Secretory Glycoprotein Research Articles

Microanatomy of the Testes and Male Genital Ducts of Banded Krait Bungarus fasciatus (Schneider, 1801)

The Banded krait is a species of venomous snakes that ranks among the top 5 in Thailand, with a significance role as a predator for controlling other animals. Despite numerous studies on the ecology, the microanatomy of body systems has still not reported clearly. The present study was to investigate the microanatomy of the testes and male genital ducts of Banded krait that collected from Phatthalung Province, Thailand. The snakes were collected after anesthetized, and their testes and genital ducts were fixed in Bouin’s fixative. The reproductive organs were collected during July to October 2022, and were sectioned of 5-µm-thick pieces for staining with Harris’s hematoxylin and eosin (H&E), periodic acid Schiff’s (PAS), alcian blue (AB) pH 2.5 and pH 1.0, bromophenol blue (BB) and Masson’s trichrome (MT). The testes contained the seminiferous tubules with 7 stages of germ cells: (I) type A spermatogonium, (II) type B spermatogonium, (III) primary spermatocyte, (IV) secondary spermatocyte, (V) round spermatid, (VI) elongated spermatid and (VII) spermatozoa. Besides, Sertoli and Leydig’s cells were appeared in the seminiferous tubules and the interstitial area, respectively. During the sampling period, the spermatozoa were observed in the seminiferous tubules and genital ducts. The extra-testicular rete testis, ductuli efferentes and ductus epididymis were embedded in the epididymal sheath. The epithelial cells of rete testis, ductus epididymis, as well as ductus deferens possessed microvilli, whereas those of the ductuli efferentes composed of cilia. The epithelial cells of all portions showed the positive staining with PAS and BB due to the presence of neutral glycoproteins and proteins, respectively, and the negative staining for AB pH 2.5 and pH 1.0 because of the absence of acidic glycoproteins. HIGHLIGHTS During the sampling period from July to October, the Banded Krait exhibited active spermatogenesis The rete testis could be divided into 2 portions: intra-rete testis and extra-rete testis The ductus epididymis was divided into 3 portions: proximal, middle and distal ductus epididymis All portions of the male genital ducts, the epithelium showed the secretion of neutral glycoproteins and proteins without sulfated and carboxylated glycoproteins GRAPHICAL ABSTRACT

ZG16 impacts gut microbiota-associated intestinal inflammation and pulmonary mucosal function through bacterial metabolites

Zymogen granule 16 (ZG16) is a secretory glycoprotein found in zymogen granules, which also plays an important role in colorectal inflammation and cancer. Herein, a ZG16 gene knock-out (ZG16−/−) mouse line was established and we found that ZG16 deletion damaged the intestinal mucosal barrier and gut microbiota, which resulted in low-level inflammation and further promoted the development of ulcerative colitis and inflammation-related colorectal cancer. Meanwhile, a metabolomics analysis on mouse feces showed that the metabolites significantly differed between ZG16−/− and WT mice, which were important mediators of host-microbiota communication and may impact the pulmonary inflammation of mice. Indeed, ZG16−/− mice showed more severe inflammation in a bronchial asthma model. Taken together, the results demonstrate that ZG16 plays a pivotal role in inhibiting inflammation and regulating immune responses in colorectum and lung of experimental animals, which may provide a better understanding of the underlying mechanism of human inflammatory diseases associated with ZG16.

Underlying Mechanism of Fluoride Inhibits Colonic Gland Cells Proliferation by Inducing an Inflammation Response.

