Aryl Hydrocarbon Receptor is Involved in the Proinflammatory Cytokine Response to Cadmium

Objective To investigate involvement of the aryl hydrocarbon receptor(Ah R)in the immunomodulatory effects of cadmium(Cd).Methods The effect of Cd on Ah R activation(CYP1 A1 and CYP1 B1 m RNA expression)was examined in lung leukocytes of Cd-exposed rats(5 and 50 mg/L,30 d orally)and by in vitro leukocyte exposure.The involvement of Ah R signaling in the effects of Cd on the interleukin(IL)-1β,IL-6,and tumor necrosis factor(TNF)lung leukocyte response was investigated in vitro using the receptor antagonist CH-223191.Results Cd increased CYP1 B1(in vivo and in vitro)and CYP1 A1(in vitro)m RNA,indicating Ah R involvement in the action of Cd.In response to Cd,lung leukocytes increased IL-6 and decreased TNF at the gene expression and protein levels,but decreased IL-1βproduction due to reduced NLRP3.The Ah R antagonist CH-223191 abrogated the observed effects of Cd on the cytokine response.The absence of Ah R reactivity and cytokine response to Cd of leukocytes from the lungs of a rat strain that is less sensitive to Cd toxicity coincided with a high Ah R repressor m RNA level.Conclusion Ah R signaling is involved in the lung leukocyte proinflammatory cytokine response to Cd.The relevance of the Ah R to the cytokine response to Cd provides new insight into the mechanisms of Cd immunotoxicity.

The HMGB1 signaling pathway activates the inflammatory response in Schwann cells

Schwann cells are not only myelinating cells, but also function as immune cells and express numerous innate pattern recognition receptors, including the Toll-like receptors. Injury to peripheral nerves activates an inflammatory response in Schwann cells. However, it is unclear whether specific endogenous damage-associated molecular pattern molecules are involved in the inflammatory response following nerve injury. In the present study, we demonstrate that a key damage-associated molecular pattern molecule, high mobility group box 1（HMGB1）, is upregulated following rat sciatic nerve axotomy, and we show colocalization of the protein with Schwann cells. HMGB1 alone could not enhance expression of Toll-like receptors or the receptor for advanced glycation end products（RAGE）, but was able to facilitate migration of Schwann cells. When Schwann cells were treated with HMGB1 together with lipopolysaccharide, the expression levels of Toll-like receptors and RAGE, as well as inflammatory cytokines were upregulated. Our novel findings demonstrate that the HMGB1 pathway activates the inflammatory response in Schwann cells following peripheral nerve injury.

Antiviral,immunomodulatory,and anticoagulant effects of quercetin and its derivatives:Potential role in prevention and management of COVID-19

The coronavirus disease 2019(COVID-19)pandemic caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection has caused a devastating health crisis worldwide.In this review,we have discussed that prophylactic phytochemical quercetin supplementation in the form of foods or nutraceuticals may help manage the COVID-19 pandemic.The following evidence supports our argument.First,nuclear factor erythroid-derived 2-like 2(NRF2)agonists abrogate replication of SARS-CoV-2 in lung cells,and quercetin is a potent NRF2 agonist.Second,quercetin exerts antiviral activity against several zoonotic coronaviruses,including SARS-CoV-2,mainly by inhibiting the entry of virions into host cells.Third,inflammatory pathways activated by nuclear factor kappa B,inflammasome,and interleukin-6 signals elicit cytokine release syndrome that promotes acute respiratory distress syndrome in patients with COVID-19,and quercetin inhibits these pro-inflammatory signals.Fourth,patients with COVID-19 develop thrombosis,and quercetin mitigates coagulation abnormalities by inhibiting plasma protein disulfide isomerase.This review provides a strong rationale for testing quercetin for the management of COVID-19.

Antiviral activity of five Asian medicinal pant crude extracts against highly pathogenic H5N1 avian influenza virus

Objective: To study the antiviral properties of the five Asian medicinal plants against in vitro infection by the highly pathogenic avian influenza virus(H5N1).Methods: Crude extracts of Andrographis paniculata, Curcuma longa(C. longa),Gynostemma pentaphyllum, Kaempferia parviflora(K. parviflora), and Psidium guajava obtained by both water and ethanol extractions were investigated for their cytotoxicity in the Madin–Darby canine kidney cells. Thereafter, they were investigated in vitro for antiviral activity and cytokine response upon H5N1 virus infection.Results: The results revealed that both water and ethanol extracts of all the five studied plants showed significant antiviral activity against H5N1 virus. Among these plants,C. longa and K. parviflora showed strong anti-H5N1 activity. Thus, they were selected for further studies on their cytokine response upon virus infection. It was found that ethanol and water crude extracts of C. longa and K. parviflora induced significant upregulation of TNF-a and IFN-b m RNA expressions, suggesting their roles in the inhibition of H5N1 virus replication.Conclusions: To the best of the authors' knowledge, this study is among the earliest reports to illustrate the antiviral property of these Asian medicinal plants against the highly pathogenic avian H5N1 influenza virus. The results of this study shed light on alternative therapeutic sources for treatment of H5N1 influenza virus infection in the future.

Hidradenitis Suppurativa: An Exploration of Genetic Perturbations and Immune Dysregulation

Hidradenitis suppurativa(HS)is a chronic,inflammatory skin condition that poses a significant diagnostic and therapeutic challenge for clinicians,as the underlying etiology and pathogenesis remains unclear.The host of genetic mutations and immune dysfunction has been identified to be involved in the pathogenesis of HS during recent years.These genetic defects,including monogenetic mutations altering subunits ofγ-secretase,a protease that functions through Notch signaling to maintain skin appendages,promote epithelial stability,suppress/terminate innate immune responses(ie,Toll-receptors),further have the propensity to induce aberrant cytokine responses that create to a proinflammatory environment,consequently induce hyperkeratosis and promote expression of pro-inflammatory,locally destructive matrix metalloproteinases.Cytokine-driven inflammation propagates the disease state of HS and contributes to the formation of painful subcutaneous nodules,abscesses,and eventually,fistulas and draining sinus tracts.A closer look at genetic mutations linked to the disease may explain the immune perturbations seen in HS.An understanding of the immune cells and inflammatory markers expressed in affected individuals provides insight into disease pathogenesis and can help identify therapeutic targets.