Fibroblast growth factor 21 attenuates ventilator-induced lung injury by inhibiting the NLRP3/caspase-1/GSDMD pyroptotic pathway.

BACKGROUND: Ventilator-induced lung injury (VILI) is caused by overdistension of the alveoli by the repetitive recruitment and derecruitment of alveolar units. This study aims to investigate the potential role and mechanism of fibroblast growth factor 21 (FGF21), a metabolic regulator secreted by the liver, in VILI development. METHODS: Serum FGF21 concentrations were determined in patients undergoing mechanical ventilation during general anesthesia and in a mouse VILI model. Lung injury was compared between FGF21-knockout (KO) mice and wild-type (WT) mice. Recombinant FGF21 was administrated in vivo and in vitro to determine its therapeutic effect. RESULTS: Serum FGF21 levels in patients and mice with VILI were significantly higher than in those without VILI. Additionally, the increment of serum FGF21 in anesthesia patients was positively correlated with the duration of ventilation. VILI was aggravated in FGF21-KO mice compared with WT mice. Conversely, the administration of FGF21 alleviated VILI in both mouse and cell models. FGF21 reduced Caspase-1 activity, suppressed the mRNA levels of Nlrp3, Asc, Il-1ß, Il-18, Hmgb1 and Nf-κb, and decreased the protein levels of NLRP3, ASC, IL-1ß, IL-18, HMGB1 and the cleaved form of GSDMD. CONCLUSIONS: Our findings reveal that endogenous FGF21 signaling is triggered in response to VILI, which protects against VILI by inhibiting the NLRP3/Caspase-1/GSDMD pyroptosis pathway. These results suggest that boosting endogenous FGF21 or the administration of recombinant FGF21 could be promising therapeutic strategies for the treatment of VILI during anesthesia or critical care.

Comparison of acute pneumonia caused by SARS-COV-2 and other respiratory viruses in children: a retrospective multi-center cohort study during COVID-19 outbreak.

BACKGROUND: Until January 18, 2021, coronavirus disease-2019 (COVID-19) has infected more than 93 million individuals and has caused a certain degree of panic. Viral pneumonia caused by common viruses such as respiratory syncytial virus, rhinovirus, human metapneumovirus, human bocavirus, and parainfluenza viruses have been more common in children. However, the incidence of COVID-19 in children was significantly lower than that in adults. The purpose of this study was to describe the clinical manifestations, treatment and outcomes of COVID-19 in children compared with those of other sources of viral pneumonia diagnosed during the COVID-19 outbreak. METHODS: Children with COVID-19 and viral pneumonia admitted to 20 hospitals were enrolled in this retrospective multi-center cohort study. A total of 64 children with COVID-19 were defined as the COVID-19 cohort, of which 40 children who developed pneumonia were defined as the COVID-19 pneumonia cohort. Another 284 children with pneumonia caused by other viruses were defined as the viral pneumonia cohort. The epidemiologic, clinical, and laboratory findings were compared by Kolmogorov-Smirnov test, t-test, Mann-Whitney U test and Contingency table method. Drug usage, immunotherapy, blood transfusion, and need for oxygen support were collected as the treatment indexes. Mortality, intensive care needs and symptomatic duration were collected as the outcome indicators. RESULTS: Compared with the viral pneumonia cohort, children in the COVID-19 cohort were mostly exposed to family members confirmed to have COVID-19 (53/64 vs. 23/284), were of older median age (6.3 vs. 3.2 years), and had a higher proportion of ground-glass opacity (GGO) on computed tomography (18/40 vs. 0/38, P < 0.001). Children in the COVID-19 pneumonia cohort had a lower proportion of severe cases (1/40 vs. 38/284, P = 0.048), and lower cases with high fever (3/40 vs. 167/284, P < 0.001), requiring intensive care (1/40 vs. 32/284, P < 0.047) and with shorter symptomatic duration (median 5 vs. 8 d, P < 0.001). The proportion of cases with evaluated inflammatory indicators, biochemical indicators related to organ or tissue damage, D-dimer and secondary bacterial infection were lower in the COVID-19 pneumonia cohort than those in the viral pneumonia cohort (P < 0.05). No statistical differences were found in the duration of positive PCR results from pharyngeal swabs in 25 children with COVID-19 who received antiviral drugs (lopinavir-ritonavir, ribavirin, and arbidol) as compared with duration in 39 children without antiviral therapy [median 10 vs. 9 d, P = 0.885]. CONCLUSION: The symptoms and severity of COVID-19 pneumonia in children were no more severe than those in children with other viral pneumonia. Lopinavir-ritonavir, ribavirin and arbidol do not shorten the duration of positive PCR results from pharyngeal swabs in children with COVID-19. During the COVID-19 outbreak, attention also must be given to children with infection by other pathogens infection.