The integrity of colonic gland cells is a prerequisite for normal colonic function and maintenance. To evaluate the underlying injury mechanisms in colonic gland cells induced by excessive fluoride (F), forty-eight female Kunming mice were randomly allocated into four groups and treated with different concentrations of NaF (0, 25, 50, and 100 mg F-/L) for 70 days. As a result, the integrity of the colonic mucosa and the cell layer was seriously damaged after F treatment, as manifested by atrophy of the colonic glands, colonic cell surface collapse, breakage of microvilli, and mitochondrial vacuolization. Alcian blue and periodic acid Schiff staining revealed that F decreased the number of goblet cells and glycoprotein secretion. Furthermore, F increased the protein expression of TLR4, NF-κB, and ERK1/2 and decreased IL-6, interfered with NF-κB signaling, following induced colonic gland cells inflammation. The accumulation of F inhibited proliferation via the JAK/STAT signaling pathway, as characterized by decreased mRNA and protein expression of JAK, STAT3, STAT5, PCNA, and Ki67 in colon tissue. Additionally, the expression of CDK4 was up-regulated by increased F concentration. In conclusion, excessive F triggered colonic inflammation and inhibited colonic gland cell proliferation via regulation of the NF-κB and JAK/STAT signaling pathways, leading to histopathology and barrier damage in the colon. The results explain the damaging effect of the F-induced inflammatory response on the colon from the perspective of cell proliferation and provide a new idea for explaining the potential mechanism of F-induced intestinal damage.

Osteoprotegerin (OPG): A potential biomarker for adverse cardiovascular events in stable coronary artery disease.

Osteoprotegerin (OPG) is a secretory glycoprotein known for its involvement in bone metabolism and immune regulation. Research has extended OPG's significance in cardiovascular diseases (CVDs). Elevated OPG levels have been associated with increased cardiovascular risks, prompting interest in its role as a potential biomarker. This study summarizes several studies that investigated the relationship between OPG levels and the incidence of CVD. The studies indicate that higher plasma levels of OPG are associated with an increased incidence of all-cause death, cardiovascular death, and heart failure, even after adjusting for clinical confounders. Moreover, the findings suggest that OPG has the potential to serve as a predictive biomarker for adverse cardiovascular events in the patient population studied. The findings suggest that OPG could aid in risk stratification, allowing clinicians to identify high-risk patients who might benefit from intensified preventive measures or tailored therapeutic interventions. Therefore, early identification of individuals at risk for adverse cardiovascular events could lead to improved patient outcomes and reduced disease burden. OPG's role in bone health and immune regulation has expanded to potential use as a biomarker for adverse cardiovascular events in stable coronary artery disease (CAD) patients. Despite limitations, its association with cardiovascular risks highlights its importance in risk assessment and personalized interventions.

Sargassum polysaccharide attenuates osteoarthritis in rats and is associated with the up-regulation of the ITGβ1-PI3K-AKT signaling pathway

BackgroundOsteoarthritis (OA) presents a formidable challenge, characterized by as-yet-unclear mechanical intricacies within cartilage and the dysregulation of bone homeostasis. Our preliminary data revealed the encouraging potential of a Sargassum polysaccharide (SP), in promoting chondrogenesis. The aim of our study is to comprehensively assess the therapeutic effects of SP on OA models and further elucidate its potential mechanism. MethodsThe protective effects of SP were initially evaluated in an inflammation-induced human chondrocyte (C28) cell model. CCK-8 assays, Alcian blue staining, RT-qPCR and Western blotting were used to verify the chondrogenesis of SP in vitro. To assess the efficacy of SP in vivo, surgically induced medial meniscus destabilization (DMM) OA rats underwent an 8-week SP treatment. The therapeutic effects of SP in OA rats were comprehensively evaluated using X-ray imaging, micro-computed tomography (μ-CT), histopathological analysis, as well as immunohistochemical and immunofluorescent staining. Following these assessments, we delved into the potential signaling pathways of SP in inflammatory chondrocytes utilizing RNA-seq analysis. Validation of these findings was conducted through RT-qPCR and western blotting techniques. ResultsSP significantly enhance the viability of C28 chondrocytes, and increased the secretion of acidic glycoproteins. Moreover, SP stimulated the expression of chondrogenic genes (Aggrecan, Sox9, Col2a1) and facilitated the synthesis of Collagen II protein in C28 inflammatory chondrocytes. In vivo experiments revealed that SP markedly ameliorated knee joint stenosis, alleviated bone and cartilage injuries, and reduced the histopathological scores in the OA rats. μ-CT analysis confirmed that SP lessened bone impairments in the medial femoral condyle and the subchondral bone of the tibial plateau, significantly improving the microarchitectural parameters of the subchondral bone. Histopathological analyses indicated that SP notably enhanced cartilage quality on the surface of the tibial plateau, leading to increased cartilage thickness and area. Immunohistochemistry staining and immunofluorescence staining corroborated these findings by showing a significant promotion of Collagen II expression in OA joints treated with SP. RNA-seq analysis suggest that SP's effects were mediated through the regulation of the ITGβ1-PI3K-AKT signaling axis, thereby stimulating chondrogenesis. Verification through RT-qPCR and Western blot analyses confirmed that SP significantly upregulated the expression of ITGβ1, p110δ, AKT1, ACAN, and Col2a1. Notably, knock-down of ITGβ1 using siRNA in C28 chondrocytes inhibited the expression of ITGβ1, p110δ, AKT1, and ACAN. However, these inhibitory effects were not completely reversed by supplemental SP intervention. ConclusionsIn summary, our findings reveal that SP significantly enhances chondrogenesis both in vitro and in vivo, alleviating OA progression both in bone and cartilage. The observed beneficial effects are intricately linked to the activation of the ITGβ1-PI3K-AKT signaling axis. The translational potential of this articleOur research marks the first instance unveiling the advantageous effects and underlying mechanisms of SP in OA treatment. With its clinical prospects, SP presents compelling new evidence for the advancement of a next-generation polysaccharide drug for OA therapy.

