Development of a SARS-CoV-2-derived receptor-binding domain-based ACE2 biosensor.

The global outbreak of coronavirus disease and rapid spread of the causative severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) represent a significant threat to human health. A key mechanism of human SARS-CoV-2 infection is initiated by the combination of human angiotensin-converting enzyme 2 (hACE2) and the receptor-binding domain (RBD) of the SARS-CoV-2-derived spike glycoprotein. Despite the importance of these protein interactions, there are still insufficient detection methods to observe their activity at the cellular level. Herein, we developed a novel fluorescence resonance energy transfer (FRET)-based hACE2 biosensor to monitor the interaction between hACE2 and SARS-CoV-2 RBD. This biosensor facilitated the visualization of hACE2-RBD activity with high spatiotemporal resolutions at the single-cell level. Further studies revealed that the FRET-based hACE2 biosensors were sensitive to both exogenous and endogenous hACE2 expression, suggesting that they might be safely applied to the early stage of SARS-CoV-2 infection without direct virus use. Therefore, our novel biosensor could potentially help develop drugs that target SARS-CoV-2 by inhibiting hACE2-RBD interaction.

Hydroxychloroquine and QTc prolongation in patients with COVID-19: A systematic review and meta-analysis.

BACKGROUND: Among many drugs that hold potential in COVID-19 pandemic, chloroquine (CQ), and its derivative hydroxychloroquine (HCQ) have generated unusual interest. With increasing usage, there has been growing concern about the prolongation of QTc interval and Torsades de Pointes (TdP) with HCQ, especially in combination with azithromycin. AIMS: This meta-analysis is planned to study the risk of QTc prolongation and Torsades de pointes (TdP) by a well-defined criterion for HCQ, CQ alone, and in combination with Azithromycin in patients with COVID-19. METHODS: A comprehensive literature search was made in two databases (PubMed, Embase). Three outcomes explored in the included studies were frequency of QTc > 500 ms (ms) or ΔQTc > 60 ms (Outcome 1), frequency of QTc > 500 ms (Outcome 2) and frequency of TdP (Outcome 3). Random effects method with inverse variance approach was used for computation of pooled summary and risk ratio. RESULTS: A total of 13 studies comprising of 2138 patients were included in the final analysis. The pooled prevalence of outcome 1, outcome 2 and outcome 3 for HCQ, CQ with or without Azithromycin were 10.18% (5.59-17.82%, I2 - 92%), 10.22% (6.01-16.85%, I2 - 79%), and 0.72% (0.34-1.51, I2 - 0%) respectively. The prevalence of outcome 2 in subgroup analysis for HCQ and HCQ + Azithromycin was 7.25% (3.22-15.52, I2 - 59%) and 8.61% (4.52-15.79, I2 - 76%), respectively. The risk ratio (RR) for outcome 1 and outcome 2 between HCQ + Azithromycin and HCQ was 1.22 (0.77-1.93, I2 - 0%) & 1.51 (0.79-2.87, I2 - 13%), respectively and was not significant. Heterogeneity was noted statistically as well clinically (regimen types, patient numbers, study design, and outcome definition). CONCLUSION: The use of HCQ/CQ is associated with a high prevalence of QTc prolongation. However, it is not associated with a high risk of TdP.

Chloroquine, hydroxychloroquine, and COVID-19: Systematic review and narrative synthesis of efficacy and safety.

The COVID-19 pandemic has required clinicians to urgently identify new treatment options or the re-purposing of existing drugs. Of particular interest are chloroquine (CQ) and hydroxychloroquine (HCQ). The aims of this systematic review are to systematically identify and collate 24 studies describing the use of CQ and HCQ in human clinical trials and to provide a detailed synthesis of evidence of its efficacy and safety. Of clinical trials, 100% showed no significant difference in the probability of viral transmission or clearance in prophylaxis or therapy, respectively, compared to the control group. Among observational studies employing an endpoint specific to efficacy, 58% concurred with the finding of no significant difference in the attainment of outcomes. Three-fifths of clinical trials and half of observational studies examining an indicator unique to drug safety discovered a higher probability of adverse events in those treated patients suspected of, and diagnosed with, COVID-19. Of the total papers focusing on cardiac side-effects, 44% found a greater incidence of QTc prolongation and/or arrhythmias, 44% found no evidence of a significant difference, and 11% mixed results. The strongest available evidence points towards the inefficacy of CQ and HCQ in prophylaxis or in the treatment of hospitalised COVID-19 patients.