Changes in innate and permissive immune responses after hbv transgenic mouse vaccination and long-term-siRNA treatment [corrected].

BACKGROUND: Currently, no licensed therapy can thoroughly eradicate hepatitis B virus (HBV) from the body, including interferon α and inhibitors of HBV reverse-transcription. Small interfering RNA (siRNA) seem to be a promising tool for treating HBV, but had no effect on the pre-existing HBV covalently closed circular DNA. Because it is very difficult to thoroughly eradicate HBV with unique siRNAs, upgrading the immune response is the best method for fighting HBV infection. Here, we aim to explore the immune response of transgenic mice to HBV vaccination after long-term treatment with siRNAs and develop a therapeutic approach that combines siRNAs with immunopotentiators. METHODOLOGY/PRINCIPAL FINDINGS: To explore the response of transgenic mice to hepatitis B vaccine, innate and acquired immunity were detected after long-term treatment with siRNAs and vaccination. Antiviral cytokines and level of anti-hepatitis B surface antigen antibody (HBsAg-Ab) were measured after three injections of hepatitis B vaccine. RESULTS: Functional analyses indicated that toll-like receptor-mediated innate immune responses were reinforced, and antiviral cytokines were significantly increased, especially in the pSilencer4.1/HBV groups. Analysis of CD80+/CD86+ dendritic cells in the mouse liver indicated that dendritic cell antigen presentation was strengthened. Furthermore, the siRNA-treated transgenic mice could produce detectable HBsAg-Ab after vaccination, especially in the CpG oligonucleotide vaccine group. CONCLUSIONS/SIGNIFICANCE: For the first time, our studies demonstrate that siRNAs with CpG HBV vaccine could strengthen the immune response and break the immune tolerance status of transgenic mice to HBV. Thus, siRNAs and HBV vaccine could provide a sharp double-edged sword against chronic HBV infection.

[Effects of Wuling mycelia on pentylenetetrazole-induced epilepsy in rats].

OBJECTIVE: To investigate the effects and mechanisms of Wuling mycelia on seizure development and learning ability induced by pentylenetetrazole-kindling epilepsy in rats. METHODS: SD rats were randomly divided into four groups: pentylenetetrazole-kindling model group (model group), low dose Wuling mycelia (0.3 g*kg(-1)) group (LD-WM group), high dose Wuling mycelia (0.6 g*kg(-1)) group (HD-WM group) and control group. The rats were intraperitoneal injected with a subconvulsive dose (35 mg*kg(-1)) of pentylenetetrazole (saline in control group) every 48 h for 12 times. Wuling mycelia was intragastrically applied 30 min before pentylenetetrazole injection. An 8-arm radial maze ( 4 arms baited) was used to measure the learning ability. Histamine was measured by chemical fluorometric enzyme immunoassay. RESULTS: Compared with the model group, the kindling stage of LD-WM group degraded significantly after 7th injection, the latency to the onset of myoclonic jerks (LTMJ) and the latency to the onset of generalized seizures (LTGS) prolonged after the 6th and 7th injection, respectively (P<0.05). The kindling stage of HD-WM group also degraded markedly after the 6th to 8th injection, and the LTMJ and the LTGS extended after the 8th to 9th and 6th injection, respectively (P<0.05). Compared with the control group, the frequency of working memory error (WME) and reference memory error (RME) of the model group in the 8-arm radial maze increased through 3-d training (P<0.05). The memory tests showed that the impairment induced by pentylenetetrazole was partially reversed by Wuling mycelia. Compared with the control group, brain histamine contents (hippocampus, cortex, thalamus and hypothalamus) were significantly lower in model group (P<0.05). But compared with the model group, hippocampal histamine contents in LD-WM group and hippocampal, thalamic and hypothalamic histamine contents in HD-WM group were elevated (P<0.05). CONCLUSION: Wuling mycelia can delay the kindling and ameliorate the ability of learning in rats with pentylenetetrazole-induced epilepsy and the enhancement of neuronal histamine activity may be one of possible mechanisms.

