The coronavirus disease 2019 (COVID-19) is an acute infectious disease caused by the new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, which has led to serious worldwide economic burden. Due to the continuous emergence of variants, vaccines and monoclonal antibodies are only partial effective against infections caused by distinct strains of SARS-CoV-2. Therefore, it is still of great importance to call for the development of broad-spectrum and effective small molecule drugs to combat both current and future outbreaks triggered by SARS-CoV-2. Cathepsin L (CatL) cleaves the spike glycoprotein (S) of SARS-CoV-2, playing an indispensable role in enhancing virus entry into host cells. Therefore CatL is one of the ideal targets for the development of pan-coronavirus inhibitor-based drugs. In this study, a CatL enzyme inhibitor screening model was established based on fluorescein labeled substrate. Two CatL inhibitors IMB 6290 and IMB 8014 with low cytotoxicity were obtained through high-throughput screening, the half inhibition concentrations (IC₅₀) of which were 11.53 ± 0.68 and 1.56 ± 1.10 μmol·L^-1, respectively. SDS-PAGE and cell-cell fusion experiments confirmed that the compounds inhibited the hydrolysis of S protein by CatL in a concentration-dependent manner. Surface plasmon resonance (SPR) detection showed that both compounds exhibited moderate binding affinity with CatL. Molecular docking revealed the binding mode between the compound and the CatL active pocket. The pseudovirus experiment further confirmed the inhibitory effects of IMB 8014 on the S protein mediated entry process. In vitro pharmacokinetic evaluation indicated that the compounds had relatively good drug-likeness properties. Our research suggested that these two compounds have the potential to be further developed as antiviral drugs for COVID-19 treatment.

The chemical constituents from the fruiting bodies of Lyophyllum decastes (Fr.) Singer were studied in this paper. Thirteen compounds were isolated and purified by column chromatographies on silica gel and Sephadex LH-20. Their structures were identified by MS and NMR data analysis as adenosine (1), 2R, 3S, 4S, 8E)-2-[(2'R)-2-hydroxyheneicosanoylamino]-8-octadecene-1, 3, 4-triol (2), (2R, 3S, 4S, 8E)-2-[(2'R)-2-hydroxypentacosanoylamino]-8-octadecene-1, 3, 4-triol (3), nicotinic acid (4), (4E, 8E) -2-N-2-hydroxytetracosanoyl-1-O-beta-D-glycopyranosyl-9-methyl-4, 8-sphingadienine (5), D-mannitol (6), ergosteryl-3-O-beta-D-glucopyranoside (7), tuberoside (8), (2R, 3S, 4S, 8E)-2-[(2'R)-2-hydroxybehenoylamino]-8-octadecene-1, 3, 4-triol (9),(2R, 3S, 4S, 8E)-2-[(2'R) -2-hydroxytricosanoylamino] -8-octadecene-1, 3, 4-triol (10), (22E, 24R)-ergosta-7, 22-dien-3beta, 5alpha, 6beta-triol (11), (22E, 24R)-ergosta-5, 7, 22-trien-3beta-ol (12), and 5alpha, 8alpha-epidiory-(22E, 24R)-ergosta-6, 22-dien-3beta-ol (13), respectively. All the above compounds are first obtained from the mushroom and compounds 2-10 are reported to be obtained from the Lyophyllum for the first time.
Agaricales ; chemistry ; Drugs, Chinese Herbal ; chemistry ; Fruit ; chemistry

Anti-Arrhythmia Agents ; therapeutic use ; Cardiomyopathies ; drug therapy ; etiology ; Child, Preschool ; Female ; Humans ; Moricizine ; therapeutic use ; Tachycardia ; complications ; drug therapy ; Treatment Outcome