Targeting the Autophagy-Lysosome Pathway in a Pathophysiologically Relevant Murine Model of Reversible Heart Failure.

The key biological "drivers" that are responsible for reverse left ventricle (LV) remodeling are not well understood. To gain an understanding of the role of the autophagy-lysosome pathway in reverse LV remodeling, we used a pathophysiologically relevant murine model of reversible heart failure, wherein pressure overload by transaortic constriction superimposed on acute coronary artery (myocardial infarction) ligation leads to a heart failure phenotype that is reversible by hemodynamic unloading. Here we show transaortic constriction + myocardial infarction leads to decreased flux through the autophagy-lysosome pathway with the accumulation of damaged proteins and organelles in cardiac myocytes, whereas hemodynamic unloading is associated with restoration of autophagic flux to normal levels with incomplete removal of damaged proteins and organelles in myocytes and reverse LV remodeling, suggesting that restoration of flux is insufficient to completely restore myocardial proteostasis. Enhancing autophagic flux with adeno-associated virus 9-transcription factor EB resulted in more favorable reverse LV remodeling in mice that had undergone hemodynamic unloading, whereas overexpressing transcription factor EB in mice that have not undergone hemodynamic unloading leads to increased mortality, suggesting that the therapeutic outcomes of enhancing autophagic flux will depend on the conditions in which flux is being studied.

PfSPZ-CVac malaria vaccine demonstrates safety among malaria-experienced adults: A randomized, controlled phase 1 trial.

Background: Plasmodium falciparum (Pf) Sporozoite (SPZ) Chemoprophylaxis Vaccine (PfSPZ-CVac) involves concurrently administering infectious PfSPZ and malaria drug, often chloroquine (CQ), to kill liver-emerging parasites. PfSPZ-CVac (CQ) protected 100% of malaria-naïve participants against controlled human malaria infection. We investigated the hypothesis that PfSPZ-CVac (CQ) is safe and efficacious against seasonal, endemic Pf in malaria-exposed adults. Methods: Healthy 18-45 year olds were enrolled in a double-blind, placebo-controlled trial in Bougoula-Hameau, Mali, randomized 1:1 to 2.048 × 105 PfSPZ (PfSPZ Challenge) or normal saline administered by direct venous inoculation at 0, 4, 8 weeks. Syringes were prepared by pharmacy staff using online computer-based enrolment that randomized allocations. Clinical team and participant masking was assured by identical appearance of vaccine and placebo. Participants received chloroquine 600mg before first vaccination, 10 weekly 300mg doses during vaccination, then seven daily doses of artesunate 200mg before 24-week surveillance during the rainy season. Safety outcomes were solicited adverse events (AEs) and related unsolicited AEs within 12 days of injections, and all serious AEs. Pf infection was detected by thick blood smears performed every four weeks and during febrile illness over 48 weeks. Primary vaccine efficacy (VE) endpoint was time to infection at 24 weeks. NCT02996695. Findings: 62 participants were enrolled in April/May 2017. Proportions of participants experiencing at least one solicited systemic AE were similar between treatment arms: 6/31 (19.4%, 95%CI 9.2-36.3) of PfSPZ-CVac recipients versus 7/31 (22.6%, 95%CI 29.2-62.2) of controls (p value = 1.000). Two/31 (6%) in each group reported related, unsolicited AEs. One unrelated death occurred. Of 59 receiving 3 immunizations per protocol, fewer vaccinees (16/29, 55.2%) became infected than controls (22/30, 73.3%). VE was 33.6% by hazard ratio (p = 0.21, 95%CI -27·9, 65·5) and 24.8% by risk ratio (p = 0.10, 95%CI -4·8, 54·3). Antibody responses to PfCSP were poor; 28% of vaccinees sero-converted. Interpretation: PfSPZ-CVac (CQ) was well-tolerated. The tested dosing regimen failed to significantly protect against Pf infection in this very high transmission setting. Funding: U.S. National Institutes of Health, Sanaria. Registration number: ClinicalTrials.gov identifier (NCT number): NCT02996695.

