Inflammation suppression by dexamethasone via inhibition of CD147-mediated NF-κB pathway in collagen-induced arthritis rats

Omics-based pharmacological evaluation reveals Yuanhu Zhitong oral liquid ameliorates arthritis by regulating PKC/ERK/NF-κB signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Successful use of herbal medicine in the treatment of rheumatoid arthritis (RA) creates opportunities for alternative therapies. Yuanhu Zhitong oral liquid (YZOL) is an herbal preparation known for its potent analgesic and anti-inflammatory properties in traditional use. However, the pharmacological mechanism of YZOL for treating RA remains unclear.

AIM OF THE STUDY

The aim of this study was to evaluate the efficacy of YZOL in the treatment of RA and to explore its potential mechanisms through omics analysis.

MATERIALS AND METHODS

Type II collagen was used to induce an arthritis rat model. The effects of YZOL on paw swelling, inflammatory cytokines, oxidative stress, and histopathological changes were systematically investigated. A pathway-driven transcriptomic analysis was performed to identify key signaling pathways associated with YZOL therapy. The key alterations were validated by qRT-PCR, Western blot, and immunohistochemistry assays.

RESULTS

YZOL significantly attenuated arthritis progression, reduced paw swelling rate, and lowered arthritis score in CIA rats. YZOL also inhibited systemic inflammation and associated oxidative stress during RA. Transcriptomic analysis identified 341 genes with significantly altered expression following YZOL treatment. These genes were enriched in inflammation-related pathways, particularly in the NF-κB and MAPK signaling pathways. In addition, we discovered that YZOL can alleviate inflammation in the local synovial tissue. The effect of YZOL was confirmed by the suppression of PKC/ERK/NF-κB p65 signaling at systemic and local levels.

CONCLUSIONS

This study provides novel evidence that YZOL treatment ameliorates RA by suppressing the PKC/ERK/NF-κB pathway, suggesting its potential as an alternative therapy for RA.

MiR-204/-211 double knockout exacerbates rheumatoid arthritis progression by promoting splenic inflammation

OBJECTIVE

Collagen-induced arthritis (CIA) model was induced in C57BL/6 wild-type (wt) and C57BL/6 miR-204/-211 double-knockout (dKO) mice to investigate the role of miR-204/-211 in suppressing splenic inflammation in rheumatoid arthritis (RA).

METHODS

Differences of miR-204/-211 and structure-specific recognition protein 1 (SSRP1) in the spleen of DBA/1J wt and CIA mice were detected via PCR and immunohistochemistry. CIA was induced in both C57BL/6 wt and C57BL/6 miR-204/-211 dKO mice, and the onset of CIA and disease severity were statistically analyzed. Immunohistochemistry staining of interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and SSRP1 in spleen or knee joints was performed and analyzed. In CIA miR-204/-211 dKO mice, AAV-shSSRP1 was intra-articularly injected, with both the AAV-shRNA Ctrl and AAV-shRNA Ctrl CIA groups receiving the same dose of AAV-shRNA. Spleen sections were stained with hematoxylin and eosin (H&E).

RESULTS

Compared to wt mouse spleens, aberrant expression of miR-204/-211 and SSRP1 was observed in the spleens of CIA mice. Immunized dKO mice exhibited a higher incidence of CIA onset and a more exacerbated RA disease phenotype, characterized by increased spleen inflammation score and elevated levels of IL-1β, TNF-α, and SSRP1 expression. AAV-shSSRP1 injection in CIA dKO mice significantly reduced spleen inflammation scores, IL-1β and TNF-α expression levels, and down-regulated Ki-67 expression compared to CIA dKO mice.

CONCLUSION

Knockout of miR-204/-211 exacerbated the onset of CIA in C57BL/6 mice, while miR-204/-211 played a protective role against the progression of splenic inflammatory and proliferative progression in RA by targeting SSRP1.