CREG1 promotes bovine placental trophoblast cells exosome release by targeting IGF2R and participates in regulating organoid differentiation via exosomes transport

BackgroundPlacental exosomes are a kind of intercellular communication media secreted by placental cells during pregnancy, exosomogenesis and release are regulated by many secretory glycoproteins. CREG1 is a kind of secreted glycoprotein widely expressed in various organs and tissues of the body, which inhibits cell proliferation and enhances cell differentiation. The aim of this study was to explore the role of CREG1 in regulating exosomogenesis during the proliferation and differentiation of placental trophoblast cells in early pregnant dairy cows by targeting IGF2R and participating in regulating organoid differentiation via exosomes transport. MethodsMolecular biological methods were firstly used to investigate the expression patterns of CREG1, IGF2R and exosomal marker proteins in early placental development of pregnant dairy cows. Subsequently, the effects of CREG1 on the formation and release of bovine placental trophoblast (BTCs) derived exosomes by targeting IGF2R were investigated. Further, the effects of CREG1 on the change of gene expression patterns along with the transport of exosomes to recipient cells and participate in regulating the differentiation of organoids were explored. ResultsThe expression of CREG1, IGF2R and exosomal marker proteins increased with the increase of pregnancy months during the early evolution of placental trophoblast cells in dairy cows. Overexpression of Creg1 enhanced the genesis and release of exosomes derived from BTCs, while knocking down the expression of Igf2r gene not only inhibited the genesis of exosomes, but also inhibited the genesis and release of exosomes induced by overexpression of CREG1 protein. Interestingly, IGF2R can regulate the expression of CREG1 through reverse secretion. What's more, the occurrence and release of trophoblast-derived exosomes are regulated by CREG1 binding to IGF2R, which subsequently binds to Rab11. CREG1 can not only promote the formation and release of exosomes in donor cells, but also regulate the change of gene expression patterns along with the transport of exosomes to recipient cells and participate in regulating the early development of placenta. ConclusionsOur study confirmed that CREG1 is involved in the exosomogenesis and release of exosomes during the proliferation and differentiation of placental trophoblast cells in early pregnant dairy cows by targeting IGF2R, and is involved in the regulation of organoid differentiation through exosome transport.

N-glycosylation of Wnt3 regulates the progression of hepatocellular carcinoma by affecting Wnt/β-catenin signal pathway.

