Switch-associated protein 70 protects against nonalcoholic fatty liver disease through suppression of TAK1.

BACKGROUND AND AIMS: NAFLD is a progressive disease without known effective drug treatments. Switch-associated protein 70 (SWAP70) is a guanine nucleotide exchange factor that participates in the regulation of many cellular processes. However, the role of SWAP70 in NAFLD remains unclear. This study aimed to identify the function and mechanism of SWAP70 in NAFLD. APPROACH AND RESULTS: The results showed that the expression of SWAP70 was significantly increased in mice and hepatocytes after metabolic stimulation. Overexpression of SWAP70 in hepatocytes suppressed lipid deposition and inflammation, and SWAP70 knockdown created the inverse effect. Using hepatocyte-specific Swap70 knockout and overexpression mice fed a high-fat, high-cholesterol diet, we demonstrated that SWAP70 suppressed the progression of nonalcoholic steatohepatitis by inhibiting lipid accumulation, inflammatory response, and fibrosis. Mechanically, RNA sequencing analysis and immunoprecipitation assays revealed that SWAP70 inhibited the interaction between transforming growth factor ß-activated kinase 1 (TAK1) binding protein 1 and TAK1 and sequentially suppressed the phosphorylation of TAK1 and subsequent c-Jun N-terminal kinase/P38 signaling. Inhibition of TAK1 activation blocked hepatocyte lipid deposition and inflammation caused by SWAP70 knockdown. CONCLUSIONS: SWAP70 is a protective molecule that can suppress the progression of NAFLD by inhibiting hepatic steatosis and inflammation. SWAP70 may be important for mitigating the progression of NAFLD.

MicroRNA-7 Exerts Antiangiogenic Effect on Colorectal Cancer via ERK Signaling.

BACKGROUND: Recent studies have suggested that microRNA-7 (miR-7) family members may play important roles in human cancer by regulating cell proliferation, apoptosis, migration, and invasion. Therefore, the present study aimed to investigate the clinical significance and biological function of miR-7 in colorectal cancer (CRC). METHODS: Initially, cancer and adjacent tissues were collected from 76 patients with CRC. Then, microvascular density was detected using the Weidner counting method. The functional role of miR-7 in CRC was determined using ectopic expression, knockdown, and reporter assay experiments. The vasculogenic mimicry density was determined. Expression of miR-7, epidermal growth factor receptor (EGFR), extracellular signal-regulated kinase (ERK1/2), vascular endothelial growth factor, and thrombospondin-1 was determined. 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assays, scratch tests, and Transwell assays were conducted to examine cell proliferation, migration, and invasion, respectively. Finally, flow cytometry was applied to evaluate cell apoptosis. RESULTS: CRC tissues showed increased microvascular density and EGFR expression, activated ERK signaling, and miR-7 downregulation. EGFR was a target gene of miR-7. miR-7 overexpression and EGFR silencing decreased vasculogenic mimicry density, cell migration, and cell invasion, but increased cell apoptosis. In addition, miR-7 overexpression and EGFR silencing upregulated thrombospondin-1 and downregulated EGFR, ERK1/2, and vascular endothelial growth factor. Furthermore, we observed that the effect of miR-7 inhibition was abolished after EGFR silencing. CONCLUSIONS: Overexpressed miR-7 suppresses angiogenesis of CRC cells through ERK signaling by downregulating EGFR. It may identify new targets for CRC treatment.

Promoted Delivery of Salinomycin to Lung Cancer Through Epidermal Growth Factor Receptor Aptamers Coupled DSPE-PEG2000 Nanomicelles.

