TSG101 Research Articles

TSG101 Promotes the Proliferation, Migration, and Invasion of Human Glioma Cells by Regulating the AKT/GSK3β/β-Catenin and RhoC/Cofilin Pathways.

The tumor susceptibility gene 101 (TSG101) has been reported to play important roles in the development and progression of several human cancers, such as pancreatic cancer, prostate cancer, and hepatocellular carcinoma. However, its potential roles and underlined mechanisms in human glioma are still needed to be further clarified. This study was designed to assess the expression of TSG101 in glioma patients and its effects on glioma cell proliferation, migration, and invasion. Publicly available data revealed that TSG101 mRNA was significantly upregulated in glioma tissues, and high levels of TSG101 were associated with poor prognosis in glioma patients. Western blot and immunohistochemistry experiments further showed that the expression level of TSG101 protein was significantly upregulated in glioma patients, especially in the patients with high-grade glioma. The functional studies showed that knockdown of TSG101 suppressed the proliferation, migration, and invasion of glioma cells, while overexpression of TSG101 facilitated them. Mechanistic studies indicated that the proliferation, migration, and invasion induced by TSG101 in human glioma were related to AKT/GSK3β/β-catenin and RhoC/Cofilin signaling pathways. In conclusion, the above results suggest that the expression of TSG101 is elevated in glioma patients, which accelerates the proliferation, migration, and invasion of glioma cells by regulating the AKT/GSK3β/β-catenin and RhoC/Cofilin pathways.

Inducible heat shock protein A1A (HSPA1A) is markedly expressed in rat myometrium by labour and secreted via myometrial cell-derived extracellular vesicles.

The myometrium goes through physiological, cellular and molecular alterations during gestation that necessitate effective cellular proteostasis. Inducible heat shock protein A1A (HSPA1A) is a member of the 70-kDa heat shock protein A (HSPA) family, which acts as a chaperone to regulate proteostasis; however, HSPA1A also participates as a cytokine in inflammatory regulation, leading to its designation as a chaperokine. This study examined the spatiotemporal expression of HSPA1A protein in the rat myometrium throughout gestation and assessed whether it is secreted as cargo of myometrial cell-derived extracellular vesicles (EVs). Immunoblot analysis demonstrated that HSPA1A expression was markedly elevated during late pregnancy and labour and increased by uterine distension. Myometrial HSPA1A expression insitu increased in myocytes of longitudinal and circular muscle layers from Day 19 through to postpartum, specifically in the cytoplasm and nuclei of myocytes from both muscle layers, but frequently detectable just outside myocyte membranes. Scanning electron microscopy examination of samples isolated from hTERT-HM cell-conditioned culture medium, using EV isolation spin columns, confirmed the presence of EVs. EV lysates contained HSPA8, HSPA1A and the EV markers apoptosis-linked gene 2-interacting protein X (Alix), the tetraspanin cluster of differentiation 63 (CD63), tumour susceptibility gene 101 (TSG101) and HSP90, but not the endoplasmic reticulum protein calnexin. These results indicate that HSPA1A may act as a chaperokine in the myometrium during pregnancy.

A wild-derived inbred mouse strain, MSM/Ms, provides insights into novel skin tumor susceptibility genes.

Cancer is one of the most catastrophic human genetic diseases. Experimental animal cancer models are essential for gaining insights into the complex interactions of different cells and genes in tumor initiation, promotion, and progression. Mouse models have been extensively used to analyze the genetic basis of cancer susceptibility. They have led to the identification of multiple loci that confer, either alone or in specific combinations, an increased susceptibility to cancer, some of which have direct translatability to human cancer. Additionally, wild-derived inbred mouse strains are an advantageous reservoir of novel genetic polymorphisms of cancer susceptibility genes, because of the evolutionary divergence between wild and classical inbred strains. Here, we review mapped Stmm (skin tumor modifier of MSM) loci using a Japanese wild-derived inbred mouse strain, MSM/Ms, and describe recent advances in our knowledge of the genes responsible for Stmm loci in the 7,12-dimethylbenz(a)anthracene (DMBA)/12-O-tetradecanoylphorbol-13-acetate (TPA) two-stage skin carcinogenesis model.