[Epidemiological and clinical analysis of Mycoplasma pneumoniae infection in children with acute respiratory tract infection].

OBJECTIVE: To summarize the epidemiology and clinical characteristics of Mycoplasma pneumoniae (MP) infection in children with acute respiratory tract infection (ARI) in Guangzhou. METHODS: MP was detected using an indirect immunofluorescent method in 2084 children with ARI. The relations between MP infection rate and the gender, age, season, site of infection and wheezing diseases were analyzed. RESULTS: A total of 433 children (20.8%) were positive for MP, including 222 boys (19.8%) and 211 girls (21.9%) without significant difference in the infection rate between the genders (P>0.05). In 0- to 3-year-old group, 106 children were positive for MP (15.0%), while in 3- to 5-year-old group and 5- to 14-year-old group, 163 (25.2%) and 164 (22.5%) were positive, respectively, showing a significant difference in the infection rate between the 3 groups (P<0.05). The MP infection rate was 18.0% in January to March, 25.1% in April to June, 17.7% in July to September, and 20.5% in October to December, showing significant differences between the periods (P<0.05). No significant difference was found in the infection rate between children with acute upper respiratory tract infection (URI) and those with lower respiratory tract infection (LRI) (P>0.05). Among the children with LRI, those having wheezing disease had significantly higher MP positivity rate than those without wheezing. CONCLUSION: MP is a common causative agent for ARI in children. MP infection is not related to gender and infection site, but to age and season. Children over 3 years old are vulnerable to MP infection. MP infection can be associated with wheezing in LRI.

The short hairpin RNA driven by polymerase II suppresses both wild-type and lamivudine-resistant hepatitis B virus strains.

BACKGROUND: Chronic infection with hepatitis B virus (HBV) is widespread because of the limited availability of therapeutic treatments. Although previous reports have suggested that RNA interference has promise as a treatment for HBV infection, further studies of long-term and off-target drug effects on HBV, especially on drug-resistant strains of HBV, are needed. Therefore, seven vectors that express short hairpin RNAs (shRNAs), driven by the polymerase II promoter, pSilencer4.1/HBV, were constructed to target open reading frames (ORFs) of the HBV C and S genes from wild-type and drug-resistant strains. Treatment efficiency was also assessed. METHODS: The pSilencer4.1/HBV vectors were investigated in HepG2.2.15 cells and transgenic mice that consistently produce wild-type HBV. Additionally, vectors that produce a lamivudine-resistant strain of HBV were developed and cotransfected, along with pSilencer/HBV, into both HepG2 cells and mice. The effects of polymerase-II-driven pSilencer4.1/HBV were compared with those of polymerase-III-driven pSilencer3.1/HBV at both the gene and protein level. RESULTS: pSilencer4.1/HBV inhibited the expression of viral protein, DNA and HBV subtype ayw mRNA in both HepG2.2.15 cells and transgenic mice. Toxicity, as well as off-target effects, did not occur after a short- to medium-term examination. Moreover, an HBV strain resistant to lamivudine, subtype adr, was suppressed by shRNA in both HepG2 cells and mice. In contrast to polymerase III, vectors that used polymerase II could drive efficient silencing without off-target effects. CONCLUSIONS: Silencing by shRNA dramatically inhibited HBV expression and replication regardless of strain type. ShRNA could therefore be a promising treatment for HBV infection.

