Bauhinia championii alleviates extracellular matrix degradation in IL-1β induced chondrocytes via miRNA-145-5p/TLR4/NF-κB axis

Bauhinia championii is a herbal medicine used to treat osteoarthritis (OA) in Chinese traditional medicine. However, the molecular mechanisms underlying the therapeutic effects of this medicinal herb against OA have rarely been reported. Given that it has been established that extracellular matrix metabolism plays an important role in the pathogenesis of OA, the present study focused on the effects and mechanisms of Bauhinia championii in the regulation of extracellular matrix metabolism in chondrocytes induced by IL-1β. Rat chondrocytes were isolated, cultured and identified in vitro. The CCK-8 method was used to detect the cell viability of Bauhinia championii aqueous extract (BCAE)-treated chondrocytes. The chondrocyte inflammatory and degeneration models were induced by 10 ng/mL IL-1β, then chondrocytes were grouped into different groups to evaluate the effect of BCAE on extracellular matrix degradation and the regulation of TLR4/NF-κB signaling pathway. Furthermore, whether the regulatory effect of BCAE on TLR4/NF-κB signaling pathway is related to miRNA-145-5p was also investigated by cell transfection. We found that BCAE promoted chondrocyte viability in a dose- and time-dependent manner. BCAE delayed chondrocyte degeneration induced by IL-1β. BCAE could reduce the degradation of the cartilage extracellular matrix by inhibiting the TLR4/NF-κB signaling pathway. miRNA-145-5p negatively regulated the expression of TLR4 in chondrocytes, while BCAE could upregulate the expression of miRNA-145-5p in chondrocytes induced by IL-1β. These results suggest that BCAE upregulates the expression of miRNA-145-5p to inhibit the TLR4/NF-κB signaling pathway, thereby alleviating the metabolic imbalance of the extracellular matrix and protecting chondrocytes from degeneration.

Small Molecule Potentiator of Adjuvant Activity Enhancing Survival to Influenza Viral Challenge

As viruses continue to mutate the need for rapid high titer neutralizing antibody responses has been highlighted. To meet these emerging threats, agents that enhance vaccine adjuvant activity are needed that are safe with minimal local or systemic side effects. To respond to this demand, we sought small molecules that would sustain and improve the protective effect of a currently approved adjuvant, monophosphoryl lipid A (MPLA), a Toll-like receptor 4 (TLR4) agonist. A lead molecule from a high-throughput screen, (N-(4-(2,5-dimethylphenyl)thiazol-2-yl)-4-(piperidin-1-ylsulfonyl)benzamide, was identified as a hit compound that sustained NF-κB activation by a TLR4 ligand, lipopolysaccharide (LPS), after an extended incubation (16 h). In vitro, the resynthesized compound (2D216) enhanced TLR4 ligand-induced innate immune activation and antigen presenting function in primary murine bone marrow-derived dendritic cells without direct activation of T cells. In vivo murine vaccination studies demonstrated that compound 2D216 acted as a potent co-adjuvant when used in combination with MPLA that enhanced antigen-specific IgG equivalent to that of AS01B. The combination adjuvant MPLA/2D216 produced Th1 dominant immune responses and importantly protected mice from lethal influenza virus challenge. 2D216 alone or 2D216/MPLA demonstrated minimal local reactogenicity and no systemic inflammatory response. In summary, 2D216 augmented the beneficial protective immune responses of MPLA as a co-adjuvant and showed an excellent safety profile.

Toll-like receptor 2/4 inhibitors can reduce preterm birth in mice

Objectives

Preterm birth (PTB) occurs in 5% to 18% of newborns. However, the underlying inflammatory mechanisms have not been elucidated.

Methods

We established a mouse model of infection-associated PTB. Physical signs in pregnant mice with or without lipopolysaccharide (LPS) treatment were observed, and the frequencies of Toll-like receptor (TLR)2- and TLR4-positive CD11b+ cells were analyzed. Cytokine levels in plasma and pathological changes were assessed following LPS treatment. A rescue experiment was used to probe potential immunologic mechanisms underlying PTB.

Results

Lymphocyte infiltration could be observed in the placentas of mice following intrauterine injection with LPS. The percentage of inflammatory cells decreased 12 hours after treatment. Moreover, TLR2 and TLR4 expression in peripheral blood cells was significantly increased 4 hours after intraperitoneal injection of LPS. Peak TLR2 and TLR4 expression in peripheral blood cells occurred 8 hours post-treatment. TLR4 and TLR-2/4 inhibitors reduced levels of interleukin-10, interferon-γ, and tumor necrosis factor-α in peripheral blood and delayed PTB.

Conclusions

TLR2 and TLR4 inhibition could play important roles in PTB.

Neurological Symptoms of COVID-19: The Zonulin Hypothesis

The irruption of SARS-CoV-2 during 2020 has been of pandemic proportions due to its rapid spread and virulence. COVID-19 patients experience respiratory, digestive and neurological symptoms. Distinctive symptom as anosmia, suggests a potential neurotropism of this virus. Amongst the several pathways of entry to the nervous system, we propose an alternative pathway from the infection of the gut, involving Toll-like receptor 4 (TLR4), zonulin, protease-activated receptor 2 (PAR2) and zonulin brain receptor. Possible use of zonulin antagonists could be investigated to attenuate neurological manifestations caused by SARS-CoV-19 infection.

Development of sensor cells using NF-κB pathway activation for detection of nanoparticle-induced inflammation

The increasing use of nanomaterials in consumer and industrial products has aroused concerns regarding their fate in biological systems. An effective detection method to evaluate the safety of bio-nanomaterials is therefore very important. Titanium dioxide (TiO(2)), which is manufactured worldwide in large quantities for use in a wide range of applications, including pigment and cosmetic manufacturing, was once thought to be an inert material, but recently, more and more studies have indicated that TiO(2) nanoparticles (TiO(2) NPs) can cause inflammation and be harmful to humans by causing lung and brain problems. In order to evaluate the safety of TiO(2) NPs for the environment and for humans, sensor cells for inflammation detection were developed, and these were transfected with the Toll-like receptor 4 (TLR4) gene and Nuclear Factor Kappa B (NF-κB) reporter gene. NF-κB as a primary cause of inflammation has received a lot of attention, and it can be activated by a wide variety of external stimuli. Our data show that TiO(2) NPs-induced inflammation can be detected by our sensor cells through NF-κB pathway activation. This may lead to our sensor cells being used for bio-nanomaterial safety evaluation.