SARS-CoV-2 infection of polarized human airway epithelium induces necroptosis that causes airway epithelial barrier dysfunction.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause the ongoing pandemic of coronavirus disease 2019 (COVID19). One key feature associated with COVID-19 is excessive pro-inflammatory cytokine production that leads to severe acute respiratory distress syndrome. Although the cytokine storm induces inflammatory cell death in the host, which type of programmed cell death mechanism that occurs in various organs and cells remains elusive. Using an in vitro culture model of polarized human airway epithelium (HAE), we observed that necroptosis, but not apoptosis or pyroptosis, plays an essential role in the damage of the epithelial barrier of polarized HAE infected with SARS-CoV-2. Pharmacological inhibitors of necroptosis, necrostatin-2 and necrosulfonamide, efficiently prevented cell death and epithelial barrier dysfunction caused by SARS-CoV-2 infection. Moreover, the silencing of genes that are involved in necroptosis, RIPK1, RIPK3, and MLKL, ameliorated airway epithelial damage of the polarized HAE infected with SARS-CoV-2. This study, for the first time, confirms that SARS-CoV-2 infection triggers necroptosis that disrupts the barrier function of human airway epithelia in vitro.

An optimized hepatocellular carcinoma prediction model for chronic hepatitis B with well-controlled viremia.

BACKGROUND AND AIMS: Hepatocellular carcinoma (HCC) risk in chronic hepatitis B (CHB) substantially decreased in the era of potent antiviral therapy. We developed an optimized HCC risk prediction model for CHB with well-controlled viremia by nucelos(t)ide analogs (NUCs). METHOD: We analysed those who achieved virological response (VR; serum HBV-DNA < 2000 IU/mL on two consecutive assessments) by NUCs. Liver stiffness by transient elastography, ultrasonography and laboratory tests was performed at the time of confirmed VR. Patients with decompensated cirrhosis or HCC at baseline were excluded. Multivariate Cox-regression analysis was used to determine key variables to construct a novel risk-scoring model. RESULTS: Among 1511 patients, 9.5% developed HCC. Cirrhosis on ultrasonography (adjusted HR [aHR] 2.47), age (aHR 1.04), male (aHR 1.90), platelet count <135 000/uL (aHR 1.57), albumin <4.5 g/dL (aHR 1.77) and liver stiffness ≥11 kPa (aHR 6.09) were independently associated with HCC. Using these, CAMPAS model was developed with c-index of 0.874. The predicted and observed HCC probabilities were calibrated with a reliable agreement. Such results were reproduced from internal validation and external validation among the independent cohort (n = 252). The intermediate-risk (CAMPAS model score 75 ~ 161) and high-risk (score >161) groups were more likely to develop HCC compared with the low-risk group (score ≤75) with statistical significances (HRs; 4.43 and 47.693 respectively; both P < .001). CONCLUSION: CAMPAS model derived through comprehensive clinical evaluation of liver disease allowed the more delicate HCC prediction for CHB patients with well-controlled viremia by NUCs.

GPR177 promotes gastric cancer proliferation by suppressing endoplasmic reticulum stress-induced cell death.

Gastric cancer is the fourth most common cancer worldwide. Despite the high incidence of gastric cancer, efficient chemotherapy treatments still need to be developed. In this study, we examined the anticancer effects of endoplasmic reticulum (ER) stress inducer tunicamycin in gastric cancer. Previously, we found that overexpression of WLS1/GPR177 correlated with poor prognosis in patients with gastric cancer. Furthermore, tunicamycin treatment downregulated GPR177 expression in a dose-dependent manner. GPR177 transports WNT ligand from ER to the plasma membrane, mediating its secretion to the extracellular matrix. In gastric cancer cells, GPR177 preferentially localizes to the ER. Small interfering RNA-mediated knockdown of GPR177 leads to sensitization to ER stress and induces apoptosis of cancer cells along with tunicamycin treatment. GPR177 suppression promoted the ER stress-mediated proapoptotic pathway, such as PERK-CHOP cascade. Furthermore, fluorouracil treatment combined with tunicamycin dramatically reduced cancer cell proliferation. Efficacy of tunicamycin chemotherapy treatments depended on GPR177 expression in gastric cancer cell lines. Together, our results indicate that ER stress can potentiate anticancer effects and suggest GPR177 as a potential gastric cancer therapeutic target.

Mouse mandibular-derived osteoclast progenitors have differences in intrinsic properties compared with femoral-derived progenitors.