Toll-like receptor 4 siRNA attenuates LPS-induced secretion of inflammatory cytokines and chemokines by macrophages.

Toll-like receptor 4 (TLR4) is critical for activation of macrophages by Lipopolysaccharide (LPS). In this study, we investigated the silencing effects of TLR4-specific 21-nt small interfering RNAs (siRNA) on TLR4 expression in RAW264.7 cells. It was found that treatment with TLR4 siRNA down-regulated the TLR4 mRNA and protein expression in macrophage RAW264.7 cells, and reduced the sensitivity of the cells to LPS stimulation. Our findings also demonstrate that treatment with TLR4 siRNA significantly decreased the tumor necrosis factor-alpha (TNF-alpha) and macrophage inflammatory protein 2 (MIP-2) expression induced by LPS. TLR4 siRNA treatment also impaired the signalling of mitogen-activated protein kinases (MAPK) induced by LPS in RAW264.7 cells. These data suggest that inhibition of TLR4 expression by TLR4 siRNA may be therapeutically beneficial in controlling the overall responses of immune cells to LPS.

Effects of insulin-like growth factor I on the development of osteoblasts in hyperglycemia.

The delayed wound healing of tooth extraction, the activation of alveolar absorption and the being hindered bone formation around the implants in diabetes are difficult to be solved for dentists. So, the aim of the study was to investigate the influences of hyperglycemia and insulin-like growth factor I (IGF-I) on osteoblasts. Osteoblasts were cultured in different conditions: normal glucose, mimic hyperglycemia, hyperglycemia with IGF-I, hyperglycemia with insulin. The proliferation and mineralization of osteoblasts were observed. As abnormal transport of glucose involved in the development of chronic complications in diabetes. The expression of glucose transporter 1 (GLUT1) was further evaluated by RT-PCR, immunofluorescence and Western blot in different groups. These results showed that hyperglycemia increased the proliferation and inhibited the mineralization of osteoblasts, while IGF-I seemed to reverse these effects. The levels of GLUT1 mRNA and protein in hyperglycemia were elevated by 51% and 35%, respectively, compared with that in normal glucose, while the levels in hyperglycemia with IGF-I were almost the same as that in normal glucose. In conclusion, the increased expression of GLUT1 may contribute to the delayed mineralization of osteoblasts in hyperglycemia. Also IGF-I may be a new drug for diabetic bone disease through normalizing the expression of GLUT1.

Stable inhibition of hepatitis B virus expression and replication by expressed siRNA.

RNA interference might be an efficient antiviral therapy for some obstinate illness. Here, we studied the effects of hepatitis B virus (HBV)-specific 21-nt small interfering RNAs (siRNA) on HBV gene expression and replication in 2.2.15 cells. Seven vectors expressing specific hairpin siRNA driven by the RNA polymerase II-promoter were constructed and transfected into 2.2.15 cells. In the cell strain that can stably express functional siRNA, the HBV surface antigen (HBsAg) and the HBV e antigen (HBeAg) secretion into culture media was inhibited by 86% and 91%, respectively, as shown by an enzyme-linked immunosorbent assay. Immunofluorescence and Western blot indicated similar results. HBV DNA was markedly restrained by 3.28-fold, as assessed by the fluorescent quantitation PCR. Moreover, the HBV mRNA was significantly reduced by 80% based on semiquantitative RT-PCR. In conclusion, the specific siRNA can knock down the HBV gene expression and replication in vitro, and the silence effects have no relationship with interferon response.