Autophagy enhanced by curcumin ameliorates inflammation in atherogenesis via the TFEB-P300-BRD4 axis.

Disturbance of macrophage-associated lipid metabolism plays a key role in atherosclerosis. Crosstalk between autophagy deficiency and inflammation response in foam cells (FCs) through epigenetic regulation is still poorly understood. Here, we demonstrate that in macrophages, oxidized low-density lipoprotein (ox-LDL) leads to abnormal crosstalk between autophagy and inflammation, thereby causing aberrant lipid metabolism mediated through a dysfunctional transcription factor EB (TFEB)-P300-bromodomain-containing protein 4 (BRD4) axis. ox-LDL led to macrophage autophagy deficiency along with TFEB cytoplasmic accumulation and increased reactive oxygen species generation. This activated P300 promoted BRD4 binding on the promoter regions of inflammatory genes, consequently contributing to inflammation with atherogenesis. Particularly, ox-LDL activated BRD4-dependent super-enhancer associated with liquid-liquid phase separation (LLPS) on the regulatory regions of inflammatory genes. Curcumin (Cur) prominently restored FCs autophagy by promoting TFEB nuclear translocation, optimizing lipid catabolism, and reducing inflammation. The consequences of P300 and BRD4 on super-enhancer formation and inflammatory response in FCs could be prevented by Cur. Furthermore, the anti-atherogenesis effect of Cur was inhibited by macrophage-specific Brd4 overexpression or Tfeb knock-out in Apoe knock-out mice via bone marrow transplantation. The findings identify a novel TFEB-P300-BRD4 axis and establish a new epigenetic paradigm by which Cur regulates autophagy, inhibits inflammation, and decreases lipid content.

MicroRNA-34c-5p provokes isoprenaline-induced cardiac hypertrophy by modulating autophagy via targeting ATG4B.

Pathological cardiac hypertrophy serves as a significant foundation for cardiac dysfunction and heart failure. Recently, growing evidence has revealed that microRNAs (miRNAs) play multiple roles in biological processes and participate in cardiovascular diseases. In the present research, we investigate the impact of miRNA-34c-5p on cardiac hypertrophy and the mechanism involved. The expression of miR-34c-5p was proved to be elevated in heart tissues from isoprenaline (ISO)-infused mice. ISO also promoted miR-34c-5p level in primary cultures of neonatal rat cardiomyocytes (NRCMs). Transfection with miR-34c-5p mimic enhanced cell surface area and expression levels of foetal-type genes atrial natriuretic factor (Anf) and ß-myosin heavy chain (ß-Mhc) in NRCMs. In contrast, treatment with miR-34c-5p inhibitor attenuated ISO-induced hypertrophic responses. Enforced expression of miR-34c-5p by tail intravenous injection of its agomir led to cardiac dysfunction and hypertrophy in mice, whereas inhibiting miR-34c-5p by specific antagomir could protect the animals against ISO-triggered hypertrophic abnormalities. Mechanistically, miR-34c-5p suppressed autophagic flux in cardiomyocytes, which contributed to the development of hypertrophy. Furthermore, the autophagy-related gene 4B (ATG4B) was identified as a direct target of miR-34c-5p, and miR-34c-5p was certified to interact with 3' untranslated region of Atg4b mRNA by dual-luciferase reporter assay. miR-34c-5p reduced the expression of ATG4B, thereby resulting in decreased autophagy activity and induction of hypertrophy. Inhibition of miR-34c-5p abolished the detrimental effects of ISO by restoring ATG4B and increasing autophagy. In conclusion, our findings illuminate that miR-34c-5p participates in ISO-induced cardiac hypertrophy, at least partly through suppressing ATG4B and autophagy. It suggests that regulation of miR-34c-5p may offer a new way for handling hypertrophy-related cardiac dysfunction.