Tumor Susceptibility Gene 101 facilitates rapamycin-induced autophagic flux in neuron cells

Tumor Susceptibility Gene 101 (TSG101) is a member of endosomal sorting complexes responsible for endocytic pathway, which is associated with autophagic process. However, the role of TSG101 in autophagy remains unclear. To investigate the effect of TSG101 on the membrane-bound MAP1LC3-II, p62 and ubiquitinated protein levels in neuron cells, immunoblotting was used to evaluate the effects in cells silenced with siRNA against TSG101 and treated with autophagy inducer rapamycin. GFP-MAP1LC3 and tandem fluorescent-tagged LC3 (mTagRFP-mWasabi-MAP1LC3) reporter vectors were used to monitor autophagy in cells using confocal microcopy. The autophagic vacuoles were further validated with transmission electron microscopy. Our results showed that TSG101 expression was slightly increased in neuron cells when exposed to rapamycin. Depletion of TSG101 with siRNA lead to accumulation of MAP1LC3-II, GFP-MAP1LC3 puncta and autophagic vacuoles in the cells. Rapamycin-elevated MAP1LC3-II turnover and RFP+Wasabi− puncta were repressed in TSG101 silenced cells, indicating that TSG101 is involved in rapamycin-induced autophagic flux in cells. Moreover, silencing TSG101 reduced colocalization of Rab7, MAP1LC3 and cell viability, increased p62, ubiquitinated proteins in the neuron cells. Taken together, our results suggested that TSG101 might be required for amphisome formation to promote autophagic flux in neuron cells when exposed to rapamycin.

A High-Fat Diet Attenuates AMPK α1 in Adipocytes to Induce Exosome Shedding and Nonalcoholic Fatty Liver Development In Vivo.

Exosomes are important for intercellular communication, but the role of exosomes in the communication between adipose tissue (AT) and the liver remains unknown. The aim of this study is to determine the contribution of AT-derived exosomes in nonalcoholic fatty liver disease (NAFLD). Exosome components, liver fat content, and liver function were monitored in AT in mice fed a high-fat diet (HFD) or treated with metformin or GW4869 and with AMPKα1-floxed (Prkaα1fl/fl/wild-type [WT]), Prkaα1−/−, liver tissue-specific Prkaα1−/−, or AT-specific Prkaα1−/− modification. In cultured adipocytes and white AT, the absence of AMPKα1 increased exosome release and exosomal proteins by elevating tumor susceptibility gene 101 (TSG101)–mediated exosome biogenesis. In adipocytes treated with palmitic acid, TSG101 facilitated scavenger receptor class B (CD36) sorting into exosomes. CD36-containing exosomes were then endocytosed by hepatocytes to induce lipid accumulation and inflammation. Consistently, an HFD induced more severe lipid accumulation and cell death in Prkaα1−/− and AT-specific Prkaα1−/− mice than in WT and liver-specific Prkaα1−/− mice. AMPK activation by metformin reduced adipocyte-mediated exosome release and mitigated fatty liver development in WT and liver-specific Prkaα1−/− mice. Moreover, administration of the exosome inhibitor GW4869 blocked exosome secretion and alleviated HFD-induced fatty livers in Prkaα1−/− and adipocyte-specific Prkaα1−/− mice. We conclude that HFD-mediated AMPKα1 inhibition promotes NAFLD by increasing numbers of AT CD36-containing exosomes.

HIF2α supports pro-metastatic behavior in pheochromocytomas/paragangliomas.

Mutations that drive the stabilization of hypoxia inducible factor 2α (HIF2α) and downstream pseudohypoxic signaling are known to predispose to the development of pheochromocytomas and paragangliomas (PPGLs). However, any role of HIF2α in predisposition to metastatic disease remains unclear. To assess such a role we combined gene-manipulations in pheochromocytoma cell lines with retrospective analyses of patient data and gene expression profiling in tumor specimens. Among 425 patients with PPGLs identified with mutations in tumor-susceptibility genes, those with tumors due to activation of pseudohypoxic pathways had a higher frequency of metastatic disease than those with tumors due to activation of kinase-signaling pathways, even without inclusion of patients with mutations in SDHB (18.6% vs 4.3% in, P < 0.0001). Three out of nine (33%) patients with gain-of-function mutations in HIF2α had metastatic disease. In cell line studies, elevated expression of HIF2α enhanced cell proliferation and led to increased migration and invasion capacity. Moreover, HIF2α expression in HIF2α-deficient cells resulted in increased cell motility, diffuse cluster formation and emergence of pseudopodia indicating changes in cell adhesion and cytoskeletal remodeling. In a mouse liver metastasis model, Hif2a enhanced the metastatic load. Transcriptomics data revealed alterations in focal adhesion and extracellular matrix-receptor interactions in HIF2α-mutated PPGLs. Our translational findings demonstrate that HIF2α supports pro-metastatic behavior in PPGLs, though other factors remain critical for subsequent transition to metastasis. We identified LAMB1 and COL4A2 as new potential therapeutic targets for HIF2α-driven PPGLs. Identified HIF2α downstream targets might open a new therapeutic window for aggressive HIF2α-expressing tumors.

