Toll-like receptors are key participants in innate immune responses

Conventional type 1 dendritic cells are essential for the development of primary biliary cholangitis

BACKGROUND & AIMS

Primary biliary cholangitis (PBC) is a progressive-cholestatic autoimmune liver disease. Dendritic cells (DC) are professional antigen-presenting cells and their prominent presence around damaged bile ducts of PBC patients are documented. cDC1 is a rare subset of DC known for its cross-presentation abilities and interleukin 12 production. Our aim was to assess the role of cDC1 in the pathogenesis of PBC.

METHODS

We utilized an inducible murine model of PBC and took advantage of the DC reporter mice Zbtb46gfp and the Batf3-/- mice that specifically lack the cDC1 subset. cDC1 cells were sorted from blood of PBC patients and healthy individuals and subjected to Bulk-MARS-seq transcriptome analysis.

RESULTS

Histopathology assessment demonstrated peri-portal inflammation in wild type (WT) mice, whereas only minor abnormalities were observed in Batf3-/- mice. Flow cytometry analysis revealed a two-fold reduction in hepatic CD8/CD4 T cells ratio in Batf3-/- mice, suggesting reduced intrahepatic CD8 T cells expansion. Histological evidence of portal fibrosis was detected only in the WT but not in Batf3-/- mice. This finding was supported by decreased expression levels of pro-fibrotic genes in the livers of Batf3-/- mice. Transcriptome analysis of human cDC1, revealed 78 differentially expressed genes between PBC patients and controls. Genes related to antigen presentation, TNF and IFN signalling and mitochondrial dysfunction were significantly increased in cDC1 isolated from PBC patients.

CONCLUSION

Our data illustrated the contribution the cDC1 subset in the pathogenesis of PBC and provides a novel direction for immune based cell-specific targeted therapeutic approach in PBC.

Specific binding sites on Rhesus rotavirus capsid protein dictate the method of endocytosis inducing the murine model of biliary atresia

Biliary atresia (BA) is the leading indication for pediatric liver transplantation. Rhesus rotavirus (RRV)-induced murine BA develops an obstructive cholangiopathy that mirrors the human disease. We have previously demonstrated the "SRL" motif on RRV's VP4 protein binds to heat shock cognate 70 protein (Hsc70) facilitating entry into cholangiocytes. In this study, we analyzed how binding to Hsc70 affects viral endocytosis, intracellular trafficking, and uniquely activates the signaling pathway that induces murine BA. Inhibition of clathrin- and dynamin-mediated endocytosis in cholangiocytes following infection demonstrated that blocking dynamin decreased the infectivity of RRV, whereas clathrin inhibition had no effect. Blocking early endosome trafficking resulted in decreased viral titers of RRV, whereas late endosome inhibition had no effect. After infection, TLR3 expression and p-NF-κB levels increased in cholangiocytes, leading to increased release of CXCL9 and CXCL10. Infected mice knocked out for TLR3 had decreased levels of CXCL9 and CXCL10, resulting in reduced NK cell numbers. Human patients with BA experienced an increase in CXCL10 levels, suggesting this as a possible pathway leading to biliary obstruction. Viruses that use Hsc70 for cell entry exploit a clathrin-independent pathway and traffic to the early recycling endosome uniquely activating NF-κB through TLR3, leading to the release of CXCL9 and CXCL10 and inducing NK cell recruitment. These results define how the "SRL" peptide found on RRV's VP4 protein modulates viral trafficking, inducing the host response leading to bile duct obstruction.NEW & NOTEWORTHY In this study, we have determined that the presence of the "SRL" peptide on RRV alters its method of endocytosis and intracellular trafficking through viral binding to heat shock cognate 70 protein. This initiates an inflammatory pathway that stimulates the release of cytokines associated with biliary damage and obstruction.

Discovery of KT-413, a Targeted Protein Degrader of IRAK4 and IMiD Substrates Targeting MYD88 Mutant Diffuse Large B-Cell Lymphoma

Developing therapies for the activated B-cell like (ABC) subtype of diffuse large B-cell lymphomas (DLBCL) remains an area of unmet medical need. A subset of ABC DLBCL tumors is driven by activating mutations in myeloid differentiation primary response protein 88 (MYD88), which lead to constitutive activation of interleukin-1 receptor associated kinase 4 (IRAK4) and cellular proliferation. IRAK4 signaling is driven by its catalytic and scaffolding functions, necessitating complete removal of this protein and its escape mechanisms for complete therapeutic suppression. Herein, we describe the identification and characterization of a dual-functioning molecule, KT-413 and show it efficiently degrades IRAK4 and the transcription factors Ikaros and Aiolos. KT-413 achieves concurrent degradation of these proteins by functioning as both a heterobifunctional degrader and a molecular glue. Based on the demonstrated activity and safety of KT-413 in preclinical studies, a phase 1 clinical trial in B-cell lymphomas, including MYD88 mutant ABC DLBCL, is currently underway.

Research Progress of Drug Delivery Systems Targeting the Kidneys

Chronic kidney disease (CKD) affects more than 10% of the global population, and its incidence is increasing, partially due to an increase in the prevalence of disease risk factors. Acute kidney injury (AKI) is an independent risk factor for CKD and end-stage renal disease (ESRD). The pathogenic mechanisms of CKD provide several potential targets for its treatment. However, due to off-target effects, conventional drugs for CKD typically require high doses to achieve adequate therapeutic effects, leading to long-term organ toxicity. Therefore, ideal treatments that completely cure the different types of kidney disease are rarely available. Several approaches for the drug targeting of the kidneys have been explored in drug delivery system research. Nanotechnology-based drug delivery systems have multiple merits, including good biocompatibility, suitable degradability, the ability to target lesion sites, and fewer non-specific systemic effects. In this review, the development, potential, and limitations of low-molecular-weight protein-lysozymes, polymer nanomaterials, and lipid-based nanocarriers as drug delivery platforms for treating AKI and CKD are summarized.

Effects on growth performance and immunity of Monopterus albus after high temperature stress

To investigate the impact of the effect of high temperature stimulation on Monopterus albus larvae after a certain period of time, five experimental groups were established at different temperatures. Then, the M. albus under high temperature stress was fed at 30°C for 70 days. After that, the growth index of the M. albus was counted and analyzed. In terms of growth index, high temperature stress had significant effects on FCR, FBW, WGR, and SGR of M. albus (p < 0.05). The SR increased after being stimulated by temperature (p < 0.1). The study revealed that liver cells of M. albus were harmed by elevated temperatures of 36°C and 38°C. In the experimental group, the activities of digestive enzymes changed in the same trend, reaching the highest point in the 32°C group and then decreasing, and the AMS activity in the 38°C group was significantly different from that in the 30°C group (p < 0.05). The activities of antioxidase in liver reached the highest at 34°C, which was significantly different from those at 30°C (p < 0.05). In addition, the expression levels of TLR1, C3, TNF-α, and other genes increased in the experimental group, reaching the highest point at 34°C, and the expression level of the IL-1β gene reached the highest point at 32°C, which was significantly different from that at 30°C (p < 0.05). However, the expression level of the IRAK3 gene decreased in the experimental group and reached its lowest point at 34°C (p < 0.05). The expression level of the HSP90α gene increased with the highest temperature stimulus and reached its highest point at 38°C (p < 0.05). In the α diversity index of intestinal microorganisms in the experimental group, the observed species, Shannon, and Chao1 indexes in the 34°C group were the highest (p < 0.05), and β diversity analysis revealed that the intestinal microbial community in the experimental group was separated after high temperature stimulation. At the phylum level, the three dominant flora are Proteus, Firmicutes, and Bacteroides. Bacteroides and Macrococcus abundance increased at the genus level, but Vibrio and Aeromonas abundance decreased. To sum up, appropriate high-temperature stress can enhance the immunity and adaptability of M. albus. These results show that the high temperature stimulation of 32°C-34°C is beneficial to the industrial culture of M. albus.

Advances in lung ischemia/reperfusion injury: unraveling the role of innate immunity

BACKGROUND

Lung ischemia/reperfusion injury (LIRI) is a common occurrence in clinical practice and represents a significant complication following pulmonary transplantation and various diseases. At the core of pulmonary ischemia/reperfusion injury lies sterile inflammation, where the innate immune response plays a pivotal role. This review aims to investigate recent advancements in comprehending the role of innate immunity in LIRI.

METHODS

A computer-based online search was performed using the PubMed database and Web of Science database for published articles concerning lung ischemia/reperfusion injury, cell death, damage-associated molecular pattern molecules (DAMPs), innate immune cells, innate immunity, inflammation.