Craniofacial osteoclasts are essential for site-specific processes such as alveolar bone resorption, tooth eruption, and orthodontic tooth movement. Much of the current understanding of osteoclast development and function comes from studies using long bone-derived cells. Minimal investigation has been done to explore skeletal site differences. The overall goal of this study was to determine if mandibular- and femoral-derived osteoclasts represent distinct populations. To test this hypothesis, bone marrow cells were initially analyzed from the mandible and femur of 2-month-old mice. It was shown that mandibular-derived osteoclasts have enhanced size (mm2) compared with femoral-derived osteoclasts. Since bone marrow macrophages are a heterogenous population, we additionally selected for monocytes and demonstrated that mandibular-derived monocytes also form osteoclasts with increased size compared with femoral-derived monocytes. Osteoclast precursor populations from both skeletal sites were analyzed by flow cytometry. A newly described Ly6CHigh+ population as well as the Ly6Cint population was increased in the mandibular-derived cells. The difference in differentiation potential between monocyte cultures suggests that the increase in the Ly6CHigh+ population may explain the enhanced differentiation potential in mandibular-derived cells. Monocyte genes such as Pu.1, C/ebp-a, and Prdm1 are increased in expression in mandibular-derived monocytes compared with femoral-derived monocytes. As expected with enhanced differentiation, osteoclast genes including Nfatc1, Dc-stamp, Ctsk, and Rank are upregulated in mandibular-derived osteoclast precursors. Future studies will determine how changes in the environment of the mandible lead to changes in percentages of osteoclast progenitors and their differentiation potential.

Cyclosporine A Suppresses the Malignant Progression of Oral Squamous Cell Carcinoma in vitro.

BACKGROUND: The Oral Squamous Cell Carcinoma (OSCC) is one of the most frequent cancer types. Failure of treatment of OSCC is potentially lethal because of local recurrence, regional lymph node metastasis, and distant metastasis. Chemotherapy plays a vital role through suppression of tumorigenesis. Cyclosporine A (CsA), an immunosuppressant drug, has been efficiently used in allograft organ transplant recipients to prevent rejection, and also has been used in a subset of patients with autoimmunity related disorders. The present study aims to investigate novel and effective chemotherapeutic drugs to overcome drug-resistance in the treatment of OSCC. METHODS: Cells were incubated in the standard way. Cell viability was assayed using the MTT assay. Cell proliferation was determined using colony formation assay. The cell cycle assay was performed using flow cytometry. Apoptosis was assessed using fluorescence-activated cell sorting after stained by the Annexin V-fluorescein isothiocyanate (FITC). Cell migration and invasion were analyzed using wound healing assay and tranwell. The effect of COX-2, c-Myc, MMP-9, MMP-2, and NFATc1 protein expression was determined using Western blot analysis while NFATc1 mRNA expression was determined by RT-PCR. RESULTS: In vitro studies indicated that CsA inhibited partial OSCC growth by inducing cell cycle arrest, apoptosis, and the migration and invasion of OSCC cells. We also demonstrated that CsA could inhibit the expression of NFATc1 and its downstream genes COX-2, c-Myc, MMP-9, and MMP-2 in OSCC cells. Furthermore, we analyzed the expression of NFATc1 in head and neck cancer through the Oncomine database. The data was consistent with the experimental findings. CONCLUSION: The present study initially demonstrated that CsA could inhibit the progression of OSCC cells and can mediate the signal molecules of NFATc1 signaling pathway, which has strong relationship with cancer development. That explains us CsA has potential to explore the possibilities as a novel chemotherapeutic drug for the treatment of OSCC.

Robot-assisted right colectomy with lymphadenectomy and intracorporeal anastomosis for colon cancer: technical considerations.

BACKGROUND: A surgical robot (the da Vinci system) was developed to overcome the disadvantages of laparoscopic surgery, and applications of this system have been widely used. In this study, we present our standardized technique of robotic right colectomy with lymphadenectomy and intracorporeal anastomosis, with an assessment of feasibility in a series of 15 patients. METHODS: All robotic right colectomies with lymphadenectomy were performed by a single surgeon between April 2009 and March 2010. Robotic assistance was used for the colonic mobilization, lymphadenectomy, and bowel reconstruction. Patient demographics, perioperative clinical outcomes, and pathologic results were reviewed. RESULTS: Robotic-assisted right colectomy was successfully performed on 15 patients with colon cancer. The total operative time was 201.4 ± 8.1 minutes, with a mean robotic time of 114.4 ± 7.5 minutes. No patient required conversion to conventional surgery. The median time to clear liquid intake was 3 days, and the median length of stay after surgery was 8 days. The mean tumor diameter was 3.0 ± 0.3 cm, and the mean number of harvested lymph nodes was 24.2 ± 15.5. Tumors were diagnosed as stage I in 7 patients, stage II in 5, and stage III in 3. CONCLUSIONS: Robotic right colectomy with lymphadenectomy can be performed successfully and safely. The robotic system was safe and feasible for the following steps: accurate node dissection, suturing for intracorporeal anastomosis, and natural orifice specimen extraction. Further comparative studies must be performed to verify the advantages of robotic surgery over conventional laparoscopic surgery.