Clinical application of drug sensitive gene detection in postoperative instillation for non-muscle invasive bladder cancer

BackgroundBladder cancer is the most common malignant tumor of the urinary system. One of the biological characteristics of NMIBC is the high recurrence rate after surgery. The implementation of this project aimed to investigate the role of pharmacogenomic testing-guided intravesical perfusion of chemotherapeutic agents in the postoperative perfusion therapy for non-muscle invasive bladder cancer.MethodFrom January 2015 to December 2016, 298 patients with non-muscle-invasive bladder cancer were enrolled in this prospective study. These patients received chemotherapy drugs after electrotherapy. According to the presence or absence of tumor susceptibility gene detection after surgery, they were divided into two groups, including the drug sensitive group(N = 44) and the control group(N = 254). The drug sensitive group received bladder infusion therapy with sensitive chemotherapy drugs based on drug sensitivity gene detection results. The control group received intravesical instillation of pirarubicin. The preoperative general data and tumor grade of patients were recorded. Cystoscopy was performed before and every 3 months after surgery. The chest CT, upper abdomen CT, renal function, and urinary routine tests were performed. Tumor recurrence, metastasis and tumor-related death were recorded and evaluated during follow-up.ResultsThe drug sensitive group, which selected high-sensitivity drugs for intravesical instillation therapy based on gene expression, has a significantly lower relapse rate (11.36% vs 37.40%, P < 0.05) and a significantly longer time to relapse (17.80 ± 7.20 month vs11.20 ± 6.10 month, P < 0.05) compared with the control group. There were no significant differences in the time of mortality and death time between two groups.ConclusionThe pharmacogenomic testing-directed bladder instillation of chemotherapeutic drugs may be more effective than empiric drug administration in reducing the recurrence rate of non-muscle-invasive bladder cancer.

MiR-17-5p-mediated endoplasmic reticulum stress promotes acute myocardial ischemia injury through targeting Tsg101.

Cardiovascular diseases are the leading cause of death globally, among which acute myocardial infarction (AMI) frequently occurs in the heart and proceeds from myocardium ischemia and endoplasmic reticulum (ER) stress-induced cell death. Numerous studies on miRNAs indicated their potential as diagnostic biomarkers and treatment targets for heart diseases. Our study investigated the role of miR-17-5p and its regulatory mechanisms during AMI. Echocardiography, MTT, flow cytometry assay, evaluation of caspase-3 and lactate dehydrogenase (LDH) activity were conducted to assess cell viability, apoptosis in an MI/R mice model, and an H2O2-induced H9c2 hypoxia cell model, respectively. The expression levels of ER stress response-related biomarkers were detected using qRT-PCR, IHC, and western blotting assays. The binding site of miR-17-5p on Tsg101 mRNA was determined by bioinformatic prediction and luciferase reporter assay. The expression levels of miR-17-5p were notably elevated in MI/R mice and hypoxia cell models, accompanied by enhanced cell apoptosis. Inhibition of miR-17-5p led to decreased apoptosis related to ER stress response in the hypoxia model, which could be counteracted by knockdown of Tsg101 (tumor susceptibility gene 101). Transfection with miR-17-5p mimics downregulated the expression of Tsg101 in H9c2 cells. Luciferase assay demonstrated the binding between miR-17-5p and Tsg101. Moreover, 4-PBA, the inhibitor of the ER stress response, abolished shTsg101 elevated apoptosis in hypoxic H9c2 cells. Our findings investigated the pro-apoptotic role of miR-17-5p during MI/R, disclosed the specific mechanism of miR-17-5p/Tsg101 regulatory axis in ER stress-induced myocardium injury and cardiomyocytes apoptosis, and presented a promising diagnostic biomarker and potential target for therapy of AMI.