In vivo evaluation of efficacy and safety of Coagulansin-A in treating arthritis

The current study aimed to determine the safety and efficacy of Coag-A through in vivo analysis in CFA induced mice model. Treatment of CFA induced arthritis in mice with Coagulansin-A (10 mg/kg i.p. daily for 28 days), a withanolide obtained from Withania coagulans, as well as standard drug treatment with Dexamethasone (5 mg/kg i.p) was provided. The effect of Coag-A on body weight, relative organ weight, hematology, serum biochemistry, survival rate, oxidative stress markers, and antioxidant enzymes was evaluated. The liver and kidney histopathology were also assessed to ascertain its safety profile. Treatment of arthritic mice with Coag-A considerably improved body weight, relative organ weight of liver, kidney, and spleen, ameliorated hematology and serum biochemistry, and increased survival and antioxidant potential. Coag-A was found to be safer with fewer adverse effects showing hepato-protective, nephroprotective, and anti-inflammatory effect. It also significantly (p < 0.001) improved histopathology of CFA-induced mice when compared with Dexa. In conclusion, compared to dexamethasone, Coag-A has demonstrated a greater therapeutic benefit and fewer side effects in the treatment of arthritis against the CFA-induced model.

Anti-rheumatoid arthritis effects of traditional Chinese medicine Fufang Xiaohuoluo pill on collagen-induced arthritis rats and MH7A cells

Background

Fufang Xiaohuoluo pill (FFXHL) is a commonly used prescription in clinical practice for treating rheumatoid arthritis in China, yet its specific mechanism remains unclear. This study aims to elucidate the pharmacological mechanisms of FFXHL using both in vivo and in vitro experiments.

Methods

The collagen-induced arthritis (CIA) rat model was established to evaluate FFXHL's therapeutic impact. Parameters that include paw swelling, arthritis scores, and inflammatory markers were examined to assess the anti-inflammatory and analgesic effects of FFXHL. Human fibroblast-like synoviocytes (MH7A cells) is activated by tumour necrosis factor-alpha (TNF-α) were used to explore the anti-inflammatory mechanism on FFXHL.

Results

Our findings indicate that FFXHL effectively reduced paw swelling, joint pain, arthritis scores, and synovial pannus hyperplasia. It also lowered serum levels of TNF-α, interleukin-1β (IL1β), and interleukin-6 (IL-6). Immunohistochemical analysis revealed decreased expression of nuclear factor-kappa B (NF-κB) p65 in FFXHL-treated CIA rat joints. In vitro experiments demonstrated FFXHL's ability to decrease protein secretion of IL-1β and IL-6, suppress mRNA expression of matrix metalloproteinases (MMP) -3, -9, and -13, reduce reactive oxygen species (ROS) levels, and inhibit NF-κB p65 translocation in TNF-α stimulated MH7A cells. FFXHL also suppressed protein levels of extracellular signal-regulated kinase (ERK), c-Jun Nterminal kinase (JNK), p38 MAP kinase (p38), protein kinase B (Akt), p65, inhibitor of kappa B kinase α/β (IKKα/β), Toll-like receptor 4 (TLR4), and myeloid differentiation primary response 88 (MyD88) induced by TNF-α in MH7A cells.

Conclusion

The findings imply that FFXHL exhibits significant anti-inflammatory and antiarthritic effects in both CIA rat models and TNF-α-induced MH7A cells. The potential mechanism involves the inactivation of TLR4/MyD88, mitogen-activated protein kinases (MAPKs), NF-κB, and Akt pathways by FFXHL.

Glucocorticoid receptors involved in ginsenoside compound K ameliorate adjuvant arthritis by inhibiting the glycolysis of fibroblast-like synoviocytes via the NF-κB/HIF-1α pathway

CONTEXT

Ginsenoside metabolite compound K (CK) is an active metabolite produced by ginsenosides in vivo that has an anti-arthritic effect related to the glucocorticoid receptor (GR). However, the potential mechanisms of CK remain unclear.

OBJECTIVE

This study explores the role and potential mechanisms of CK in vivo and in vitro.

MATERIALS AND METHODS

Adjuvant arthritis (AA) model was induced in Sprague-Dawley (SD) rats; the rats were randomly divided into four groups (n = 10): normal, AA, CK (80 mg/kg), and dexamethasone (Dex) group (1 mg/kg). From day 15, rats were treated with CK (once a day, i.g.) and Dex (once every 3 days, i.p.) for 18 days. To further verify the mechanism of CK, fibroblast-like synoviocytes (FLS) were stimulated by tumour necrosis factor α (TNF-α) to establish an inflammatory model in vitro.