Cardiac Toxicity of Chloroquine or Hydroxychloroquine in Patients With COVID-19: A Systematic Review and Meta-regression Analysis.

OBJECTIVE: To systematically review the literature and to estimate the risk of chloroquine (CQ) and hydroxychloroquine (HCQ) cardiac toxicity in patients with coronavirus disease 2019 (COVID-19). METHODS: We searched multiple data sources including PubMed/MEDLINE, Ovid Embase, Ovid EBM Reviews, Scopus, and Web of Science and medrxiv.org from November 2019 through May 27, 2020. We included studies that enrolled patients with COVID-19 treated with CQ or HCQ, with or without azithromycin, and reported on cardiac toxic effects. We performed a meta-analysis using the arcsine transformation of the different incidences. RESULTS: A total of 19 studies with a total of 5652 patients were included. The pooled incidence of torsades de pointes arrhythmia, ventricular tachycardia, or cardiac arrest was 3 per 1000 (95% CI, 0-21; I 2 =96%) in 18 studies with 3725 patients. Among 13 studies of 4334 patients, the pooled incidence of discontinuation of CQ or HCQ due to prolonged QTc or arrhythmias was 5% (95% CI, 1-11; I 2 =98%). The pooled incidence of change in QTc from baseline of 60 milliseconds or more or QTc of 500 milliseconds or more was 9% (95% CI, 3-17; I 2 =97%). Mean or median age, coronary artery disease, hypertension, diabetes, concomitant QT-prolonging medications, intensive care unit admission, and severity of illness in the study populations explained between-studies heterogeneity. CONCLUSION: Treatment of patients with COVID-19 with CQ or HCQ is associated with an important risk of drug-induced QT prolongation and relatively higher incidence of torsades de pointes, ventricular tachycardia, or cardiac arrest. Therefore, these agents should not be used routinely in the management of COVID-19 disease. Patients with COVID-19 who are treated with antimalarials for other indications should be adequately monitored.

Rivaroxaban, a Direct Oral Factor Xa Inhibitor, Attenuates Atherosclerosis by Alleviating Factor Xa-PAR2-Mediated Autophagy Suppression.

The authors showed a mechanism for attenuating atherosclerosis by directly administering an oral factor Xa inhibitor (ie, rivaroxaban [RIV]). The autophagy activity of macrophages was significantly suppressed by factor Xa and was alleviated by the administration of RIV. However, factor Xa failed to inhibit 7-ketocholesterol-induced autophagy and inflammasome activation in protease-activated receptor 2 (PAR2) knockout macrophages. The atherosclerotic area of apolipoprotein E knockout mice was significantly reduced by the genetic ablation of PAR2, which was partially reversed by chloroquine. Thus, the authors found that RIV attenuates atherogenesis by inhibiting the factor Xa-PAR2-mediated suppression of macrophage autophagy and abrogating inflammasome activity.

Tubeimoside-1 induces TFEB-dependent lysosomal degradation of PD-L1 and promotes antitumor immunity by targeting mTOR.

