SENP1-Mediated HSP90ab1 DeSUMOylation in Cardiomyocytes Prevents Myocardial Fibrosis by Paracrine Signaling.

Myocardial infarction (MI) triggers a poor ventricular remodeling response, but the underlying mechanisms remain unclear. Here, the authors show that sentrin-specific protease 1 (SENP1) is downregulated in post-MI mice and in patients with severe heart failure. By generating cardiomyocyte-specific SENP1 knockout and overexpression mice to assess cardiac function and ventricular remodeling responses under physiological and pathological conditions. Increased cardiac fibrosis in the cardiomyocyte-specific SENP1 deletion mice, associated with increased fibronectin (Fn) expression and secretion in cardiomyocytes, promotes fibroblast activation in response to myocardial injury. Mechanistically, SENP1 deletion in mouse cardiomyocytes increases heat shock protein 90 alpha family class B member 1 (HSP90ab1) SUMOylation with (STAT3) activation and Fn secretion after ventricular remodeling initiated. Overexpression of SENP1 or mutation of the HSP90ab1 Lys72 ameliorates adverse ventricular remodeling and dysfunction after MI. Taken together, this study identifies SENP1 as a positive regulator of cardiac repair and a potential drug target for the treatment of MI. Inhibition of HSP90ab1 SUMOylation stabilizes STAT3 to inhibit the adverse ventricular remodeling response.

Protein interactome analysis of ATP1B1 in alveolar epithelial cells using Co-Immunoprecipitation mass spectrometry and parallel reaction monitoring assay.

Aims: Alveolar epithelial barrier integrity is essential for lung homeostasis. Na, K-ATPase ß1 subunit (ATP1B1) involves alveolar edema fluid clearance and alveolar epithelial barrier stability. However, the underlying molecular mechanism of ATP1B1 in alveolar epithelial cells still needs to be understood. Main methods: We utilized Co-Immunoprecipitation mass spectrometry proteomic analysis, protein-protein interaction (PPI) analysis, enrichment analysis, and parallel reaction monitoring (PRM) analysis to investigate proteins interacting with ATP1B1 in A549 cells. Key findings: A total of 159 proteins were identified as significant proteins interacting with ATP1B1 in A549 cells. Ribosomal and heat shock proteins were major constituents of the two main functional modules based on the PPI network. Enrichment analysis showed that significant proteins were involved in protein translation, posttranslational processing, and function regulation. Moreover, 10 proteins of interest were verified by PRM, and fold changes in 6 proteins were consistent with proteomics results. Finally, HSP90AB1, EIF4A1, TUBB4B, HSPA8, STAT1, and PLEC were considered candidates for binding to ATP1B1 to function in alveolar epithelial cells. Significance: Our study provides new insights into the role of ATP1B1 in alveolar epithelial cells and indicates that six proteins, in particular HSP90AB1, may be key proteins interacting with and regulating ATP1B1, which might be potential targets for the treatment of acute respiratory distress syndrome.

Txnip deletions and missense alleles prolong the survival of cones in a retinitis pigmentosa mouse model.

Retinitis pigmentosa (RP) is an inherited retinal disease in which there is a loss of cone-mediated daylight vision. As there are >100 disease genes, our goal is to preserve cone vision in a disease gene-agnostic manner. Previously we showed that overexpressing TXNIP, an α-arrestin protein, prolonged cone vision in RP mouse models, using an AAV to express it only in cones. Here, we expressed different alleles of Txnip in the retinal pigmented epithelium (RPE), a support layer for cones. Our goal was to learn more of TXNIP's structure-function relationships for cone survival, as well as determine the optimal cell type expression pattern for cone survival. The C-terminal half of TXNIP was found to be sufficient to remove GLUT1 from the cell surface, and improved RP cone survival, when expressed in the RPE, but not in cones. Knock-down of HSP90AB1, a TXNIP-interactor which regulates metabolism, improved the survival of cones alone and was additive for cone survival when combined with TXNIP. From these and other results, it is likely that TXNIP interacts with several proteins in the RPE to indirectly support cone survival, with some of these interactions different from those that lead to cone survival when expressed only in cones.

Exploring the Molecular Targets and Therapeutic Potential of Coptisine in Colon Cancer: A Network Pharmacology Approach.