Wnt/FZD-mediated signaling pathways are activated in more than 90% of hepatocellular carcinoma (HCC) cell lines. As a well-known secretory glycoprotein, Wnt3 can interact with FZD receptors on the cell surface, thereby activating the Wnt/β-catenin signaling pathway. However, the N-glycosylation modification site of Wnt3 and the effect of this modification on the biological function of the protein are still unclear. To investigate the effect of Wnt3 N-glycosylation on the biological function of HCC cells. Site-directed mutagenesis was used to verify the Wnt3 N-glycosylation sites, actinomycin D treatment was used to detect the stability of Wnt3 after site-directed mutation, the binding of the N-glycosylation site-directed mutant Wnt3 to FZD7 was observed by laser confocal microscopy, and the effects of the N-glycosylation site-directed mutation of Wnt3 on the Wnt/β-catenin signaling pathway and the progression of HCC cells were detected by western blot and cell function experiments. Wnt3 has two N-glycosylation-modified sites (Asn90 and Asn301); when a single site at amino acid 301 is mutated, the stability of Wnt3 is weakened; the binding ability of Wnt3 to FZD7 decreases when both sites are mutated simultaneously; and the level of proteins related to the Wnt/β-catenin signaling pathway is downregulated. Cell proliferation, migration and invasion are also weakened in the case of single 301 site and double-site mutations. These results indicate that by inhibiting the N-glycosylation of Wnt3, the proliferation, migration, invasion and colony formation abilities of liver cancer cells can be weakened, which might provide new therapeutic strategies for clinical liver cancer in the future.

Angiopoietin-like protein 4 induces growth hormone variant secretion and aggravates insulin resistance during pregnancy, linking obesity to gestational diabetes mellitus.

Angiopoietin-like protein 4 (ANGPTL4) is a secretory glycoprotein involved in regulating glucose homeostasis in non-pregnant subjects. However, its role in glucose metabolism during pregnancy and the pathophysiology of gestational diabetes mellitus (GDM) remains elusive. Thus, this study aimed to clarify the relationship between ANGPTL4 and GDM and investigate the pathophysiology of placental ANGPTL4 in glucose metabolism. We investigated this issue using blood and placenta samples in 957 pregnant women, the human 3A-sub-E trophoblast cell line, and the L6 skeletal muscle cell line. We found that ANGPTL4 expression in the placenta was higher in obese pregnant women than in lean controls. Palmitic acid significantly induced ANGPTL4 expression in trophoblast cells in a dose-response manner. ANGPTL4 overexpression in trophoblast cells resulted in endoplasmic reticulum (ER) stress, which stimulated the expression and secretion of growth hormone-variant (GH2) but not human placental lactogen. In L6 skeletal muscle cells, soluble ANGPTL4 suppressed insulin-mediated glucose uptake through the epidermal growth factor receptor (EGFR)/extracellular signal-regulated kinases 1/2 (ERK 1/2) pathways. In pregnant women, plasma ANGPTL4 concentrations in the first trimester predicted the incidence of GDM and were positively associated with BMI, plasma triglyceride, and plasma GH2 in the first trimester. However, they were negatively associated with insulin sensitivity index ISI0,120 in the second trimester. Overall, placental ANGPTL4 is induced by obesity and is involved in the pathophysiology of GDM via the induction of ER stress and GH2 secretion. Soluble ANGPTL4 can lead to insulin resistance in skeletal muscle cells and is an early biomarker for predicting GDM.

Lipocalin-2 as a prognostic marker in patients with acute exacerbation of idiopathic pulmonary fibrosis

BackgroundLipocalin-2 (LCN2) is a secretory glycoprotein upregulated by oxidative stress; moreover, patients with idiopathic pulmonary fibrosis (IPF) have shown increased LCN2 levels in bronchoalveolar lavage fluid (BALF). This study aimed to determine whether circulatory LCN2 could be a systemic biomarker in patients with IPF and to investigate the role of LCN2 in a bleomycin-induced lung injury mouse model.MethodsWe measured serum LCN2 levels in 99 patients with stable IPF, 27 patients with acute exacerbation (AE) of IPF, 51 patients with chronic hypersensitivity pneumonitis, and 67 healthy controls. Further, LCN2 expression in lung tissue was evaluated in a bleomycin-induced lung injury mouse model, and the role of LCN2 was investigated using LCN2-knockout (LCN2 -/-) mice.ResultsSerum levels of LCN2 were significantly higher in patients with AE-IPF than in the other groups. The multivariate Cox proportional hazards model showed that elevated serum LCN2 level was an independent predictor of poor survival in patients with AE-IPF. In the bleomycin-induced lung injury mouse model, a higher dose of bleomycin resulted in higher LCN2 levels and shorter survival. Bleomycin-treated LCN2 -/- mice exhibited increased BALF cell and protein levels as well as hydroxyproline content. Moreover, compared with wild-type mice, LCN2-/- mice showed higher levels of circulatory 8-isoprostane as well as lower Nrf-2, GCLC, and NQO1 expression levels in lung tissue following bleomycin administration.ConclusionsOur findings demonstrate that serum LCN2 might be a potential prognostic marker of AE-IPF. Moreover, LCN2 expression levels may reflect the severity of lung injury, and LCN2 may be a protective factor against bleomycin-induced acute lung injury and oxidative stress.