Programmed cell death ligand 1 (PD-L1)/programmed cell death protein 1 (PD-1) cascade is an effective therapeutic target for immune checkpoint blockade (ICB) therapy. Targeting PD-L1/PD-1 axis by small-molecule drug is an attractive approach to enhance antitumor immunity. Using flow cytometry-based assay, we identify tubeimoside-1 (TBM-1) as a promising antitumor immune modulator that negatively regulates PD-L1 level. TBM-1 disrupts PD-1/PD-L1 interaction and enhances the cytotoxicity of T cells toward cancer cells through decreasing the abundance of PD-L1. Furthermore, TBM-1 exerts its antitumor effect in mice bearing Lewis lung carcinoma (LLC) and B16 melanoma tumor xenograft via activating tumor-infiltrating T-cell immunity. Mechanistically, TBM-1 triggers PD-L1 lysosomal degradation in a TFEB-dependent, autophagy-independent pathway. TBM-1 selectively binds to the mammalian target of rapamycin (mTOR) kinase and suppresses the activation of mTORC1, leading to the nuclear translocation of TFEB and lysosome biogenesis. Moreover, the combination of TBM-1 and anti-CTLA-4 effectively enhances antitumor T-cell immunity and reduces immunosuppressive infiltration of myeloid-derived suppressor cells (MDSCs) and regulatory T (Treg) cells. Our findings reveal a previously unrecognized antitumor mechanism of TBM-1 and represent an alternative ICB therapeutic strategy to enhance the efficacy of cancer immunotherapy.

SQSTM1L341V variant that is linked to sporadic ALS exhibits impaired association with MAP1LC3 in cultured cells.

Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are genetically, pathologically and clinically-related progressive neurodegenerative diseases. Thus far, several SQSTM1 variations have been identified in patients with ALS and FTD. However, it remains unclear how SQSTM1 variations lead to neurodegeneration. To address this issue, we investigated the effects of ectopic expression of SQSTM1 variants, which were originally identified in Japanese and Chinese sporadic ALS patients, on the cellular viability, their intracellular distributions and the autophagic activity in cultured cells. Expression of SQSTM1 variants in PC12 cells exerted no observable effects on viabilities under both normal and oxidative-stressed conditions. Further, although expression of SQSTM1 variants in PC12 cells and Sqstm1-deficient mouse embryonic fibroblasts resulted in the formation of numerous granular SQSTM1-positive structures, called SQSTM1-bodies, their intracellular distributions were indistinguishable from those of wild-type SQSTM1. Nonetheless, quantitative colocalization analysis of SQSTM1-bodies with MAP1LC3 demonstrated that among ALS-linked SQSTM1 variants, L341V variant showed the significantly lower level of colocalization. However, there were no consistent effects on the autophagic activities among the variants examined. These results suggest that although some ALS-linked SQSTM1 variations have a discernible effect on the intracellular distribution of SQSTM1-bodies, the impacts of other variations on the cellular homeostasis are rather limited at least under transiently-expressed conditions.

Recent advances in drug delivery systems for targeting cancer stem cells.

Cancer stem cells (CSCs) are a subpopulation of cancer cells with functions similar to those of normal stem cells. Although few in number, they are capable of self-renewal, unlimited proliferation, and multi-directional differentiation potential. In addition, CSCs have the ability to escape immune surveillance. Thus, they play an important role in the occurrence and development of tumors, and they are closely related to tumor invasion, metastasis, drug resistance, and recurrence after treatment. Therefore, specific targeting of CSCs may improve the efficiency of cancer therapy. A series of corresponding promising therapeutic strategies based on CSC targeting, such as the targeting of CSC niche, CSC signaling pathways, and CSC mitochondria, are currently under development. Given the rapid progression in this field and nanotechnology, drug delivery systems (DDSs) for CSC targeting are increasingly being developed. In this review, we summarize the advances in CSC-targeted DDSs. Furthermore, we highlight the latest developmental trends through the main line of CSC occurrence and development process; some considerations about the rationale, advantages, and limitations of different DDSs for CSC-targeted therapies were discussed.

Treatment Armamentarium of COVID-19: Evolving Strategies and Evidence So Far.

