Soluble E-cadherin participates in BLM-induced pulmonary fibrosis by promoting EMT and lung fibroblast migration.

Soluble E-cadherin (sE-cad) is an 80 kDa fragment derived from E-cadherin that is shed from the cell surface through proteolytic cleavage and is a biomarker in various cancers that promotes invasion and migration. Alveolar epithelial destruction, aberrant lung fibroblast migration and inflammation contribute to pulmonary fibrosis. Here, we hypothesized that E-cadherin plays an important role in lung fibrosis. In this study, we found that E-cadherin was markedly increased in the bronchoalveolar lavage fluid (BALF) and serum of mice with pulmonary fibrosis and that blocking sE-cad with HECD-1, a neutralizing antibody targeting the ectodomain of E-cadherin, effectively inhibited myofibroblast accumulation and collagen deposition in the lungs after bleomycin (BLM) exposure. Moreover, transforming growth factor-ß (TGF-ß1) induced the shedding of sE-cad from A549 cells, and treatment with HECD-1 inhibited epithelial-mesenchymal transition (EMT) stimulated by TGF-ß1. Fc-E-cadherin (Fc-Ecad), which is an exogenous form of sE-cad, robustly promoted lung fibroblast migration. E-cadherin participates in bleomycin (BLM)-induced lung fibrosis by promoting EMT in the alveolar epithelium and fibroblast activation. E-cadherin may be a novel therapeutic target for lung fibrosis.

Amyloid Fibril Formation of Arctic Amyloid-ß 1-42 Peptide is Efficiently Inhibited by the BRICHOS Domain.

Amyloid-ß peptide (Aß) aggregation is one of the hallmarks of Alzheimer's disease (AD). Mutations in Aß are associated with early onset familial AD, and the Arctic mutant E22G (Aßarc) is an extremely aggregation-prone variant. Here, we show that BRICHOS, a natural anti-amyloid chaperone domain, from Bri2 efficiently inhibits aggregation of Aßarc by mainly interfering with secondary nucleation. This is qualitatively different from the microscopic inhibition mechanism for the wild-type Aß, against which Bri2 BRICHOS has a major effect on both secondary nucleation and fibril end elongation. The monomeric Aß42arc peptide aggregates into amyloid fibrils significantly faster than wild-type Aß (Aß42wt), as monitored by thioflavin T (ThT) binding, but the final ThT intensity was strikingly lower for Aß42arc compared to Aß42wt fibrils. The Aß42arc peptide formed large aggregates, single-filament fibrils, and multiple-filament fibrils without obvious twists, while Aß42wt fibrils displayed a polymorphic pattern with typical twisted fibril architecture. Recombinant human Bri2 BRICHOS binds to the Aß42arc fibril surface and interferes with the macroscopic fibril arrangement by promoting single-filament fibril formation. This study provides mechanistic insights on how BRICHOS efficiently affects the aggressive Aß42arc aggregation, resulting in both delayed fibril formation kinetics and altered fibril structure.

ATP-independent molecular chaperone activity generated under reducing conditions.

Molecular chaperones are essential to maintain proteostasis. While the functions of intracellular molecular chaperones that oversee protein synthesis, folding and aggregation, are established, those specialized to work in the extracellular environment are less understood. Extracellular proteins reside in a considerably more oxidizing milieu than cytoplasmic proteins and are stabilized by abundant disulfide bonds. Hence, extracellular proteins are potentially destabilized and sensitive to aggregation under reducing conditions. We combine biochemical and mass spectrometry experiments and elucidate that the molecular chaperone functions of the extracellular protein domain Bri2 BRICHOS only appear under reducing conditions, through the assembly of monomers into large polydisperse oligomers by an intra- to intermolecular disulfide bond relay mechanism. Chaperone-active assemblies of the Bri2 BRICHOS domain are efficiently generated by physiological thiol-containing compounds and proteins, and appear in parallel with reduction-induced aggregation of extracellular proteins. Our results give insights into how potent chaperone activity can be generated from inactive precursors under conditions that are destabilizing to most extracellular proteins and thereby support protein stability/folding in the extracellular space. SIGNIFICANCE: Chaperones are essential to cells as they counteract toxic consequences of protein misfolding particularly under stress conditions. Our work describes a novel activation mechanism of an extracellular molecular chaperone domain, called Bri2 BRICHOS. This mechanism is based on reducing conditions that initiate small subunits to assemble into large oligomers via a disulfide relay mechanism. Activated Bri2 BRICHOS inhibits reduction-induced aggregation of extracellular proteins and could be a means to boost proteostasis in the extracellular environment upon reductive stress.