RESULTS

During the process of lung ischemia/reperfusion, cellular injury even death can occur. When cells are injured or undergo cell death, endogenous ligands known as DAMPs are released. These molecules can be recognized and bound by pattern recognition receptors (PRRs), leading to the recruitment and activation of innate immune cells. Subsequently, a cascade of inflammatory responses is triggered, ultimately exacerbating pulmonary injury. These steps are complex and interrelated rather than being in a linear relationship. In recent years, significant progress has been made in understanding the immunological mechanisms of LIRI, involving novel types of cell death, the ability of receptors other than PRRs to recognize DAMPs, and a more detailed mechanism of action of innate immune cells in ischemia/reperfusion injury (IRI), laying the groundwork for the development of novel diagnostic and therapeutic approaches.

CONCLUSIONS

Various immune components of the innate immune system play critical roles in lung injury after ischemia/reperfusion. Preventing cell death and the release of DAMPs, interrupting DAMPs receptor interactions, disrupting intracellular inflammatory signaling pathways, and minimizing immune cell recruitment are essential for lung protection in LIRI.

Ecological insights into hematopoiesis regulation: unraveling the influence of gut microbiota

The gut microbiota constitutes a vast ecological system within the human body, forming a mutually interdependent entity with the host. In recent years, advancements in molecular biology technologies have provided a clearer understanding of the role of the gut microbiota. They not only influence the local immune status and metabolic functions of the host's intestinal tract but also impact the functional transformation of hematopoietic stem cells (HSCs) through the gut-blood axis. In this review, we will discuss the role of the gut microbiota in influencing hematopoiesis. We analyze the interactions between HSCs and other cellular components, with a particular emphasis on the direct functional regulation of HSCs by the gut microbiota and their indirect influence through cellular components in the bone marrow microenvironment. Additionally, we propose potential control targets for signaling pathways triggered by the gut microbiota to regulate hematopoietic function, filling crucial knowledge gaps in the development of this research field.

Isolation and functional identification of immune cells in hemolymph of blood clams Tegillarca granosa

Blood clam Tegillarca granosa is a type of economically cultivated bivalve mollusk with red blood, and it primarily relies on hemocytes in its hemolymph for immune defense. However, there are currently no reports on the isolation and identification of immune cells in T. granosa, which hinders our understanding of their immune defense. In this study, we employed single-cell transcriptome sequencing (scRNA-seq) to visualize the molecular profile of hemocytes in T. granosa. Based on differential expression of immune genes and hemoglobin genes, hemocytes can be molecularly classified into immune cells and erythrocytes. In addition, we separated immune cells using density gradient centrifugation and demonstrated their stronger phagocytic capacity compared to erythrocytes, as well as higher levels of ROS and NO. In summary, our experiments involved the isolation and functional identification of immune cells in hemolymph of T. granosa. This study will provide valuable insights into the innate immune system of red-blood mollusks and further deepen the immunological research of mollusks.

Regulation of cellular senescence by innate immunity

During the COVID-19 pandemic, the interplay between the processes of immunity and senescence is drawing more and more intensive attention. SARS-CoV-2 infection induces senescence in lung cells, failure to clear infected cells and increased presence of inflammatory factors could lead to a cytokine storm and acute respiratory disease syndrome (ARDS), which together with aging and age-associated disease lead to 70% of COVID-19-related deaths. Studies on how senescence initiates upon viral infection and how to restrict excessive accumulation of senescent cells to avoid harmful inflammation are crucially important. Senescence can induce innate immune signaling, and innate immunity can engage cell senescence. Here, we mainly review the innate immune pathways, such as cGAS-STING, TLRs, NF-κB, and NLRP3 inflammasome, participating in the senescence process. In these pathways, IFN-I and inflammatory factors play key roles. At the end of the review, we propose the strategies by which we can improve the immune function and reduce inflammation based on these findings.

Alterations of Plasma Biochemical and Immunological Parameters and Spatiotemporal Expression of TLR2 and TLR9 in Gibel Carp (Carassius auratus gibelio) after CyHV-2 Infection

Cyprinid herpesvirus II (CyHV-2), a highly contagious pathogen of gibel carp (Carassius auratus gibelio), causes herpesviral hematopoietic necrosis disease (HVHND) and enormous financial losses. However, there is limited information available regarding the changes in plasma biochemical and immunological parameters and the response characteristics of Toll-like receptor 2 (TLR2) and Toll-like receptor 9 (TLR9) in gibel carp after CyHV-2 infection. To address this knowledge gap, a sub-lethal CyHV-2 infection was conducted in gibel carp, and the sample was collected daily from 1 to 7 days post infection. The plasma biochemical analyses showed significant decreases in the content of glucose, total cholesterol (TCHO), and total protein (TP), along with marked increases in the level of uric acid, urea, creatinine (CREA), Complement 3 (C3), immunoglobulin D (IgD), and immunoglobulin M (IgM) as well as in the activity of alanine aminotransferase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), and lactate dehydrogenase (LDH) in the infected group. Compared with the control group, the concentration of cortisol, triglyceride (TG), and Complement 4 (C4) had no noticeable alterations in the infected group. Real-time quantitative PCR analysis showed significant upregulation of TLR2 and TLR9 mRNA expression in the spleen, kidney, brain, liver, intestine, and gill post CyHV-2 infection. Interestingly, a time- and tissue-dependent expression profile has been comparatively observed for TLR2 and TLR9 in the above tissues of gibel carp after CyHV-2 infection, suggesting distinct roles between TLR2 and TLR9 in antiviral response to CyHV-2 infection. Overall, our results demonstrated that CyHV-2 infection led to the disruption of the physiological metabolic process and damage to the liver and kidney, and induced different spatiotemporal expression patterns of TLR2 and TLR9, ultimately stimulating antiviral response via innate and adaptive immune system. These findings may provide a deeper understanding of the host immunity response to CyHV-2 infection and offer novel perspectives for the prevention and treatment and therapeutic drug development against CyHV-2.

How Toll-like Receptor 9 Plays a Key Role in the Development of Gastric Cancer and Is Linked to Epstein-Barr Virus Infection

The relationship between Toll-like receptor 9 (TLR-9) signaling and its involvement with Epstein-Barr virus (EBV) in gastric cancer (GC) is complex and currently under study. This research intended to understand TLR-9's role in certain T and B lymphocytes and the serum levels of TLR-9 in GC patients versus healthy subjects. The team explored links between these immune markers and various GC traits, such as histological grade, tumor progression stages, cancer types, and survival rates. Additionally, the research sought to find if EBV genetic material influences these immune reactions. Using flow cytometry, TLR-9 levels in different immune cells were analyzed. At the same time, the amount of TLR-9 in the serum was determined. The results showed GC patients had varied TLR-9 levels compared to healthy subjects, with specific cells showing noticeable changes. When grouped by GC attributes, key relationships emerged between TLR-9 amounts, the histological grade, progression stages, and cancer types. A notable finding was the connection between TLR-9 levels and EBV genetic presence, suggesting possible interactions between TLR-9 responses and EBV-related GC processes. Survival data also hinted at TLR-9's potential as a predictor linked to clinical traits. Overall, this research emphasizes TLR-9's complex role in GC's immune responses, pinpointing its interactions with particular cells, clinical features, and EBV. The study unveils a complex web affecting GC and paves the way for new treatment avenues targeting TLR-9 pathways.

Characterization of the Inflammatory Response Evoked by Bacterial Membrane Vesicles in Intestinal Cells Reveals an RIPK2-Dependent Activation by Enterotoxigenic Escherichia coli Vesicles

Although the immunomodulatory potency of bacterial membrane vesicles (MVs) is widely acknowledged, their interactions with host cells and the underlying signaling pathways have not been well studied. Herein, we provide a comparative analysis of the proinflammatory cytokine profile secreted by human intestinal epithelial cells exposed to MVs derived from 32 gut bacteria. In general, outer membrane vesicles (OMVs) from Gram-negative bacteria induced a stronger proinflammatory response than MVs from Gram-positive bacteria. However, the quality and quantity of cytokine induction varied between MVs from different species, highlighting their unique immunomodulatory properties. OMVs from enterotoxigenic Escherichia coli (ETEC) were among those showing the strongest proinflammatory potency. In depth analyses revealed that the immunomodulatory activity of ETEC OMVs relies on a so far unprecedented two-step mechanism, including their internalization into host cells followed by intracellular recognition. First, OMVs are efficiently taken up by intestinal epithelial cells, which mainly depends on caveolin-mediated endocytosis as well as the presence of the outer membrane porins OmpA and OmpF on the MVs. Second, lipopolysaccharide (LPS) delivered by OMVs is intracellularly recognized by novel caspase- and RIPK2-dependent pathways. This recognition likely occurs via detection of the lipid A moiety as ETEC OMVs with underacylated LPS exhibited reduced proinflammatory potency but similar uptake dynamics compared to OMVs derived from wild-type (WT) ETEC. Intracellular recognition of ETEC OMVs in intestinal epithelial cells is pivotal for the proinflammatory response as inhibition of OMV uptake also abolished cytokine induction. The study signifies the importance of OMV internalization by host cells to exercise their immunomodulatory activities. IMPORTANCE The release of membrane vesicles from the bacterial cell surface is highly conserved among most bacterial species, including outer membrane vesicles (OMVs) from Gram-negative bacteria as well as vesicles liberated from the cytoplasmic membrane of Gram-positive bacteria. It is becoming increasingly evident that these multifactorial spheres, carrying membranous, periplasmic, and even cytosolic content, contribute to intra- and interspecies communication. In particular, gut microbiota and the host engage in a myriad of immunogenic and metabolic interactions. This study highlights the individual immunomodulatory activities of bacterial membrane vesicles from different enteric species and provides new mechanistic insights into the recognition of ETEC OMVs by human intestinal epithelial cells.