RESULTS

CK (80 mg/kg) reduced paw swelling (52%) and arthritis global assessment (31%) compared to that in AA rats. In addition, CK (80 mg/kg) suppressed GLUT1 (38%), HK2 (50%), and PKM2 (56%) levels compared with those in AA FLS. However, the effects of CK (30 μM) on these events were weakened or enhanced after GR knockdown or overexpression in FLS stimulated by TNF-α (30 ng/mL). CK (80 mg/kg) also downregulated the expression of P65 (61%), p-IκB (92%), and HIF-1α (59%).

DISCUSSION AND CONCLUSIONS

The inhibition of CK on glycolysis and the NF-κB/HIF-1α pathway is potentially mediated through activating GR. These findings provide experimental evidence for elucidating the molecular mechanism of CK in treating rheumatoid arthritis (RA).

Efficacy and safety of Tripterygium wilfordii multiglucoside for idiopathic membranous nephropathy: a systematic review with bayesian meta-analysis

Background: Currently, the optimal therapy plan for idiopathic membranous nephropathy (IMN) remains controversial as there has been no comprehensive and systematic comparison of therapy plans for IMN. Therefore, in this study, a Bayesian meta-analysis was used to systematically evaluate the clinical efficacy and safety of various intervention plans involving traditional Chinese medicine TWM in the treatment of IMN. Methods: An electronic search in 7 databases was conducted from their inception to August 2022 for all published randomized controlled trials (RCTs) of various intervention plans for IMN. Network meta-analysis (NMA) was performed by using software R, and the surface under the cumulative ranking area (SUCRA) probability curve was plotted for each outcome indicator to rank the efficacy and safety of different intervention plans. Results: A total of 30 RCTs were included, involving 13 interventions. The results showed that (1) in terms of total remission (TR), ① GC + CNI + TWM was the best effective among all plans, and the addition and subtraction plan of CNI + TWM was the best effective for IMN; ② All plans involving TWM were more effective than GG; ③ Among monotherapy plans for IMN, TWM was more effective distinctly than GC, while TWM and CNI were similarly effective; ④ Among multidrug therapy plans for IMN, the addition of TWM to previously established therapy plans made the original plans more effective; ⑤The efficacy of combining TWM with other plans was superior to that of TWM alone. (2) In terms of lowering 24 h-UTP, GC + TWM was the best effective and more effective than TWM. (3) In terms of safety, there was no statistically significant difference between all groups. However, CNI + TWM was the safest. No serious adverse events (AEs) occurred in all the included studies. Conclusion: The addition of TWM may be beneficial to patients with IMN. It may enhance the efficacy of previously established treatment protocols without leading to additional safety risks. In particular, GC + CNI + TWM, GC + TWM, and CNI + TWM with better efficacy and higher safety can be preferred in clinical decision-making as the therapy plans for IMN.

Lipopolysaccharide induces inflammatory microglial activation through CD147-mediated matrix metalloproteinase expression

Microglia-mediated neuroinflammation plays a vital role in the pathophysiological processes of multiple neurodegenerative diseases. Lipopolysaccharide (LPS) is an environmental poison that can induce inflammatory microglial activation. Matrix metalloproteinases (MMPs) are vital factors regulating microglial activation, and CD147 is a key MMP inducer, which can induce inflammation by inducing MMPs. However, whether it is involved in the regulation of microglial activation has not been reported. In this study, the role of CD147 in LPS-induced microglial inflammatory activation was investigated by establishing in vivo and in vitro models. The results suggested that LPS-induced microglial activation was accompanied by the induction of CD147 expression while the inhibition of CD147 expression could inhibit LPS-induced microglial inflammatory activation. In addition, the results also indicated that the role of CD147 in LPS-induced pro-inflammatory activation of microglia was related to its downstream MMP-3, MMP-8, and autophagy. Furthermore, the inhibition of MMP-3, MMP-8, and autophagy attenuated LPS-induced inflammatory activation of microglia. At the same time, there was a certain interaction between MMPs and autophagy, which is shown that inhibiting the expression of MMPs could inhibit autophagy, whereas inhibiting autophagy could inhibit the expression of MMPs. Taken together, we provided the first evidence that CD147/MMPs can be involved in LPS-induced inflammatory activation of microglia through an autophagy-dependent manner.