Orthogonal combination design was adopted in examining the Spirulina platensis (S. platensis) yield and the influence of four factors (Se content, Se-adding method, S content and NaHCO3 content) on algae growth. The results showed that Se content, Se-adding method and NaHCO3 content were key factors in cultivation conditions of Se-enriched S. platensis with the optimal combination being Se at 300 mg/L, Se-adding amount equally divided into three times and NaHCO3 at 16.8 g/L. Algae yield had a remarkable correlation with OD560 and floating rate by linear regression analysis. There was a corresponding relationship between effects of the four factors on algae yield and on OD560, floating rate too. In conclusion, OD560 and floating rate could be served as yield-forming factors.
Bicarbonates ; analysis ; Culture Media ; Cyanobacteria ; growth & development ; Selenium ; analysis ; pharmacology

Objective To study the incidence of osteopenia in patients with initial systemic lupus erythematosus(SLE). Investigate the levels of the vitamin D (VitD) endocrine system in peripheral blood of SLE patients and its relation to bone mineral density (BMD). Analyse the relationship between the estrogen receptor (ER) and BMD and evaluate the role of ER in the pathogenesis osteopenia. Methods Serum levels of 25-OH VitD_3 and 1,25-(OH)_2 VitD_3 were detected by enzyme linked immunosorbent assay. The gene expression levels of VitD receptor (VDR) and ER were determined by real-time PCR. BMD measurements in the lumbar spine (L1-L4) and left proximal femur (femoral neck) were performed using dual X-ray absorptiometry before treatment. Results The initial SLE patients had significantly lower BMD values, and higher frequency of bone loss at both sites of measurement compared with normal controls (P < 0. 05). The levels of 25-OH VitD_3 and 1,25-(OH)_2 VitD3 were lower in the initial SLE patients than normal controls(P<0.01 both). There is no difference in the levels of 25-OH VitD_3 and 1,25-(OH)_2 VitD_3 between the osteopenia SLE group and the normal BMD SLE group (P > 0. 05, P > 0. 05). There are no correlations between the Vitd and BMD in initial SLE patients (P>0.05 both). The expressions of VDR gene were significantly increased in the initial SLE patients compared with the normal controls(P<0.01). There was no difference in VDR gene expression between osteopenia SLE group and normal BMD SLE group (P>0.05). The VDR gene expression does not correlate with the bone mass (P>0.05). The levels of ER-β gene expression are higher in the initial SLE group than the normal controls (P<0.01).Conclusions The incipient SLE patients may have lower BMD than expected. SLE patients present abnormal VitD endocrine system and higher ER-β mRNA expression than those in normal controls, but these weren't concerned with osteopenia.

Objective ① To investigate the level of the vitamin D endocrine system in peripheral relationships with bone mineral density (BMD) and the disease activity respectively. Methods The level of the 25-hydroxylate vitamin D3 (25OHD3) and 1,25-dihydroxyvitamin D3 [1,25(OH)D3] in plasma from 43 SLE patients and 44 normal controls were detected by enzyme linked immunosorbent assay. Vitamin D receptor (VDR) gene expression was determinied by real-time PCR in peripheral blood. BMD measurements in the lumbar spine (L1-4) and left proximal femur (femoral neck) were performed using dual X-ray absorptiometry before treatment. The relationship between the vitamin D endocrine system and the bone mass were studied. We also discussed the relationship between the vitamin D endocrine system and the disease activity. Results The levels of 25OHD3 and 1,25 (OH)2D3 were lower in the initial SLE patients than normal controls (P<0.01, P<0.01). The expressions of VDR gene were significantly increased in initial SLE compared with normal controls (P<0.01). The initial SLE patients had significantly lower BMD values, and higher frequency of osteopenia (35%) at both sites of measurement compared with matched healthy controls (P<0.01). The initial SLE patients were divided into two groups by BMD, abnormal group and normal group. There were no differences in 25OHD3, 1,25 (OH)D3 and VDR gene expression (P0.05). There was no correlation between the vitamin D endocrine system and BMD in initial SLE patients. There was no correlation between the vitamin D endocrine system and the disease activity either. Conclusion Vitamin D endocrine system may play an important role in SLE, but the level of VDR gene is not correlated with BMD and disease activity.