Unraveling the Role of Toll-like Receptors in the Immunopathogenesis of Selected Primary and Secondary Immunodeficiencies

The human immune system is a complex network of cells, tissues, and molecules that work together to defend the body against pathogens and maintain overall health. However, in some individuals, the immune system fails to function correctly, leading to immunodeficiencies. Immunodeficiencies can be classified into primary (PID) and secondary (SID) types, each with distinct underlying causes and manifestations. Toll-like receptors (TLRs), as key components of the immune system, have been implicated in the pathogenesis of both PID and SID. In this study, we aim to unravel the intricate involvement of TLR2, TLR4, TLR3, TLR7, TLR8, and TLR9 in the immunopathogenesis of common variable immunodeficiency-CVID (as PID)-and chronic lymphocytic leukemia-CLL (as SID). The obtained results indicate a significant increase in the percentage of all tested subpopulations of T lymphocytes and B lymphocytes showing positive expression of all analyzed TLRs in patients with CVID and CLL compared to healthy volunteers, constituting the control group, which is also confirmed by analysis of the concentration of soluble forms of these receptors in the plasma of patients. Furthermore, patients diagnosed with CVID are characterized by the percentage of all lymphocytes showing positive expression of the tested TLR2, TLR4, TLR3, and TLR9 and their plasma concentrations in relation to patients with CLL. By investigating the functions and interactions of TLRs within the immune system, we seek to shed light on their critical role in the development and progression of these immunodeficiencies. Through a comprehensive analysis of the literature and presented experimental data, we hope to deepen our understanding of the complex mechanisms by which TLRs contribute to the pathogenesis of PID and SID. Ultimately, our findings may provide valuable insights into developing targeted therapeutic strategies to mitigate the impact of these disorders on those affected by immunodeficiency.

Photobiomodulation, alone or combined with adipose-derived stem cells, reduces inflammation by modulation of microRNA-146a and interleukin-1ß in a delayed-healing infected wound in diabetic rats

Diabetic wounds are categorized by chronic inflammation, leading to the development of diabetic foot ulcers, which cause amputation and death. Herewith, we examined the effect of photobiomodulation (PBM) plus allogeneic diabetic adipose tissue-derived stem cells (ad-ADS) on stereological parameters and expression levels of interleukin (IL)-1ß and microRNA (miRNA)-146a in the inflammatory (day 4) and proliferation (day 8) stages of wound healing in an ischemic infected (with 2×107 colony-forming units of methicillin-resistant Staphylococcus aureus) delayed healing wound model (IIDHWM) in type I diabetic (TIDM) rats. There were five groups of rats: group 1 control (C); group 2 (CELL) in which rat wounds received 1×106 ad-ADS; group 3 (CL) in which rat wounds received the ad-ADS and were subsequently exposed to PBM(890 nm, 80 Hz, 3.5 J/cm2, in vivo); group 4 (CP) in which the ad-ADS preconditioned by the PBM(630 nm + 810 nm, 0.05 W, 1.2 J/cm2, 3 times) were implanted into rat wounds; group 5 (CLP) in which the PBM preconditioned ad-ADS were implanted into rat wounds, which were then exposed to PBM. On both days, significantly better histological results were seen in all experimental groups except control. Significantly better histological results were observed in the ad-ADS plus PBM treatment correlated to the ad-ADS alone group (p<0.05). Overall, PBM preconditioned ad-ADS followed by PBM of the wound showed the most significant improvement in histological measures correlated to the other experimental groups (p<0.05). On days 4 and 8, IL-1 β levels of all experimental groups were lower than the control group; however, on day 8, only the CLP group was different (p<0.01). On day 4, miR-146a expression levels were substantially greater in the CLP and CELL groups correlated to the other groups, on day 8 miR-146a in all treatment groups was upper than C (p<0.01). ad-ADS plus PBM, ad-ADS, and PBM all improved the inflammatory phase of wound healing in an IIDHWM in TIDM1 rats by reducing inflammatory cells (neutrophils, macrophages) and IL-1ß, and increasing miRNA-146a. The ad-ADS+PBM combination was better than either ad-ADS or PBM alone, because of the higher proliferative and anti-inflammatory effects of the PBM+ad-ADS regimen.

Extracellular vesicles of Clonorchis sinensis promote IL-6 and TNF-α secretion via the Toll-like receptor 9-mediated ERK pathway in biliary epithelial cells

Clonorchis sinensis is closely associated with cholangitis, cholecystitis, biliary fibrosis and cholangiocarcinoma. The present study elucidated the role of extracellular vesicles of C. sinensis (CsEVs) in activating Toll-like receptor 9 (TLR9) and regulating inflammatory responses. The results showed that TLR9 expression was increased in the livers of C. sinensis-infected mice. CsEVs were cup-shaped or saucer-shaped and 80-120 nm in diameter. CsEVs activated TLR9 and promoted IL-6 and TNF-α expression in mouse biliary epithelial cells (BECs), and TLR9 siRNA interference reduced the secretion of the two cytokines. CsEV stimulation promoted the phosphorylation of ERK, p38, AKT, and p65, and TLR9 siRNA interference regulated the phosphorylated ERK, AKT and p65 levels. The ERK inhibitor decreased the CsEVs-induced IL-6 and TNF-α secretion. The present study elucidated for the first time that CsEVs induced IL-6 and TNF-α production in BECs via the TLR9-mediated ERK pathway.

Interaction between nanomaterials and the innate immune system across evolution

Interaction of engineered nanomaterials (ENMs) with the immune system mainly occurs with cells and molecules of innate immunity, which are present in interface tissues of living organisms. Immuno-nanotoxicological studies aim at understanding if and when such interaction is inconsequential or may cause irreparable damage. Since innate immunity is the first line of immune reactivity towards exogenous agents and is highly conserved throughout evolution, this review focuses on the major effector cells of innate immunity, the phagocytes, and their major sensing receptors, Toll-like receptors (TLRs), for assessing the modes of successful versus pathological interaction between ENMs and host defences. By comparing the phagocyte- and TLR-dependent responses to ENMs in plants, molluscs, annelids, crustaceans, echinoderms and mammals, we aim to highlight common recognition and elimination mechanisms and the general sufficiency of innate immunity for maintaining tissue integrity and homeostasis.

The transient receptor potential channels in rheumatoid arthritis: Need to pay more attention

Rheumatoid arthritis (RA) is characterized by the augment of vascular permeability, increased inflammatory cells infiltration, dysregulated immune cells activation, pannus formation and unbearable pain hyperalgesia. Ca²⁺ affect almost every aspect of cellular functions, involving cell migration, signal transduction, proliferation, and apoptosis. Transient receptor potential channels (TRPs) as a type of non-selective permeable cation channels, can regulate Ca²⁺ entry and intracellular Ca²⁺ signal in cells including immune cells and neurons. Researches have demonstrated that TRPs in the mechanisms of inflammatory diseases have achieved rapid progress, while the roles of TRPs in RA pathogenesis and pain hyperalgesia are still not well understood. To solve this problem, this review presents the evidence of TRPs on vascular endothelial cells in joint swelling, neutrophils activation and their trans-endothelial migration, as well as their bridging role in the reactive oxygen species/TRPs/Ca²⁺/peptidyl arginine deiminases networks in accelerating citrullinated proteins formation. It also points out the distinct functions of TRPs subfamilies expressed in the nervous systems of joints in cold hyperalgesia and neuro-inflammation mutually influenced inflammatory pain in RA. Thus, more attention could be paid on the impact of TRPs in RA and TRPs are useful in researches on the molecular mechanisms of anti-inflammation and analgesic therapeutic strategies.