CD147 and MMPs as key factors in physiological and pathological processes

Cluster of differentiation 147 (CD147) or extracellular matrix metalloproteinase inducer (EMMPRIN) is a transmembrane glycoprotein that induces the synthesis of matrix metalloproteinases (MMPs). MMPs, as zinc-dependent proteases and versatile enzymes, play critical roles in the degradation of the extracellular matrix (ECM) components, cleaving of the receptors of cellular surfaces, signaling molecules, and other precursor proteins, which may lead to attenuation or activation of such targets. CD147 and MMPs play essential roles in physiological and pathological conditions and any disorder in the expression, synthesis, or function of CD147 and MMPs may be associated with various types of disease. In this review, we have focused on the roles of CD147 and MMPs in some major physiological and pathological processes.

Characterizations of alveolar repair after mandibular second molar extraction: an experimental study in rats

BACKGROUND

Characterizations of rat mandibular second molar extraction socket with significantly different buccal and lingual alveolar ridge width remain unclear.

OBJECTIVE

To observe alterations in the alveolar ridge after extraction of mandibular second molars, and to examine processes of alveolar socket healing in an experimental model of alveolar ridge absorption and preservation.

METHODOLOGY

Eighteen Wistar rats were included and divided into six groups regarding healing time in the study. Bilateral mandibular second molars were extracted. The rats with tooth extraction sockets took 0, 1.5, 2, 3, 4 and 8 weeks of healing. Histological observation, tartrate-resistant acidic phosphatase (TRAP) staining, Masson's trichrome staining, immunohistochemical staining and micro-computed tomography (micro-CT) were applied to estimate alterations in the alveolar ridge.

RESULTS

Different buccal and lingual alveolar ridge width led to different height loss. Lingual wall height (LH) decreased significantly two weeks after tooth extraction. Buccal wall height rarely reduced its higher ridge width. From two to eight weeks after extraction, bone volume (BV/TV), density (BMD), and trabecular thickness (Tb.Th) progressively increased in the alveolar socket, which gradually decreased in Tb.Sp and Tb.N. LH showed no significant change during the same period. Osteogenic marker OCN and OPN increased during bone repair from two to eight weeks. The reduced height of the lingual wall of the tooth extraction socket was rarely repaired in the later repair stage. Osteoclast activity led to absorption of the alveolar ridge of the alveolar bone wall within two weeks after operation. We observed positive expression of EMMPRIN and MMP-9 in osteoclasts that participated in the absorption of the spire region.

CONCLUSION

Extraction of rat mandibular second molars may help the study of alveolar ridge absorption and preservation. The EMMPRIN-MMP-9 pathway may be a candidate for further study on attenuating bone resorption after tooth extraction.

Potential roles of gut microbiota and microbial metabolites in chronic inflammatory pain and the mechanisms of therapy drugs

Observational findings achieved that gut microbes mediate human metabolic health and disease risk. The types of intestinal microorganisms depend on the intake of food and drugs and are also related to their metabolic level and genetic factors. Recent studies have shown that chronic inflammatory pain is closely related to intestinal microbial homeostasis. Compared with the normal intestinal flora, the composition of intestinal flora in patients with chronic inflammatory pain had significant changes in Actinomycetes, Firmicutes, Bacteroidetes, etc. At the same time, short-chain fatty acids and amino acids, the metabolites of intestinal microorganisms, can regulate neural signal molecules and signaling pathways, thus affecting the development trend of chronic inflammatory pain. Glucocorticoids and non-steroidal anti-inflammatory drugs in the treatment of chronic inflammatory pain, the main mechanism is to affect the secretion of inflammatory factors and the abundance of intestinal bacteria. This article reviews the relationship between intestinal microorganisms and their metabolites on chronic inflammatory pain and the possible mechanism.

