Transcriptional regulation and small compound targeting of ACE2 in lung epithelial cells.

Angiotensin-converting enzyme 2 (ACE2) is the receptor of COVID-19 pathogen SARS-CoV-2, but the transcription factors (TFs) that regulate the expression of the gene encoding ACE2 (ACE2) have not been systematically dissected. In this study we evaluated TFs that control ACE2 expression, and screened for small molecule compounds that could modulate ACE2 expression to block SARS-CoV-2 from entry into lung epithelial cells. By searching the online datasets we found that 24 TFs might be ACE2 regulators with signal transducer and activator of transcription 3 (Stat3) as the most significant one. In human normal lung tissues, the expression of ACE2 was positively correlated with phosphorylated Stat3 (p-Stat3). We demonstrated that Stat3 bound ACE2 promoter, and controlled its expression in 16HBE cells stimulated with interleukin 6 (IL-6). To screen for medicinal compounds that could modulate ACE2 expression, we conducted luciferase assay using HLF cells transfected with ACE2 promoter-luciferase constructs. Among the 64 compounds tested, 6-O-angeloylplenolin (6-OAP), a sesquiterpene lactone in Chinese medicinal herb Centipeda minima (CM), represented the most potent ACE2 repressor. 6-OAP (2.5 µM) inhibited the interaction between Stat3 protein and ACE2 promoter, thus suppressed ACE2 transcription. 6-OAP (1.25-5 µM) and its parental medicinal herb CM (0.125%-0.5%) dose-dependently downregulated ACE2 in 16HBE and Beas-2B cells; similar results were observed in the lung tissues of mice following administration of 6-OAP or CM for one month. In addition, 6-OAP/CM dose-dependently reduced IL-6 production and downregulated chemokines including CXCL13 and CX3CL1 in 16HBE cells. Moreover, we found that 6-OAP/CM inhibited the entry of SARS-CoV-2 S protein pseudovirus into target cells. These results suggest that 6-OAP/CM are ACE2 inhibitors that may potentially protect lung epithelial cells from SARS-CoV-2 infection.

[Establishment of fingerprint of Astragali Radix polysaccharides based on endo-1,4-ß-mannanase hydrolysis and identification of Astragali Radix of different germplasm resources].

The polysaccharides of different germplasm resources of Astragalus membranaceus var. mongholicus〓(cultured Astragalus Radix (RA) and natural RA) and A. membranaceus (MJ) (cultured RA and natural RA) were studied by using the optimal enzymatic conditions of endo-1,4-ß-mannanase. Saccharide fingerprints were obtained for the identification and evaluation of the germplasm resources of RA by Fluorophore-assisted Carbohydrate Electrophoresis (FACE). The data were analyzed by principal component analysis to obtain the difference between RA of different germplasm resources. The results showed that trisaccharide, tetrasaccharide and pentasaccharide of endo-1,4-ß-mannanase hydrolyzate could be used as the differential fragments to distinguish MG (cultured RA and natural RA); the pentasaccharide and hexasaccharide can be used as differentially expressed carbohydrate fragments that distinguish MJ (cultured RA and natural RA); the trisaccharide and tetrasaccharide can be used as the differential fragments to distinguish the cultured MG and cultured MJ. Studies have shown that polysaccharide products degraded by endo-1,4-ß-mannanase can well distinguish RA species (MG and MJ), growth mode (cultured RA and natural RA). This study laid the foundation for the quality evaluation of Astragalus medicinal herbs and screening of active oligosaccharides.

Xinfeng capsule for the treatment of rheumatoid arthritis patients with decreased pulmonary function--a randomized controlled clinical trial.