Novel insight into FCSK-congenital disorder of glycosylation through a CRISPR-generated cell model.

FCSK-congenital disorder of glycosylation (FCSK-CDG) is a recently discovered rare autosomal recessive genetic disorder with defective fucosylation due to mutations in the fucokinase encoding gene, FCSK. Despite the essential role of fucokinase in the fucose salvage pathway and severe multisystem manifestations of FCSK-CDG patients, it is not elucidated which cells or which types of fucosylation are affected by its deficiency. In this study, CRISPR/Cas9 was employed to construct an FCSK-CDG cell model and explore the molecular mechanisms of the disease by lectin flow cytometry and real-time PCR analyses. Comparison of cellular fucosylation by lectin flow cytometry in the created CRISPR/Cas9 FCSK knockout and the same unedited cell lines showed no significant change in the amount of cell surface fucosylated glycans, which is consistent with the only documented previous study on different cell types. It suggests a probable effect of this disease on secretory glycoproteins. Investigating O-fucosylation by analysis of the NOTCH3 gene expression as a potential target revealed a significant decrease in the FCSK knockout cells compared with the same unedited ones, proving the effect of fucokinase deficiency on EGF-like repeats O-fucosylation. This study expands insight into the FCSK-CDG molecular mechanism; to the best of our knowledge, it is the first research conducted to reveal a gene whose expression level alters due to this disease.

Preparation of natural high-mannose-type oligosaccharides (Glc1Man9GlcNAc2) with the asparagine-glycine-threonine as consensus sequence from chicken egg yolk

High-mannose-type glycan structure of N-glycoproteins plays important roles in the proper folding of proteins in sorting glycoprotein secretion and degradation of misfolded proteins in the endoplasmic reticulum (ER). The Glc1Man9GlcNAc2 (G1M9)-type N-glycan is one of the most important signaling molecules in the ER. However, current chemical synthesis strategies are laborious, warranting more practical approaches for G1M9-glycopeptide development. Wang et al. reported the procedure to give G1M9-Asn-Fmoc through chemical modifications and purifications from 40 chicken eggs, but only 3.3 mg of G1M9-glycopeptide was obtained. Therefore, better methods are needed to obtain more than 10 mg of G1M9-glycopeptide. In this study, we report the preparation of G1M9-glycopeptide (13.2 mg) linking Asn-Gly-Thr triad as consensus sequence from 40 chicken eggs. In this procedure, λ-carrageenan treatment followed by papain treatment was used to separate the Fc region of IgY antibody that harbors high-mannose glycans. Moreover, cotton hydrophilic interaction liquid chromatography was adapted for easy purification. The resulting G1M9-Asn(Fmoc)-Gly-Thr was identified by nuclear magnetic resonance and mass spectroscopy. G1M9-Asn(Fmoc)-Gly, G1M9-Asn(Fmoc), and G1M9-OH were also detected by mass spectroscopy. Here, our developed G1M9-tripeptide might be useful for the elucidation of glycoprotein functions as well as the specific roles of the consensus sequence.