Tsg101 Is Involved in the Sorting and Re-Distribution of Glucose Transporter-4 to the Sarcolemma Membrane of Cardiac Myocytes.

Cardiac cells can adapt to pathological stress-induced energy crisis by shifting from fatty acid oxidation to glycolysis. However, the use of glucose-insulin-potassium (GIK) solution in patients undergoing cardiac surgery does not alleviate ischemia/reperfusion (I/R)-induced energy shortage. This indicates that insulin-mediated translocation of glucose transporter-4 (Glut-4) is impaired in ischemic hearts. Indeed, cardiac myocytes contain two intracellular populations of Glut-4: an insulin-dependent non-endosomal pool (also referred to as Glut-4 storage vesicles, GSVs) and an insulin-independent endosomal pool. Tumor susceptibility gene 101 (Tsg101) has been implicated in the endosomal recycling of membrane proteins. In this study, we aimed to examine whether Tsg101 regulated the sorting and re-distribution of Glut-4 to the sarcolemma membrane of cardiomyocytes under basal and ischemic conditions, using gain- and loss-of-function approaches. Forced overexpression of Tsg101 in mouse hearts and isolated cardiomyocytes could promote Glut-4 re-distribution to the sarcolemma, leading to enhanced glucose entry and adenosine triphosphate (ATP) generation in I/R hearts which in turn, attenuation of I/R-induced cardiac dysfunction. Conversely, knockdown of Tsg101 in cardiac myocytes exhibited opposite effects. Mechanistically, we identified that Tsg101 could interact and co-localize with Glut-4 in the sarcolemma membrane of cardiomyocytes. Our findings define Tsg101 as a novel regulator of cardiac Glut-4 trafficking, which may provide a new therapeutic strategy for the treatment of ischemic heart disease.

Abstract 4509: Targeting tumor-derived exosomes using a lectin affinity hemofiltration device

Abstract Background: Tumor-derived exosomes (TEX) are 30-150 nm vesicles that are released by tumor cells and have systemic disease-promoting effects. Despite abundant research showing that TEX are purveyors of tumor growth-promoting and immunosuppressive cargo, a clinical strategy for addressing exosomes in oncology is lacking. Aethlon Medical is initiating clinical trials in cancer patients with the Hemopurifier®, a hollow fiber hemofiltration device that is operated using dialysis infrastructure, for removing exosomes from circulating blood. The Hemopurifier incorporates size exclusion and a lectin (Galanthus nivalis agglutinin; GNA) affinity matrix for capturing nanoparticles having high mannose glycoprotein surface structures. Experimental Procedures: A benchtop version of the Hemopurifier was operated by recirculating samples of cancer patients' plasma through the hollow fiber filters ex vivo. The exosomes remaining in plasma were quantified using nanoparticle tracking analysis measurements and the ExoView instrument. To identify the Hemopurifier-bound material, an elution technique was developed to displace the GNA-bound material from the Hemopurifier. The recovered vesicles were assessed using ExoView and flow cytometry and compared to an established exosome isolation method, size exclusion chromatography, which utilizes small-size ion exchange columns (mini-SEC). In vitro assays were also performed by co-culturing the recovered exosomes with T cells to evaluate their immunosuppressive functions. Results: The results demonstrate that the GNA affinity capture mechanism of the Hemopurifier is effective for clearing 92-99% of exosomes from input concentrations of 109-1010 exosomes per mL of plasma. The device captures exosomes from diverse tumor types including head and neck cancer, melanoma, ovarian cancer, esophageal cancer and breast cancer. Analysis of plasma samples from Stages III and IV triple negative and human epidermal growth factor receptor 2 overexpressing breast cancer showed that Hemopurifier-bound material comprised the appropriately-sized vesicles expressing tumor susceptibility gene 101 and tetraspanins. In comparison to mini-SEC-isolated exosomes, tumor-specific epitopes and immunosuppressive proteins exhibited equivalent expression among Hemopurifier-isolated exosomes. The immunosuppressive functions of Hemopurifier- and mini-SEC-isolated exosomes were also equivalent. Conclusions: The Hemopurifier effectively clears exosomes present in plasma that originate from diverse types of cancer. The Hemopurifier-captured exosomes exhibit signatures of malignancy and immunosuppression and are therefore relevant therapeutic targets. This research was supported by the National Cancer Institute of the National Institutes of Health under award number 1R43CA232977-01. Citation Format: Annette M. Marleau, Michael T. Jacobs, Nadia Gruber, Timothy C. Rodell, Soldano Ferrone, Theresa L. Whiteside. Targeting tumor-derived exosomes using a lectin affinity hemofiltration device [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4509.