COVID-19 Vaccines and the Virus: Impact on Drug Metabolism and Pharmacokinetics

This article reports on an American Society of Pharmacology and Therapeutics, Division of Drug Metabolism and Disposition symposium held at Experimental Biology on April 2, 2022, in Philadelphia. As of July 2022, over 500 million people have been infected with SARS-CoV-2 (the virus causing COVID-19) and over 12 billion vaccine doses have been administered. Clinically significant interactions between viral infections and hepatic drug metabolism were first recognized over 40 years ago during a cluster of pediatric theophylline toxicity cases attributed to reduced hepatic drug metabolism amid an influenza B outbreak. Today, a substantive body of research supports that the activated innate immune response generally decreases hepatic cytochrome P450 activity. The interactions extend to drug transporters and other organs and have the potential to impact drug absorption, distribution, metabolism, and excretion (ADME). Based on this knowledge, altered ADME is predicted with SARS-CoV-2 infection or vaccination. The report begins with a clinical case exploring the possibility of SARS-CoV-2 vaccination increasing clozapine levels. This is followed by discussions of how SARS-CoV-2 infection or vaccines alter the metabolism and disposition of complex drugs, such as nanoparticles and biologics and small molecule therapies. The review concludes with a discussion of the effects of viral infections on placental amino acid transport and their potential to impact fetal development. The session improved our understanding of the impact of emerging viral infections and vaccine technologies on drug metabolism and disposition, which will help mitigate drug toxicity and improve drug and vaccine safety and effectiveness. SIGNIFICANCE STATEMENT: Altered pharmacokinetics of small molecule and complex molecule drugs and fetal brain distribution of amino acids following SARS-CoV-2 infection or immunization are possible. The proposed mechanisms involve decreased liver cytochrome P450 metabolism of small molecules, enhanced innate immune system metabolism of complex molecules, and altered placental and fetal blood-brain barrier amino acid transport, respectively. Future research is needed to understand the effects of these interactions on adverse drug responses, drug and vaccine safety, and effectiveness and fetal neurodevelopment.

Tongue sole creatine kinases function as DAMP and activate antimicrobial immunity via TLR2

Creatine kinase (CK) is an enzyme that regulates adenosine triphosphate (ATP) metabolism to maintain energy homeostasis. Although CK has been reported to be involved in pathogen infection, the immune function of CK remains elusive. In this study, we identified two muscle-type CK from the teleost tongue sole Cynoglossus semilaevis (designated CsCKM-1 and CsCKM-2). Bacterial infection modulated CsCKM-1/2 expression in tongue sole tissues and induced the release of CsCKM-1/2 into serum. Recombinant CsCKM-1/2 (rCsCKM-1/2) exhibited robust kinase activity and bound to bacterial pathogens and pathogen-associated molecular patterns. rCsCKM-1/2 also bound to tongue sole peripheral blood leukocytes (PBLs) and promoted PBLs to uptake bacterial pathogens, inhibit bacterial proliferation, and express proinflammatory cytokines. When co-expressed in HEK293T cells, CsCKM-1/2 were found to interact with the leucine rich domain of toll-like receptor 2 (TLR2). The presence of TLR2 antagonist significantly reduced CsCKM-1/2-induced immune response and antibacterial effect. Taken together, these results indicated that tongue sole creatine kinases function as damage-associated molecular pattern (DAMP) molecules and play an important role in antimicrobial immunity via TLR2.

Salmonid alphavirus non-structural protein 2 is a key protein that activates the NF-κB signaling pathway to mediate inflammatory responses

Salmonid alphavirus (SAV) infection of Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss) causes pancreas disease (PD) with typical inflammatory responses, such as necrosis of the exocrine pancreas, cardiomyopathy and skeletal myopathy. However, the pathogenic mechanism underlying SAV infection is still unclear. Inflammation may cause damage to the body, but it is a defense response against infection by pathogenic microorganisms, of which nuclear factor-kappa B (NF-κB) is the main regulator. This study revealed that SAV can activate NF-κB, of which the viral nonstructural protein Nsp2 is the major activating protein. SAV activates the NF-κB signaling pathway by simultaneously up-regulating TLR3, 7, 8 and then the expression of the signaling molecule myeloid differentiation factor 88 (Myd88) and tumor necrosis factor receptor-associated factor 6 (TRAF6). We found that Nsp2 can induce IκB degradation and p65 phosphorylation and transnucleation, and activate NF-κB downstream inflammatory cytokines. Nsp2 may simultaneously activate NF-κB through TLR3,7,8-dependent signaling pathways. Overexpression of Nsp2 can up-regulate mitochondrial antiviral signaling protein (MAVS) and then promote the expression of IFNa1 and antiviral protein Mx, which inhibits viral replication. This study shows that Nsp2 acts as a key activator protein for the NF-κB signaling pathway, which induces inflammation post-SAV infection. This study systematically analyzes the molecular mechanism of SAV activation of the NF-κB signaling pathway, and provides a theoretical basis for revealing the mechanism of innate immune response and inflammatory injury caused by SAV.

Systemic immune responses after ischemic stroke: From the center to the periphery

Ischemic stroke is a leading cause of disability and death. It imposes a heavy economic burden on individuals, families and society. The mortality rate of ischemic stroke has decreased with the help of thrombolytic drug therapy and intravascular intervention. However, the nerve damage caused by ischemia-reperfusion is long-lasting and followed by multiple organ dysfunction. In this process, the immune responses manifested by systemic inflammatory responses play an important role. It begins with neuroinflammation following ischemic stroke. The large number of inflammatory cells released after activation of immune cells in the lesion area, along with the deactivated neuroendocrine and autonomic nervous systems, link the center with the periphery. With the activation of systemic immunity and the emergence of immunosuppression, peripheral organs become the second “battlefield” of the immune response after ischemic stroke and gradually become dysfunctional and lead to an adverse prognosis. The purpose of this review was to describe the systemic immune responses after ischemic stroke. We hope to provide new ideas for future research and clinical treatments to improve patient outcomes and quality of life.

Signaling pathways involved in ischemic stroke: molecular mechanisms and therapeutic interventions

Ischemic stroke is caused primarily by an interruption in cerebral blood flow, which induces severe neural injuries, and is one of the leading causes of death and disability worldwide. Thus, it is of great necessity to further detailly elucidate the mechanisms of ischemic stroke and find out new therapies against the disease. In recent years, efforts have been made to understand the pathophysiology of ischemic stroke, including cellular excitotoxicity, oxidative stress, cell death processes, and neuroinflammation. In the meantime, a plethora of signaling pathways, either detrimental or neuroprotective, are also highly involved in the forementioned pathophysiology. These pathways are closely intertwined and form a complex signaling network. Also, these signaling pathways reveal therapeutic potential, as targeting these signaling pathways could possibly serve as therapeutic approaches against ischemic stroke. In this review, we describe the signaling pathways involved in ischemic stroke and categorize them based on the pathophysiological processes they participate in. Therapeutic approaches targeting these signaling pathways, which are associated with the pathophysiology mentioned above, are also discussed. Meanwhile, clinical trials regarding ischemic stroke, which potentially target the pathophysiology and the signaling pathways involved, are summarized in details. Conclusively, this review elucidated potential molecular mechanisms and related signaling pathways underlying ischemic stroke, and summarize the therapeutic approaches targeted various pathophysiology, with particular reference to clinical trials and future prospects for treating ischemic stroke.

Immunomodulatory Effect of Polysaccharide from Fermented Morinda citrifolia L. (Noni) on RAW 264.7 Macrophage and Balb/c Mice

This study aims to determine the immunomodulatory effects of a polysaccharide fraction from fermented M. citrifolia L. (FMP) in RAW 264.7 macrophages and Balb/c mice. M. citrifolia was fermented for 72 h using Lactobacillus brevis; polysaccharides were extracted using ethanol precipitation. The RAW 264.7 cells exposed to FMP (50, 100, and 200 μg/mL) for 24 h showed increased NO production, proinflammatory cytokine (IL-1β, IL-6, and TNF-α) release, and COX-2 and iNOS protein expression. FMP (100, 200 mg/kg) and deacetylasperulosidic acid (DAA) (20 mg/kg) administered orally to Balb/c mice for 14 days upregulated NO production and NK cytotoxicity in abdominal cavity and spleen, respectively. Th1 and Th2 cytokines production and immune cell numbers increased in spleen, mesenteric lymph nodes (MLN), peritoneal exudate cells (PEC), Peyer's patches (PP), and peripheral blood mononuclear cells (PBMC). Therefore, FMP containing DAA can be used as materials for health functional foods to enhance immune responses.

Chronic Inflammation in Obesity and Cancer Cachexia

Chronic inflammation has long been linked to obesity and related conditions such as type 2 diabetes and metabolic syndrome. According to current research, the increased risk of cancer in people with certain metabolic diseases may be due to chronic inflammation. Adipocytokines, which are pro-inflammatory cytokines secreted in excess, are elevated in many chronic metabolic diseases. Cytokines and inflammatory mediators, which are not directly linked to DNA, are important in tumorigenesis. Cachexia, a type of metabolic syndrome linked to the disease, is associated with a dysregulation of metabolic pathways. Obesity and cachexia have distinct metabolic characteristics, such as insulin resistance, increased lipolysis, elevated free fatty acids (FFA), and ceramide levels, which are discussed in this section. The goal of this research project is to create a framework for bringing together our knowledge of inflammation-mediated insulin resistance.

