Role of the tumor microenvironment in PD-L1/PD-1-mediated tumor immune escape

Tumor immune escape is an important strategy of tumor survival. There are many mechanisms of tumor immune escape, including immunosuppression, which has become a research hotspot in recent years. The programmed death ligand-1/programmed death-1 (PD-L1/PD-1) signaling pathway is an important component of tumor immunosuppression, which can inhibit the activation of T lymphocytes and enhance the immune tolerance of tumor cells, thereby achieving tumor immune escape. Therefore, targeting the PD-L1/PD-1 pathway is an attractive strategy for cancer treatment; however, the therapeutic effectiveness of PD-L1/PD-1 remains poor. This situation requires gaining a deeper understanding of the complex and varied molecular mechanisms and factors driving the expression and activation of the PD-L1/PD-1 signaling pathway. In this review, we summarize the regulation mechanisms of the PD-L1/PD-1 signaling pathway in the tumor microenvironment and their roles in mediating tumor escape. Overall, the evidence accumulated to date suggests that induction of PD-L1 by inflammatory factors in the tumor microenvironment may be one of the most important factors affecting the therapeutic efficiency of PD-L1/PD-1 blocking.

The role of microenvironment in tumor angiogenesis

Tumor angiogenesis is necessary for the continued survival and development of tumor cells, and plays an important role in their growth, invasion, and metastasis. The tumor microenvironment—composed of tumor cells, surrounding cells, and secreted cytokines—provides a conducive environment for the growth and survival of tumors. Different components of the tumor microenvironment can regulate tumor development. In this review, we have discussed the regulatory role of the microenvironment in tumor angiogenesis. High expression of angiogenic factors and inflammatory cytokines in the tumor microenvironment, as well as hypoxia, are presumed to be the reasons for poor therapeutic efficacy of current anti-angiogenic drugs. A combination of anti-angiogenic drugs and antitumor inflammatory drugs or hypoxia inhibitors might improve the therapeutic outcome.

Bone marrow mesenchymal stem cell-secreted exosomes carrying microRNA-125b protect against myocardial ischemia reperfusion injury via targeting SIRT7

MicroRNA-125b (miR-125b) reduces myocardial infarct area and restrains myocardial ischemia reperfusion injury (I/R). In this study, we aimed to investigate the effect of bone marrow mesenchymal stem cell (BMSC)-derived exosomes carrying miR-125b on I/R rats. The myocardial I/R model in rats was constructed by ligation of the left anterior descending coronary artery (LAD). Rats were randomly divided into I/R and Sham group. Lv-cel-miR-67 (control) or Lv-miR-125b was transfected into BMSCs. Exosomes were extracted from transfected BMSCs, and separately named BMSC-Exo-67, BMSC-Exo-125b, and BMSC-Exo. MTT assay and flow cytometry were used to detect the viability and apoptosis of I/R myocardium cells, respectively. The expression of cell apoptosis proteins and the levels of inflammatory factors were examined by Western blot and ELISA assay, respectively. The target relationship between miR-125b and SIRT7 was predicted by using StarBase3.0, and was confirmed by using dual-luciferase reporter gene assay. qRT-PCR, immunohistochemistry staining, and Western blot were used to evaluate the expression of SIRT7 in myocardium tissues in I/R rats. BMSC-derived exosomes were successfully isolated and identified by TEM and positive expression of CD9 and CD63. The expression of miR-125b was down-regulated in I/R myocardium tissues and cells. BMSC-Exo-125b significantly up-regulated miR-125b in I/R myocardium cells. The intervention of BMSC-Exo-125b significantly increased the cell viability, decreased the apoptotic ratio, down-regulated Bax and caspase-3, up-regulated Bcl-2, and decreased the levels of IL-1β, IL-6, and TNF-α in I/R myocardium cells. SIRT7 was a target of miR-125b, and BMSC-Exo-125b significantly down-regulated SIRT7 in myocardium cells. In addition, the injection of BMSC-Exo-125b alleviated the pathological damages and down-regulated SIRT7 in myocardium tissues of I/R rats. BMSC-derived exosomes carrying miR-125b protected against myocardial I/R by targeting SIRT7.

Effects of selenium-lead interaction on the gene expression of inflammatory factors and selenoproteins in chicken neutrophils

Lead (Pb) is one of the most highly toxic metal pollutant that can cause damage to the immune system. It is known that selenium (Se) can antagonize heavy metals. To explore the toxic effects of Pb poisoning on bird immune cells, as well as the alleviating effects of Se on Pb, Se supplement and/or Pb poisoning chicken models were established. One hundred and eighty Hyline 7-day-old male chickens received either Se (1mg Se per kg of diet), Pb (350mg Pb per liter water) or Se+Pb in their diet and water for 90 days. Then, whole blood was collected from the four groups of chickens, and serum and neutrophils were isolated. The levels of Se and Pb in chicken serum, mRNA levels of 24 selenoproteins (GPX1, GPX2, GPX3, GPX4, Dio1, Dio2, Dio3, Txnrd1, Txnrd2, Txnrd3, SELS, SPS2, SELK, SELW1, SEP15, SEPX1, SELT, SELI, SELO, SELM, SEPN1, SEPP1, SELU, SELH) and inflammatory factors (TNF-α, COX-2, iNOS, NF-κB), and iNOS protein level in chicken neutrophils were determined, and protein-protein interaction prediction and principal component analysis were performed. The data showed that Pb exposure increased Pb content in serum, activated the NF-κB pathway, and increased the expression of selenoproteins in chicken neutrophils. Se supplements could reduce Pb concentration in serum, had a mitigative effect on the activation of the NF-κB pathway and further enhanced the upward trend of selenoprotein expression induced by Pb exposure. These results suggest that Se supplement could eliminate Pb in serum and alleviate the activation of the NF-κB pathway under Pb exposure by increasing the expression of selenoproteins.