Application of Post Solid-Phase Oxime Ligation to Fine-Tune Peptide-Protein Interactions.

Protein–protein interactions (PPIs) represent an extremely attractive class of potential new targets for therapeutic intervention; however, the shallow extended character of many PPIs can render developing inhibitors against them as exceptionally difficult. Yet this problem can be made tractable by taking advantage of the fact that large interacting surfaces are often characterized by confined “hot spot” regions, where interactions contribute disproportionately to overall binding energies. Peptides afford valuable starting points for developing PPI inhibitors because of their high degrees of functional diversity and conformational adaptability. Unfortunately, contacts afforded by the 20 natural amino acids may be suboptimal and inefficient for accessing both canonical binding interactions and transient “cryptic” binding pockets. Oxime ligation represents a class of biocompatible “click” chemistry that allows the structural diversity of libraries of aldehydes to be rapidly evaluated within the context of a parent oxime-containing peptide platform. Importantly, oxime ligation represents a form of post solid-phase diversification, which provides a facile and empirical means of identifying unanticipated protein–peptide interactions that may substantially increase binding affinities and selectivity. The current review will focus on the authors’ use of peptide ligation to optimize PPI antagonists directed against several targets, including tumor susceptibility gene 101 (Tsg101), protein tyrosine phosphatases (PTPases) and the polo-like kinase 1 (Plk1). This should provide insights that can be broadly directed against an almost unlimited range of physiologically important PPIs.

Loss of tumor susceptibility gene 101 (TSG101) perturbs endoplasmic reticulum structure and function

Tumor susceptibility gene 101 (TSG101), an ESCRT-I protein, is implicated in multiple cellular processes and its functional depletion can lead to blocked lysosomal degradation, cell cycle arrest, demyelination and neurodegeneration. Here, we show that loss of TSG101 results in endoplasmic reticulum (ER) stress and this causes ER membrane remodelling (EMR). This correlates with an expansion of ER, increased vacuolation, altered relative distribution of the rough and smooth ER and disruption of three-way junctions. Blocked lysosomal degradation due to TSG101 depletion leads to ER stress and Ca2+ leakage from ER stores, causing destabilization of actin cytoskeleton. Inhibiting Ca2+ release from the ER by blocking ryanodine receptors (RYRs) with Dantrolene partially rescues the ER stress phenotypes. Hence, in this study we have identified the involvement of TSG101 in modulating ER stress mediated remodelling by engaging the actin cytoskeleton. This is significant because functional depletion of TSG101 effectuates ER-stress, perturbs the structure, mobility and function of the ER, all aspects closely associated with neurodegenerative diseases. Summary statementWe show that tumor susceptibility gene (TSG) 101 regulates endoplasmic reticulum (ER) stress and its membrane remodelling. Loss of TSG101 perturbs structure, mobility and function of the ER as a consequence of actin destabilization.

MON-218 Clinical and Genetic Aspects of Pediatric Pheochromocytomas and Paragangliomas