INTRODUCTION: Colon cancer is a frequent malignancy, and surgery is still the primary therapy for people with colon cancer. Other treatments, including radiation, chemotherapy, and biologic therapy, may be utilized as a supplement. Chemotherapy, a prominent treatment for colon cancer, has failed to provide positive outcomes. This necessitates the development of more effective and less harmful treatment drugs. Coptisine was discovered to inhibit the development of colon cancer cell line HCT-116 in vivo, decrease the growth of HCT-116 cells, and cause apoptosis in vitro in colon cancer. Coptisine (COP) has shown antitumor activity in colon cancer, but its molecular mechanism and its molecular targets have not been fully understood. METHODS: In this study, the biological behavior was verified in vitro. The targets of Huanglian alkaloids on colon cancer were predicted, and the protein-protein interaction (PPI) network was constructed. The core targets of safranine for colon cancer were extracted and analyzed by GO and KEGG enrichment to identify the possible molecular mechanisms of safranine treatment. Western blot was used to detect the changes of related pathway proteins in colon cancer cells. The differential expression of hub genes in colon cancer was analyzed using the GEPIA2 website. The binding ability of safranine to the target was verified by molecular docking. Finally, the targets were preliminarily verified by q-PCR analysis. RESULTS: Coptisine can inhibit the survival, migration, and proliferation of colon cancer cells DLD1 and HCT-116. Based on network pharmacology, ninety-one targets for colon cancer were screened. ESR1, ALB, AR, CDK2, PARP1, HSP90AB1, IGF1R, CCNE1, and CDC42 were found in the top 10. Enrichment analysis showed that these targets were mainly related to pathways in cancer, FC γ R-mediated phagocytosis, prostate cancer, progesterone-mediated oocyte maturation, the oestrogen signal pathway, proteoglycan in cancer and the PI3K-Akt signal pathway. WB results showed that after the treatment of colon cancer DLD1 cells with coptisine, the expression of P-AKT and AKT decreased, that of its downstream protein Bcl-2 decreased, and that of BAX increased. Differential expression analysis of hub genes showed that CCNE1, CDK2, HSP90AB1, and CHEK2 were upregulated in colon cancer samples, and molecular docking showed that these targets had a good ability to bind to coptisine. After the treatment of colon cancer DLD1 cells with coptisine, q-PCR results showed that CCNE1 and HSP90AB1 were significantly downregulated, while CDK2 and CHEK2 had no significant changes. CONCLUSION: Coptisine may be a candidate drug for the treatment of colon cancer, and its therapeutic effect may be related to the cancer pathway and PI3K-Akt signalling pathway. CCNE1 and HSP90AB1 may be potential targets of coptisine in the treatment of colon cancer.

HSP90AB1 is a host factor that promotes porcine deltacoronavirus replication.

Porcine deltacoronavirus (PDCoV) is an emerging enteropathogenic coronavirus. It causes mortality in neonatal piglets and is of growing concern because of its broad host range, including humans. To date, the mechanism of PDCoV infection remains poorly understood. Here, based on a genome-wide CRISPR screen of PDCoV-infected cells, we found that HSP90AB1 (heat shock protein 90 alpha family class B1) promotes PDCoV infection. Knockdown or KO of HSP90AB1 in LLC-PK cells resulted in a significantly suppressed PDCoV infection. Infected cells treated with HSP90 inhibitors 17-AAG and VER-82576 also showed a significantly suppressed PDCoV infection, although KW-2478, which does not affect the ATPase activity of HSP90AB1, had no effect on PDCoV infection. We found that HSP90AB1 interacts with the N, NS7, and NSP10 proteins of PDCoV. We further evaluated the interaction between N and HSP90AB1 and found that the C-tail domain of the N protein is the HSP90AB1-interacting domain. Further studies showed that HSP90AB1 protects N protein from degradation via the proteasome pathway. In summary, our results reveal a key role for HSP90AB1 in the mechanism of PDCoV infection and contribute to provide new host targets for PDCoV antiviral research.

DSCC1 interacts with HSP90AB1 and promotes the progression of lung adenocarcinoma via regulating ER stress.