Histomorphometrical and histochemical study of small intestine development in local chicken (Gallus gallus domesticus) and duck (Anas platyrhynchos domesticus) embryos

This study demonstrated for the first time the histomorphometry of the small intestine (SI) and distribution of goblet and Paneth cells, collagen, and smooth muscle fibers in (SI) of the local chicken and duck during embryological development using the combined PAS and Alcian blue (pH2.5), Geimsa, and Masson's trichrome stains. One hundred and four fertilized chicken eggs and one hundred and forty fertilized duck eggs were collected from Mosul city. The sample placed in an incubator with automatic movement, ventilation, and humidity was (60%) and the temperature was (37.7 °C) for chicken and (37.5 °C) for duck. The histomorphometry showed significant differences between chicken and duck embryos at the 19th and 21st days of incubation of the villi's length, width, and apparent surface area. As for the epithelium height and the intestinal crypts, there were significant differences between chicken and duck embryos at the 18th and 20th days of incubation in the ileum and jejunum. Furthermore, the mucosa was thicker in chicken embryos in the day of hatching, the submucosa was thicker in ducks during the 18th day of the incubation in the duodenum. During day 15 of the incubation in chicken embryos in the jejunum and ileum, the muscularis layer was thicker in the duodenum and jejunum and less thick in the ileum, and the collagen fibers were less too in the duck embryos at hatching d. The serosa was thicker in the duck embryos. The percentage of the goblet cells was higher with a larger density in duck embryos than chicken at hatching day. Paneth cells were characterized by acidic granular cytoplasm. The achieved outcomes of histomorphometry and the density variances of the glycoprotein secretion are probably linked with numerous definite roles of (SI) parts in the progressions of nutrient absorption.

Plasma THBS1 as a predictive biomarker for poor prognosis and brain metastasis in patients with HER2-enriched breast cancer.

Thrombospondin-1 (THBS1) is a secretory adhesive glycoprotein involved in the progression of multiple malignancies, including breast cancer. However, the clinical significance and prognostic role of plasma THBS1 in breast cancer have yet to be clarified. Plasma THBS1 levels in 627 breast cancer patients were analyzed by enzyme-linked immunosorbent assay. Bone marrow blood was drawn from the anterior/posterior superior iliac spine to detect the presence of disseminated tumor cells (DTCs). The effects of plasma THBS1 on the clinicopathological characteristics and survival prediction of breast cancer patients were explored. Plasma THBS1 did not correlate with overall survival, breast cancer-specific survival (BCSS), and distant disease-free survival (DDFS) in the entire breast cancer cohort. Notably, HER2-enriched patients with high-plasma THBS1 levels had significantly shorter BCSS (P = 0.027) and DDFS (P = 0.011) than those with low levels. Multivariate analyses revealed that plasma THBS1 was an independent prognostic marker of BCSS (P = 0.026) and DDFS (P = 0.007) in HER2-enriched patients. THBS1 levels were 24% higher in positive DTC patients than in negative DTC patients (P = 0.031), and high levels were significantly associated with poor BCSS in positive DTC patients (HR 2.08, 95% CI 1.17-3.71; P = 0.019). Moreover, high-plasma THBS1 levels were specifically associated with an increased occurrence of brain metastasis in HER2-enriched patients (P = 0.041). These findings suggest that plasma THBS1 may be serving as an unfavorable prognosis predictor for HER2-enriched breast cancer and justifies the need for further research.

Oligomeric Structure of Yeast and Other Invertases Governs Specificity.

Invertases, or β-fructofuranosidases, are metabolic enzymes widely distributed among plants and microorganisms that hydrolyze sucrose and release fructose from various substrates. Invertase was one of the earliest discovered enzymes, first investigated in the mid-nineteenth century, becoming a classical model used in the primary biochemical studies on protein synthesis, activity, and the secretion of glycoproteins. However, it was not until 20years ago that a member of this family of enzymes was structurally characterized, showing a bimodular arrangement with a β-propeller catalytic domain, and a β-sandwich domain with unknown function. Since then, many studies on related plant and fungal enzymes have revealed them as basically monomeric. By contrast, all yeast enzymes in this family that have been characterized so far have shown sophisticated oligomeric structures mediated by the non-catalytic domain, which is also involved in substrate binding, and how this assembly determines the particular specificity of each enzyme. In this chapter, we will review the available structures of yeast invertases to elucidate the mechanism regulating oligomer formation and compare them with other reported dimeric invertases in which the oligomeric assembly has no apparent functional implications. In addition, recent work on a new family of invertases with absolute specificity for the α-(1,2)-bond of sucrose found in cyanobacteria and plant invertases is highlighted.

