Porcine epidemic diarrhea virus E protein induces unfolded protein response through activating both PERK and ATF6 rather than IRE1 signaling pathway.

Porcine epidemic diarrhea virus (PEDV) small envelope protein (E) plays important roles in virus budding, assembly, and release. Our previous study found that PEDV E protein localizes in the endoplasmic reticulum (ER) to trigger the unfolded protein response (UPR). However, how UPR is directly regulated by PEDV E protein remains elusive. Thus, in this study, we investigated the expression of ER chaperone glucose-regulated protein 78 (GRP78) and activations of the three main UPR signaling pathways to elucidate the underlying mechanisms of UPR triggered by PEDV E protein. The results showed that over-expression of PEDV E protein increased expression of GRP78 and induced stronger phosphorylation of both protein kinase RNA-like ER kinase (PERK) and eukaryotic initiation factor-2α (eIF2α), as well as caused the significant degradation of activating transcription factor 6 (ATF6), in both dose- and time-dependent manners. However, PEDV E protein did not induce UPR through the inositol-requiring enzyme 1 (IRE1) signaling pathway, as revealed by the splicing of XBP1 remaining unaffected and unchanged when PEDV E protein was overexpressed. Taken together, these results demonstrate that PEDV E protein induces UPR through activation of both PERK and ATF6 pathways rather than IRE1 signaling. This study not only provides mechanistic details of UPR induced by the PEDV E protein, but also provides insights into these new biologic functions to help us better understand the interactions between PEDV and host cells.

Synergistic effects of selenium and zinc on Bletilla striata (Thunb.) Reichb. F. growth and polysaccharide antioxidation.

Selenium (Se) is a beneficial trace element for plants, while zinc (Zn) is a vital micronutrient. Bletilla striata (Thunb.) Reichb. F. is widely recognized as a medicinal herb. In this study, Se and Zn were introduced to determine the medicinal properties of B. striata. The plant's biomass, polysaccharides, Se and Zn contents, and the antioxidant properties of polysaccharide solutions were all examined. A notable increase in polysaccharide synthesis in B. striata tubers was observed following the application of 0.2 kg ha-1 of Se, and 1.0 kg ha-1 of Zn, either individually or in combination. Se and Zn content in polysaccharides were 3.33 to 3.77 mg kg-1 and 82.82 to 121.78 mg kg-1, at 1.0 kg ha-1 Se and 10.0 kg ha-1 Zn treatments, respectively. These values were 2.1-3.1 times and 1.8-2.8 times higher than those observed in control samples. Polysaccharide antioxidation has resulted in an increase in antioxidant activity as the concentration of polysaccharide solutions increased. The largest scavenging of 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radicals and the most excellent reducing power of the polysaccharide solutions were observed when a mixture of Se and Zn was applied at a rate of 1.0 kg ha-1 and 10.0 kg ha-1. The individual application of Se at 1.0 kg ha-1 and Zn at 10.0 kg ha-1 also resulted in significant DPPH radicals scavenging and reduced power. These data suggested that Se-Zn enriched B. striata is a new source of Se and Zn supplementation and an antioxidant resource.

Porcine epidemic diarrhea virus E protein induces formation of stress granules and attenuates protein translation through activation of the PERK/eIF2α signaling pathway.

Porcine epidemic diarrhea virus (PEDV) envelope protein (E) has been characterized as an important structural protein that plays critical roles in the interplay with its host to affect the virus life cycle. Stress granules (SGs) are host translationally silent ribonucleoproteins, which are mainly induced by the phosphorylation of eIF2α in the PERK/eIF2α signaling pathway. Our previous study found that PEDV E protein caused endoplasmic reticulum stress response (ERS)-mediated suppression of antiviral proteins' translation. However, the link and the underlying mechanism by which PEDV induces SGs formation and suppresses host translation remain elusive. In this study, our results showed that PEDV E protein significantly elevated the expression of GRP78, CANX, and phosphorylation of PERK and eIF2α, indicating that the PERK/eIF2α branch of ERS was activated. PEDV E protein localized to the ER and aggregated into puncta to reconstruct ER structure, and further induced SGs formation, which has been caused through upregulating the G3BP1 expression level. In addition, a significant global translational stall and endogenous protein translation attenuation were detected in the presence of E protein overexpression, but the global mRNA transcriptional level remained unchanged, suggesting that the shutoff of protein translation was associated with the translation, not with the transcription process. Collectively, this study demonstrates that PERK/eIF2α activation is required for SGs formation and protein translation stall. This study is beneficial for us to better understand the mechanism by which PEDV E suppresses host protein synthesis, and provides us a new insight into the host translation regulation during virus infection.