Lung cancer is a leading cause of cancer-related deaths, and the most common type is lung adenocarcinoma (LUAD). LUAD is frequently diagnosed in people who never smoked, patients are always diagnosed at advanced inoperable stages, and the prognosis is ultimately poor. Thus, there is an urgent need for the development of novel targeted therapeutics to suppress LUAD progression. In this study, we demonstrated that the expression of DNA replication and sister chromatid cohesion 1 (DSCC1) was higher in LUAD samples than normal tissues, and the overexpression of DSCC1 or its coexpressed genes were highly correlated with poor outcomes of LUAD patients, highlighting DSCC1 might be involved in LUAD progression. Furthermore, the expression of DSCC1 was positively correlated with multiple genetic mutations which drive cancer development, including TP53, TTN, CSMD, and etc. More importantly, DSCC1 could promote the cell proliferation, stemness, EMT, and metastatic potential of LUAD cells. In addition, DSCC1 interacted with HSP90AB1 and promoted the progression of LUAD via regulating ER stress. Meanwhile, DSCC1 expression negatively correlated with immune cell infiltration in lung cancer, and DSCC1 positively regulated the expression of PD-L1 in LUAD cells. Collectively, this study revealed that DSCC1 is a novel therapeutic target to treat LUAD and a biomarker for predicting the efficiency of PD-1/PD-L1 blockade treatment.

Aberrant Expressions of PSMD14 in Tumor Tissue are the Potential Prognostic Biomarkers for Hepatocellular Carcinoma after Curative Resection.

Introduction: Hepatocellular carcinoma (HCC) has a high mortality rate, with curative resection being the primary treatment. However, HCC patients have a large possibility of recurrence within 5 years after curative resection. Methods: Thus, identifying biomarkers to predict recurrence is crucial. In our study, we analyzed data from CCLE, GEO, and TCGA, identifying eight oncogenes associated with HCC. Subsequently, the expression of 8 genes was tested in 5 cases of tumor tissues and the adjacent non-tumor tissues. Then ATP6AP1, PSMD14 and HSP90AB1 were selected to verify the expression in 63 cases of tumor tissues and the adjacent non-tumor tissues. The results showed that ATP6AP1, PSMD14, HSP90AB1 were generally highly expressed in tumor tissues. A five-year follow-up of the 63 clinical cases, combined with Kaplan-Meier Plotter's relapse-free survival (RFS) analysis, found a significant correlation between PSMD14 expression and recurrence in HCC patients. Subsequently, we analyzed the PSMD14 mutations and found that the PSMD14 gene mutations can lead to a shorter disease-free survival time for HCC patients. Results: The results of enrichment analysis indicated that the differentially expressed genes related to PSMD14 are mainly enriched in the signal release pathway. Conclusion: In conclusion, our research showed that PSMD14 might be related to recurrence in HCC patients, and the expression of PSMD14 in tumor tissue might be a potential prognostic biomarker after tumor resection in HCC patients.

Maggot Extract Inhibits Cell Migration and Tumor Growth by Targeting HSP90AB1 in Ovarian Cancer.

Ovarian cancer is one of the most lethal gynecological malignancies, because of metastatic dissemination with poor late clinical therapy. Maggots have been used in traditional Chinese medicine, where they are also known as 'Wu Gu Chong'. Previous studies have indicated that maggot extract (ME) was beneficial for the treatment of gastric cancer when combined with other drugs, but the effect on anti-ovarian cancer and the underlying mechanism remains unclear. The aim of this study was to investigate the effects of ME on suppressing the proliferation and migration of ovarian cancer cells, and to clarify the underlying mechanism. In this research, Cell Counting Kit-8 (CCK-8), colony formation assay, and luciferase-positive cell quantification assay were employed to identify the inhibitory effects of ME on cell proliferation. Then, the pro-apoptosis and anti-metastasis effects of ME were explored by Western blot, dual annexin V-fluorescein isothiocyanate/propidium iodide (FITC/PI) assay, immunofluorescent staining, and wound-healing assay. We further established a xenograft model by subcutaneously or intraperitoneally injecting BALB/c nude mice with SKOV3 cells stably expressing luciferase, and the mice were treated with ME. The results showed that ME therapy effectively restrained the growth and metastasis of ovarian tumors in vivo. Furthermore, the mRNA levels of cancer factors including heat shock protein 90 alpha family class B member 1 (HSP90AB1), MYC, and insulin like growth factor 1 receptor (IGF1R) were analyzed by quantitative real-time PCR assay to explore the possible antitumor mechanisms of ME. Next, HSP90 ATPase activity was inhibited by geldanamycin in A2780, and the cell viability was shown to be dramatically reduced, decreasing further with the combination of ME and cisplatin. In turn, HSP90AB1 overexpression effectively inhibited the effect of ME in suppressing capability for cell viability and migration. In addition, HSP90AB1 overexpression limited the ability of ME to inhibit expression of MYC and IGF1R, while the opposite effect was observed for expression of pro-apoptosis protein caspase3 and BAX. Therefore, this study confirmed the potential roles and mechanisms of ME in inhibiting the growth and metastasis of ovarian tumors and promoting apoptosis of ovarian cancer cells by inhibiting overexpression of HSP90AB1.