The outbreak of SARS-CoV-2 started in Hubei province of China in December 2019 and rapidly spread all over the world. It has infected more than 7 million people worldwide and has pushed half of the world in a state of lockdown. There is an urgent unmet need of interventions both for prevention and treatment of this disease and more than 500 clinical trials are ongoing in this regard. At present, no study with robust methodology have clearly demonstrated benefits of hydroxychloroquine for treatment, preexposure prophylaxis in healthcare workers or post exposure prophylaxis in COrona VIrus Disease-2019. Remdesivir has been shown to have modest benefits in moderate to severe disease, if administered early. Given the rapid pace of clinical information and discoveries, it is important for clinicians to be up to date with the latest, evidence-based treatment options available for this novel disease. Keeping up with this current pace of information, we review the clinical studies of different therapeutic options available to treat SARS-CoV-2.

A Narrative Review of Emerging Therapeutics for COVID-19.

The novel severe acute respiratory syndrome coronavirus 2, the causal agent of coronavirus disease 2019 (COVID-19), quickly spread around the world, resulting in the most aggressive pandemic experienced in more than 100 years. Research on targeted therapies and vaccines has been initiated on an unprecedented scale and speed but will take months and even years to come to fruition. Meanwhile, the efficacy of emerging therapeutics for use in treating COVID-19 is feverishly being investigated to identify the best available treatment options for dealing with the current wave of disease. This review of publications with a "treatment" tag through June 29, 2020 in the National Library of Medicine's LitCovid literature hub, provides frontline clinicians with a pragmatic summary of the current state of the rapidly evolving evidence supporting emerging candidate therapeutics for COVID-19. Two main categories of pharmaceutical therapeutics are showing promise: those with antiviral activity directly addressing infection and those that counteract the inflammatory cytokine storm induced by severe disease. Preliminary results suggest that other approaches such as convalescent plasma therapy and lung radiation therapy may have some efficacy. The current clinical evidence for potential treatments is preliminary-often small retrospective series or early results of randomized trials-and the science is evolving rapidly. The long-term results from large, well-designed randomized controlled trials will provide definitive evidence for therapeutic effectiveness and are likely months away. The trial landscape for promising therapies is described.

Safety and efficacy of lopinavir/ritonavir combination in COVID-19: A systematic review, meta-analysis, and meta-regression analysis.

BACKGROUND: Being protease inhibitors and owing to their efficacy in SARS-CoV, lopinavir + ritonavir (L/R) combination is being used in the management of COVID-19. In this systematic review and meta-analysis, we have evaluated the comparative safety and efficacy of L/R combination. MATERIALS AND METHODS: Comparative, observational studies and controlled clinical trials comparing L/R combination to standard of care (SOC)/control or any other antiviral agent/combinations were included. A total of 10 databases were searched to identify 13 studies that fulfilled the predefined inclusion/exclusion criteria. RESULTS: No discernible beneficial effect was seen in the L/R group in comparison to SOC/control in terms of "progression to more severe state" (4 studies, odds ratio [OR]: 1.446 [0.722-2.895]), "mortality" (3 studies, OR: 1.208 [0.563-2.592]), and "virological cure on days 7-10" (3 studies, OR: 0.777 [0.371-1.630]), while the L/R combination arm performed better than the SOC/control arm in terms of "duration of hospital stay" (3 studies, mean difference (MD): -1.466 [-2.403 to - 0.529]) and "time to virological cure" (3 studies, MD: -3.272 [-6.090 to - 0.454]). No difference in efficacy was found between L/R versus hydroxychloroquine (HCQ) and L/R versus arbidol. However, in a single randomized controlled trail (open label), chloroquine (CQ) performed better than L/R. The combination L/R with arbidol may be beneficial (in terms of virological clearance and radiological improvement); however, we need more dedicated studies. Single studies report efficacy of L/R + interferon (IFN, either alpha or 1-beta) combination. We need more studies to delineate the proper effect size. Regarding adverse effects, except occurrence of diarrhea (higher in the L/R group), safety was comparable to SOC. CONCLUSION: In our study, no difference was seen between the L/R combination and the SOC arm in terms of "progression to more severe state," "mortality," and virological cure on days 7-10;" however, some benefits in terms of "duration of hospital stay" and "time to virological cure" were seen. No significant difference in efficacy was seen when L/R was compared to arbidol and HCQ monotherapy. Except for the occurrence of diarrhea, which was higher in the L/R group, safety profile of L/R is comparable to SOC. Compared to L/R combination, CQ, L/R + arbidol, L/R + IFN-α, and L/R + IFN-1ß showed better efficacy, but the external validity of these findings is limited by limited number of studies (1 study each).