Development of peptide vaccine candidate using highly antigenic PE-PGRS family proteins to stimulate the host immune response against Mycobacterium tuberculosis H37Rv: an immuno-informatics approach

Tuberculosis (TB) is a fast spreading; transmissible disease caused by the Mycobacterium tuberculosis (M. tuberculosis). M. tuberculosis has a high death rate in its endemic regions due to a lack of appropriate treatment and preventative measures. We have used a vaccinomics strategy to create an effective multi-epitope vaccine against M. tuberculosis. The antigenic proteins with the highest antigenicity were utilised to predict cytotoxic T-lymphocyte (CTL), helper T-lymphocyte (HTL), and linear B-lymphocyte (LBL) epitopes. CTL and HTL epitopes were covered in 99.97% of the population. Seven epitopes each of CTL, HTL, and LBL were ultimately selected and utilised to develop a multi-epitope vaccine. A vaccine design was developed by combining these epitopes with suitable linkers and LprG adjuvant. The vaccine chimera was revealed to be highly immunogenic, non-allergenic, and non-toxic. To ensure a better expression within the Escherichia coli K12 (E. coli K12) host system, codon adaptation and in silico cloning were accomplished. Following that, various validation studies were conducted, including molecular docking, molecular dynamics simulation, and immunological simulation, all of which indicated that the designed vaccine would be stable in the biological environment and effective against M. tuberculosis infection. The immune simulation revealed higher levels of T-cell and B-cell activity, which corresponded to the actual immune response. Exposure simulations were repeated several times, resulting in increased clonal selection and faster antigen clearance. These results suggest that, if proposed vaccine chimera would test both in-vitro and in-vivo, it could be a viable treatment and preventive strategy for TB.Communicated by Ramaswamy H. Sarma.

Blocking Toll-like receptor 9 attenuates bleomycin-induced pulmonary injury

Background

Acute respiratory distress syndrome (ARDS) is one of the most common complications in coronavirus disease 2019 patients suffering from acute lung injury (ALI). In ARDS, marked distortion of pulmonary architecture has been reported. The pulmonary lesions in ARDS include hemodynamic derangements (such as alveolar edema and hemorrhage), vascular and bronchiolar damage, interstitial inflammatory cellular aggregations, and eventually fibrosis. Bleomycin induces ARDS-representative pulmonary damage in mice and rats; therefore, we used bleomycin model mice in our study. Recently, Toll-like receptor 9 (TLR9) was implicated in the development of ARDS and ALI.

Methods

In this study, we evaluated the efficiency of a TLR9 blocker (ODN2088) on bleomycin-induced pulmonary damage. We measured the apoptosis rate, inflammatory reaction, and fibroplasia in bleomycin- and bleomycin + ODN2088-treated mice.

Results

Our results showed a significant amelioration in bleomycin-induced damage to pulmonary architecture following ODN2088 treatment. A marked decrease in pulmonary epithelial and endothelial apoptosis rate as measured by cleaved caspase-3 expression, inflammatory reaction as indicated by tumor necrosis factor α expression, and pulmonary fibrosis as demonstrated by Van Gieson staining and α-smooth muscle actin immunohistochemistry were observed following ODN2088 treatment.

Conclusions

All these findings indicate that blocking downstream TLR9 signaling could be beneficial in prevention or mitigation of ARDS through hemodynamic derangements, inflammation, apoptosis, and fibrosis.

Early continuous blood purification affects TNF-α, IL-1β, and IL-6 in patients with severe acute pancreatitis via inhibiting TLR4 signaling pathway

To exploit whether early continuous blood purification (CBP) inhibits the Toll-like receptors 4 (TLR4) signaling pathway in the peripheral blood of patients with severe acute pancreatitis (SAP) and whether it affects the abundance of inflammatory factors; 130 SAP patients were randomly selected and divided into Groups B and C. Both groups received conventional treatment. Among them, Group C was given early CBP treatment. Another 60 healthy cases in physical examination at the same time were selected as Group A. The abundances of TLR4 and inflammatory factors were detected before and after treatment. Compared with Group B, (1) the symptoms in Group C improved more markedly; (2) protein contents of TLR4 and nuclear factor kappa B (NF-κB) in Group C diminished more signally; (3) the abundances of tumor necrosis factor alpha (TNF-α), cytokine interleukin-1β (IL-1β), and cytokine interleukin 6 (IL-6) in Group C decreased (p < 0.05); and (4) the abundance of TLR4 in Group C was positively correlated with those of TNF-α, IL-1β, and IL-6 after treatment (all p < 0.001). Early CBP inhibits TLR4 signaling pathway in SAP patients and attenuates the abundance of inflammatory factors to a certain extent, which may provide a new clinical treatment strategy for SAP.

Expression of TLR2 and TLR5 in distal ileum of mice with obstructive jaundice and their role in intestinal mucosal injury

INTRODUCTION

The aim was to investigate the expression of TLR2 and TLR5 in the distal ileum of mice with obstructive jaundice (OJ) and their role in intestinal mucosal injury.

MATERIAL AND METHODS

A total of 100 male C57BL/6J mice were randomly assigned to two groups: (I) sham operation (SH); (II) bile duct ligation (BDL). The mice were respectively sacrificed before operation and on the 1^st, 3^rd, 5^th and 7^th days after operation to collect specimens. Various indicators were detected by PCR, immunohistochemistry and other methods.

RESULTS

TLR2 was increased gradually with the extension of OJ time in the BDL group (p < 0.05). However, the changes in the expression of TLR5 were not obvious at different time points. The amount of Bifidobacteria and Lactobacillus showed downward trends in intestinal tract of the BDL group. Furthermore, the amount of Escherichia coli was increased in intestinal tract of the BDL group. The pathological score of intestinal mucosa and the expression of NF-κB increased gradually in the BDL group with the extension of OJ time. There were positive correlations between the pathological score of intestinal mucosa and expressions of TLR2(r = 0.767, p < 0.05) and NF-κB (r = 0.817, p < 0.05) in BDL group. NF-κB expression was positively correlated with TLR2 expression(r = 0.706, p < 0.05).

CONCLUSIONS

Disturbance of intestinal flora caused by OJ could increase the expression of NF-κB via up-regulating the expression of TLR2 to activate the downstream signaling pathway, thus aggravated the injury of intestinal mucosa.

CD38 in the age of COVID-19: a medical perspective

This medical review addresses the hypothesis that CD38/NADase is at the center of a functional axis (i.e., intracellular Ca2+ mobilization/IFNγ response/reactive oxygen species burst) driven by severe acute respiratory syndrome coronavirus 2 infection, as already verified in respiratory syncytial virus pathology and CD38 activity in other cellular settings. Key features of the hypothesis are that 1) the substrates of CD38 (e.g., NAD+ and NADP+) are depleted by viral-induced metabolic changes; 2) the products of the enzymatic activity of CD38 [e.g., cyclic adenosine diphosphate-ribose (ADPR)/ADPR/nicotinic acid adenine dinucleotide phosphate] and related enzymes [e.g., poly(ADP-ribose)polymerase, Sirtuins, and ADP-ribosyl hydrolase] are involved in the anti‐viral and proinflammatory response that favors the onset of lung immunopathology (e.g., cytokine storm and organ fibrosis); and 3) the pathological changes induced by this kinetic mechanism may be reduced by distinct modulators of the CD38/NAD+ axis (e.g., CD38 blockers, NAD+ suppliers, among others). This view is supported by arrays of associative basic and applied research data that are herein discussed and integrated with conclusions reported by others in the field of inflammatory, immune, tumor, and viral diseases.

Impact of tooth loss due to periodontal disease on the prognosis of rehabilitation

When periodontal disease is diagnosed, it is difficult to predict the clinical response of treatment of a tooth over time because the result of treatment is affected by several factors and will depend on the maintenance and support of periodontal treatment. Rehabilitation with removable dental prostheses, fixed prostheses, and dental implants makes it possible to restore the function and esthetics of patients with tooth loss due to periodontal disease. The predictive factors of tooth loss in periodontitis patients should be assessed by dentists to inform their clinical decision-making during dental treatment planning. This will provide detailed individualized information and level of risk of patients considered suitable for dental rehabilitation. Therefore, the aim of this article was to review the subject of "Impact of tooth loss due to periodontal disease on the prognosis of rehabilitation" and the effect of fixed, removable, and implant-supported prostheses in periodontal patients.