High Uric Acid-Induced Epithelial-Mesenchymal Transition of Renal Tubular Epithelial Cells via the TLR4/NF-kB Signaling Pathway

BACKGROUND

Hyperuricemia is an independent risk factor for causing chronic kidney disease and contributes to kidney fibrosis. After urate crystals get deposited in the kidney, they can cause hyperuricemia nephropathy, leading to glomerular hypertrophy and renal tubular interstitial fibrosis. Recent data showed that uric acid (UA) could induce epithelial mesenchymal transition (EMT) of renal tubular cells, in which NRLP3 inflammatory pathway was involved. However, whether TLR4/NF-κB signaling pathway is also involved in EMT of renal tubular cells induced by UA is not clear.

METHODS

Human renal tubular epithelial cells (HK-2) were directly treated with UA and the phenotypic transition was detected by morphological changes and the molecular markers of EMT. The activation of the TLR4/NF-κB signaling pathway induced by UA was measured by Western blot and its involvement was further confirmed by the inhibition of NF-κB activation or knockdown of toll like receptor 4 (TLR4) expression.

RESULTS

UA induced obvious morphological changes of HK-2 cell, accompanied with altered molecular markers of EMT including fibronectin, α-SMA and E-cadherin. In addition, UA significantly upregulated the gene expression of interleukin-1β and tumor necrosis factor-α in a time- and dose-dependent manner. Furthermore, UA significantly activated the TLR4/NF-κB signaling pathway in HK-2 cells, while the inhibition of the TLR4 expression by siRNA and NF-κB activation by PDTC significantly attenuated EMT induced by UA in HK-2 cells.

CONCLUSIONS

UA can induce EMT in renal tubular epithelial cells by the activation of the TLR4/NF-κB signaling pathway, and the targeted intervention of the TLR4/NF-κB signaling pathway might effectively inhibit UA-induced renal interstitial fibrosis mediated by EMT.

Lycium barbarum polysaccharide LBPF4-OL may be a new Toll-like receptor 4/MD2-MAPK signaling pathway activator and inducer

Recognition of the utility of the traditional Chinese medicine Lycium barbarum L. has been gradually increasing in Europe and the Americas. Many immunoregulation and antitumor effects of L. barbarum polysaccharides (LBP) have been reported, but its molecular mechanism is not yet clear. In this study, we reported that the activity of the polysaccharide LBPF4-OL, which was purified from LBP, is closely associated with the TLR4-MAPK signaling pathway. We found that LBPF4-OL can significantly induce TNF-α and IL-1β production in peritoneal macrophages isolated from wild-type (C3H/HeN) but not TLR4-deficient mice (C3H/HeJ). We also determined that the proliferation of LBPF4-OL-stimulated lymphocytes from C3H/HeJ mice is significantly weaker than that of lymphocytes from C3H/HeN mice. Furthermore, through a bio-layer interferometry assay, we found that LPS but not LBPF4-OL can directly associate with the TLR4/MD2 molecular complex. Flow cytometry analysis indicated that LBPF4-OL markedly upregulates TLR4/MD2 expression in both peritoneal macrophages and Raw264.7 cells. As its mechanism of action, LBPF4-OL increases the phosphorylation of p38-MAPK and inhibits the phosphorylation of JNK and ERK1/2, as was observed through Western blot analysis. These data suggest that the L. barbarum polysaccharide LBPF4-OL is a new Toll-like receptor 4/MD2-MAPK signaling pathway activator and inducer.

The protective role of selenium against cadmium-induced hepatotoxicity in laying hens: Expression of Hsps and inflammation-related genes and modulation of elements homeostasis

The purpose of this study was to examine the potential role of high selenium (Se) diets in alleviating chronic cadmium (Cd) hepatic toxicity in laying hens. In the present study, 128 healthy 31-week-old laying hens were fed a diet supplemented with Se (Na₂SeO₃, 2 mg/kg), Cd (CdCl₂, 150 mg/kg), or both Se and Cd (150 mg/kg of CdCl₂ and 2 mg/kg of Na₂SeO₃) for 90 days. The expression levels of heat shock proteins (Hsps, including Hsp60, Hsp70 and Hsp90) and inflammation-related factors, including nuclear factor-kappa B p50 (NF-κB), cyclooxygenase-2 (COX-2), prostaglandin E synthases (PTGES), interleukin 1-beta (IL-1β), and tumor necrosis factor-α (TNF-α) were investigated. The concentrations of 28 elements were also determined. The results indicated that Cd treatment significantly increased the mRNA and protein expression levels of Hsps and significantly improved the expression of inflammation-related genes. Moreover, Cd addition to the diets resulted in disturbances in the systemic balance of 13 elements, leading to decrease in the concentrations of Cr, Mn, Sr, Ba, and Hg and increase in Li, B, Ca, Ti, Fe, Cu, Mo, and Cd concentrations. Treatment with Se significantly alleviated Cd-induced hepatic toxicity, as evidenced by a reduction in Hsp60, Hsp70, Hsp90, NF-κB, COX-2, PTGES, TNF-α, and IL-1β expression. Additionally, Se and Cd co-treatment alleviated the changes in Li, B, Ca, Fe, Ti, Cu, Mo, Cd, Cr, Se, Sr, Ba, and Hg concentrations, which was in contrast to that upon Cd induction. The study indicated that Se could help against the negative effects of Cd and may be related to the alleviation of Cd-induced Hsps stress and the inflammatory responses along with modulating the element homeostasis.