OBJECTIVE: To determine the effectiveness and safety of Xinfeng Capsules (XFC) for the treatment of rheumatoid arthritis (RA) patients with decreased pulmonary function. METHODS: This was a randomized controlled clinical trial of 80 RA patients. Participants were assigned to the trial group (40 cases) and the control group (40 cases) by block randomization. The trial group was treated with XFC, three pills each time three times daily for 2 months. The control group was treated with tripterygium glycoside (TPT), two pills each time three times daily for 2 months. Both groups were followed up after 2 months. The clinical effects, changes in joint and pulmonary function, and quality of life before and after treatment were observed; safety indices were also evaluated. RESULTS: Pain, swelling, tenderness, and duration of morning stiffness of joints were obviously decreased after treatment in both the trial and the control groups compared with baseline (P<0.01). Compared with before treatment, hand grip strength increased significantly after treatment in the trial group (P=0.0000); pulmonary function parameters such as forced expiratory volume in the first second of expiration/forced vital capacity (FEV1/FVC), 50% of the expiratory flow of forced vital capacity (FEF50), carbon monoxide diffusing capacity (DLco) were increased (P<0.01 or P<0.05); measures of quality of life such as role-physical, body pain, vitality and mental health were also improved after treatment in the trial group (all P<0.05). Joint swelling in the trial group decreased compared with the control group (P=0.0043), while hand grip strength was increased after treatment (P=0.0000). The increase in FEF50, DLco, and the dimensions of quality of life such as vitality and mental health were all significantly greater in the trial group than the control group (P<0.05 or P<0.01). CONCLUSIONS: XFC not only relieved joint pain in RA patients, but also significantly improved the ventilation and diffusion function of the lungs. Therefore, XFC could improve the whole body function and enhance the quality of life of RA patients.

Skp1 in lung cancer: clinical significance and therapeutic efficacy of its small molecule inhibitors.

Skp1 is an essential adaptor protein of the Skp1-Cul1-F-box protein complex and is able to stabilize the conformation of some ubiquitin E3 ligases. However, the role Skp1 plays during tumorigenesis remains unclear and Skp1-targeting agent is lacking. Here we showed that Skp1 was overexpressed in 36/64 (56.3%) of non-small cell lung cancers, and elevated Skp1 was associated with poor prognosis. By structure-based high-throughput virtual screening, we found some Skp1-targeting molecules including a natural compound 6-O-angeloylplenolin (6-OAP). 6-OAP bound Skp1 at sites critical to Skp1-Skp2 interaction, leading to dissociation and proteolysis of oncogenic E3 ligases NIPA, Skp2, and ß-TRCP, and accumulation of their substrates Cyclin B1, P27 and E-Cadherin. 6-OAP induced prometaphase arrest and exerted potent anti-lung cancer activity in two murine models and showed low adverse effect. These results indicate that Skp1 is critical to lung cancer pathogenesis, and Skp1 inhibitor inactivates crucial oncogenic E3 ligases and exhibits significant therapeutic potentials.

[Treatment of rheumatoid arthritis by xinfeng capsule: an efficacy observation].

OBJECTIVE: To observe the curative effect of Xinfeng Capsule (XC) in treatment of rheumatoid arthritis (RA). METHODS: Recruited were 80 active RA patients, who were randomly assigned to the normal control group and the treatment group, 40 in each group. All patients received the same routine anti-rheumatic treatment: Methotrexate 10 mg per week; Diclofenac 50 mg when pain was obvious, twice daily. Patients in the treatment group took XC 3 tablets each time, thrice daily. All treatment lasted for 12 consecutive weeks. Serum iron (SI), serum ferritin (SF), transferrin (TRF); and RA disease activity index (DAS-28) were detected in all patients. RESULTS: XC could improve HAQ, DAS-28, hypersensitive C reactive protein (hs-CRP), prostaglandins A (PGA), erythrocyte sedimentation rate (ESR), number of swelling joints, number of tender joints, and morning stiffness time in acute RA patients, showing statistical difference when compared with those of the control group (P < 0.01, P < 0.05). Compared with the control group, SI, SF, DAS-28, and TRF significantly decreased in the treatment group (P < 0.05). CONCLUSION: XC could improve DAS-28, and SI reserve in patients with active RA, and lower DAS-28 related indicators.