Initiation and recurrence of lung cancer, the most fatal cancer worldwide, are attributed to lung cancer stem cells (CSCs). Evidence suggests that cancer cells can be turned into CSCs in a spontaneous way, and therefore simultaneous elimination of lung CSCs and cancer cells is crucial to achieve effective therapy of lung cancer. In lung cancer, epidermal growth factor receptor (EGFR) is overexpressed in both CSCs and cancer cells. The present study developed salinomycin poly(ethylene glycol) 2000-distearoylphosphatidylethanolamine nanomicelles conjugated with EGFR aptamers (M-SAL-EGFR) to kill lung CSCs and cancer cells. The 24 nm sized M-SAL-EGFR was prepared by a lipid film based method. The EGFR was overexpressed in lung CSCs and cancer cells. Results revealed that the M-SAL-EGFR could efficiently bind to EGFR-overexpressing lung CSCs and cancer cells, and induced enhanced cyotoxic effect than non-targeted M-SAL and salinomycin. Administration of M-SAL-EGFR in mice with lung cancer xenograft inhibited tumor growth more effectively compared with M-SAL and salinomycin. The EGFR aptamers were thus able to promote effective salinomycin delivery to lung cancer. Our results also suggest that the M-SAL-EGFR represents a promising approach for targeting both lung CSCs and cancer cells.

Gefitinib-loaded DSPE-PEG2000 nanomicelles with CD133 aptamers target lung cancer stem cells.

BACKGROUND: Lung cancer stem cells (CSCs) are considered to be the seed of lung cancer, and CD133 is a marker of lung CSCs. Here, we developed gefitinib-loaded poly(ethylene glycol) 2000-distearoylphosphatidylethanolamine nanomicelles with CD133 aptamers (M-Gef-CD133) to eliminate CD133+ lung CSCs. METHODS: M-Gef-CD133 was prepared using a lipid-film-based approach. The targeting and activity of M-Gef-CD133 towards lung CSCs were evaluated. RESULTS: M-Gef-CD133 were small (25 nm) and showed enhanced cytotoxic effect towards CD133+ lung CSCs compared with non-targeted M-Gef and gefitinib. Notably, M-Gef-CD133 could significantly reduce tumor sphere formation and the percentage of CD133+ lung CSCs, indicating that it possesses selective toxicity against CD133+ lung CSCs. CONCLUSIONS: The interaction of CD133 aptamers and CD133 shows promise in the delivery of gefitinib to CD133+ lung CSCs, and M-Gef-CD133 represents a promising treatment to target lung CSCs.

SWAP70 Overexpression Protects Against Pathological Cardiac Hypertrophy in a TAK1-Dependent Manner.

Background Pathological cardiac hypertrophy is regarded as a critical precursor and independent risk factor of heart failure, and its inhibition prevents the progression of heart failure. Switch-associated protein 70 (SWAP70) is confirmed important in immunoregulation, cell maturation, and cell transformation. However, its role in pathological cardiac hypertrophy remains unclear. Methods and Results The effects of SWAP70 on pathological cardiac hypertrophy were investigated in Swap70 knockout mice and Swap70 overexpression/knockdown cardiomyocytes. Bioinformatic analysis combined with multiple molecular biological methodologies were adopted to elucidate the mechanisms underlying the effects of SWAP70 on pathological cardiac hypertrophy. Results showed that SWAP70 protein levels were significantly increased in failing human heart tissues, experimental transverse aortic constriction-induced mouse hypertrophic hearts, and phenylephrine-stimulated isolated primary cardiomyocytes. Intriguingly, phenylephrine treatment decreased the lysosomal degradation of SWAP70 by disrupting the interaction of SWAP70 with granulin precursor. In vitro and in vivo experiments revealed that Swap70 knockdown/knockout accelerated the progression of pathological cardiac hypertrophy, while Swap70 overexpression restrained the cardiomyocyte hypertrophy. SWAP70 restrained the binding of transforming growth factor ß-activated kinase 1 (TAK1) and TAK1 binding protein 1, thus blocking the phosphorylation of TAK1 and downstream c-Jun N-terminal kinase/P38 signaling. TAK1 interacted with the N-terminals (1-192) of SWAP70. Swap70 (193-585) overexpression failed to inhibit cardiac hypertrophy when the TAK1-SWAP70 interaction was disrupted. Either inhibiting the phosphorylation or suppressing the expression of TAK1 rescued the exaggerated cardiac hypertrophy induced by Swap70 knockdown. Conclusions SWAP70 suppressed the progression of cardiac hypertrophy, possibly by inhibiting the mitogen-activated protein kinases signaling pathway in a TAK1-dependent manner, and lysosomes are involved in the regulation of SWAP70 expression level.