Structural basis for a human broadly neutralizing influenza A hemagglutinin stem-specific antibody including H17/18 subtypes.

Influenza infection continues are a persistent threat to public health. The identification and characterization of human broadly neutralizing antibodies can facilitate the development of antibody drugs and the design of universal influenza vaccines. Here, we present structural information for the human antibody PN-SIA28's heterosubtypic binding of hemagglutinin (HA) from circulating and emerging potential influenza A viruses (IAVs). Aside from group 1 and 2 conventional IAV HAs, PN-SIA28 also inhibits membrane fusion mediated by bat-origin H17 and H18 HAs. Crystallographic analyses of Fab alone or in complex with H1, H14, and H18 HA proteins reveal that PN-SIA28 binds to a highly conserved epitope in the fusion domain of different HAs, with the same CDRHs but different CDRLs for different HAs tested, distinguishing it from other structurally characterized anti-stem antibodies. The binding characteristics of PN-SIA28 provides information to support the design of increasingly potent engineered antibodies, antiviral drugs, and/or universal influenza vaccines.

Analysis of Chinese Herbal Formulae Recommended for COVID-19 in Different Schemes in China: A Data Mining Approach.

BACKGROUND: Novel coronavirus pneumonia (NCP), or coronavirus disease 2019 (COVID-19), is a worldwide health threat that has affected millions of people globally. Traditional Chinese medicine (TCM) has been introduced for the treatment of COVID-19. However, efficacy differs among herbal medicines, and the ideal prescription pattern for TCM herbal formulae for COVID-19 treatment needs to be explored. Therefore, the data mining method has been used in this study to analyze the TCM prescription pattern for COVID-19. OBJECTIVE: The aim of this study was to analyze the TCM prescription pattern in Regional Schemes in China for COVID-19 in order to provide a new reference for the use of TCM in COVID-19 treatment. METHODS: By searching the TCM treatment protocols of COVID-19 in 23 Regional Schemes, TCM syndromes and herbal medicines were analyzed by data mining. The Ancient and Modern Medical Case Cloud Platform (V2.1 personal Edition) was used to perform frequency statistics, correlation analysis, and cluster analysis. A total of 82 TCM syndromes and 171 Chinese herbal medicines were found. The course of the disease can be divided into the early stage, middle stage, severe stage, and recovery stage. RESULTS: In the early stage, the focus is primarily on resolving dampness, dispelling cold, and diffusing the lungs. In the middle stage, the treatment priority is clearing heat and resolving toxins, promoting lung function, and relieving asthma. In the severe stage, the focus is on tonifying Qi, restoring Yang, and relieving the depletion of Yin and Yang. In the recovery stage, the main treatment is to invigorate the spleen and regulate Qi, tonify Qi, nourish Yin, and clear residual disease. There are certain differences between the Regional Schemes and the Nation Schemes, but the core prescription pattern of the former is consistent with the latter. The effectiveness of these 171 Chinese herbs include but are not limited to inhibiting COVID-19, strengthening immune system function, preventing heart failure, acting as antioxidants, oxidative stress inhibitory effects, maintaining organ function, and improving leukocyte survival. CONCLUSION: This study may help to improve understanding of TCM herbal prescription pattern, practices, reveal the efficacy of combinations of Chinese herbs, and provide new ideas for TCM treatment for COVID-19.