Ferulic acid exhibits anti-inflammatory effects by inducing autophagy and blocking NLRP3 inflammasome activation

Background

Inflammation is involved in the healing process; however, when inflammation is overactivated, multiple diseases can occur. The continued discovery of new anti-inflammatory drugs is crucial in the treatment of inflammation-linked diseases.

Objectives

Ferulic acid (FA), a precursor necessary for lignan synthesis, is widely distributed in plant-based whole foods and is a strong antioxidant. However, the effect of FA on the expression level of inflammatory factors in macrophages has not been fully clarified. The current study aimed to explore the anti-inflammatory effect and mechanism of ferulic acid.

Results

The results showed that THP-1 cells were induced to differentiate into macrophages by Phorbol-12-myristate-13-acetate (PMA), and THP-1-derived macrophages were stimulated by LPS to establish an inflammatory cell model. Compared with the control group, low (5 μmol·mL⁻¹), medium (10 μmol·mL⁻¹), and high (20 μmol·mL⁻¹) concentration ferulic acid groups have decreased cell viability and increased apoptosis rate in a dose-dependent manner. FA reduced the transcriptional levels of Interleukin-1β (IL-1β), Interleukin-6 (IL-6) and tumor necrosis factor α (TNF-α). Importantly, FA-induced autophagy and inhibited NLRP3 inflammasome activation. 3-MA (a widely used autophagy inhibitor) enhanced the secretion of TNF-α, IL-6 and IL-1β. Moreover, autophagy inhibition by 3-MA resulted in increased proteins expression associated with NLRP3 inflammasome signaling pathway. Besides, the inhibition of inflammasome activation by MCC950 reduced the expression of TNF-α, IL-6 and IL-1β.

Conclusion

It is concluded that FA enhanced autophagy, inhibited the activation of NLRP3 inflammasome and reduced the expression and release of inflammatory factors.

The Antagonistic Effect of Selenium on Lead-Induced Inflammatory Factors and Heat Shock Proteins mRNA Expression in Chicken Livers

The aim of this study was to investigate the effect of lead (Pb) poisoning on nitric oxide (NO) content, inducible nitric oxide synthase (iNOS) activity, the messenger RNA (mRNA) levels of inflammatory factors (nuclear factor-kappa B (NF-κB), tumor necrosis factor-α (TNF-α), cyclooxygenase-2 (COX-2), prostaglandin E synthases (PTGEs), and iNOS), heat shock proteins (HSPs) (HSP27, HSP40, HSP60, HSP70, and HSP90), and the antagonistic effect of selenium (Se) on Pb in chicken livers. One hundred eighty 7-day-old male chickens were randomly divided into four groups and were fed commercial diet and drinking water, Na2SeO3-added commercial diet and drinking water, commercial diet and (CH3OO)2Pb-added drinking water, and Na2SeO3-added commercial diet and (CH3OO)2Pb-added drinking water, respectively, for 30, 60, and 90 days. Then, NO content, iNOS activity, and the mRNA levels of NF-κB, TNF-α, COX-2, PTGEs, iNOS, HSP27, HSP40, HSP60, HSP70, and HSP90 were examined in chicken livers. The results showed that Pb poisoning induced NO content, iNOS activity, and mRNA expression of inflammation factors and HSPs in chicken livers. In addition, Se alleviated Pb-induced increase of inflammation factor and HSP expression in chicken livers.

APOE ε4 allele elevates the expressions of inflammatory factors and promotes Alzheimer's disease progression: A comparative study based on Han and She populations in the Wenzhou area

OBJECTIVE

This study aimed to investigate the impact of apolipoprotein E 4 (APOE4) gene polymorphisms on the expressions of inflammatory factors and the progression of Alzheimer's disease (AD).

METHODS

A total of 185 AD patients (the case group, 130 cases from the Han ethnic group and 55 cases from the She ethnic group) and 190 healthy individuals (the control group, 130 cases from the Han ethnic group and 60 cases from the She ethnic group) were recruited for our study. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was conducted to detect APOE4 genotype and allele frequency. Enzyme-linked immunosorbent assay (ELISA) was used to determine the expressions of inflammatory factors in plasma.