Dual-targeting nanomicelles with CD133 and CD44 aptamers for enhanced delivery of gefitinib to two populations of lung cancer-initiating cells.

Lung cancer is an aggressive type of cancer that is associated with a high mortality rate. Lung cancer-initiating cells are populations of self-renewing cancer cells with pluripotent differentiation ability. Cancers typically originate from multiple phenotypically distinct cancer-initiating cells. CD133 and CD44 are specific markers that maybe used to distinguish lung cancer-initiating cells. The ability to target a variety of subsets of cancer-initiating cells instead of targeting only one population of cancer initiating-cells has the potential to increase the cancer therapeutic efficacy. In the present study, CD133 and CD44 aptamer-conjugated nanomicelles loaded with gefitinib (CD133/CD44-NM-Gef) were developed to target CD133+ and CD44+ lung cancer-initiating cells. The therapeutic efficacy of CD133/CD44-NM-Gef against lung cancer-initiating cells was assessed by evaluating cell proliferation, tumorsphere formation and detection of CD44+ and CD133+ cells using flow cytometry. The results indicated that CD133/CD44-NM-Gef targeted CD133+ and CD44+ lung cancer-initiating cells and exhibited greater therapeutic efficacy against lung cancer-initiating cells than single-target and non-targeted nanomicelles, suggesting that CD133/CD44-NM-Gef represents a promising treatment for lung cancer by specifically targeting lung cancer-initiating cells. To the best of our knowledge, the present study was the first to report on drug delivery via nanomedicines targeted to multiple populations of cancer-initiating cells using aptamers. As cancer is typically derived from phenotypically distinct cancer-initiating cells, the nanomicelle-based multiple targeting strategy provided is promising for targeting multiple subsets of cancer-initiating cell within a tumor.

Approaching Otolaryngology Patients During the COVID-19 Pandemic.

Objective. To describe coronavirus disease 2019 (COVID-19) patient presentations requiring otolaryngology consultation and provide recommendations for protective measures based on the experience of ear, nose, and throat (ENT) departments in 4 Chinese hospitals during the COVID-19 pandemic. Study Design. Retrospective case series. Setting. Multicenter. Subjects and Methods. Twenty hospitalized COVID-19 patients requiring ENT consultation from 3 designated COVID-19 hospitals in Wuhan, Shanghai, and Shenzhen were identified. Data on demographics, comorbidities, COVID-19 symptoms and severity, consult reason, treatment, and personal protective equipment (PPE) use were collected and analyzed. Infection control strategies implemented for ENT outpatients and emergency room visits at the Eye and ENT Hospital of Fudan University were reported. Results. Median age was 63 years, 55% were male, and 95% were in severe or critical condition. Six tracheotomies were performed. Posttracheotomy outcomes were mixed (2 deaths, 2 patients comatose, all living patients still hospitalized). Other consults included epistaxis, pharyngitis, nasal congestion, hyposmia, rhinitis, otitis externa, dizziness, and tinnitus. At all hospitals, powered air-supply filter respirators (PAPRs) were used for tracheotomy or bleeding control. PAPR or N95-equivalent masks plus full protective clothing were used for other complaints. No inpatient ENT providers were infected. After implementation of infection control strategies for outpatient clinics, emergency visits, and surgeries, no providers were infected at the Eye and ENT Hospital of Fudan University. Conclusions and Relevance. COVID-19 patients require ENT consultation for many reasons, including tracheotomy. Otolaryngologists play an indispensable role in the treatment of COVID-19 patients but, due to their work, are at high risk of exposure. Appropriate protective strategies can prevent infection of otolaryngologists.