Oral Immunization of Larvae and Juvenile of Lumpfish (Cyclopterus lumpus) against Vibrio anguillarum Does Not Influence Systemic Immunity

Vibrio anguillarum, a marine bacterial pathogen that causes vibriosis, is a recurrent pathogen of lumpfish (Cyclopterus lumpus). Lumpfish is utilized as a cleaner fish in the Atlantic salmon (Salmo salar) aquaculture in the North Atlantic region because of its ability to visualize and prey on the ectoparasite sea lice (Lepeophtheirus salmonis) on the skin of Atlantic salmon, and its performance in cold environments. Lumpfish immunity is critical for optimal performance and sea lice removal. Oral vaccine delivery at a young age is the desired method for fish immunization because is easy to use, reduces fish stress during immunization, and can be applied on a large scale while the fish are at a young age. However, the efficacy of orally delivered inactivated vaccines is controversial. In this study, we evaluated the effectiveness of a V. anguillarum bacterin orally delivered to cultured lumpfish and contrasted it to an intraperitoneal (i.p.) boost delivery. We bio-encapsulated V. anguillarum bacterin in Artemia salina live-feed and orally immunized lumpfish larvae. Vaccine intake and immune response were evaluated by microscopy and quantitative polymerase chain reaction (qPCR) analysis, respectively. qPCR analyses showed that the oral immunization of lumpfish larvae resulted in a subtle stimulation of canonical immune transcripts such as il8b, il10, igha, ighmc, ighb, ccl19, ccl20, cd8a, cd74, ifng, and lgp2. Nine months after oral immunization, one group was orally boosted, and a second group was both orally and i.p. boosted. Two months after boost immunization, lumpfish were challenged with V. anguillarum (7.8 × 10⁵ CFU dose⁻¹). Orally boosted fish showed a relative percentage of survival (RPS) of 2%. In contrast, the oral and i.p. boosted group showed a RPS of 75.5% (p < 0.0001). V. anguillarum bacterin that had been orally delivered was not effective in lumpfish, which is in contrast to the i.p. delivered bacterin that protected the lumpfish against vibriosis. This suggests that orally administered V. anguillarum bacterin did not reach the deep lymphoid tissues, either in the larvae or juvenile fish, therefore oral immunization was not effective. Oral vaccines that are capable of crossing the epithelium and reach deep lymphoid tissues are required to confer an effective protection to lumpfish against V. anguillarum

Toll-Like Receptor 9-Mediated Neuronal Innate Immune Reaction Is Associated with Initiating a Pro-Regenerative State in Neurons of the Dorsal Root Ganglia Non-Associated with Sciatic Nerve Lesion

One of the changes brought about by Wallerian degeneration distal to nerve injury is disintegration of axonal mitochondria and consequent leakage of mitochondrial DNA (mtDNA)—the natural ligand for the toll-like receptor 9 (TLR9). RT-PCR and immunohistochemical or Western blot analyses were used to detect TLR9 mRNA and protein respectively in the lumbar (L4-L5) and cervical (C7-C8) dorsal root ganglia (DRG) ipsilateral and contralateral to a sterile unilateral sciatic nerve compression or transection. The unilateral sciatic nerve lesions led to bilateral increases in levels of both TLR9 mRNA and protein not only in the lumbar but also in the remote cervical DRG compared with naive or sham-operated controls. This upregulation of TLR9 was linked to activation of the Nuclear Factor kappa B (NFκB) and nuclear translocation of the Signal Transducer and Activator of Transcription 3 (STAT3), implying innate neuronal immune reaction and a pro-regenerative state in uninjured primary sensory neurons of the cervical DRG. The relationship of TLR9 to the induction of a pro-regenerative state in the cervical DRG neurons was confirmed by the shorter lengths of regenerated axons distal to ulnar nerve crush following a previous sciatic nerve lesion and intrathecal chloroquine injection compared with control rats. The results suggest that a systemic innate immune reaction not only triggers the regenerative state of axotomized DRG neurons but also induces a pro-regenerative state further along the neural axis after unilateral nerve injury.

Innate immunity in lung transplantation

Innate immune pathways early after pulmonary transplantation have been shown to cause primary graft dysfunction (PGD) and also predispose to late graft failure. Recent studies in animal models have elucidated critical mechanisms governing such innate immune responses. Here, we discuss pathways of inflammatory cell death, triggers for sterile and infectious inflammation, and signaling cascades that mediate lung injury early after transplantation. These studies highlight potential avenues for lung-specific therapies early following lung transplantation to dampen innate immune responses and improve outcomes.

MYD88, NFKB1, and IL6 transcripts overexpression are associated with poor outcomes and short survival in neonatal sepsis

Toll-like receptor (TLR) family signature has been implicated in sepsis etiopathology. We aimed to evaluate the genetic profile of TLR pathway-related key genes; the myeloid differentiation protein 88 (MYD88), IL1 receptor-associated kinase 1 (IRAK1), the nuclear factor kappa-B1 (NFKB1), and interleukin 6 (IL6) in the blood of neonates with sepsis at the time of admission and post-treatment for the available paired-samples. This case–control study included 124 infants with sepsis admitted to the neonatal intensive care unit and 17 controls. The relative gene expressions were quantified by TaqMan Real-Time qPCR and correlated to the clinic-laboratory data. MYD88, NFKB1, and IL6 relative expressions were significantly higher in sepsis cases than controls. Higher levels of MYD88 and IL6 were found in male neonates and contributed to the sex-based separation of the cases by the principal component analysis. ROC analysis revealed MYD88 and NFKB1 transcripts to be good biomarkers for sepsis. Furthermore, patients with high circulatory MYD88 levels were associated with poor survival, as revealed by Kaplan–Meier curves analysis. MYD88, NFKB1, and IL6 transcripts showed association with different poor-outcome manifestations. Clustering analysis split the patient cohort into three distinct groups according to their transcriptomic signature and CRP levels. In conclusion, the study TLR pathway-related transcripts have a gender-specific signature, diagnostic, and prognostic clinical utility in neonatal sepsis.

What do we know about the mechanisms of action of probiotics on factors involved in the pathogenesis of periodontitis? A scoping review of in vitro studies

OBJECTIVE

Probiotics are increasingly used in oral prevention and treatment conditions, but little is known about their abilities. The aim of this review is to clarify, summarize and disseminate current knowledge about the mode of action of in vitro probiotics on factors involved in the pathogenesis of periodontitis.

METHOD

2495 articles were identified in three databases (Medline, Web of Science, SpringerLink) and 26 studies included in this scoping review.

RESULTS

Twenty-three probiotic species were identified, the majority of which were Lactobacilli or Bifidobacteria. Lactobacillus rhamnosus (30.8 %) and Lactobacillus reuteri (42.3 %) were found to be the two predominantly studied probiotic species and three main mechanisms of action of probiotics could be classified as: (i) modulation of the immuno-inflammatory response, (ii) direct actions of probiotics on periodontopathogens by adhesion or nutritive competitions and/or the secretion of antimicrobial molecules and (iii) indirect actions through environmental modifications. A combination of several probiotic strains seems to be beneficial via synergistic action amplifying the functions of each strain used. However, heterogeneity of the methodologies and probiotic species included in studies leads us to consider the following avenues for future research: (i) implementation of standardized periodontal models as close as possible to in vivo periodontal conditions to identify the functions of each strain for appropriate medication, (ii) updating data about interactions within oral biofilms to identify new candidates and to predict then analyze their behavior within these biofilms.

CONCLUSION

Probiotics may have their place in the response to inter-individual variability in periodontitis, provided that the choice of the probiotic strain or combination of them will be personalized and optimal for each patient.

Toll-Like Receptor Signaling Pathways: Novel Therapeutic Targets for Cerebrovascular Disorders

Toll-like receptors (TLRs), a class of pattern recognition proteins, play an integral role in the modulation of systemic inflammatory responses. Cerebrovascular diseases (CVDs) are a group of pathological conditions that temporarily or permanently affect the brain tissue mostly via the decrease of oxygen and glucose supply. TLRs have a critical role in the activation of inflammatory cascades following hypoxic-ischemic events and subsequently contribute to neuroprotective or detrimental effects of CVD-induced neuroinflammation. The TLR signaling pathway and downstream cascades trigger immune responses via the production and release of various inflammatory mediators. The present review describes the modulatory role of the TLR signaling pathway in the inflammatory responses developed following various CVDs and discusses the potential benefits of the modulation of different TLRs in the improvement of functional outcomes after brain ischemia.