RESULTS

In both Han and She populations, the frequency of ε3/4 and ε4/4 genotypes and the ε4 allele was significantly higher in the case group than that in the control group. ε3/4 and ε4/4 genotypes and the ε4 allele were the risk factors for AD. In both Han and She populations, the ε2/4, ε3/4 and ε4/4 carriers showed increased levels of TNF-α, IL-6, and IL-1β when compared with the ε2/2 + ε2/3 + ε3/3 carriers. The TNF-α, IL-6, and IL-1β levels were higher in the ε4/4 carriers than those in the ε2/4 and ε3/4 carriers, and ε2/4, ε3/4 and ε4/4 carriers in the case group exhibited increased levels of TNF-α, IL-6, and IL-1β when compared with the control group (P<0.05). Logistic regression analysis indicated that the ε3/4 genotype and TNF-α, IL-6, and IL-1β levels were associated with the susceptibility to AD in the Han population, while ε3/4 and ε4/4 genotypes and TNF-α, IL-6, and IL-1β levels were related to the susceptibility to AD in the She population.

CONCLUSIONS

The APOE4 ε4 allele may enhance susceptibility to AD and promotes the expressions of inflammatory factors in AD.

Platelet-rich plasma inhibits inflammatory factors and represses rheumatoid fibroblast-like synoviocytes in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic disease affecting daily life of numerous patients, and uncontrolled proliferation of synovial fibroblasts plays vital role during the pathology of RA. Platelet-rich plasma (PRP), widely used in tissue regeneration and pain management, is rarely studied in RA. This study aims to investigate the effect of PRP on synovial fibroblasts during RA. Rheumatoid fibroblast-like synoviocyte MH7A cells were stimulated by lipopolysaccharide (LPS) to simulate RA conditions and treated with PRP, after that the concentration of inflammatory factors interleukin (IL) 1β, tumor necrosis factor alpha (TNFα) and IL6 in the supernatant of culture medium was quantified by ELISA. MTT assay, flow cytometry and tube formation assay were performed to assess changes in cell viability, apoptosis and effect on angiogenesis in vitro, respectively. Besides, the expression levels of main factors in the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signal pathway were examined. Results showed that PRP markedly inhibited the production of IL1β, TNFα and IL6 (P < 0.05) that was stimulated by LPS. LPS promoted MH7A cell viability, inhibited apoptosis and accelerated angiogenesis in vitro, while PRP could markedly relieve these effects (P < 0.05). The mRNA and protein levels of AKT1, PI3K (p58) and nuclear factor κ beta were elevated by LPS and then suppressed by PRP (P < 0.01). This study uncovered the potential of PRP in inhibiting inflammation, repressing synovial fibroblasts and regulating the PI3K/AKT signaling, providing basic proof for future application of PRP in managing RA. Further investigation is necessary to reveal detailed mechanism of PRP.

Emodin attenuates acute lung injury in Cecal-ligation and puncture rats

Acute lung injury (ALI) is a major cause of sepsis-induced acute respiratory failure. Emodin has been considered to play a protective role for acute lung edema in cecal ligation and puncture (CLP)-induced sepsis model. In this study we aimed to investigate whether emodin could improve CLP-induced lung sepsis via regulating aquaporin (AQP) and tight junction (TJ), inflammatory factors, and pulmonary apoptosis. The results showed that sepsis-induced pulmonary pathological changes were significantly improved after emodin treatment. Emodin was found to upregulate AQP and TJ expression in the CLP model. Meanwhile, inflammatory cytokine release and pulmonary apoptosis was remarkably reduced after emodin treatment in lung sepsis. Our data demonstrated that emodin could suppresse inflammation, restore pulmonary epithelial barrier and reduce mortality in CLP-induced ALI, suggesting the potential therapeutic application of emodin in sepsis.

Resolvin D1 mitigates energy metabolism disorder after ischemia-reperfusion of the rat lung

BACKGROUND

Energy metabolism disorder is a critical process in lung ischemia-reperfusion injury (LIRI). This study was aimed to determine the effects of resolvin D1 (RvD1) on the energy metabolism in LIRI.

METHODS

Forty Sprague-Dawley rats were divided into the following groups: Sham group; untreated ischemia-reperfusion (IR) control; IR treated with normal saline (IR-NS); and IR treated with RvD1 (IR-RV) (100 μg/kg, iv). LIRI and energy metabolism disorder were determined in these rats.

RESULTS

The results revealed that the levels of interleukin (IL)-1β, tumor necrosis factor-α, IL-10, monocyte chemoattractant protein-1, macrophage inflammatory protein-2, cytokine-induced neutrophil chemoattractant-1, injured alveoli rate, apoptosis index, pulmonary permeability index, malondialdehyde, ADP, and lactic acid were increased, whereas the levels of ATP, ATP/ADP, glycogen, Na(+)-K(+)-ATPase, superoxide dismutase, glutathione peroxidase activity, pulmonary surfactant associated protein-A, and oxygenation index were decreased in rats with LIRI. Except for IL-10, all these biomarkers of LIRI and its related energy metabolism disorder were significantly inhibited by RvD1 treatment. In addition, histological analysis via hematoxylin-eosin staining, and transmission electron microscopy confirmed that IR-induced structure damages of lung tissues were reduced by RvD1.