[Clinical Trials for Thyroidectomy Under Acupuncture-aided Anesthesia by Using Electroacupuncture or Transcutaneous Acupoint Electrical Stimulation of Different Acupoints].

OBJECTIVE: To observe the effectiveness of transcutaneous acupoint electrical stimulation (TAES) or electroacupuncture (EA) stimulation of different acupoints in combination with anesthetics in the management of thyroidectomy patients, so as to choose a better stimulating method and most effective acupoints for thyroidectomy. METHODS: A total of 216 thyroidectomy patients (ASA Ⅰ-Ⅱ grades) with thyroid gland adenoma, thyroid cyst or thyroid nodules from 3 hospitals (3 research centers) were randomized into 6 groups, i.e., local anesthesia (LA, n=34), Futu (LI 18)-EA (n=36), Hegu (LI 4)-Neiguan (PC 6)-TAES (n=34), LI 4-PC 6-EA (n=36), Yanglingquan (GB 34)-EA (n=36) and non-acupoint (NA, about 1.5 cm latero-posterior to KI 9)-EA (n=34) groups according to the hospitalizition sequence. For patients of the LI 18-EA, LI 4-PC 6-TAES/EA, GB 34 and non-acupoint-EA groups, EA or TAES (2 Hz/100 Hz) was applied to the abovementioned bilateral acupoints or non-acupoint till the termination of the surgical operation. The surgery was conducted under anesthesia by local injection of 0.5% lidocaine and midazolam, and intravenous injection of fentanyl (for severe pain cases) 20 min after beginning of TAES or EA. The patients' scores of visual analogue scale (VAS),mean arterial pressure (MAP) and heart rate (HR) at the time-points of pre-anesthesia (T 0), skin-incision (T 1), skin flap-freeing (T 2), anterior cervical muscle traction (T 3), thyroid upper/lower-pole-sectioning (T 4/T 5), and thyroidectomy (T 6), and the dosages of the administered fentanyl and lidocaine were recorded. RESULTS: Compared with the corresponding time-points of the non-acupoint group, the VAS scores at T 1 and T 4 time-points in the LI 18-EA group and LI 4-PC 6-EA group, at T 1, T 5 and T 6 time-points in the LI 4-PC 6-TAES group were significantly lower (P<0.05). Compared with the corresponding time-points of the LA group, the VAS scores at T 2, T 3, T 5 and T 6 time-points in the LI 18-EA group and LI 4-PC 6-EA group, at T 3, T 5 and T 6 in the LI 4-PC 6-TAES group, and the MAP levels at T 2, T 3, T 4 and T 6 time-points in the LI 18-EA group, at T 3, T 4 in the LI 4-PC 6-EA group, at T 3, T 4, T 6 in the LI 4-PC 6 TAES group, as well as the HR levels at T 4, T 5 and T 6 in the LI 18-EA group, and at T 5, T 6 in the LI 4-PC 6-TAES group were significantly lower (P<0.05). The dosages of fentanyl in the LI 18-EA and LI 4-PC 6-TAES groups, and those of lidocaine in the LI 18-EA, LI 4-PC 6-EA and TAES groups were significantly lower relevant to the LA group and non-acupoint group (P<0.05). No significant differences were found between the LA and GB 34-EA groups, and between the LA and non-acupoint groups, as well as between the LI 4-PC 6-EA and LI 4-PC 6-TAES groups in the VAS scores, the MAP and HR levels, the dosages of lidocaine and fentanyl consumption (P>0.05). CONCLUSIONS: EA stimulation of both LI 18 and LI 4-PC 6 and TAES of LI 4-PC 6 combined with anesthetics have a better effect in inducing analgesia and controlling MAP and HR, and need lower dosages of anesthetics for patients undergoing thyroidectomy, for which LI 18 and LI 4-PC 6 are evidently superior to GB 34 and non-acupoint. Hence, combined EA or TAES and anesthetics is highly recommended for thyroidectomy.