Integrated analysis reveals the pivotal interactions between immune cells in the melanoma tumor microenvironment.

Melanoma is the most lethal type of skin cancer. Despite the breakthroughs in the clinical treatment of melanoma using tumor immunotherapy, many patients do not benefit from these immunotherapies because of multiple immunosuppressive mechanisms. Therefore, there is an urgent need to determine the mechanisms of tumor-immune system interactions and their molecular determinants to improve cancer immunotherapy. In this study, combined analysis of microarray data and single-cell RNA sequencing data revealed the key interactions between immune cells in the melanoma microenvironment. First, differentially expressed genes (DEGs) between normal and malignant tissues were obtained using GEO2R. The DEGs were then subjected to downstream analyses, including enrichment analysis and protein-protein interaction analysis, indicating that these genes were associated with the immune response of melanoma. Then, the GEPIA and TIMER databases were used to verify the differential expression and prognostic significance of hub genes, and the relationship between the hub genes and immune infiltration. In addition, we combined single cell analysis from GSE123139 to identify immune cell types, and validated the expression of the hub genes in these immune cells. Finally, cell-to-cell communication analysis of the proteins encoded by the hub genes and their interactions was performed using CellChat. We found that the CCL5-CCR1, SELPLG-SELL, CXCL10-CXCR3, and CXCL9-CXCR3 pathways might play important roles in the communication between the immune cells in tumor microenvironment. This discovery may reveal the communication basis of immune cells in the tumor microenvironment and provide a new idea for melanoma immunotherapy.

A "spindle and thread" mechanism unblocks p53 translation by modulating N-terminal disorder.

Disordered proteins pose a major challenge to structural biology. A prominent example is the tumor suppressor p53, whose low expression levels and poor conformational stability hamper the development of cancer therapeutics. All these characteristics make it a prime example of "life on the edge of solubility." Here, we investigate whether these features can be modulated by fusing the protein to a highly soluble spider silk domain (NT∗). The chimeric protein displays highly efficient translation and is fully active in human cancer cells. Biophysical characterization reveals a compact conformation, with the disordered transactivation domain of p53 wrapped around the NT∗ domain. We conclude that interactions with NT∗ help to unblock translation of the proline-rich disordered region of p53. Expression of partially disordered cancer targets is similarly enhanced by NT∗. In summary, we demonstrate that inducing co-translational folding via a molecular "spindle and thread" mechanism unblocks protein translation in vitro.

Molecular Chaperone BRICHOS Inhibits CADASIL-Mutated NOTCH3 Aggregation In Vitro.

CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy) is the most common familial form of stroke, which is caused by mutations located in the epidermal growth factor (EGF)-like repeats of the NOTCH3 gene. Mutations cause the NOTCH3 (N3) protein to misfold and aggregate. These aggregates will be a component of granular osmiophilic material, which when accumulated around the arteries and arterioles is believed to cause the degradation of vascular smooth muscle cells (VSMC). VSMC degradation affects blood flow regulation and leads to white matter and neuronal death. Currently, there is no treatment for CADASIL. The dementia-relevant BRICHOS domain is a small multitalented protein with functions that include ATP-independent chaperone-like properties. BRICHOS has been shown to prevent the aggregation of both fibrillar and non-fibrillar structures. Therefore, the objective of this study is to investigate whether BRICHOS exhibits anti-aggregating properties on a recombinant CADASIL-mutated N3 protein consisting of the first five repeats of EGF (EGF1-5), harboring a cysteine instead of an arginine in the position 133, (R133C). We found that the N3 EGF1-5 R133C mutant is more prone to aggregate, while the wildtype is more stable. Recombinant human Bri2 BRICHOS is able to interact and stabilize the R133C-mutated N3 protein in a dose-dependent manner. These results suggest an anti-aggregating impact of BRICHOS on the N3 EGF1-5 R133C protein, which could be a potential treatment for CADASIL.

The surgical strategies of vaginoplasty for vaginal agenesis patients with or without functional uterus.