CONCLUSION

RvD1 improves the energy metabolism of LIRI disturbance, protects the mitochondrial structure and function, increases the ATP, glycogen content and Na(+)-K(+)-ATPase activity of lung tissue, balances the ratio of ATP/ADP and finally decreases the rate of apoptosis, resulting in the protection of IR-induced lung injury. The improved energy metabolism after LIRI may be related to the reduced inflammatory response, the balance of the oxidative/antioxidant and the pro-inflammatory/anti-inflammatory systems in rats.

Helicobacter pylori infection is correlated with the incidence of erosive oral lichen planus and the alteration of the oral microbiome composition

BACKGROUND

Oral lichen planus (OLP), a common clinical oral disease, is associated with an increased risk of malignant transformation. The mechanism underlying the pathogenesis of OLP is unknown. Oral dysbacteriosis is reported to be one of the aetiological factors of OLP. Although Helicobacter pylori infection is associated with various oral diseases, the correlation between H. pylori infection and OLP is unclear. This study aimed to investigate the effect of H. pylori infection on OLP pathogenesis and oral microbiome composition in the Chinese population, which has a high incidence of H. pylori infection.

RESULT

In this study, saliva samples of 30 patients with OLP (OLP group) and 21 negative controls (NC group) were collected. H. pylori infection was detected using the carbon-13-labeled urea breath test (UBT). The saliva samples were divided into the following four groups based on the H. pylori status: H. pylori-positive OLP (OLP+), H. pylori-positive NC (NC+), H. pylori-negative OLP (OLP-), and H. pylori-negative NC (NC-). Oral microbiome compositions were significantly different between the OLP and NC groups and between the OLP- and OLP+ groups. Compared with those in the OLP- group, those in the OLP+ group had a higher incidence of erosive OLP and higher levels of salivary cytokines. In contrast, the oral microbiome composition and cytokine levels were not significantly different between the NC- and NC+ groups.

CONCLUSIONS

This is the first report to demonstrate that H. pylori infection is significantly correlated with the pathogenesis of erosive OLP.

Abnormal expression of HSP70 may contribute to PCOS pathology

Background

The mechanism of the pathological change of polycystic ovary syndrome (PCOS) is still unclear. Previous studies have shown that PCOS is a chronic nonspecific low-grade inflammatory condition, and that heat shock protein (HSP)70 has a potent anti-inflammatory property. So the aim of this study is to investigate the correlation between HSP70 and the hormones and inflammatory factors and to find out the role of HSP70 in the pathogenesis of PCOS.

Methods

Twenty female Sprague–Dawley (SD) rats (aged 23 days and weighted 80-90 g) were randomly divided into two groups (n = 10 per group), PCOS group and control group. PCOS group were subcutaneously injected with 6 mg/100 g dehydro-epiandrosterone (DHEA) for 20 consecutive days, the control group were subcutaneously injected with a solvent of equivalent amount. All the samples were collected in the morning fasting state, 12 h after the last administration. Histological examinations of ovarian tissues were analyzed. Hormone levels and inflammatory factors levels were measured by enzyme-linked immunosorbent assay (ELISA) kits.

Results

Serum concentrations of testosterone (T) and luteinizing hormone (LH) were significantly higher in the PCOS group than the control group (P < 0.001), but the concentrations of estradiol (E₂), follicle stimulating hormone (FSH) and insulin didn’t show significant difference between these two groups. All the concentrations of inflammatory factors including C-reactive protein (CRP), interleukin (IL)-6, IL-18, and tumor necrosis factor (TNF)-α. were significantly higher in PCOS group than the control group (P < 0.001). The expressions of HSP70 were significantly lower in serum but higher in ovarian tissues in the PCOS group than the control group. Spearman rank correlation analysis showed strong negative correlation of serum HSP70 levels with T, LH and all the detected inflammatory factors.

Conclusion

The abnormal expression of HSP70 correlated with testosterone and inflammatory factors, which indicates that HSP70 may play an important role in PCOS pathology.

Early immune responses and prognostic factors in children with COVID-19: a single-center retrospective analysis

BACKGROUND

Early diagnostic indicators and the identification of possible progression to severe or critical COVID-19 in children are unknown. To investigate the immune characteristics of early SARS-CoV-2 infection in children and possible key prognostic factors for early identification of critical COVID-19, a retrospective study including 121 children with COVID-19 was conducted. Peripheral blood lymphocyte subset counts, T cell-derived cytokine concentrations, inflammatory factor concentrations, and routine blood counts were analyzed statistically at the initial presentation.

RESULTS

The T lymphocyte subset and natural killer cell counts decreased with increasing disease severity. Group III (critical cases) had a higher Th/Tc ratio than groups I and II (common and severe cases); group I had a higher B cell count than groups II and III. IL-6, IL-10, IFN-γ, SAA, and procalcitonin levels increased with increasing disease severity. Hemoglobin concentration, and RBC and eosinophil counts decreased with increasing disease severity. Groups II and III had significantly lower lymphocyte counts than group I. T, Th, Tc, IL-6, IL-10, RBC, and hemoglobin had relatively high contribution and area under the curve values.

CONCLUSIONS

Decreased T, Th, Tc, RBC, hemoglobin and increased IL-6 and IL-10 in early SARS-CoV-2 infection in children are valuable indices for early diagnosis of severe disease. The significantly reduced Th and Tc cells and significantly increased IL-6, IL-10, ferritin, procalcitonin, and SAA at this stage in children with critical COVID-19 may be closely associated with the systemic cytokine storm caused by immune dysregulation.