Malignant tumors are major diseases that endanger human health. Due to their complex and variable microenvironment, most anti-tumor drugs cannot precisely reach the focal tissue and be released in a controlled manner. Intelligent responsive nano carriers have become a hot spot in the field of anti-tumor drug delivery systems. As an excellent nano material, mesoporous silica has the advantages of non-toxic, stable, adjustable pore volume and pore diameter, and easy functional modification on the surface. By virtue of its perceptive response to the tumor microenvironment or physiological changes, it can achieve the targeted drug release or controlled drug release of the drug delivery system in the tissue, making it an ideal carrier for intelligent response drug delivery system. In this paper, we review the design strategies and current research status of smart responsive anti-tumor drug delivery systems based on mesoporous silica, in order to provide a reference for the development of anti-tumor drug nanoformulations.

Objective To study the inhibitory effect of small interference RNA(siRNA) ofcyclin E gene on the growth ofK562cells. Methods siRNA targeting the 940 bp site of the cyclin E mRNA were designed and generated by PCR amplification.The PCR products containing U6 promoter and the siRNA were then transfected into K562 cells via LipofectamineTM2000.The cells transfected with non-functional siRNA served as the negative control group and those only treated with serum-free RPMI1640 as the blank control group. Cell counting, reverse transcriptase (RT)-PCR and flow cytometry were employed to evaluate the effect of RNA interference. Results Compared with the negative and blank control groups, the viable cell count in the interference group was decreased by approximately 80%, the ratio of G1-phase cells increased by nearly 30%, and growth arrest was observed. Cyclin E mRNA expression in the cells of the interference group was significantly lowered by about 70%as compared with that of the negative and blank control groups, whereas the latter two groups had similar expression levels.Conclusion RNA interference induces obvious inhibition of cyclin E gene expression, which consequently affects the proliferation ofK562 cells.

Objective To study the inhibitory effect of small interference RNA(siRNA) ofcyclin E gene on the growth ofK562cells. Methods siRNA targeting the 940 bp site of the cyclin E mRNA were designed and generated by PCR amplification.The PCR products containing U6 promoter and the siRNA were then transfected into K562 cells via LipofectamineTM2000.The cells transfected with non-functional siRNA served as the negative control group and those only treated with serum-free RPMI1640 as the blank control group. Cell counting, reverse transcriptase (RT)-PCR and flow cytometry were employed to evaluate the effect of RNA interference. Results Compared with the negative and blank control groups, the viable cell count in the interference group was decreased by approximately 80%, the ratio of G1-phase cells increased by nearly 30%, and growth arrest was observed. Cyclin E mRNA expression in the cells of the interference group was significantly lowered by about 70%as compared with that of the negative and blank control groups, whereas the latter two groups had similar expression levels.Conclusion RNA interference induces obvious inhibition of cyclin E gene expression, which consequently affects the proliferation ofK562 cells.

Objective To analyze and predict the structure and function of mosquito densovirus(MDV)nostmetual proteinl(NSI).Methods Using different bioinformafics software,the EXPASY pmtparam tool,ClustalX1.83,Bioedit,MEGA3.1,ScanProsite,and Motifscan,respectively to comparatively analyze and predict the physic-chemical parameters,homology,evolutionary relation,secondary structure and main functional motifs of NS1.Results MDV NS1 protein wag a unstable hydrophilic protein and the amino acid sequence wag highly conserved which had a relatively closer evolutionary distance with infectious hypodermal and hematopoietic necrosis virus(IHHNV).MDV NS1 hag a specific domain of superfamily 3 helicage of small DNA viruses.This domain contains the NTP-binding region with a metal ion-dependent ATPase activity.A virus replication roller rolling-circle replication(RCR)initiation domain wag found near the N terminal of this protein.This protien has the biological function of single stranded incision enzyme.Conclusion The bioinformatics prediction results suggest that MDV NS1 protein phys a key role in viral replication,packaging,and the other stages of viral life.