Glycogen synthase kinase‑3β inhibitor reduces LPS‑induced acute lung injury in mice

Icariin ameliorates LPS-induced acute lung injury in mice via complement C5a-C5aR1 and TLR4 signaling pathways

Acute lung injury (ALI) is an acute respiratory-related progressive disorder, which lacks specific pharmacotherapy. Icariin (ICA) has been shown to be effective in treating ALI. However, the targets and pharmacological mechanisms underlying the effects of ICA in the treatment of ALI are relatively lacking. Based on network pharmacology and molecular docking analyses, the gene functions and potential target pathways of ICA in the treatment of ALI were determined. In addition, the underlying mechanisms of ICA were verified by immunohistochemistry, immunofluorescence, quantitative Real-time PCR, and Western blot in LPS-induced ALI mice. The biological processes targeted by ICA in the treatment of ALI included the pathological changes, inflammatory response, and cell signal transduction. Network pharmacology, molecular docking, and in vivo experimental results revealed that ICA inhibited the complement C5a-C5aR1 axis, TLR4 mediated NF-κB, MAPK, and JAK2-STAT3 signaling pathways related gene and protein expressions, and decreased inflammatory cytokine, chemokine, adhesion molecule expressions, and mitochondrial apoptosis in LPS-induced ALI.

Glycogen Synthase Kinase-3 Inhibition by CHIR99021 Promotes Alveolar Epithelial Cell Proliferation and Lung Regeneration in the Lipopolysaccharide-Induced Acute Lung Injury Mouse Model

Acute respiratory distress syndrome (ARDS) is a life-threatening lung injury that currently lacks effective clinical treatments. Evidence highlights the potential role of glycogen synthase kinase-3 (GSK-3) inhibition in mitigating severe inflammation. The inhibition of GSK-3α/β by CHIR99021 promoted fetal lung progenitor proliferation and maturation of alveolar epithelial cells (AECs). The precise impact of CHIR99021 in lung repair and regeneration during acute lung injury (ALI) remains unexplored. This study intends to elucidate the influence of CHIR99021 on AEC behaviour during the peak of the inflammatory phase of ALI and, after its attenuation, during the repair and regeneration stage. Furthermore, a long-term evaluation was conducted post CHIR99021 treatment at a late phase of the disease. Our results disclosed the role of GSK-3α/β inhibition in promoting AECI and AECII proliferation. Later administration of CHIR99021 during ALI progression contributed to the transdifferentiation of AECII into AECI and an AECI/AECII increase, suggesting its contribution to the renewal of the alveolar epithelial population and lung regeneration. This effect was confirmed to be maintained histologically in the long term. These findings underscore the potential of targeted therapies that modulate GSK-3α/β inhibition, offering innovative approaches for managing acute lung diseases, mostly in later stages where no treatment is available.

Protective effects of Stephania pierrei tuber-derived oxocrebanine against LPS-induced acute lung injury in mice

Acute lung injury and acute respiratory distress syndrome (ALI/ARDS) have high mortality rates. Though corticosteroids are commonly used for the treatment of these conditions, their efficacy has not been conclusively demonstrated and their use can induce various adverse reactions. Hence, the application of corticosteroids as therapeutic modalities for ALI/ARDS is limited. Meanwhile, the aporphine alkaloid oxocrebanine isolated from Stephania pierrei tubers has demonstrated anti-inflammatory efficacy in murine/human macrophage cell lines stimulated by lipopolysaccharide (LPS). Accordingly, the primary objectives of the present study are to investigate the anti-inflammatory effects of oxocrebanine on LPS-induced murine alveolar epithelial (MLE-12) cells and its efficacy against LPS-induced murine ALI. Results show that oxocrebanine downregulates the abundance of interleukin (IL)-1beta, IL-6, and inducible nitric oxide synthase, as well as the phosphorylation of nuclear factor-kappaB (NF-κB), stress-activated protein kinase (SAPK)/c-Jun N-terminal kinase (JNK), p38, protein kinase B (Akt), and glycogen synthase kinase-3beta signalling proteins in LPS-induced MLE-12 cells. Moreover, in a murine ALI model, oxocrebanine lowers lung injury scores and lung wet/dry weight ratios while reducing inflammatory cell infiltration. It also suppresses LPS-induced tumour necrosis factor-alpha and IL-6 in the bronchoalveolar lavage fluid and plasma. Moreover, oxocrebanine downregulates NF-κB, SAPK/JNK, p38, and Akt phosphorylation in the lung tissues of LPS-treated mice. Taken together, the foregoing results show that oxocrebanine provides significant protection against LPS-induced ALI in mice primarily by suppressing various inflammatory signalling pathways in alveolar epithelial cells and lung tissues. Hence, oxocrebanine might prove effective as an anti-inflammatory agent for the treatment of lung inflammation.