Dexmedetomidine regulates inflammatory molecules contributing to ventilator-induced lung injury in dogs

BACKGROUND

Dexmedetomidine reduced mortality and inhibited the inflammatory response during endotoxemia in rats. The aim of this study was to clarify the effect of dexmedetomidine-regulating inflammation on a noninfectious, ventilator-induced lung injury (VILI) in dogs.

METHODS

Thirty healthy Beagles weighing between 8 and 12 kg were randomly divided into five groups: control group (group C, n = 6), mechanical ventilation (group MV, n = 6), and three different doses of dexmedetomidine group (group DEX1-3, n = 6). VILI was induced by high-tidal volume ventilation (tidal volume 20 mL/kg; respiratory rate 15 breaths/min; FiO2 0.5). Group DEX received intravenous Dex 20 min before endotracheal intubation (0.5, 1.0, and 2.0 μg/kg Dex was infused within 20 min and then a maintenance dose of 0.5, 1.0, and 2.0 μg/kg/h Dex was infused intravenously). Arterial blood samples were obtained from femoral artery at base state, MV1h, MV2h, and MV4h for blood gas analysis. After being mechanically ventilated for 4 h, dogs were killed and the levels of pulmonary inflammatory response and polymorphonuclear neutrophils (PMNs) count in bronchoalveolar lavage fluid were evaluated.

RESULTS

Histologic findings of the MV, DEX1, DEX2, and DEX3 groups revealed severe, moderate, mild, and normal to minimal inflammation, respectively. Myeloperoxidase level, PMNs/alveoli ratio, nuclear factor-κB messenger RNA (mRNA), tumor necrosis factor-alpha mRNA, and inducible nitric oxide synthase mRNA expression in lung tissues of the DEX2 and DEX3 were significantly lower than those of the MV group. Partial pressures of oxygen was decreased significantly at MV4h as compared with the baseline. There was no statistical significance in partial pressures of oxygen between MV and DEX2 group as well as between group MV and group DEX3.

CONCLUSIONS

Dexmedetomidine could mitigate pulmonary inflammatory response induced by VILI in dogs.

Effects of Dietary Selenium on Inflammation and Hydrogen Sulfide in the Gastrointestinal Tract in Chickens

Selenium (Se) is an essential trace element for humans and animals and is associated with many physiological functions. Previous studies have shown that low-Se diet may affect inflammatory cytokine productions and histology in the digestive system and that sulfide hydrogen (H₂S) may contribute to the protection against tissue injury and the inhibition of inflammation in the gastrointestinal tract. In this study, we investigated the relationship between Se deficiency-induced inflammation and H₂S production in the small intestine in chickens. One hundred twenty 1-day-old chickens were fed with diets with different Se concentrations (0.15 mg/kg in the control and 0.028 mg/kg in the low-Se-diet group). Chickens were euthanized and small intestinal tissues were extracted. We observed histology, measured H₂S concentration, and evaluated the mRNA expression of H₂S-producing enzymes cystathionine γ-lyase (CSE), cystathionine β-synthase (CBS), and 3-mercaptopyruvate sulfurtransferase (3-MST), and inflammatory factors TNF-α, NF-κB p50, COX-2, and PTGES. Our results showed that chickens fed with low-Se diet exhibited histological changes, lower H₂S production, and lower mRNA expression of H₂S-producing enzymes (CSE, CBS, and 3-MST) whereas higher mRNA expression of intestinal inflammatory factors (TNF-α, NF-κB p50, COX-2, and PTGES) compared to controls. Our results indicate that low-Se diet could impact H₂S, H₂S-producing enzymes, and inflammatory factors in the small intestine, implying that Se is important in maintaining intestinal functions and H₂S production is downregulated in Se deficiency-induced inflammation. The downregulation exacerbates the inflammation and impacts H₂S-mediated intestinal functions.

The Antagonistic Effect of Selenium on Lead-Induced Inflammatory Factors and Heat Shock Protein mRNA Level in Chicken Cartilage Tissue

Selenium (Se) is recognized as a necessary trace mineral in animal diets, including those of birds. Lead (Pb) is a toxic heavy metal and can damage organs in humans and animals. Complex antagonistic interactions between Se and heavy metals have been reported in previous studies. However, little is known regarding the effects of Se on Pb-induced toxicity and the expression of inflammatory factors and heat shock proteins (HSPs) in the cartilage of chickens. In this present study, we fed chickens either with Se or Pb or both Se and Pb supplement and later analyzed the mRNA expressions of inflammatory factors (inducible nitric oxide synthase (iNOS), nuclear factor-kappa B (NF-κB), tumor necrosis factor-α (TNF-α), and cyclooxygenase-2 (COX-2)) and HSPs (Hsp27, Hsp40, Hsp60, Hsp70, and Hsp90). The results showed that Se and Pb influenced the expression of inflammatory factors and HSP genes in the chicken cartilage tissues. Additionally, we also found that antagonistic interaction existed between Se and Pb supplementation. Our findings suggested that Se could exert a antagonistic effect on Pb in chicken cartilage tissues.