Nuclear factor-kappa B (NF-κB) in pathophysiology of Parkinson disease: Diverse patterns and mechanisms contributing to neurodegeneration

Parkinson's disease (PD), the most common movement disorder, comprises several pathophysiologic mechanisms including misfolded alpha-synuclein aggregation, inflammation, mitochondrial dysfunction, and synaptic loss. Nuclear Factor-Kappa B (NF-κB), as a key regulator of a myriad of cellular reactions, is shown to be involved in such mechanisms associated with PD, and the changes in NF-κB expression is implicated in PD. Alpha-synuclein accumulation, the characteristic feature of PD pathology, is known to trigger NF-κB activation in neurons, thereby propagating apoptosis through several mechanisms. Furthermore, misfolded alpha-synuclein released from degenerated neurons, activates several signaling pathways in glial cells which culminate in activation of NF-κB and production of pro-inflammatory cytokines, thereby aggravating neurodegenerative processes. On the other hand, NF-κB activation, acting as a double-edged sword, can be necessary for survival of neurons. For instance, NF-κB activation is necessary for competent mitochondrial function and deficiency in c-Rel, one of the NF-κB proteins, is known to propagate DA neuron loss via several mechanisms. Despite the dual role of NF-κB in PD, several agents by selectively modifying the mechanisms and pathways associated with NF-κB, can be effective in attenuating DA neuron loss and PD, as reviewed in this paper.

CD38 in the age of COVID-19: a medical perspective

This medical review addresses the hypothesis that CD38/NADase is at the center of a functional axis (i.e., intracellular Ca²⁺ mobilization/IFNγ response/reactive oxygen species burst) driven by severe acute respiratory syndrome coronavirus 2 infection, as already verified in respiratory syncytial virus pathology and CD38 activity in other cellular settings. Key features of the hypothesis are that 1) the substrates of CD38 (e.g., NAD⁺ and NADP⁺) are depleted by viral-induced metabolic changes; 2) the products of the enzymatic activity of CD38 [e.g., cyclic adenosine diphosphate-ribose (ADPR)/ADPR/nicotinic acid adenine dinucleotide phosphate] and related enzymes [e.g., poly(ADP-ribose)polymerase, Sirtuins, and ADP-ribosyl hydrolase] are involved in the anti‐viral and proinflammatory response that favors the onset of lung immunopathology (e.g., cytokine storm and organ fibrosis); and 3) the pathological changes induced by this kinetic mechanism may be reduced by distinct modulators of the CD38/NAD⁺ axis (e.g., CD38 blockers, NAD⁺ suppliers, among others). This view is supported by arrays of associative basic and applied research data that are herein discussed and integrated with conclusions reported by others in the field of inflammatory, immune, tumor, and viral diseases.

Fibroblast contributions to ischemic cardiac remodeling

The heart can respond to increased pathophysiological demand through alterations in tissue structure and function 1 . This process, called cardiac remodeling, is particularly evident following myocardial infarction (MI), where the blockage of a coronary artery leads to widespread death of cardiac muscle. Following MI, necrotic tissue is replaced with extracellular matrix (ECM), and the remaining viable cardiomyocytes (CMs) undergo hypertrophic growth. ECM deposition and cardiac hypertrophy are thought to represent an adaptive response to increase structural integrity and prevent cardiac rupture. However, sustained ECM deposition leads to the formation of a fibrotic scar that impedes cardiac compliance and can induce lethal arrhythmias. Resident cardiac fibroblasts (CFs) are considered the primary source of ECM molecules such as collagens and fibronectin, particularly after becoming activated by pathologic signals. CFs contribute to multiple phases of post-MI heart repair and remodeling, including the initial response to CM death, immune cell (IC) recruitment, and fibrotic scar formation. The goal of this review is to describe how resident fibroblasts contribute to the healing and remodeling that occurs after MI, with an emphasis on how fibroblasts communicate with other cell types in the healing infarct scar 1 –6 .

Betaine inhibits Toll-like receptor 4 responses and restores intestinal microbiota in acute liver failure mice

Previous research has revealed that the gut microbiome has a marked impact on acute liver failure (ALF). Here, we evaluated the impact of betaine on the gut microbiota composition in an ALF animal model. The potential protective effect of betaine by regulating Toll-like receptor 4 (TLR4) responses was explored as well. Both mouse and cell experiments included normal, model, and betaine groups. The rat small intestinal cell line IEC-18 was used for in vitro experiments. Betaine ameliorated the small intestine tissue and IEC-18 cell damage in the model group by reducing the high expression of TLR4 and MyD88. Furthermore, the intestinal permeability in the model group was improved by enhancing the expression of the (ZO)-1 and occludin tight junction proteins. There were 509 operational taxonomic units (OTUs) that were identified in mouse fecal samples, including 156 core microbiome taxa. Betaine significantly improved the microbial communities, depleted the gut microbiota constituents Coriobacteriaceae, Lachnospiraceae, Enterorhabdus and Coriobacteriales and markedly enriched the taxa Bacteroidaceae, Bacteroides, Parabacteroides and Prevotella in the model group. Betaine effectively improved intestinal injury in ALF by inhibiting the TLR4/MyD88 signaling pathway, improving the intestinal mucosal barrier and maintaining the gut microbiota composition.

Leishmania amazonensis Promastigotes or Extracellular Vesicles Modulate B-1 Cell Activation and Differentiation

B-1 cells are considered an innate-like B cell population that participates in effective innate and adaptive responses to pathogens. B-1 cells produce immunoglobulins, cytokines, chemokines, migrate to inflammatory sites, and differentiate into mononuclear phagocyte-like cells. Murine B-1 cells phagocytosed Leishmaniain vitro and in vivo and participate in immunity against Leishmania. Our group showed that B-1 cells or their extracellular vesicles (EVs) led to a resistance to experimental infection by L. amazonensis. However, the B-1 cells’ responses to Leishmania or EVs isolated from parasites are still poorly characterized. Studying the activation and differentiation of B-1 cells in vivo can contribute to a better understanding of how these cells participate in immunity to L. amazonensis. Thus, we evaluated the expression of myeloid (M-csfr, G-csfr, Spi-1) and lymphoid (EBF, E2A, IL-7R) lineage commitment factors, Toll-like receptors (TLRs), activation cell surface markers, nitric oxide (NO) and reactive oxygen species (ROS) production in murine peritoneal B-1 cells collected after 24 or 48 h post-infection with Leishmania (Leishmania) amazonensis promastigotes or EVs released by the parasites. Our results demonstrated that L. amazonensis infection did not stimulate the expression of CD40, CD80, CD86, F4/80, and MHC II in B-1 cells, but a significant decrease in the production of NO and ROS was observed. The infection induced a significantly higher arginase expression in B-1 cells, but the stimulation with EVs led to a decrease in this gene expression. TLR-2 and TLR-6 had significantly higher expression in B-1 cells from mice intraperitoneally stimulated with the parasite. The TLR-9 expression was higher in animals infected or stimulated for 48 h with EVs. Interestingly, in B-1 cells the stimulus with L. amazonensis led to a substantial increase in the expression of myeloid restricted transcription factors. Thus, our study suggests that the parasites or EVs differently modulated the activation and differentiation of B-1 cells.

Candesartan could ameliorate the COVID-19 cytokine storm

BACKGROUND

Angiotensin receptor blockers (ARBs) reducing inflammation and protecting lung and brain function, could be of therapeutic efficacy in COVID-19 patients.

METHODS

Using GSEA, we compared our previous transcriptome analysis of neurons injured by glutamate and treated with the ARB Candesartan (GSE67036) with transcriptional signatures from SARS-CoV-2 infected primary human bronchial epithelial cells (NHBE) and lung postmortem (GSE147507), PBMC and BALF samples (CRA002390) from COVID-19 patients.

RESULTS

Hundreds of genes upregulated in SARS-CoV-2/COVID-19 transcriptomes were similarly upregulated by glutamate and normalized by Candesartan. Gene Ontology analysis revealed expression profiles with greatest significance and enrichment, including proinflammatory cytokine and chemokine activity, the NF-kappa B complex, alterations in innate and adaptive immunity, with many genes participating in the COVID-19 cytokine storm.

CONCLUSIONS

There are similar injury mechanisms in SARS-CoV-2 infection and neuronal injury, equally reduced by ARB treatment. This supports the hypothesis of a therapeutic role for ARBs, ameliorating the COVID-19 cytokine storm.

Pros and cons for use of statins in people with coronavirus disease-19 (COVID-19)

BACKGROUND AND AIMS

Morbidity and mortality from coronavirus disease 2019 (COVID-19) is higher among people with diabetes mellitus (DM), hypertension, and cardiovascular disease (CVD). Statins are used in the majority of people with DM and CVD. This mini-review discusses the current understanding of benefit-risk ratio of use of statins in COVID-19.

METHODS

We searched PubMed database using specific keywords related to our aims till June 12, 2020. Full text of relevant articles published in English language were retrieved and reviewed.

RESULTS

Statins, with their immunomodulatory, anti-inflammatory, anti-thrombotic, and anti-oxidant properties, have the potential to reduce severity of lung injury in, and mortality from, severe acute respiratory syndrome-coronavirus 2 (SARS-CoV2) infections. Statin-induced upregulation of angiotensin-converting enzyme-2 (ACE2) has the potential to reduce lung injury from excess angiotensin II. By disrupting lipid rafts, statins have the potential to reduce viral entry into cells. However, benefit-risk ratio of its complex interaction with MYD88 gene expression on outcomes in COVID-19, and the putative role of low serum LDL cholesterol in increasing severity of SARS-CoV2 infection need further clarification.