Targeting the lncMST-EPRS/HSP90AB1 complex as novel therapeutic strategy for T-2 toxin-induced growth retardation.

Growth retardation is a global public health problem that is highly prevalent especially in low-and middle-income countries, which is closely related to the consumption of grains contaminated with T-2 toxin, a risk for human and animal health. However, the possible targets that can relieve T-2 toxin-induced growth retardation still need to be explored. In the present study, T-2 toxin was used as an environmental exposure factor to induce growth retardation and further explore the regulatory role of lncRNA in growth retardation. The present study systematically characterised the expression profiles of lncRNAs and identified a lncRNA lncMST that is related to growth retardation in T-2 toxin-administered rats. Functionally, lncMST could alleviate cell cycle arrest and apoptosis in T-2 toxin-treated GH3 cells. Mechanistically, lncMST, serve as an inducible chaperone RNA, involved in the paradigm "Chemical-induced stress related growth retardation", through recruiting the EPRS/HSP90AB1 complex to increase HDAC6 expression, thus further alleviating T-2 toxin-induced growth retardation. These findings for the first time demonstrate that the probable therapeutic relationship between lncMST and growth retardation, providing an explanation and therapeutic targets for the pathogenesis of growth retardation.

PI3K-activated MSC proteomes inhibit mammary tumors via Hsp90ab1 and Myh9.

Despite the advance in medications in the past decade, aggressive breast cancer such as triple-negative breast cancer is difficult to treat. Here, we examined a counter-intuitive approach to converting human bone marrow-derived mesenchymal stem cells (MSCs) into induced tumor-suppressing cells by administering YS49, a PI3K/Akt activator. Notably, PI3K-activated MSCs generated tumor-suppressive proteomes, while PI3K-inactivated MSCs tumor-promotive proteomes. In a mouse model, the daily administration of YS49-treated MSC-derived CM decreased the progression of primary mammary tumors as well as the colonization of tumor cells in the lung. In the ex vivo assay, the size of freshly isolated human breast cancer tissues, including estrogen receptor positive and negative as well as human epidermal growth factor receptor 2 (HER2) positive and negative, was decreased by YS49-treated MSC-derived CM. Hsp90ab1 was enriched in CM as an atypical tumor-suppressing protein and immunoprecipitated a non-muscle myosin, Myh9. Extracellular Hsp90ab1 and Myh9 exerted the anti-tumor action and inhibited the maturation of bone-resorbing osteoclasts. Collectively, this study demonstrated that the activation of PI3K generated tumor-suppressive proteomes in MSCs and supported the possibility of using patient-derived MSCs for the treatment of breast cancer and bone metastasis.

Generation of the Chondroprotective Proteomes by Activating PI3K and TNFα Signaling.