Mir204 and Mir211 suppress synovial inflammation and proliferation in rheumatoid arthritis by targeting Ssrp1

Rheumatoid arthritis (RA) is a chronic inflammatory joint disease characterized by synovial hyperplasia. Mir204 and Mir211 are homologous miRNAs with the same gene targeting spectrum. It is known that Mir204/211 play an important role in protecting osteoarthritis development; however, the roles of Mir204/211 in RA disease have not been determined. In the present study, we investigated the effects and molecular mechanisms of Mir204/211 on synovial inflammation and hyperproliferation in RA. The effects of Mir204/211 on the inflammation and abnormal proliferation in primary fibroblast-like synoviocytes (FLSs) were examined by Mir204/211 gain-of-function and loss-of-function approaches in vitro and in vivo. We identified the structure-specific recognition protein 1 (Ssrp1) as a downstream target gene of Mir204/211 based on the bioinformatics analysis. We overexpressed Ssrp1and Mir204/211 in FLS to determine the relationship between Ssrp1 and Mir204/211 and their effects on synovial hyperplasia. We created a collagen-induced arthritis (CIA) model in wild-type as well as Mir204/211 double knockout (dKO) mice to induce RA phenotype and administered adeno-associated virus (AAV)-mediated Ssrp1-shRNA (AAV-shSsrp1) by intra-articular injection into Mir204/211 dKO mice. We found that Mir204/211 attenuated excessive cell proliferation and synovial inflammation in RA. Ssrp1 was the downstream target gene of Mir204/211. Mir204/211 affected synovial proliferation and decelerated RA progression by targeting Ssrp1. CIA mice with Mir204/211 deficiency displayed enhanced synovial hyperplasia and inflammation. RA phenotypes observed in Mir204/211 deficient mice were significantly ameliorated by intra-articular delivery of AAV-shSsrp1, confirming the involvement of Mir204/211-Ssrp1signaling during RA development. In this study, we demonstrated that Mir204/211 antagonize synovial hyperplasia and inflammation in RA by regulation of Ssrp1. Mir204/211 may serve as novel agents to treat RA disease.

Effects of β-Blockers on the Sympathetic and Cytokines Storms in Covid-19

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a causative virus in the development of coronavirus disease 2019 (Covid-19) pandemic. Respiratory manifestations of SARS-CoV-2 infection such as acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) leads to hypoxia, oxidative stress, and sympatho-activation and in severe cases leads to sympathetic storm (SS). On the other hand, an exaggerated immune response to the SARS-CoV-2 invasion may lead to uncontrolled release of pro-inflammatory cytokine development of cytokine storm (CS). In Covid-19, there are interactive interactions between CS and SS in the development of multi-organ failure (MOF). Interestingly, cutting the bridge between CS and SS by anti-inflammatory and anti-adrenergic agents may mitigate complications that are induced by SARS-CoV-2 infection in severely affected Covid-19 patients. The potential mechanisms of SS in Covid-19 are through different pathways such as hypoxia, which activate the central sympathetic center through carotid bodies chemosensory input and induced pro-inflammatory cytokines, which cross the blood-brain barrier and activation of the sympathetic center. β2-receptors signaling pathway play a crucial role in the production of pro-inflammatory cytokines, macrophage activation, and B-cells for the production of antibodies with inflammation exacerbation. β-blockers have anti-inflammatory effects through reduction release of pro-inflammatory cytokines with inhibition of NF-κB. In conclusion, β-blockers interrupt this interaction through inhibition of several mediators of CS and SS with prevention development of neural-cytokine loop in SARS-CoV-2 infection. Evidence from this study triggers an idea for future prospective studies to confirm the potential role of β-blockers in the management of Covid-19.

Sinapic Acid Attenuates Rheumatoid Arthritis Through Reducing Inflammation and Oxidative Stress by Downregulating IκB Kinase

Sinapic acid (SA) was reported to protect against inflammation in various types of diseases. However, the role of SA in rheumatoid arthritis remains unclear. This study was designed to investigate the role of SA on rheumatoid arthritis. Rheumatoid arthritis mouse model was established by collagen immunization [collagen-induced arthritis (CIA)]. Histological analysis of articular cartilage tissue was carried out by hematoxylin and eosin (H&E) staining. Serum concentrations of tumor necrosis factor alpha and interleukin 6 were determined through enzyme-linked immunosorbent assay (ELISA). Oxidative damage indexes such as superoxide dismutase activity, malondialdehyde detection, glutathione detection, and catalase were determined by biochemical analysis. The protein levels of related genes were determined using Western blot. In CIA model, SA treatment attenuated paw swelling and clinical score of arthritis, attenuated articular cartilage tissues edema and infiltration of inflammatory cells, suppressed inflammatory cytokines release, and attenuated oxidative damage indexes. Mechanically, SA suppressed immune responses through inhibiting the IκB kinase (IKKs). SA attenuates rheumatoid arthritis through reducing inflammation and oxidative stress by downregulating IKKs.