The macamide relieves fatigue by acting as inhibitor of inflammatory response in exercising mice: From central to peripheral

Macamides are the major and unique bioactive compounds of Lepidium meyenii (Walp.) or Maca. N-benzyl-(9Z, 12Z)-octadecadienamide (N-benzyl-linoleamide) is one of the most biologically active macamides with various pharmacological activities - anti-fatigue, neuroprotective, antioxidant, anti-tumoral activities, anti-inflammatory, and analgesic. In this study, the anti-fatigue properties of N-benzyl-(9Z, 12Z)-octadecadienamide were further evaluated by a weight-loaded forced swimming test. Results indicated N-benzyl-(9Z, 12Z)-octadecadienamide supplementation increased the forelimb grip strength of mice and exercising time remaining on the Rota-rod test. Furthermore, significant decreases in pro-inflammatory factors and reactive oxygen species (ROS) contents were observed in mice receiving N-benzyl-(9Z, 12Z)-octadecadienamide treatment after a 30 min swimming test, which was equivalent to that of caffeine. Histological analysis also indicated that N-benzyl-(9Z, 12Z)-octadecadienamide attenuated damage to the liver in mice by up-regulating the expression of heme oxygenase-1 (HO-1) and inhibiting the expression of Interleukin (IL)-1β during exercise. Pearson correlation analysis suggested peripheral fatigue indexes, including energy sources, metabolites were significantly correlated with inflammatory factors and ROS levels. Likewise, central fatigue parameters are also associated, including hippocampal inflammatory response and hypothalamic neurotransmitters. Hence, macamides can be considered to have great potential as a natural drug with high efficiency and low side effects for fatigue management.

The effect of glutamine on Dehydroepiandrosterone-induced polycystic ovary syndrome rats

Background

Previous studies have shown that chronic inflammation and oxidative stress may play an important role in the pathophysiology of polycystic ovary syndrome (PCOS), and glutamine (Gln) have showed the anti-inflammatory and antioxidant properties. So the aim of this study is to investigate the effect of glutamine supplementation on PCOS rats.

Methods

Female Sprague–Dawley rats were randomly assigned into four groups (n = 10 /group), control group, PCOS group, PCOS+ 0.5 g/kg Gln group and PCOS+ 1.0 g/kg Gln group. All the PCOS rats were administrated with 6 mg/100 g dehydroepiandrosterone (DHEA) for 20 consecutive days, all the PCOS+Gln groups were intraperitoneal injected glutamine twice in the next morning after the last DHEA injection. All the samples were collected 12 h after the last administration. Ovarian histological examinations were analyzed and the concentration of serum hormone, inflammatory and oxidative stress factors were measured.

Results

There was no obvious ovarian histological change among the PCOS group and PCOS+Gln groups. All the detected inflammation factors [C-reactive protein, interleukin (IL)-6, IL-18, tumor necrosis factor] showed significantly higher in all the PCOS groups compared to the control group (P < 0.01), and were significantly decreased with the supplementation of 0.5 g/kg glutamine (P < 0.01). Concentrations of superoxide dismutase were significantly lower in all the PCOS groups (P < 0.01) compared to the control group, and increased significantly with the supplementation of 0.5 g/kg glutamine (P < 0.01). Serum concentrations of malondialdehyde, nitric oxide synthase and nitric oxide were significantly higher in PCOS group (P < 0.01) compared with the control group, and significantly decreased to the comparative levels of control group with supplementation of 0.5 g/kg glutamine (P < 0.01).

Conclusion

There is low-grade inflammation and oxidative stress in DHEA-induced PCOS rats. The supplementation of 0.5 g/kg glutamine could effectively ameliorate the inflammation and oxidative stress conditions of PCOS.

Pancreatic secretory trypsin inhibitor: More than a trypsin inhibitor

Kazal-type serine protease inhibitor is one of the most important and widely distributed protease inhibitor families. Pancreatic secretory trypsin inhibitor (PSTI), also known as serine protease inhibitor Kazal type I(SPINK1), binds rapidly to trypsin, inhibits its activity and is likely to protect the pancreas from prematurely activated trypsinogen. Therefore, it is an important factor in the onset of pancreatitis. Recent studies found that PSTI/SPINK1 is also involved in self-regulation of acinar cell phagocytosis, proliferation and growth of a variety of cell lines. In addition, it takes part in the response to inflammatory factor or injury and is highly related to adult type II citrullinemia.

Human amniotic mesenchymal stem cells alleviate paraquat-induced pulmonary fibrosis in rats by inhibiting the inflammatory response

AIMS

To investigate the therapeutic effects of human amniotic mesenchymal stem cells (hAMSCs) on paraquat (PQ)-induced pulmonary fibrosis in rats and investigate the inflammatory mechanisms.

MAIN METHODS

hAMSCs were identified by morphological, flow cytometry and immunocytochemistry. A pulmonary fibrosis model was induced by administering PQ to rats. The hAMSCs group was treated with hAMSCs after 6 h of PQ poisoning. At 21 days after hAMSCs transplantation, lungs were harvested for H&E, Masson and immunohistochemical staining to evaluate pulmonary histopathology, collagen deposition, CD3+ cell infiltration and hAMSCs colonization. Arterial blood was used for lactic acid analysis and venous blood was used to detect TNF-α, IL-6, and TGF-β1 by ELISA method.