PURPOSE: To develop a novel treatment option for Chondrosarcoma (CS) and inflammatory arthritis, we evaluated a counterintuitive approach of activating tumorigenic and inflammatory signaling for generating joint-protective proteomes. METHODS: We employed mesenchymal stem cells and chondrocytes to generate chondroprotective proteomes by activating PI3K signaling and the administration of TNFα. The efficacy of the proteomes was examined using human and mouse cell lines as well as a mouse model of CS. The regulatory mechanism was analyzed using mass spectrometry-based whole-genome proteomics. RESULTS: While tumor progression and inflammatory responses were promoted by activating PI3K signaling and the administration of TNFα to CS cells and chondrocytes, those cells paradoxically generated a chondroprotective conditioned medium (CM). The application of CM downregulated tumorigenic genes in CS cells and TNFα and MMP13 in chondrocytes. Mechanistically, Hsp90ab1 was enriched in the chondroprotective CM, and it immunoprecipitated GAPDH. Extracellular GAPDH interacted with L1CAM and inhibited tumorigenic behaviors, whereas intracellular GAPDH downregulated p38 and exerted anti-inflammatory effects. CONCLUSIONS: We demonstrated that the unconventional approach of activating oncogenic and inflammatory signaling can generate chondroprotective proteomes. The role of Hsp90ab1 and GAPDH differed in their locations and they acted as the uncommon protectors of the joint tissue from tumor and inflammatory responses.

Study on the mechanism of Cortex Lycii on lung cancer based on network pharmacology combined with experimental validation.

ETHNOPHARMACOLOGICAL RELEVANCE: Xie Bai San is a Chinese medicine prescription that has been used to treat lung cancer in China for a long time. It has been proven to alleviate the symptoms and extend the survival time of lung cancer patients. Xie Bai San comprises Cortex Lycii, Cortex Mori, and Radix Glycyrrhizae Preparata. The effects and mechanisms of Cortex Mori and Glycyrrhizae on lung cancer have been reported, whereas the underlying mechanism of Cortex Lycii remains unknown. MATERIAL AND METHODS: Network pharmacology was used to explore the unknown mechanisms underlying the effect of Cortex Lycii on lung cancer. Molecular docking was used to predict the binding of a compound to the protein. The fingerprint of Cortex Lycii was obtained by HPLC. Cell counting Kit-8 assay was used to determine the appropriate concentration of Cortex Lycii extract for human lung adenocarcinoma cells, A549 and H1299. Wound healing assay and Matrigel invasion assay were used to detect the influence of Cortex Lycii extract on the migration and invasion ability of A549 and H1299. The protein expression level was detected by western blot and immunohistochemical staining. RESULTS: Using network pharmacology, 38 components of Cortex Lycii and 79 possible lung cancer-related target genes of Cortex Lycii were obtained. The targets were assigned to 35 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways and the PI3K-AKT signaling pathway contained the most targets and had the second-lowest P-value. The molecular docking showed the components of Cortex Lycii bound to HSP90AB1. Among them, 6 components bound to HSP90AB1 in which HSP90AB1 binds to and phosphorylates AKT. The functional experiments showed that Cortex Lycii suppressed the migration and invasion of human lung cancer cells in a dose-dependent manner. Cortex Lycii up-regulated E-Cadherin and down-regulated N-Cadherin, Vimentin, and MMP2. Furthermore, Cortex Lycii made no change in the total AKT and mTOR protein levels, but caused the down-regulation of p-AKT and p-mTOR in human lung cancer cells, which was reversed by Terazosin, an agonist of HSP90. Moreover, acacetin and apigenin, two components of Cortex Lycii, reduced the protein level of p-AKT and p-mTOR, and the reduction was also inhibited by Terazosin. CONCLUSION: Cortex Lycii suppressed epithelial-mesenchymal transition (EMT) in lung cancer cells through the PI3K-AKT-mTOR signaling pathway, possibly by targeting HSP90AB1 and inhibiting HSP90AB1-AKT binding.

A Comparative Transcriptomic Analysis Reveals That HSP90AB1 Is Involved in the Immune and Inflammatory Responses to Porcine Deltacoronavirus Infection.

