inner-European transport of rescued domestic cats, veterinarians in Europe should be aware of the clinical and pathomorphological presentation of this disease.

circHIPK3 Exacerbates Folic Acid-Induced Renal Tubulointerstitial Fibrosis by Sponging miR-30a

Renal tubulointerstitial fibrosis is a common pathological feature of progressive chronic kidney disease (CKD), and current treatment has limited efficacy. The circular RNA circHIPK3 is reported to participate in the pathogenesis of various human diseases. However, the role of circHIPK3 in renal fibrosis has not been examined. In this study, we aimed to determine whether and how circHIPK3 might participate in the pathogenesis of renal fibrosis. Mice received a peritoneal injection of folic acid (250 mg/kg). Of note, 30 days later, renal fibrosis was present on periodic acid–Schiff (PAS) and Masson staining, and mRNA and protein of profibrotic genes encoding fibronectin (FN) and collagen 1 (COL1) were increased. Renal circHIPK3 was upregulated, while miR-30a was downregulated, assessed by quantitative PCR (qPCR) and fluorescence in situ hybridization (FISH). The expression of transforming growth factor beta-1 (TGF-β1) was increased by qPCR analysis, immunoblotting, and immunofluorescence. Renal circHIPK3 negatively correlated with miR-30a, and kidney miR-30a negatively correlated with TGF-β1. Target Scan and miRanda algorithms predicted three perfect binding sites between circHIPK3 and miR-30a. We found that circHIPK3, miR-30a, and TGF-β1 colocalized in the cytoplasm of human tubular epithelial cells (HK-2 cells) on FISH and immunofluorescence staining. We transfected circHIPK3 and a scrambled RNA into HK-2 cells; miR-30a was downregulated, and the profibrotic genes such as TGF-β1, FN, and COL1 were upregulated and assessed by qPCR, immunoblotting, and immunofluorescence staining. Third, the upregulation of circHIPK3, downregulation of miR-30a, and overproduction of profibrotic FN and COL1 were also observed in HK-2 cells exposed to TGF-β1. Finally, renal biopsies from patients with chronic tubulointerstitial nephritis manifested similar expression patterns of circHIPK3, miR-30a, and profibrotic proteins, such as TGF-β1, FN, and COL1 as observed in the experimental model. A feed-forward cycle was observed among circHIPK3, miR-30a, and TGF-β1. Our results suggest that circHIPK3 may contribute to progressive renal fibrosis by sponging miR-30a. circHIPK3 may be a novel therapeutic target for slowing CKD progression.

Collagen and Microvascularization in Placentas From Young and Older Mares

In older mares, increasing collagen fibers (fibrosis) in the endometrium and oviduct predisposes to sub-fertility and infertility. In this study, (i) gene transcription of collagen (qPCR: COL1A1, COL1A2, COL3A1, COL5A1); (ii) total collagen protein (hydroxyproline); (iii) collagen distribution (Picrosirius red staining; polarized light microscopy); and (iv) microvascular density (Periodic acid-Schiff staining), were evaluated in mares' placenta, and related to mares age, and placenta and neonate weights. Samples were collected from the gravid horn, non-gravid horn, and body of the placenta from younger (n = 7), and older mares (n = 9) of different breeds. Transcripts of COL1A1, COL3A1 and COL5A1, total collagen protein, chorionic plate connective tissue thickness, and microvascularization increased in the gravid horn of older mares' placentas, compared to the youngest (P &lt; 0.05). Although in other species placenta fibrosis may indicate placental insufficiency and reduced neonate weight, this was not observed here. It appears that older fertile mares, with more parities, may develop a heavier, more vascularized functional placenta with more collagen, throughout a longer gestation, which enables the delivery of heavier foals. Thus, these features might represent morphological and physiological adaptations of older fertile mares' placentas to provide the appropriate nutrition to the equine fetus.