Rescue of secretion of rare-disease-associated misfolded mutant glycoproteins in UGGT1 knock-out mammalian cells.

Endoplasmic reticulum (ER) retention of misfolded glycoproteins is mediated by the ER-localized eukaryotic glycoprotein secretion checkpoint, UDP-glucose glycoprotein glucosyl-transferase (UGGT). The enzyme recognizes a misfolded glycoprotein and flags it for ER retention by re-glucosylating one of its N-linked glycans. In the background of a congenital mutation in a secreted glycoprotein gene, UGGT-mediated ER retention can cause rare disease, even if the mutant glycoprotein retains activity ("responsive mutant"). Using confocal laser scanning microscopy, we investigated here the subcellular localization of the human Trop-2-Q118E, E227K and L186P mutants, which cause gelatinous drop-like corneal dystrophy (GDLD). Compared with the wild-type Trop-2, which is correctly localized at the plasma membrane, these Trop-2 mutants are retained in the ER. We studied fluorescent chimeras of the Trop-2 Q118E, E227K and L186P mutants in mammalian cells harboring CRISPR/Cas9-mediated inhibition of the UGGT1 and/or UGGT2 genes. The membrane localization of the Trop-2 Q118E, E227K and L186P mutants was successfully rescued in UGGT1-/- cells. UGGT1 also efficiently reglucosylated Trop-2-Q118E-EYFP in cellula. The study supports the hypothesis that UGGT1 modulation would constitute a novel therapeutic strategy for the treatment of pathological conditions associated to misfolded membrane glycoproteins (whenever the mutation impairs but does not abrogate function), and it encourages the testing of modulators of ER glycoprotein folding quality control as broad-spectrum rescue-of-secretion drugs in rare diseases caused by responsive secreted glycoprotein mutants.

Morphology of the Female and Male Reproductive Tracts and More Data on the Spermatostyle in the Brazilian Gyretes sp. (Coleoptera, Adephaga, Gyrinidae).

We investigated the male and female reproductive tracts of Gyretes sp. with light and transmission electron microscopies. The male has a pair of testes with a single coiled follicle, followed by short efferent ducts, which have a similar shape and diameter to the testes. Long ducts (epididymides) with differential epithelium open in a pair of long vasa deferentia that lead to the accessory glands. Glycoprotein secretions from the vas deferens epithelium constitute the spermatostyle for spermatozoa aggregation. The female has numerous ovarioles per ovary, a coiled fertilization duct, an accessory gland, and an elongated vagina. Spermatozoa are stored as unaggregated cells in the fertilization duct. In Gyrinidae, the testes and accessory glands show diverse shapes, and the female sperm storage organs vary in shape, size, and type and may play a role in the interaction with sperm aggregates. Testes with a single follicle and vasa deferentia opening in the accessory glands of Gyretes sp. are features shared with other Gyrinidae and other Adephaga. We proposed adding this latter trait to characterize this suborder of beetles. The morphology of the reproductive organs in both sexes contributes to comparative analyses and knowledge of the reproductive biology of Gyretes and may provide additional features for systematics.

Study the effect of recombinant leukemia inhibitory factor on maintenance of pregnancy and frequency of regulatory T cells in abortion-prone mice

Recurrent spontaneous abortion (RSA) can have a significant impact on a woman's quality of life. Understanding the mechanisms behind abortion is crucial for developing potential treatments. Among various models of abortion, the CBA/J(♀) × DBA/2J(♂) model stands out as the most extensively studied. This model reveals the influence of an altered immune system on resorption during pregnancy. The leukemia inhibitory factor (LIF) holds considerable importance as a secretory glycoprotein essential for successful implantation. Regulatory T cells (Tregs) have been found to produce high levels of LIF in both mice and humans. LIF plays a vital role in the development of Tregs by upregulating the expression of the Foxp3 transcription factor while downregulating the expression of RORγt. To investigate the impact of recombinant LIF (rLIF) on pregnancy maintenance and Treg cell frequency in abortion-prone (AP) mice, a specific recombinant protein was used in this study. The AP group consisted of CBA/J(♀) × DBA/2J(♂) mice, while the control group comprised CBA/J(♀) × BALB/c(♂) mice. Intraperitoneal injections of rLIF were administered to the AP group on the third day of pregnancy, and its effects on Treg cell frequency and pregnancy maintenance were examined during this period. Following rLIF injections on the fourteenth day of pregnancy, the expression of Foxp3 significantly increased in AP mice (p = 0.02,0.008). Additionally, AP mice injected with rLIF demonstrated a significant reduction in resorption rate (p = 0.01) and a notable increase in birth rate (p = 0.01,0.0005). These findings provide new insights into the potential benefits of LIF in treating RSA patients.