Pheochromocytomas and paragangliomas (PPGLs) are neuroendocrine tumors derived from chromaffin cells. At least 30% of PPGL patients have hereditary predisposition. PPGLs in children are more often hereditary, multiple and extra-adrenal. To date, more than 14 tumor-susceptibility genes have been reported: Cluster 1 or hypoxic (VHL, SDHB, SDHD, SDHC, SDHA, SDHAF2, FH, ENGL1 and HIF2A) and cluster 2 (RET, NF1, TMEM127 and MAX). The aim of this study was to evaluate clinical and molecular aspects of a Brazilian cohort of pediatric patients with PPGLs. Out of 262 patients with PPGLs, 26 (9 %) were diagnosed before 19 yrs of age (16 males and 10 females), with a median age of 14.5 yrs (range, 4 to 18). Genetic investigation was performed in 19 patients: 14 by automated Sanger sequencing (VHL, SDHB, SDHD and RET genes) and 5 by a custom next-generation sequencing (NGS) panel including all genes previously associated with germline mutations in PPGLs. Median tumor size was 5.5 cm (1.7 to 16). Pheochromocytomas (PHEOs), paragangliomas (PGLs) or both were diagnosed in 46%, 31% and 23% of the patients, respectively. Bilateral PHEOs were diagnosed in 61% of the cases, most of them asynchronous (75%). Genetic diagnosis was confirmed in 14 out of 19 (74%) patients and all variants were found in heterozygous state: 8 VHL missense mutations from 6 kindreds (p.R167W in 2 kindreds, p.R167Q in one and p.G114S in 3); 3 SDHB mutations (p.C98Y, c.201-2A>G and p.L180L); 2 SDHD mutations (p.Y144_H145del and p.Q121*); and one RET mutation (p.C634R). All 8 VHL patients had bilateral PHEOs and 3 of them had also abdominal PGLs. All patients with SDHB mutations had abdominal PGLs. Two patients with SDHD mutation had head and neck paraganglioma (one of them had unilateral PHEO). Genetic investigation by NGS Panel was negative in all 5 cases: 2 malignant PPGLs (one PHEO and one PGL) and 3 PHEOs. Four out of 26 (15%) pediatric PPGLs were malignant: 2 with SDHB mutation and 2 with negative screening (one PHEO and one PGL). In conclusion, the majority of pediatric PPGLs (74%) were hereditary and almost exclusively caused by mutations in hypoxic genes. VHL (PHEOs) and SDHB (only PGLs) were the most frequent affected genes in this cohort of pediatric PPGLs. Support: CAPES grant to Petenuci J.

Genetic testing in endocrine surgery: Opportunities for precision surgery

Recent innovations in molecular and genetic diagnostic techniques have led to rapid advances in genomic medicine and their application to the clinic. The identification and classification of various genetic associations, syndromes, and susceptibility genes in endocrine surgical disorders are increasingly relevant to patient care. Hereditary endocrine disorders represent a significant proportion of disease encountered by endocrine surgeons. Hence, genetic testing has emerged as an important adjunct for the diagnosis and management of patients with endocrine surgical disorders. This article summarizes commonly encountered inherited endocrine disorders and their tumor susceptibility genes, with a focus on the clinical utility of genetic testing and its impact on the surgical management of endocrine disorders.

Construction of tissue engineered adipose by human adipose tissue derived extracellular vesicle combined with decellularized adipose tissues scaffold

To explore the possibility of constructing tissue engineered adipose by adipose tissue derived extracellular vesicles (hAT-EV) combined with decellularized adipose tissue (DAT) scaffolds, and to provide a new therapy for soft tissue defects. The adipose tissue voluntarily donated by the liposuction patient was divided into two parts, one of them was decellularized and observed by HE and Masson staining and scanning electron microscope (SEM). Immunohistochemical staining and Western blot detection for collagen type Ⅰ and Ⅳ and laminin were also employed. Another one was incubated with exosome-removed complete medium for 48 hours, then centrifuged to collect the medium and to obtain hAT-EV via ultracentrifugation. The morphology of hAT-EV was observed by transmission electron microscopy; the nanoparticle tracking analyzer (NanoSight) was used to analyze the size distribution; Western blot was used to analyse membrane surface protein of hAT-EV. Adipose derived stem cells (ADSCs) were co-cultured with PKH26 fluorescently labeled hAT-EV, confocal fluorescence microscopy was used to observe the uptake of hAT-EV by ADSCs. Oil red O staining was used to evaluate adipogenic differentiation after hAT-EV and ADSCs co-cultured for 15 days. The DAT was scissored and then injected into the bilateral backs of 8 C57 mice (6-week-old). In experimental group, 0.2 mL hAT-EV was injected weekly, and 0.2 mL PBS was injected weekly in control group. After 12 weeks, the mice were sacrificed, and the new fat organisms on both sides were weighed. The amount of new fat was evaluated by HE and peri-lipoprotein immunofluorescence staining to evaluate the ability of hAT-EV to induce adipogenesis in vivo. After acellularization of adipose tissue, HE and Masson staining showed that DAT was mainly composed of loosely arranged collagen with no nucleus; SEM showed that no cells and cell fragments were found in DAT, and thick fibrous collagen bundles could be seen; immunohistochemical staining and Western blot detection showed that collagen type Ⅰ and Ⅳ and laminin were retained in DAT. It was found that hAT-EV exhibited a spherical shape of double-layer envelope, with high expressions of CD63, apoptosis-inducible factor 6 interacting protein antibody, tumor susceptibility gene 101, and the particle size of 97.9% hAT-EV ranged from 32.67 nmto 220.20 nm with a peak at 91.28 nm. Confocal fluorescence microscopy and oil red O staining showed that hAT-EV was absorbed by ADSCs and induced adipogenic differentiation. In vivo experiments showed that the wet weight of fat new organisms in the experimental group was significantly higher than that in the control group ( t=2.278, P=0.048). HE staining showed that the structure of lipid droplets in the experimental group was more than that in the control group, and the collagen content in the control group was higher than that in the experimental group. The proportion of new fat in the experimental group was significantly higher than that in the control group ( t=4.648, P=0.017). DAT carrying hAT-EV can be used as a new method to induce adipose tissue regeneration and has a potential application prospect in the repair of soft tissue defects.