BACKGROUND: Vaginal agenesis is a rare condition worldwide. Most reported cases were accompanied by the absence of uterus or uterine hypoplasia; for patients with functional endometrium, hysterectomy was most likely to be conducted to lower postoperative complications. OBJECTIVE: Based on our successful experience in vaginoplasty with autologous buccal mucosal, the purpose of this article is to discuss the surgical strategies in the reconstruction of neovaginal for vaginal agenesis patients with functional uterus and cervical hypoplasia. METHODS: The uterus was preserved in our procedure, and the cervicoplasty was performed to connect the uterine cavity with the neovagina. After the vaginal cavity was formed, the cervix was confirmed and fixed. With the assistance of laparoscope, the direction and angle of the cervix and the uterine body were observed and confirmed. An incision was made in cervix to connect the uterine cavity, and a Foley's catheter was inserted. The newly formed opening of cervix and neovagina was covered by autologous buccal mucosal. RESULTS: The connection between neovagina and cervix uteri was successfully conducted in patient with functional uterus. Unimpeded and regular menstrual was achieved, and the cyclic abdominal pain was disappeared. No complications were observed. CONCLUSION: For patients without functional uterus, vaginoplasty with autologous buccal mucosal can be conducted. However, fertility-preserving surgery should be the primary choice in patients with functional endometrium. It can be concluded from our experience that the utero-vaginal connection with the assistance of laparoscope and the use of autologous buccal mucosa is a promising way to achieve ideal outcomes.

Vaginoplasty With Mesh Autologous Buccal Mucosa in Vaginal Agenesis: A Multidisciplinary Approach and Literature Review.

BACKGROUND: Vaginal agenesis, a rare condition, is treated by various surgical techniques to achieve neovaginal reconstruction. The main difference between the approaches lies in the graft material used to cover the newly formed cavity. OBJECTIVES: The purpose of this retrospective study was to describe the surgical procedure and outcomes of autologous buccal mucosal grafting in neovaginal reconstruction. METHODS: Sixteen patients with vaginal agenesis admitted to our department between January 2016 and January 2019 were included in our study. A reconstruction procedure, described in detail here, involving autologous buccal mucosa as graft material was successfully conducted in all of the patients. Long-term anatomic and functional outcomes were evaluated. RESULTS: The blood loss during operation was estimated to be 15 to 20 mL in all cases. No rectal or bladder injury occurred. The buccal mucosal wound completely healed 10 to 14 days after the operation. All patients had a well-formed neovagina 8 to 10 cm in length, with a mean diameter of >3 finger-breadths. CONCLUSIONS: The application of autologous buccal mucosa in neovaginal construction is a simple procedure. Autologous buccal mucosa is an ideal material to achieve excellent cosmetic and functional results in patients with vaginal agenesis.

Ultrasound-guided scraping of fibrous capsule plus bilayered negative pressure wound therapy for treatment of refractory postmastectomy seroma.

INTRODUCTION: Seroma is a frequent complication of breast cancer surgery. Treatment of prolonged or refractory seroma remains a clinical challenge. This study aimed to evaluate the efficacy of a novel approach for refractory seroma treatment; the method combines minimally invasive scraping for fibrous capsule removal and self-designed bilayered negative pressure wound therapy (b-NPWT) to achieve favorable wound healing. METHODS: Twenty-four patients with refractory seroma received ultrasound-guided scraping of fibrous capsule around the refractory seroma, and then a bilayered NPWT system simultaneously allowing for fluid drainage and dynamic topical pressure was manually implemented immediately. The time of NPWT application and wound healing was recorded, and pathological examination was conducted for the removed fibrous tissues. RESULTS: Removal of the fibrous capsule was securely achieved by minimally invasive scraping through a 1.5-cm incision guided with ultrasound scanning. All refractory seromas in the 24 patients healed uneventfully after an average application of NPWT for 7.2±3.3 days without recurrence during the 3-12 months of follow-up. Biopsy of the removed fibrous tissue demonstrated that single-layered endothelial cells stained with CD31, D2-40, and Ki-67 existed both on the surface of and inside the fibrous tissue. CONCLUSIONS: The combination of fibrous capsule removal by ultrasound-guided scraping with successive bilayered NPWT therapy is effective and minimally invasive for promoting wound healing of refractory postmastectomy seroma.