Berberine diminishes cancer cell PD-L1 expression and facilitates antitumor immunity via inhibiting the deubiquitination activity of CSN5.

Programmed cell death-1 (PD-1)/programmed cell death ligand-1 (PD-L1) blocking therapy has become a major pillar of cancer immunotherapy. Compared with antibodies targeting, small-molecule checkpoint inhibitors which have favorable pharmacokinetics are urgently needed. Here we identified berberine (BBR), a proven anti-inflammation drug, as a negative regulator of PD-L1 from a set of traditional Chinese medicine (TCM) chemical monomers. BBR enhanced the sensitivity of tumour cells to co-cultured T-cells by decreasing the level of PD-L1 in cancer cells. In addition, BBR exerted its antitumor effect in Lewis tumor xenograft mice through enhancing tumor-infiltrating T-cell immunity and attenuating the activation of immunosuppressive myeloid-derived suppressor cells (MDSCs) and regulatory T-cells (Tregs). BBR triggered PD-L1 degradation through ubiquitin (Ub)/proteasome-dependent pathway. Remarkably, BBR selectively bound to the glutamic acid 76 of constitutive photomorphogenic-9 signalosome 5 (CSN5) and inhibited PD-1/PD-L1 axis through its deubiquitination activity, resulting in ubiquitination and degradation of PD-L1. Our data reveals a previously unrecognized antitumor mechanism of BBR, suggesting BBR is small-molecule immune checkpoint inhibitor for cancer treatment.

Biomarkers of COVID-19 and technologies to combat SARS-CoV-2.

Due to the unprecedented public health crisis caused by COVID-19, our first contribution to the newly launching journal, Advances in Biomarker Sciences and Technology, has abruptly diverted to focus on the current pandemic. As the number of new COVID-19 cases and deaths continue to rise steadily around the world, the common goal of healthcare providers, scientists, and government officials worldwide has been to identify the best way to detect the novel coronavirus, named SARS-CoV-2, and to treat the viral infection - COVID-19. Accurate detection, timely diagnosis, effective treatment, and future prevention are the vital keys to management of COVID-19, and can help curb the viral spread. Traditionally, biomarkers play a pivotal role in the early detection of disease etiology, diagnosis, treatment and prognosis. To assist myriad ongoing investigations and innovations, we developed this current article to overview known and emerging biomarkers for SARS-CoV-2 detection, COVID-19 diagnostics, treatment and prognosis, and ongoing work to identify and develop more biomarkers for new drugs and vaccines. Moreover, biomarkers of socio-psychological stress, the high-technology quest for new virtual drug screening, and digital applications are described.

LW6 enhances chemosensitivity to gemcitabine and inhibits autophagic flux in pancreatic cancer.

The efficacy of gemcitabine therapy is often insufficient for the treatment of pancreatic cancer. The current study demonstrated that LW6, a chemical inhibitor of hypoxia-inducible factor 1α, is a promising drug for enhancing the chemosensitivity to gemcitabine. LW6 monotherapy and the combination therapy of LW6 plus gemcitabine significantly inhibited cell proliferation and enhanced cell death in pancreatic cancer cells. This combination therapy also significantly reduced the tumor weight in a syngeneic orthotopic pancreatic carcinoma model without causing toxic side effects. In addition, this study provides insight into the mechanism of how LW6 interferes with the pathophysiology of pancreatic cancer. The results revealed that LW6 inhibited autophagic flux, which is defined by the accumulation of microtubule-associated protein 1 light chain 3 (LC3) and p62/SQSTM1. Moreover, these results were verified by the analysis of a tandem RFP-GFP-tagged LC3 protein. Thence, for the first time, these data demonstrate that LW6 enhances the anti-tumor effects of gemcitabine and inhibits autophagic flux. This suggests that the combination therapy of LW6 plus gemcitabine may be a novel therapeutic strategy for pancreatic cancer patients.