PDCoV is an emerging enteropathogenic coronavirus that mainly causes acute diarrhea in piglets, seriously affecting pig breeding industries worldwide. To date, the molecular mechanisms of PDCoV-induced immune and inflammatory responses or host responses in LLC-PK cells in vitro are not well understood. HSP90 plays important roles in various viral infections. In this study, HSP90AB1 knockout cells (HSP90AB1KO) were constructed and a comparative transcriptomic analysis between PDCoV-infected HSP90AB1WT and HSP90AB1KO cells was conducted using RNA sequencing to explore the effect of HSP90AB1 on PDCoV infection. A total of 1295 and 3746 differentially expressed genes (DEGs) were identified in PDCoV-infected HSP90AB1WT and HSP90AB1KO cells, respectively. Moreover, most of the significantly enriched pathways were related to immune and inflammatory response-associated pathways upon PDCoV infection. The DEGs enriched in NF-κB pathways were specifically detected in HSP90AB1WT cells, and NF-κB inhibitors JSH-23, SC75741 and QNZ treatment reduced PDCoV infection. Further research revealed most cytokines associated with immune and inflammatory responses were upregulated during PDCoV infection. Knockout of HSP90AB1 altered the upregulated levels of some cytokines. Taken together, our findings provide new insights into the host response to PDCoV infection from the transcriptome perspective, which will contribute to illustrating the molecular basis of the interaction between PDCoV and HSP90AB1.

Suppression of breast cancer-associated bone loss with osteoblast proteomes via Hsp90ab1/moesin-mediated inhibition of TGFß/FN1/CD44 signaling.

Background: Bone is a frequent site of metastases from breast cancer, but existing therapeutic options are not satisfactory. Although osteoblasts have active roles in cancer progression by assisting the vicious bone-destructive cycle, we employed a counterintuitive approach of activating pro-tumorigenic Wnt signaling and examined the paradoxical possibility of developing osteoblast-derived tumor-suppressive, bone-protective secretomes. Methods: Wnt signaling was activated by the overexpression of Lrp5 and ß-catenin in osteoblasts as well as a pharmacological agent (BML284), and the therapeutic effects of their conditioned medium (CM) were evaluated using in vitro cell cultures, ex vivo breast cancer tissues, and a mouse model of osteolysis. To explore the unconventional regulatory mechanism of the action of Wnt-activated osteoblasts, whole-genome proteomics analysis was conducted, followed by immunoprecipitation and gain- and loss-of-function assays. Results: While osteoblasts did not present any innate tumor-suppressing ability, we observed that the overexpression of Lrp5 and ß-catenin in Wnt signaling made their CM tumor-suppressive and bone-protective. The growth of breast cancer cells and tissues was inhibited by Lrp5-overexpressing CM (Lrp5 CM), which suppressed mammary tumors and tumor-driven bone destruction in a mouse model. Lrp5 CM also inhibited the differentiation and maturation of bone-resorbing osteoclasts by downregulating NFATc1 and cathepsin K. The overexpression of Lrp5 upregulated osteopontin that enriched Hsp90ab1 (Hsp90 beta) and moesin (MSN) in Lrp5 CM. Hsp90ab1 and MSN are atypical tumor-suppressing proteins since they are multi-tasking, moonlighting proteins that promote tumorigenesis in tumor cells. Importantly, Hsp90ab1 immuno-precipitated latent TGFß and inactivated TGFß, whereas MSN interacted with CD44, a cancer stem-cell marker, as well as fibronectin 1, an ECM protein. Furthermore, Hsp90ab1 and MSN downregulated KDM3A that demethylated histones, together with PDL1 that inhibited immune responses. Conclusion: In contrast to inducing tumor-enhancing secretomes and chemoresistance in general by inhibiting varying oncogenic pathways in chemotherapy, this study presented the unexpected outcome of generation tumor-suppressive secretomes by activating the pro-tumorigenic Wnt pathway. The results shed light on the contrasting role of oncogenic signaling in tumor cells and osteoblast-derived secretomes, suggesting a counterintuitive option for the treatment of breast cancer-associated bone metastasis.

Capsid protein from red-spotted grouper nervous necrosis virus induces incomplete autophagy by inactivating the HSP90ab1-AKT-MTOR pathway.