The Multifaceted Roles of the Tumor Susceptibility Gene 101 (TSG101) in Normal Development and Disease.

The multidomain protein encoded by the Tumor Susceptibility Gene 101 (TSG101) is ubiquitously expressed and is suggested to function in diverse intracellular processes. In this review, we provide a succinct overview of the main structural features of the protein and their suggested roles in molecular and cellular functions. We then summarize, in more detail, key findings from studies using genetically engineered animal models that demonstrate essential functions of TSG101 in cell proliferation and survival, normal tissue homeostasis, and tumorigenesis. Despite studies on cell lines that provide insight into the molecular underpinnings by which TSG101 might function as a negative growth regulator, a biologically significant role of TSG101 as a tumor suppressor has yet to be confirmed using genuine in vivo cancer models. More recent observations from several cancer research teams suggest that TSG101 might function as an oncoprotein. A potential role of post-translational mechanisms that control the expression of the TSG101 protein in cancer is being discussed. In the final section of the review, we summarize critical issues that need to be addressed to gain a better understanding of biologically significant roles of TSG101 in cancer.

Tsg101 positively regulates P62-Keap1-Nrf2 pathway to protect hearts against oxidative damage

Currently, most antioxidants do not show any favorable clinical outcomes in reducing myocardial ischemia-reperfusion (I/R) injury, suggesting an urgent need for exploring a new regulator of redox homeostasis in I/R hearts. Here, using heart-specific transgenic (TG) and knockdown (KD) mouse models, tumor susceptibility gene 101 (Tsg101) is defined as a novel cardiac-protector against I/R-triggered oxidative stress. RNA sequencing and bioinformatics data surprisingly reveal that most upregulated genes in Tsg101-TG hearts are transcribed by Nrf2. Accordingly, pharmacological inhibition of Nrf2 offsets Tsg101-elicited cardio-protection. Mechanistically, Tsg101 interacts with SQSTM1/p62 through its PRR domain, and promotes p62 aggregation, leading to recruitment of Keap1 for degradation by autophagosomes and release of Nrf2 to the nucleus. Furthermore, knockout of p62 abrogates Tsg101-induced cardio-protective effects during I/R. Hence, our findings uncover a previously unrecognized role of Tsg101 in the regulation of p62/Keap1/Nrf2 signaling cascades and provide a new strategy for the treatment of ischemic heart disease.

Multivesicular body sorting and the exosomal pathway are required for the release of rat hepatitis E virus from infected cells

Recent reports have shown that rat hepatitis E virus (HEV) is capable of infecting humans. We also successfully propagated rat HEV into human PLC/PRF/5 cells, raising the possibility of a similar mechanism shared by human HEV and rat HEV. Rat HEV has the proline-rich sequence, PxYPMP, in the open reading frame 3 (ORF3) protein that is indispensable for its release. However, the release mechanism remains unclear. The overexpression of dominant-negative (DN) mutant of vacuolar protein sorting (Vps)4A or Vps4B decreased rat HEV release to 23.9 % and 18.0 %, respectively. The release of rat HEV was decreased to 8.3 % in tumor susceptibility gene 101 (Tsg101)-depleted cells and to 31.5 % in apoptosis-linked gene 2-interacting protein X (Alix)-depleted cells. Although rat HEV ORF3 protein did not bind to Tsg101, we found a 90-kDa protein capable of binding to wild-type rat HEV ORF3 protein but not to ORF3 mutant with proline to leucine mutations in the PxYPMP motif. Rat HEV release was also decreased in Ras-associated binding 27A (Rab27A)- or hepatocyte growth factor-regulated tyrosine kinase substrate (Hrs)-depleted cells (to 20.1 % and 18.5 %, respectively). In addition, the extracellular rat HEV levels in the infected PLC/PRF/5 cells were increased after treatment with Bafilomycin A1 and decreased after treatment with GW4869. These results indicate that rat HEV utilizes multivesicular body (MVB) sorting for its release and that the exosomal pathway is required for rat HEV egress. A host protein alternative to Tsg101 that can bind to rat HEV ORF3 should be explored in further study.