Three-Dimensional Organoids Reveal Therapy Resistance of Esophageal and Oropharyngeal Squamous Cell Carcinoma Cells.

Background & Aims: Oropharyngeal and esophageal squamous cell carcinomas, especially the latter, are a lethal disease, featuring intratumoral cancer cell heterogeneity and therapy resistance. To facilitate cancer therapy in personalized medicine, three-dimensional (3D) organoids may be useful for functional characterization of cancer cells ex vivo. We investigated the feasibility and the utility of patient-derived 3D organoids of esophageal and oropharyngeal squamous cell carcinomas. Methods: We generated 3D organoids from paired biopsies representing tumors and adjacent normal mucosa from therapy-naïve patients and cell lines. We evaluated growth and structures of 3D organoids treated with 5-fluorouracil ex vivo. Results: Tumor-derived 3D organoids were grown successfully from 15 out of 21 patients (71.4%) and passaged with recapitulation of the histopathology of the original tumors. Successful formation of tumor-derived 3D organoids was associated significantly with poor response to presurgical neoadjuvant chemotherapy or chemoradiation therapy in informative patients (P = 0.0357, progressive and stable diseases, n = 10 vs. partial response, n = 6). The 3D organoid formation capability and 5-fluorouracil resistance were accounted for by cancer cells with high CD44 expression and autophagy, respectively. Such cancer cells were found to be enriched in patient-derived 3D organoids surviving 5-fluorouracil treatment. Conclusions: The single cell-based 3D organoid system may serve as a highly efficient platform to explore cancer therapeutics and therapy resistance mechanisms in conjunction with morphological and functional assays with implications for translation in personalized medicine.

Targeting the Enterohepatic Bile Acid Signaling Induces Hepatic Autophagy via a CYP7A1-AKT-mTOR Axis in Mice.

BACKGROUND & AIMS: Hepatic cholesterol accumulation and autophagy defects contribute to hepatocyte injury in fatty liver disease. Bile acid synthesis is a major pathway for cholesterol catabolism in the liver. This study aims to understand the molecular link between cholesterol and bile acid metabolism and hepatic autophagy activity. METHODS: The effects of cholesterol and cholesterol 7α-hydroxylase (CYP7A1) expression on autophagy and lysosome function were studied in cell models. The effects and mechanism of disrupting enterohepatic bile acid circulation on hepatic autophagy were studied in mice. RESULTS: The results first showed differential regulation of hepatic autophagy by free cholesterol and cholesterol ester, whereby a modest increase of cellular free cholesterol, but not cholesterol ester, impaired lysosome function and caused marked autolysosome accumulation. We found that CYP7A1 induction, either by cholestyramine feeding in mice or adenovirus-mediated CYP7A1 expression in hepatocytes, caused strong autophagy induction. Mechanistically, we showed that CYP7A1 expression markedly attenuated growth factor/AKT signaling activation of mechanistic target of rapamycin (mTOR), but not amino acid signaling to mTOR in vitro and in vivo. Metabolomics analysis further found that CYP7A1 induction not only decreased hepatic cholesterol but also altered phospholipid and sphingolipid compositions. Collectively, these results suggest that CYP7A1 induction interferes with growth factor activation of AKT/mTOR signaling possibly by altering membrane lipid composition. Finally, we showed that cholestyramine feeding restored impaired hepatic autophagy and improved metabolic homeostasis in Western diet-fed mice. CONCLUSIONS: This study identified a novel CYP7A1-AKT-mTOR signaling axis that selectively induces hepatic autophagy, which helps improve hepatocellular integrity and metabolic homeostasis.