Dexamethasone-loaded thermo-sensitive hydrogel attenuates osteoarthritis by protecting cartilage and providing effective pain relief

Background

We utilized the destabilization of medial meniscus (DMM)-induced mice to illustrate the osteoarthritis (OA) suppressing and pain-relieving effects of a novel prolonged-release intra-articular (IA)-dexamethasone-loaded thermo-sensitive hydrogel (DLTH).

Methods

The effects of temperature and pH on DLTH formation and in vitro DLTH release profile were assessed. C57BL/6J mice were randomly divided into three groups: Ctrl group, Model group and DLTH group. The DLTH group received joint injections of 10 µL DLTH (1 mg/kg) into the right knee once a week from week 2 to week 11. We performed micro-computed tomography (Micro-CT) and histological analyses of safranin O-fast green, hematoxylin and eosin, and tartrate-resistant acid phosphatase in knee joints. We also carried out immunohistochemical (IHC) staining for matrix metalloproteinase-9 (MMP-9), MMP-13, and a disintegrin and metalloproteinase with thrombospondin motifs-5 (ADAMTS-5) in cartilage and Ki-67 in synovia. Pain behavioral testing was carried out in all mice. The serum content of prostaglandin E2 (PGE2) and real-time polymerase chain reaction (PCR) of inflammatory cytokines and pain-related factors in dorsal root ganglia (DRGs) were evaluated.

Results

It took 20 minutes to form DLTH at pH 7.0 and 37 °C. The cumulative release profiles of dexamethasone (Dex) from DLTH at 37 °C revealed a rapid release in the first 24 h and a sustained slow release for 7 days. In vivo study illustrated that DLTH attenuated OA bone destruction and ameliorated synovitis and progression of OA in DMM-induced mice. The chondroprotective effects of DLTH were mediated by decreased expressions of MMP-9, MMP-13, and ADAMTS-5. The results showed that IA-DLTH exerted pain-relieving effects in OA mice. Upregulation of nociceptive response time (NRT) and downregulations of serum PGE2, inflammatory factors, and pain-related mediators in DRGs of mice in the DLTH group were recorded.

Conclusions

Data presented in this study elucidated that DLTH exhibited a long and lasting Dex release and it is a potential sustainable drug delivery system (DDS) to treat OA locally. IA-DLTH injection exerted chondroprotective and pain-relieving effects in DMM-induced arthritis. The involvement of MMP-9, MMP-13, ADAMTS-5, and inflammatory and pain-related factors, may account for the suppression of OA progression and pain.

Human Basigin (CD147) Does Not Directly Interact with SARS-CoV-2 Spike Glycoprotein

Basigin, or CD147, has been reported as a coreceptor used by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to invade host cells. Basigin also has a well-established role in Plasmodium falciparum malaria infection of human erythrocytes, where it is bound by one of the parasite's invasion ligands, reticulocyte binding protein homolog 5 (RH5). Here, we sought to validate the claim that the receptor binding domain (RBD) of SARS-CoV-2 spike glycoprotein can form a complex with basigin, using RH5-basigin as a positive control. Using recombinantly expressed proteins, size exclusion chromatography and surface plasmon resonance, we show that neither RBD nor full-length spike glycoprotein bind to recombinant human basigin (expressed in either Escherichia coli or mammalian cells). Further, polyclonal anti-basigin IgG did not block SARS-CoV-2 infection of Vero E6 cells. Given the immense interest in SARS-CoV-2 therapeutic targets to improve treatment options for those who become seriously ill with coronavirus disease 2019 (COVID-19), we would caution the inclusion of basigin in this list on the basis of its reported direct interaction with SARS-CoV-2 spike glycoprotein. IMPORTANCE Reducing the mortality and morbidity associated with COVID-19 remains a global health priority. Vaccines have proven highly effective at preventing infection and hospitalization, but efforts must continue to improve treatment options for those who still become seriously ill. Critical to these efforts is the identification of host factors that are essential to viral entry and replication. Basigin, or CD147, was previously identified as a possible therapeutic target based on the observation that it may act as a coreceptor for SARS-CoV-2, binding to the receptor binding domain of the spike protein. Here, we show that there is no direct interaction between the RBD and basigin, casting doubt on its role as a coreceptor and plausibility as a therapeutic target.