A 66-Year-Old Man With Subacute Cough and Worsening Dyspnea Previously Diagnosed With COVID-19 Pneumonia

A 66-year-old man presented with subacute cough and worsening dyspnea. Labs were notable for moderate peripheral eosinophilia, and computed tomography (CT) scan demonstrated extensive crazy-paving throughout bilateral upper lung fields. Bronchoalveolar lavage (BAL) revealed macrophages with lipid-filled vacuoles and negative periodic acid-Schiff (PAS) stain. Further history obtained from the patient and family was notable for daily application of commercially available vapor rub to nares and intentional deep inhalation of nebulized fluids containing scented oils. The patient was diagnosed with exogenous lipoid pneumonia through an unusual route of lipid administration.

miR-138-5p Inhibits Vascular Mimicry by Targeting the HIF-1α/VEGFA Pathway in Hepatocellular Carcinoma

Tumor vascular mimicry (VM) is the process of new blood vessels formed by tumor cells rather than endothelial cells. An increasing number of researches have revealed that VM process is associated with cancer progression and metastasis. miR-138-5p has been reported to act as a tumor suppressor in many cancers. However, the role and underlying mechanism of miR-138-5p in hepatocellular carcinoma (HCC) VM remain unclear. In this study, VM density was detected by CD31/periodic acid-Schiff double staining in HCC clinical specimens. We found that miR-138-5p expression correlated strongly negatively with microvessel density. Additionally, miR-138-5p mimic or inhibitor decreased or increased, respectively, tube formation capacity in HepG2 and Hep3B cells. Consistent with this, miR-138-5p repressed vessel density in vivo. Moreover, miR-138-5p targeted hypoxia-inducible factor 1α (HIF-1α) and regulated expression of HIF-1α and vascular endothelial growth factor A (VEGFA), which are established classical markers of angiogenesis. Consistent with these findings, the HIF-1α inhibitor CAY10585 effectively blocked HCC cell VM and VEGFA expression. In conclusion, miR-138-5p inhibits HepG2 and Hep3B cell VM by blocking the HIF-1α/VEGFA pathway. Therefore, miR-138-5p may serve as a useful therapeutic target for miRNA-based HCC therapy.

Zhen-Wu-Tang Induced Mitophagy to Protect Mitochondrial Function in Chronic Glomerulonephritis via PI3K/AKT/mTOR and AMPK Pathways

Chronic glomerulonephritis (CGN) is one of the major causes of end-stage kidney disease. Zhen-wu-tang (ZWT), as a famous Chinese herbal prescription, is widely used in China for CGN therapy in clinic. However, the mechanism of ZWT in CGN has not been fully understood. The present study explored the therapeutic effect and the underlying mechanism of ZWT on mitochondrial function in cationic bovine serum albumin (C-BSA)-induced CGN model rats and tumor necrosis factor (TNF-α)-damaged mouse podocytes. The renal functions were measured by serum creatinine (Scr) and blood urea nitrogen (BUN). Renal pathological changes and ultrastructure of kidney tissues were evaluated by periodic acid-Schiff (PAS) staining and transmission electron microscopy. The levels of antioxidases, including mitochondrial catalase (CAT), superoxide dismutase 2 (SOD2), and peroxiredoxin 3 (PRDX3), in CGN rats were examined by real-time PCR. The mitochondrial functions of podocytes were measured by ATP concentration, mitochondrial membrane potential (MMP), and mitochondrial ROS (mtROS). For mitophagy level detection, the expressions of mitophagy-related proteins, including LC3, p62, heat shock protein 60 (HSP60), and translocase of outer mitochondrial membrane 20 (TOMM20), were measured by Western blot, as the colocation of LC3 and mitochondrial marker COX IV were evaluated by immunofluorescence. Our results manifested that ZWT ameliorated CGN model rats by a remarkable decrease in Scr and BUN, inhibition of mesangial matrix proliferation, protection against foot processes fusion, and basement membrane thickening. More importantly, ZWT protected against mitochondrial dysfunction by increasing the expressions of CAT, SOD2, and PRDX3 in CGN model rats, increased ATP content and MMP in podocytes, and decreased excessive mtROS. Furthermore, ZWT induced mitophagy in CGN through increasing the expression of LC3, and decreasing p62, HSP60, TOMM20, and ZWT also enhanced the colocation of LC3 to the mitochondria. We found that ZWT inhibited the PI3K/AKT/mTOR pathway, which could be disturbed by PI3K inhibitor LY294002 and agonist insulin-like growth factor 1. Moreover, ZWT reversed the inhibition of the AMPK pathway in CGN. Overall, ZWT ameliorated renal mitochondrial dysfunction probably by inducing mitophagy via the PI3K/AKT/mTOR and AMPK pathways.