As a highly important fish virus, nervous necrosis virus (NNV) has caused severe economic losses to the aquaculture industry worldwide. Autophagy, an evolutionarily conserved intracellular degradation process, is involved in the pathogenesis of several viruses. Although NNV can induce autophagy to facilitate infection in grouper fish spleen cells, how it initiates and mediates autophagy pathways during the initial stage of infection is still unclear. Here, we found that red-spotted grouper NNV (RGNNV) induced autophagosome formation in two fish cell lines at 1.5 and 3 h post infection, indicating that autophagy is activated upon entry of RGNNV. Moreover, autophagic detection showed that RGNNV entry induced incomplete autophagy by impairing the fusion of autophagosomes with lysosomes. Further investigation revealed that binding of the RGNNV capsid protein (CP) to the Lateolabrax japonicus heat shock protein HSP90ab1 (LjHSP90ab1), a cell surface receptor of RGNNV, contributed to RGNNV invasion-induced autophagy. Finally, we found that CP blocked the interaction of L. japonicus protein kinase B (AKT) with LjHSP90ab1 by competitively binding the NM domain of LjHSP90ab1 to inhibit the AKT-mechanistic target of the rapamycin (MTOR) pathway. This study provides novel insight into the relationship between NNV receptors and autophagy, which may help clarify the pathogenesis of NNV.

Conversion of Osteoclasts into Bone-Protective, Tumor-Suppressing Cells.

Osteoclasts are a driver of a vicious bone-destructive cycle with breast cancer cells. Here, we examined whether this vicious cycle can be altered into a beneficial one by activating Wnt signaling with its activating agent, BML284. The conditioned medium, derived from Wnt-activated RAW264.7 pre-osteoclast cells (BM CM), reduced the proliferation, migration, and invasion of EO771 mammary tumor cells. The same inhibitory effect was obtained with BML284-treated primary human macrophages. In a mouse model, BM CM reduced the progression of mammary tumors and tumor-induced osteolysis and suppressed the tumor invasion to the lung. It also inhibited the differentiation of RANKL-stimulated osteoclasts and enhanced osteoblast differentiation. BM CM was enriched with atypical tumor-suppressing proteins such as Hsp90ab1 and enolase 1 (Eno1). Immunoprecipitation revealed that extracellular Hsp90ab1 interacted with latent TGFß (LAP-TGFß) as an inhibitor of TGFß activation, while Hsp90ab1 and Eno1 interacted and suppressed tumor progression via CD44, a cell-adhesion receptor and a cancer stem cell marker. This study demonstrated that osteoclast-derived CM can be converted into a bone-protective, tumor-suppressing agent by activating Wnt signaling. The results shed a novel insight on the unexplored function of osteoclasts as a potential bone protector that may develop an unconventional strategy to combat bone metastasis.

Ovarian Serous Carcinoma With a Novel HSP90AB1 Mutation in a Patient With Synchronous Primary Fallopian Tube Serous Carcinoma.

BACKGROUND/AIM: Ovarian carcinoma is the fifth leading cause of cancer-related deaths in women in the United States. Serous papillary carcinoma is the most common histological type of ovarian carcinoma that often goes undetected until it has spread within the pelvis and abdomen leading to poor prognosis. Translation of next-generation sequencing (NGS) technology into personalized medicine and identification of new potential targets for therapeutic applications may be helpful. CASE REPORT: We report a case of a 59-year-old female who initially presented in the emergency department with increasing abdominal girth, and bloating. Computed tomography showed ascites and omental and pelvic masses. Fine needle biopsy of the omental mass showed high-grade papillary adenocarcinoma consistent with high-grade ovarian serous carcinoma. She was treated with chemotherapy followed by debulking surgery. Primary ovarian serous carcinoma and synchronous primary fallopian tube serous carcinoma with multiple leiomyomas were identified in the surgical specimen. Pleural biopsy was also positive for carcinoma. NGS and programmed death-ligand 1 (PD-L1) expression testing were performed in the ovarian serous carcinoma. The results showed mutations of breast cancer type 1 (BRCA1) and type 2 (BRCA2), tumor protein p53 (TP53) (c.524G>A at pR175H), and heat shock protein 90 alpha family class B member 1 (HSP90AB1) (p.R456C), as well as low RNA expression score of PD-L1. CONCLUSION: Identification of these mutations and PD-L1 abnormality at the diagnosis of ovarian carcinoma may shed light for clinicians to provide targeted therapy with poly (ADP-ribose) polymerase (PARP) inhibitors and immune checkpoint inhibitors for ovarian serous carcinoma. This is the first documented case of ovarian serous carcinoma to have found a HSP90AB1 (p.R456C) mutation.

Drug-repurposing against COVID-19 by targeting a key signaling pathway: An in silico study.