KEY FINDINGS

hAMSCs can improve the lung structure and decrease collagen deposition induced by PQ. The membranes of CD3+ T cell in the PQ group were round and complete, while that in the hAMSCs group rats exhibited punctate or diffuse staining. In addition, the CD3+ cell was decreased by hAMSCs administration, and MAB1281-positive cells were detected in lung of hAMSCs group rats. The survival rate of the hAMSCs group was significantly higher than that of the PQ group at 21 days after injection. TNF-α, IL-6, TGF-β1 and lactic acid were significantly decreased by hAMSCs administration.

SIGNIFICANCE

hAMSCs have a significant therapeutic effect on pulmonary fibrosis induced by acute PQ poisoning and can improve survival rate in rats. Furthermore, hAMSCs administration can improve lung histopathology and reduce collagen deposition by reducing inflammatory CD3+ T cell infiltration, inflammatory cytokine expression and lactic acid levels.

Mahuang decoction mitigates airway inflammation and regulates IL-21/STAT3 signaling pathway in rat asthma model

ETHNOPHARMACOLOGICAL RELEVANCE

Nowadays, bronchial asthma is still a severe disease threatening human health, and it is incumbent upon us to seek effective therapeutic drugs. Mahuang decoction (MHD), a classic famous Chinese prescription, has been used for thousands of years to prevent phlegm from forming, stop coughing and relieve asthma, but the relevant mechanism has not been thoroughly clarified. This study aims to investigate the anti-airway inflammation effect of MHD and the possible molecular mechanism underlying IL21/STAT3 signaling pathway, so as to provide guidance for the treatment of MHD on bronchial asthma.

MATERIALS AND METHODS

Specific pathogen free SD rats were randomly divided into 6 groups: normal control group, model group, positive group (Compound methoxyphenamine), MHD-treated groups at doses of 10 ml/kg, 5 ml/kg and 2.5 ml/kg, 10 rats in each group. Except for the normal control group, rats in other groups were sensitized with ovalbumin via introperitoneal injection and challenged with ovalbumin inhalation to trigger asthma model. At 24 h after the last excitation, bronchoalveolar lavage fluid (BALF) of every rat was drawn and the number of inflammatory cells was analyzed using cell counting method. ELISA method was performed to determine the concentrations of TXB₂, 6-keto-PGF_1α, MMP-9, TIMP-1, IL-2, IL-4, IL-5 and TNF-α in rat serum. The protein expressions of IL-21, IL-21R, STAT3 and p-STAT3 in murine pulmonary tissues were assessed with western blotting analysis.

RESULTS

Compared with the control group, the airway wall and airway smooth muscle of murine pulmonary tissues significantly thickened and massive inflammatory cells infiltration occurred around the bronchus in the model group, and the cell counts of WBC and EOS in BALF were also apparently increased, which indicated the rat asthma model was successfully established. MHD or Compound methoxyphenamine not only alleviated the pulmonary inflammatory pathological damages, but also down- regulated the numbers of WBC and EOS in BALF. What's more, the levels of TXB₂, MMP-9, TIMP-1, ILs-(2, 4, 5) and TNF-α in rat serum were lessened by the treatment of MHD. In western blotting analysis, treatment with 10 ml/kg or 5 ml/kg MHD markedly declined the increased protein expressions of IL-21, IL-21R, STAT3 and p-STAT3 in lung tissues of asthmatic rats to normal level.

CONCLUSION

MHD intervention demonstrated a strong inhibitory action on the secretion of inflammatory mediators as well as the inflammatory cell infiltration in pulmonary tissues of asthmatic rats, and also depressed the protein expressions of IL-21, IL-21R, STAT3 and p-STAT3 in pulmonary tissues. MHD effectively mitigates airway inflammation and regulates the IL-21/STAT3 signaling pathway in rat asthma model.

HO-1: A new potential therapeutic target to combat osteoporosis

Heme oxygenase-1 (HO-1) exerts a protective effect against cell damage and induces the activity of many enzymes involved in the treatment of many human diseases, including osteoporosis. The increasing prevalence of osteoporosis and the limitations of the current treatments available led to a continuous occurrence of bone loss and osteoporotic fractures, highlighting the need of a better understanding of the mechanism and function of HO-1. Many factors cause osteoporosis, including lack of estrogen, aging, and iron overload, and they either cause the increase in inflammatory factors or the increase in reactive oxygen species to break bone reconstruction balance. Therefore, regulating the production of inflammatory factors and reactive oxygen species may become a strategy for the treatment of osteoporosis. Solid evidence showed that the overexpression of HO-1 compensates high oxidation levels by increasing intracellular antioxidant levels and reduces inflammation by suppressing pro-inflammatory factors. Some extracts can target HO-1 and ameliorate osteoporosis. However, no systematic report is available on therapies targeting HO-1 to combat osteoporosis. Therefore, this review summarizes the biological characteristics of HO-1, and the relationship between inflammatory response and reactive oxygen species production regulated by HO-1 and osteoporosis. The understanding of the role of HO-1 in osteoporosis may provide ideas for a potential clinical treatment and new drugs targeting HO-1.