Azithromycin: Immunomodulatory and antiviral properties for SARS-CoV-2 infection

Azithromycin, a member of the macrolide family of antibiotics, is commonly used to treat respiratory bacterial infections. Nevertheless, multiple pharmacological effects of the drug have been revealed in several investigations. Conceivably, the immunomodulatory properties of azithromycin are among its critical features, leading to its application in treating inflammatory diseases, such as asthma and chronic obstructive pulmonary disease (COPD). Additionally, azithromycin may directly inhibit viral load as well as its replication, or it could demonstrate indirect inhibitory impacts that might be associated with the expression of antiviral genes. Currently, coronavirus disease 2019 (COVID-19) is an extra urgent issue affecting the entire world, and it is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Acute respiratory distress syndrome (ARDS), which is associated with hyper inflammation due to cytokine release, is among the leading causes of death in COVID-19 patients with critical conditions. The present paper aims to review the immunomodulatory and antiviral properties of azithromycin as well as its potential clinical applications in the management of COVID-19 patients.

Therapeutic Strategies in the Management of COVID-19

Since December 2019, SARS-CoV-2 (COVID-19), novel corona virus has caused pandemic globally, with rise in the number of cases and death of the patients. Vast majority of the countries that are dealing with rise in the active cases and death of patients suffering from novel corona viruses COVID-19 are trying to content the virus by isolating the patients and treating them with the approved antiviral that have been previously used in treating SARS, MERS, and drugs that are used to treat other viral infections. Some of these are under clinical trials. At present there are no therapeutically effective antiviral present and there are no vaccines or drugs available that are clinically approved for treating the corona virus. The current strategy is to re-purpose the available drugs or antiviral that can minimise or reduce the burden of the health care emergencies. In this article the reuse of antiviral, US-FDA approved drugs, plant based therapeutic, anti-malarial, anti-parasitic, anti-HIV drugs and the traditional medicines that are being currently used in treating the symptoms of COVID-19 patients is discussed emphasis is also given on the treatment using monoclonal antibodies. The present article provides the therapeutic strategies that will qualify as one of the best available treatment for the better management of the COVID-19 patients in order to achieve medical benefits.

Background to new treatments for COVID-19, including its chronicity, through altering elements of the cytokine storm

Anti-tumour necrosis factor (TNF) biologicals, Dexamethasone and rIL-7 are of considerable interest in treating COVID-19 patients who are in danger of, or have become, seriously ill. Yet reducing sepsis mortality by lowering circulating levels of TNF lost favour when positive endpoints in earlier simplistic models could not be reproduced in well-conducted human trials. Newer information with anti-TNF biologicals has encouraged reintroducing this concept for treating COVID-19. Viral models have had encouraging outcomes, as have the effects of anti-TNF biologicals on community-acquired COVID-19 during their long-term use to treat chronic inflammatory states. The positive outcome of a large scale trial of dexamethasone, and its higher potency late in the disease, harmonises well with its capacity to enhance levels of IL-7Rα, the receptor for IL-7, a cytokine that enhances lymphocyte development and is increased during the cytokine storm. Lymphoid germinal centres required for antibody-based immunity can be harmed by TNF, and restored by reducing TNF. Thus the IL-7- enhancing activity of dexamethasone may explain its higher potency when lymphocytes are depleted later in the infection, while employing anti-TNF, for several reasons, is much more logical earlier in the infection. This implies dexamethasone could prove to be synergistic with rIL-7, currently being trialed as a COVID-19 therapeutic. The principles behind these COVID-19 therapies are consistent with the observed chronic hypoxia through reduced mitochondrial function, and also the increased severity of this disease in ApoE4-positive individuals. Many of the debilitating persistent aspects of this disease are predictably susceptible to treatment with perispinal etanercept, since they have cerebral origins.

Dexamethasone-Loaded Thermosensitive Hydrogel Suppresses Inflammation and Pain in Collagen-Induced Arthritis Rats

Purpose

To overcome negative adverse effects and improve therapeutic index of dexamethasone (Dex) in rheumatoid arthritis (RA), we developed a novel sustained release formulation-intra-articular injectable dexamethasone-loaded thermosensitive hydrogel (DLTH) with chitosan-glycerin-borax as carrier for the remission of inflammation and pain. The focus of this article is to explore both anti-inflammatory and pain-relieving effects of DLTH joint injection in bovine type-II collagen-induced arthritis (CIA) rats.