Currently, a plethora of information has been accumulated concerning COVID-19, including the transmission pathway of SARs-CoV-2. Thus, we retrieved targets associated with the development of COVID-19 via PubChem. A total of 517 targets were identified, and signaling pathways responded after infection of SARs-CoV-2 in humans constructed a bubble chart using RPackage. The bubble chart result suggested that the key signaling pathway against COVID-19 was the estrogen signaling pathway associated with AKT1, HSP90AB1, BCL2 targets. The three targets have the strongest affinity with three ligands-Akti-1/2, HSP990, S55746, respectively. In conclusion, this work provides three key elements to alleviate COVID-19 symptoms might be anti-inflammatory effects on SARs-CoV-2-infected lung cells.

Effect of HSP90AB1 and CC domain interaction on Bcr-Abl protein cytoplasm localization and function in chronic myeloid leukemia cells.

BACKGROUND: The fusion oncoprotein Bcr-Abl is mostly located in the cytoplasm, which causes chronic myeloid leukemia (CML). After moving into the nucleus, the fusion protein can induce apoptosis of CML cells. The coiled-coil domain (CC domain) of Bcr-Abl protein plays a central role in the subcellular localization. However, how CC domain affects subcellular localization of Bcr-Abl remains unclear. METHODS: Herein, the key proteins interacting with the Bcr-Abl CC domain were screened by immunoprecipitation binding mass spectrometry. The specific site of Bcr-Abl CC domain binding to target protein was predicted by Deep Viewer. Immunoprecipitation assay was used to confirmed the specific sites of protein binding. IF and western blot were used to observe the subcellular localization of target protein. Western blot was used to examine the protein changes. CCK-8, clonal formation test and FCM cycle detection were used to observe the effect of inhibitor on the proliferation ability of CML cells. FCM apoptosis detection was used to observe the level of cells apoptosis. RESULTS: HSP90AB1 interacts with Bcr-Abl CC domain via N-terminal domain (NTD), preventing the transport of Bcr-Abl protein to the nucleus and maintaining the activation of Bcr-Abl tyrosine kinase. The nucleus-entrapped Bcr-Abl markedly inhibits the proliferation and induces apoptosis of CML cells by activating p73 and repressing the expression of cytoplasmic oncogenic signaling pathways mediated by Bcr-Abl. Moreover, the combination of 17AAG (Tanespimycin) with Leptomycin B (LMB) considerably decreased the proliferation of CML cells. CONCLUSION: Our study provides evidence that it is feasible to transport Bcr-Abl into the nucleus as an alternative strategy for the treatment of CML, and targeting the NTD of HSP90AB1 to inhibit the interaction with Bcr-Abl is more accurate for the development and application of HSP90 inhibitor in the treatment of CML and other Bcr-Abl-addicted malignancies. Video abstract.

Denatured corona proteins mediate the intracellular bioactivities of nanoparticles via the unfolded protein response.

Biomolecular corona formed on nanoparticles (NPs) influences the latter's in vivo biological effects. Nanomaterials with different physicochemical properties exert similar adverse effects, such as cytotoxicity, suggesting the existence of ubiquitous signals during various corona formations that mediate common and fundamental cellular events. Here, we discover the involvement of the unfolded protein response (UPR) and recruited chaperones in the corona. Specially, heat shock protein 90 kDa α class B member 1 (Hsp90ab1) is abundantly enriched in the corona, accompanied by substantial aggregation of misfolded protein on particles intracellularly. Further analysis reveals the particulate matter 2.5 (PM2.5) and metal-containing particles are more capable of denaturing proteins. The recruited Hsp90ab1 activates diverse NPs' pathological behaviour by heat stress response (HSR), which were significantly reversed by geldanamycin (GA), the inhibitor of Hsp90ab1. Murine lung inflammation induced by PM2.5 and iron oxide NPs (Fe3O4NPs) is suppressed by GA, highlighting that Hsp90ab1-mediated UPR is a potential target for the treatment of environmental pollution-related illnesses. Based on our findings, the UPR and Hsp90ab1 presented in the corona of particles initiate fundamental intracellular reactions that lead to common pathological outcomes, which may provide new insights for understanding nanotoxicity and designing therapeutic approaches for diseases associated with environmental pollution.