Potential urine biomarkers for the diagnosis of prediabetes and early diabetic nephropathy based on ISN CKHDP program.

Diabetic nephropathy (DN) is a major complication of diabetes mellitus (DM), and the most frequent cause of end-stage renal disease (ESRD) in many countries. Urinary extracellular vesicles (UEVs) are considered a rich non-invasive source of markers for renal diseases. In this study, UEV enrichment and analysis in diabetic nephropathy (DN) was performed in a community epidemiological survey supported through the ISN CKHDP program. Patients were divided into five groups according to severity of kidney damage. A hydrostatic dialysis method was used for UEV enrichment followed by quantitation using Coomassie protein assays and subsequent adjustment using urinary creatinine levels. UEVs were then characterized by transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), and Western blotting of tumor susceptibility gene product TSG101. Two-dimensional DIGE (2D-DIGE) was used to analyze differential protein expression in the UEVs. Mass spectrometry (MS) was conducted and MASCOT search engine was used to identify potential biomarkers. Bradford protein assay showed that protein concentration of UEVs in diabetics with kidney injury increased significantly as compared to normal controls. UEVs present a round, cup-shaped, membrane-encapsulated structure under TEM, and the main peak of UEVs show 55-110nm nanoparticles with NTA. MS and MASCOT identified 22 differential proteins, and MASP2, CALB1, S100A8, and S100A9 were selected as potential biomarkers of early DN based on bioinformatic analysis. Our results show UEV proteome changes in different stages of DN. The results of this study show four unique proteins that undergo changes in early DN. These promising discoveries may prompt a new field of research focused on improving the diagnosis of DN.

Noninvasive circulating tumor cell and urine cellular XPC (rs2228001, A2815C) and XRCC1 (rs25487, G1196A) polymorphism detection as an effective screening panel for genitourinary system cancers.

BackgroundValid cancer screening and treatment monitoring are critical for cancer patients. Although genitourinary system cancers have a high recurrence rate, when diagnosed, patients undergo surgery promptly. We sought to explore sensitive and noninvasive screening and postoperative recurrence monitoring methods, such as circulating tumor cells (CTCs) or tumor susceptibility gene detection, to determine their appropriateness for genitourinary system cancers.MethodsWe adopted multiple detection methods. Enrichment-immunofluorescence in situ hybridization (SE-iFISH) was employed to detect CTCs from the peripheral blood of patients, and Agena Bioscience MassARRAY was used to detect single-nucleotide polymorphisms (SNPs) in tumor susceptibility genes from urine cells.ResultsIn our research, CTCs showed a 76.92% positivity rate among 26 genitourinary system cancer patients, and the number of CTCs was consistent with the stage of cancer. In monitoring for bladder cancer (BC) recurrence, CTCs were more prevalent than urine cytology (66.67% vs. 41.67%). To our surprise, urine cellular XPC (rs2228001, A2815C) and XRCC1 (rs25487, G1196A) polymorphisms were specifically found in cancer patients but not in patients with inflammation or in healthy individuals. XPC polymorphism (rs2228001, A2815C) rates were 30.77%, 40%, and 50% in bladder cancer, renal carcinoma, and prostate cancer patients, respectively, and those for XRCC1 (rs25487, G1196A) were 3.85%, 20%, and 25%, respectively.ConclusionsAs a common biomarker, CTCs showed remarkable performance in cancer screening and monitoring. The noninvasive panel comprising CTCs and XPC (rs2228001, A2815C) and XRCC1 (rs25487, G1196A) polymorphisms showed high sensitivity (positive rate: 92.86%) and is suitable for genitourinary system cancer screening.