CONCLUSIONS

People with COVID-19, who are already on statins for an underlying co-morbid condition, should continue on it unless there are specific contraindications. De-novo use of statins in people with COVID-19 with no underlying co-morbidity might be beneficial but awaits substantiation in clinical trials; till that time, de novo use of statins in COVID 19 should be limited to a clinical trial setting.

Bidirectional Relation Between Parkinson's Disease and Glioblastoma Multiforme

Cancer and Parkinson's disease (PD) define two disease entities that include opposite concepts. Indeed, the involved mechanisms are at different ends of a spectrum related to cell survival - one due to enhanced cellular proliferation and the other due to premature cell death. There is increasing evidence indicating that patients with neurodegenerative diseases like PD have a reduced incidence for most cancers. In support, epidemiological studies demonstrate an inverse association between PD and cancer. Both conditions apparently can involve the same set of genes, however, in affected tissues the expression was inversely regulated: genes that are down-regulated in PD were found to be up-regulated in cancer and vice versa, for example p53 or PARK7. When comparing glioblastoma multiforme (GBM), a malignant brain tumor with poor overall survival, with PD, astrocytes are dysregulated in both diseases in opposite ways. In addition, common genes, that are involved in both diseases and share common key pathways of cell proliferation and metabolism, were shown to be oppositely deregulated in PD and GBM. Here, we provide an overview of the involvement of PD- and GBM-associated genes in common pathways that are dysregulated in both conditions. Moreover, we illustrate why the simultaneous study of PD and GBM regarding the role of common pathways may lead to a deeper understanding of these still incurable conditions. Eventually, considering the inverse regulation of certain genes in PD and GBM will help to understand their mechanistic basis, and thus to define novel target-based strategies for causative treatments.

Sterile inflammation in thoracic transplantation

The life-saving benefits of organ transplantation can be thwarted by allograft dysfunction due to both infectious and sterile inflammation post-surgery. Sterile inflammation can occur after necrotic cell death due to the release of endogenous ligands [such as damage-associated molecular patterns (DAMPs) and alarmins], which perpetuate inflammation and ongoing cellular injury via various signaling cascades. Ischemia-reperfusion injury (IRI) is a significant contributor to sterile inflammation after organ transplantation and is associated with detrimental short- and long-term outcomes. While the vicious cycle of sterile inflammation and cellular injury is remarkably consistent amongst different organs and even species, we have begun understanding its mechanistic basis only over the last few decades. This understanding has resulted in the developments of novel, yet non-specific therapies for mitigating IRI-induced graft damage, albeit with moderate results. Thus, further understanding of the mechanisms underlying sterile inflammation after transplantation is critical for identifying personalized therapies to prevent or interrupt this vicious cycle and mitigating allograft dysfunction. In this review, we identify common and distinct pathways of post-transplant sterile inflammation across both heart and lung transplantation that can potentially be targeted.

Correlation between TLR4 gene polymorphism and severe enterovirus 71 infection

OBJECTIVE

Enterovirus 71 (EV71) infection resulted in high mortality and disability in children. Immune response deficiency and cytokine genetic predispositions were associated with the severity of EV71 infection. We aim to evaluate the association between TLR4 gene polymorphisms and severity of EV71 infection in Chinese children.

METHODS

TLR4 gene polymorphisms were detected through improved multiplex ligation detection reaction technology. TLR4 expression was measured by Real-Time reverse transcriptase PCR and flow cytometry. The plasma levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were analyzed by enzyme-linked immunosorbent assay.

RESULTS

The frequency of rs10759932CC genotype and the C allele was significantly higher in cases with severe EV71 infection than those with mild infection. The levels of TLR4, serum TNF-α and IL-6 in cases with rs10759932CC genotype were also significantly elevated when compared to those with TT genotypes.

CONCLUSIONS

The rs10759932 polymorphism in TLR4 was associated with the severity of EV71 infection. The C allele of rs10759932 may be one of the risk factors of severe EV71 infection in Chinese children.

HDAC inhibitor protects chronic cerebral hypoperfusion and oxygen-glucose deprivation injuries via H3K14 and H4K5 acetylation-mediated BDNF expression

Vascular dementia (VaD) is the second most common cause of dementia, but the treatment is still lacking. Although many studies have reported that histone deacetylase inhibitors (HDACis) confer protective effects against ischemic and hypoxic injuries, their role in VaD is still uncertain. Previous studies shown, one HDACi protected against cognitive decline in animals with chronic cerebral hypoperfusion (CCH). However, the underlying mechanisms remain elusive. In this study, we tested several 10,11‐dihydro‐5H‐dibenzo[b,f]azepine hydroxamates, which act as HDACis in the CCH model (in vivo), and SH‐SY5Y (neuroblastoma cells) with oxygen‐glucose deprivation (OGD, in vitro). We identified a compound 13, which exhibited the best cell viability under OGD. The compound 13 could increase, in part, the protein levels of brain‐derived neurotrophic factor (BDNF). It increased acetylation status on lysine 14 residue of histone 3 (H3K14) and lysine 5 of histone 4 (H4K5). We further clarified which promoters (I, II, III, IV or IX) could be affected by histone acetylation altered by compound 13. The results of chromatin immunoprecipitation and Q‐PCR analysis indicate that an increase in H3K14 acetylation leads to an increase in the expression of BDNF promoter II, while an increase in H4K5 acetylation results in an increase in the activity of BDNF promoter II and III. Afterwards, these cause an increase in the expression of BDNF exon II, III and coding exon IX. In summary, the HDACi compound 13 may increase BDNF specific isoforms expression to rescue the ischemic and hypoxic injuries through changes of acetylation on histones.

Hepatic expression of lipopolysaccharide-binding protein (Lbp) is induced by the gut microbiota through Myd88 and impairs glucose tolerance in mice independent of obesity

Objective

Gut-derived inflammatory factors can impair glucose homeostasis, but the underlying mechanisms are not fully understood. In this study, we investigated how hepatic gene expression is regulated by gut colonization status through myeloid differentiation primary response 88 (MYD88) and how one of the regulated genes, lipopolysaccharide-binding protein (Lbp), affects insulin signaling and systemic glucose homeostasis.

Methods

Liver transcriptomics analysis was conducted on four groups of mice fed a chow diet: conventionally raised (CONV-R) wild-type, germ-free (GF) wild-type, CONV-R Myd88 KO, and GF Myd88 KO. Primary hepatocytes were exposed to combinations of lipopolysaccharide (LPS), LBP, and the LBP-blocking peptide LBPK95A, and the effect on insulin signaling was determined. To assess how LBP affects glucose metabolism in vivo, two mouse models were applied: treatment with LBPK95A and hepatic knockdown of Lbp using CRISPR-CAS9.

Results

We showed that the colonization status regulates gene expression in the liver and that a subset of these genes, including Lbp, is regulated through MYD88. Furthermore, we demonstrated that LBP impairs insulin signaling in hepatocytes in the presence of low levels of LPS and that the effect of LBP is abolished by LBPK95A. We showed that both systemic pharmacological blocking of LBP by LBPK95A and CRISPR-CAS9-mediated downregulation of hepatic Lbp improve glucose homeostasis.

Conclusions

Our results demonstrate that the gut microbiota regulates hepatic expression of Lbp through MYD88-dependent signaling. LBP potentiates LPS inhibition of insulin signaling in vitro and impairs systemic glucose homeostasis in vivo.

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Gut microbiota induces hepatic expression of Lbp through MYD88.

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LBP impairs insulin signalling in hepatocytes in the presence of low levels of LPS.

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Pharmacological blocking of LBP improves systemic glucose homeostasis.

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Knockdown of hepatic Lbp improves systemic glucose homeostasis.

The role of Toll-like receptor signaling pathways in cerebrovascular disorders: the impact of spreading depolarization

Cerebral vascular diseases (CVDs) are a group of disorders that affect the blood supply to the brain and lead to the reduction of oxygen and glucose supply to the neurons and the supporting cells. Spreading depolarization (SD), a propagating wave of neuroglial depolarization, occurs in different CVDs. A growing amount of evidence suggests that the inflammatory responses following hypoxic-ischemic insults and after SD plays a double-edged role in brain tissue injury and clinical outcome; a beneficial effect in the acute phase and a destructive role in the late phase. Toll-like receptors (TLRs) play a crucial role in the activation of inflammatory cascades and subsequent neuroprotective or harmful effects after CVDs and SD. Here, we review current data regarding the pathophysiological role of TLR signaling pathways in different CVDs and discuss the role of SD in the potentiation of the inflammatory cascade in CVDs through the modulation of TLRs.