Methods

Wistar rats were randomized into three groups, including the normal group (n=6), the model group (n=6) and the DLTH group (n=10). Joint injection of DLTH (1mg/kg Dex per rat) was injected on day 12 in the DLTH group twice a week for three weeks. Clinical signs of body weight, paw swelling and arthritis scores, histologic analysis, hind paw mechanical withdrawal threshold (MWT), plantar pressure pain threshold (PPT) were taken into consideration. Serum contents of IL-17A, prostaglandin E2 (PGE2), prostacyclin 2 (PGI2) and prostaglandin D2 (PGD2), real-time polymerase chain reaction (PCR) analysis of inflammatory factors and pain-related mediators in synovium and dorsal root ganglia (DRG), Western blotting of NF-κB in synovium were all evaluated.

Results

Paw swelling, arthritis scores and joint inflammation destruction were all attenuated in the DLTH-treated group. Results showed that DLTH not only down-regulated serum IL-17A, but also mRNA levels of inflammatory factors and NGF, and key proteins contents of the NF-κB pathway in synovium. Increases of MWT and PPT in DLTH-treated rats elucidated pain-reducing effects of DLTH. Elevated serum PGD2 levels and declines of serum PGE2 and PGI2, and inflammatory and pain-related genes in DRGs in the DLTH group were also recorded.

Conclusion

These data elucidated that DLTH joint injection impeded synovial inflammation processes through down-regulating transcription activity of NF-κB pathway, and intra-articular DLTH may aid in the regulation of RA pain through regulating inflammation and pain conduction process.

CypB-CD147 Signaling Is Involved in Crosstalk between Cartilage and FLS in Collagen-Induced Arthritis

To investigate the crosstalk between cartilage and fibroblast-like synoviocytes (FLS) in rheumatoid arthritis (RA), we adopted an in vitro coculture system model of collagen-induced arthritis (CIA) cartilage and CIA FLS monolayer. CIA rat samples of the synovium and femur head were collected for isolation of FLS and coculture system. Cartilages were treated with vehicle (Ctrl group), 10 ng/mL interleukin- (IL-) 1α (IL-1α group), and 10 ng/mL IL-1α plus 10 μM dexamethasone (Dex group) for 3 days before coculture with FLS for further 2 days. After the coculture, FLS were collected to determine the influences of articular cartilage on synoviocytes. Whether the CypB-CD147 signaling pathway is involved in the interactions between cartilage and FLS is assayed. Results showed that IL-1α-stimulated CIA cartilage promoted the proliferation and reduced the apoptosis of FLS. Increased inflammatory cytokines and decreased p57 expression were found in cocultured FLS stimulated by IL-1α-challenged CIA cartilage. Upregulation of NF-κB and I-κB kinase β (IKK-β) and downregulation of the inhibitor of NF-κBα (I-κBα) protein were observed in cocultured FLS. After coculture, significant increases in the expression of cyclophilin B (CypB) and CD147 were observed in CIA cartilage and FLS, respectively. Furthermore, results of immunofluorescence staining showed that the anti-CD147 antibody significantly suppressed p65 nuclear translocation in cocultured FLS stimulated by IL-1α-challenged CIA cartilage. In conclusion, inflammatory effects in the cartilage-FLS coculture system are associated with the CypB-CD147 mediating NF-κB pathway which may further enhance the inflammation in RA.

COVID-19 Therapeutic Options Under Investigation

Since its emergence in China in December 2019, COVID-19 has quickly spread around the globe causing a pandemic. Vaccination or the development of herd immunity seems the only way to slow down the spread of the virus; however, both are not achievable in the near future. Therefore, effective treatments to mitigate the burden of this pandemic and reduce mortality rates are urgently needed. Preclinical and clinical studies of potential antiviral and immunomodulatory compounds and molecules to identify safe and efficacious therapeutics for COVID-19 are ongoing. Two compounds, remdesivir, and dexamethasone have been so far shown to reduce COVID-19-associated death. Here, we provide a review of the potential therapeutic agents being considered for the treatment and management of COVID-19 patients.