Dengue virus NS1 secretion is regulated via importin-subunit β1 controlling expression of the chaperone GRp78 and targeted by the clinical drug ivermectin.

Dengue virus (DENV) is a major human pathogen that can cause hemorrhagic fever and shock syndrome. One important factor of DENV pathogenicity is non-structural protein 1 (NS1), a glycoprotein that is secreted from infected cells. Here we study the mode of action of the widely used drug ivermectin, used to treat parasitic infections and recently shown to lower NS1 blood levels in DENV-infected patients. We found that ivermectin blocks the nuclear transport of transcription factors required for the expression of chaperones that support the folding and secretion of glycoproteins, including NS1. Impairing nuclear transport of these transcription factors by ivermectin or depleting them from infected cells dampens NS1 folding and thus its secretion. These results reveal a novel mode of action of ivermectin that might apply to other flaviviruses as well.

Plasma osteoprotegerin predicts adverse cardiovascular events in stable coronary artery disease: the PEACE trial.

Osteoprotegerin (OPG) is a secretory glycoprotein and participates in the progression of atherosclerotic lesions. We aim to explore the relationship between OPG and the prognosis of coronary artery disease (CAD). Plasma OPG concentrations were measured in 3,766 patients with stable CAD enrolled in the PEACE trial. The PEACE trial (NCT00000558) group followed up the patients and examined their future clinical outcomes. In summary, 208 (5.5%) primary outcomes occurred, 295 patients (7.8%) died from all-cause death, 128 (3.4%) died from cardiovascular causes, and 94 (2.5%) experienced heart failure during a median follow-up of 1,892 days. In addition, we found that higher plasma levels of OPG were associated with a higher incidence of all-cause death, cardiovascular death, and heart failure, even after adjusting clinical cofounders. It was demonstrated that elevated plasma OPG levels were associated with an increased incidence of all-cause death, cardiovascular death, and heart failure in patients with stable CAD. https://clinicaltrials.gov/ct2/show/NCT00000558?term=NCT00000558&draw=2&rank=1, identifier: NCT00000558.

HRG inhibits liver cancer lung metastasis by suppressing neutrophil extracellular trap formation.

Distant metastasis is a sign of poor prognosis for cancer patients. Extrahepatic liver cancer metastases commonly spread to the lung. Remodelling of the metastatic microenvironment is essential for tumour metastasis. Neutrophil-associated metastatic microenvironment contributes to the early metastatic colonisation of cancer cells in the lung. The lung metastasis models were constructed via treated cancer cells by tail vein injection into mice. And samples of lung were harvested at the indicated time to analyze tumor growth and immune cells in the microenvironment. Tumors and lung metastasis specimens were obtained via surgical operations for research purposes. Neutrophils were obtained from peripheral blood of patients with liver cancer or healthy donors (HD). Hepatocellular carcinoma cells reduce the secretion of histidine-rich glycoprotein (HRG), regulate the recruitment and activation of neutrophils in the metastatic microenvironment and promote the production of neutrophil extracellular traps (NETs), thereby promoting liver cancer lung metastasis. HRG binds to FCγR1 on the neutrophil membrane while inhibiting PI3K and NF-κB activation, thereby reducing IL-8 secretion to reduce neutrophil recruitment. Meanwhile, HRG inhibited IL8-MAPK and NF-κB pathway activation and ROS production, resulting in reduced NETs formation. Our study reveals that liver cancer regulates neutrophil recruitment and NETs formation in the metastatic microenvironment by reducing HRG secretion, thereby promoting tumour lung metastasis. The results of this study will contribute to the development of possible strategies for treating metastases.