Mesenchymal stem cells inhibited the apoptosis of alveolar epithelial cells caused by ARDS through CXCL12/CXCR4 axis

Mesenchymal stem cells (MSCs) have a wide range of anti-inflammatory and immunomodulatory effects and have been observed to have potential therapeutic potential in the clinical treatment of various diseases. We pretreated lung cancer cells A549 with tumor necrosis factor (TNF-α), knocked down the key chemokine receptor CXCR4 on MSCs using lentivirus, and induced acute respiratory distress syndrome (ARDS) mouse model using lipopolysaccharide (LPS) and CXCL12 expression in vivo by adeno-associated virus (AAV-rh10) infection in mice. By co-culturing the MSCs with A549 and in vivo experiments, we observed the effects of MSCs on cell biological functions after inflammatory stimulation, oxidative stress, and the amelioration of lung injury in ARDS mice. TNF-α inhibited A549 proliferation and promoted apoptosis, scorch death-related factor activity, and oxidative stress factor were increased and CXCL12 levels in the cell supernatant were decreased. The co-culture of MSCs was able to increase cell activity and decrease oxidative stress factor levels, and this effect was not present after the knockdown of CXCR4 in MSCs. In vivo transplantation of MSCs significantly attenuated lung injury in ARDS, inhibited serum pro-inflammatory factors in mice, and down-regulated expression of apoptotic and focal factors in lung tissues while blocking CXCR4 or CXCL12 lost the repairing effect of MSCs on ARDS lung tissues. After the co-culture of MSC and lung cancer cells, the expression of CXCR4 on the surface of lung cancer cells was significantly increased, and more CXCR4 and CXCL12 acted together to activate more pro-survival pathways and inhibit apoptosis induced by TNF-α.

Kinases as Potential Therapeutic Targets for Anti-coronaviral Therapy

The global coronavirus disease-19 (COVID-19) has affected more than 140 million and killed more than 3 million people worldwide as of April 20, 2021. The novel human severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has been identified as an etiological agent for COVID-19. Several kinases have been proposed as possible mediators of multiple viral infections, including life-threatening coronaviruses like SARS-CoV-1, Middle East syndrome coronavirus (MERS-CoV), and SARS-CoV-2. Viral infections hijack abundant cell signaling pathways, resulting in drastic phosphorylation rewiring in the host and viral proteins. Some kinases play a significant role throughout the viral infection cycle (entry, replication, assembly, and egress), and several of them are involved in the virus-induced hyperinflammatory response that leads to cytokine storm, acute respiratory distress syndrome (ARDS), organ injury, and death. Here, we highlight kinases that are associated with coronavirus infections and their inhibitors with antiviral and potentially anti-inflammatory, cytokine-suppressive, or antifibrotic activity.

Functional differences and similarities in activated peripheral blood mononuclear cells by lipopolysaccharide or phytohemagglutinin stimulation between human and cynomolgus monkeys

Background

The monkey is a primary species used in toxicological research. However, the failures of preclinical studies to predict a life-threatening “cytokine storm”, which, for instance, rapidly occurred in six healthy volunteers with the CD28 superagonist monoclonal antibody (mAb) TGN1412 in the first-in-human phase I clinical trial, have emphasized a need to clarify the differences between human and monkey immune systems.

Methods

In the present study, we analyzed and compared the lymphocyte proliferation, cytokine secretion, and gene expression profiles after phytohemagglutinin (PHA) and lipopolysaccharide (LPS) stimulation of peripheral blood mononuclear cells (PBMCs) from three healthy humans and cynomolgus monkeys (Macaca fascicularis).

