Enantiomers of Chloroquine and Hydroxychloroquine Exhibit Different Activities Against SARS-CoV-2 in vitro, Evidencing S-Hydroxychloroquine as a Potentially Superior Drug for COVID-19

In all of the clinical trials for COVID-19 conducted thus far and among those ongoing involving chloroquine or hydroxychloroquine, the drug substance used has invariably been chloroquine (CQ) diphosphate or hydroxychloroquine (HCQ) sulfate, i.e., the phosphoric or sulfuric acid salt of a racemic mixture of R- and S-enantiomer (50/50), respectively. As a result, the clinical outcome from previous CQ or HCQ trials were, in fact, the collective manifestation of both R and S- enantiomers with inherent different pharmacodynamic and pharmacokinetic properties, and toxicity liabilities. Our data for the first time demonstrated the stereoselective difference of CQ and HCQ against live SARS-CoV-2 virus in a Biosafety Level 3 laboratory. S-chloroquine (S-CQ) and S-hydroxychloroquine (S-HCQ) significantly more active against SARS-CoV-2, as compared to R-CQ and R-HCQ, respectively. In addition, Mpro, as one of the critical enzymes for viral transcription and replication, also exhibited an enantioselective binding affinity toward the S-enantiomers. The most significant finding from this study is the pronounced difference of the two enantiomers of CQ and HCQ observed in hERG inhibition assay. The IC50 value of S-HCQ was higher than 20 M against hERG channel, which was much less active over all tested CQ and HCQ compounds. Moreover, S-HCQ alone did not prolong QT interval in guinea pigs after 3 days and 6 days of administration, indicating a much lower cardiac toxicity potential. With these and previous findings on the enantio-differentiated metabolism, we recommend that future clinical studies should employ S-HCQ, substantially free of the R-enantiomer, to potentially improve the therapeutic index for the treatment of COVID-19 over the racemic CQ and HCQ.

PiggyBac transposon system with polymeric gene carrier transfected into human T cells.

CAR-T cell-based immunotherapy has shown great promise in clinical trials for the treatment of hematological malignancies. The majority of these trials utilize retroviral and lentiviral vectors to introduce CAR transgene. In spite of its satisfactory efficiency, the concerns about the potential carcinogenicity and complicated synthesis procedure restrict widespread clinical applications of viral vectors. Recent studies show that transposon-based gene transfer is a safer and simpler non-viral approach for stable transgene expression. Here, we developed an in house made polymeric nanomicelles carrier for piggyBac (PB) transposon delivery to primary T lymphocytes. The properties, transfection efficiency and toxicity of this carrier was analyzed. Results indicated that nanomicelles produced in our study were stable and reduction-sensitive. These micelles can completely condense DNA and mediate transfection with efficiency of average 30.2% with high cell viability (> 80%). Furthermore, incorporating piggyBac transposase elements into polyplexes promoted persistent expression of the transgene (up to 55%). At the end of culture, CAR-T cells mainly exhibited memory phenotype and consisted of CD3+CD8+ T cells. The cytotoxicity of these CAR-T cells was average 17% at 20:1 ratio. In conclusion, polymeric nanomicelles provide a flexible and safe method for gene delivery to T lymphocytes.

High-frequency echocardiography for assessment of regional wall motion abnormality and cardiac function in mice with myocardial infarction / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the value of high-frequency echocardiography in assessing cardiac structure and function in a mouse model of myocardial infarction.</p><p><b>METHODS</b>Twenty-five C57BL/6 mice were randomly divided into sham-operated group (n=10) and myocardial infarction model group (n=15) established by ligation of the left anterior descending artery. The cardiac structure, regional wall motion and cardiac function of mice were examined with pulsed wave Doppler (PWD), tissue Doppler imaging (TDI), EKV and M-mode echocardiography 3 days before and at 1 week after the operation. The histological changes and myocardial structure of the heart were observed at 1 week after the operation.</p><p><b>RESULTS</b>High-frequency echocardiography and HE staining detected obvious myocardial infarction in the mice in the model group. Compared with the sham-operated mice, the mice with myocardial infarction showed significant left ventricular expansion, obvious thinning of the ventricular wall, and significantly decreased ventricular systolic function and diastolic function with regional wall motion abnormality and ventricular remodeling.</p><p><b>CONCLUSION</b>s 2D-type echocardiography combined with M-mode, PWD, TDI and EKVTM for allows accurate and sensitive detection of the loci and severity of myocardial infarction to provide important evidence for clinical diagnosis and treatment of myocardial infarction.</p>

Changes and roles of VEGF and VCAM-1 in cerebrospinal fluid of children with viral encephalitis / 中国当代儿科杂志

<p><b>OBJECTIVE</b>Vascular endothelial cell injury contributes to the pathogenesis of viral encephalitis. This study was designed to investigate the roles of vascular endothelial growth factor (VEGF) and vascular cell adhesion molecule-1(VCAM-1) in cerebral spinal fluid (CSF) in the pathogenesis of viral encephalitis and in the evaluation of the severity and the prognosis of viral encephalitis in children.</p><p><b>METHODS</b>CSF VEGF and VCAM-1 levels were measured using ELISA in 65 children with viral encephalitis and 20 age-matched controls (10 cases of epilepsy and 10 cases of congenital abnormality).</p><p><b>RESULTS</b>CSF levels of VEGF and VCAM-1 in the viral encephalitis group in the acute phase were significantly elevated compared with those in the congenital abnormality (P<0.01) and the epilepsy groups (P<0.05). CSF levels of VEGF and VCAM-1 in the viral encephalitis group in the recovery phase decreased significantly and were similar to the levels of the epilepsy group, but remained higher than those in the congenital abnormality group (P<0.05). There was a positive correlation between CSF levels of VEGF and VCAM-1 in the viral encephalitis group in the acute and recovery phases. CSF levels of VEGF and VCAM-1 were positively correlated to CSF protein contents and the degree of MRI abnormality in the viral encephalitis group.</p><p><b>CONCLUSIONS</b>VEGF and VCAM-1 may participate in the pathogenesis of viral encephalitis. Detection of the two parameters may be helpful to the evaluation of the severity and prognosis of viral encephalitis.</p>