Results

The results derived from comparison with the corresponding control groups showed that PHA in humans induced a stronger proliferation and wider range of cytokine secretion, along with a greater number of differently expressed genes (DEGs), than when PHA was applied in cynomolgus monkeys. The significant upregulation of genes involved in the mitotic cell cycle, including cyclin B2, TOP2A, TYMS, and CEP55, was observed in human PBMCs with PHA stimulation, while only infrequent or slight upregulation occurred in cynomolgus monkey PBMCs, which may be one of the reasons for a stronger response to PHA in humans. In contrast to PHA, LPS in both species induced a similar proliferation ratio, cytokine profile, and DEG count, suggesting that human and cynomolgus monkeys have a similar response intensity for innate immune responses. Furthermore, 38 and 20 overlapped genes under PHA and LPS stimulation, respectively, were found in both species. These overlapped DEGs were associated with the same biological functions, including DNA replication, mitosis, immune response, chemotaxis, and inflammatory response. Thus, these results might reflect the highly conserved signatures of immune responses to PHA/LPS stimulation across the primates. Moreover, there were some differences in antigen processing and presentation, and the interferon gamma (INF-γ)–mediated signaling pathway in these species detected by gene expression profile study.

Conclusions

In conclusion, this is the first study to compare data on the responses of PBMCs to PHA and LPS in humans versus cynomolgus monkeys, and these findings may provide crucial insights into translating non-human primate (NHP) studies into human trials.

CircC3P1 attenuated pro-inflammatory cytokine production and cell apoptosis in acute lung injury induced by sepsis through modulating miR-21

Acute lung injury (ALI) induced by sepsis is characterized by an inflammatory process related to the up‐regulation of inflammatory cytokines and chemokines. In the present study, we explored the role of circC3P1 in sepsis‐induced ALI in vitro and in vivo. The caecal ligation and puncture (CLP)‐induced sepsis model was established through CLP surgery. Forty adult male C57BL/6 mice were randomly assigned into sham, CLP, CLP + vector and CLP + circC3P1 (each n = 10). Primary murine pulmonary microvascular endothelial cells (MPVECs) were transfected with circC3P1 or empty vector 24 hours prior to LPS treatment via Lipofectamine 2000. The expressions of circC3P1, tumour necrosis factor‐α (TNF‐α), interleukin‐6 (IL‐6) and IL‐1β were evaluated after 6‐h LPS treatment. Cell apoptosis was evaluated via flow cytometry. The CLP group demonstrated pulmonary morphological abnormalities, increased concentrations of TNF‐α, IL‐6 and IL‐1β in the lung tissue, compared with the sham group. MPVECs treated with LPS significantly elevated TNF‐α, IL‐6 and IL‐1β levels and increased cell apoptosis than that in the control group. The circC3P1 overexpression in sepsis‐induced ALI mice attenuated pulmonary injury, inflammation and apoptosis. Besides, circC3P1 revealed anti‐inflammatory and anti‐apoptotic effect in MPVEC‐treated LPS. CircC3P1 overexpression reduced cell apoptosis and pro‐inflammatory cytokines levels via down‐regulating miR‐21. CircC3P1 attenuated pro‐inflammatory cytokine production and cell apoptosis in ALI induced by sepsis through modulating miR‐21, indicating that circC3P1 is a promising therapeutic biomarker for sepsis‐induced ALI.

Mesenchymal Stem/Stromal Cells Therapy for Sepsis and Acute Respiratory Distress Syndrome

Sepsis and acute respiratory distress syndrome (ARDS) constitute devastating conditions with high morbidity and mortality. Sepsis results from abnormal host immune response, with evidence for both pro- and anti-inflammatory activation present from the earliest phases. The "proinflammatory" response predominates initially causing host injury, with later-phase sepsis characterized by immune cell hypofunction and opportunistic superinfection. ARDS is characterized by inflammation and disruption of the alveolar-capillary membrane leading to injury and lung dysfunction. Sepsis is the most common cause of ARDS. Approximately 20% of deaths worldwide in 2017 were due to sepsis, while ARDS occurs in over 10% of all intensive care unit patients and results in a mortality of 30 to 45%. Given the fact that sepsis and ARDS share some-but not all-underlying pathophysiologic injury mechanisms, the lack of specific therapies, and their frequent coexistence in the critically ill, it makes sense to consider therapies for both conditions together. In this article, we will focus on the therapeutic potential of mesenchymal stem/stromal cells (MSCs). MSCs are available from several tissues, including bone marrow, umbilical cord, and adipose tissue. Allogeneic administration is feasible, an important advantage for acute conditions like sepsis or ARDS. They possess diverse mechanisms of action of relevance to sepsis and ARDS, including direct and indirect antibacterial actions, potent effects on the innate and adaptive response, and pro-reparative effects. MSCs can be preactivated thereby potentiating their effects, while the use of their extracellular vesicles can avoid whole cell administration. While early-phase clinical trials suggest safety, considerable challenges exist in moving forward to phase III efficacy studies, and to implementation as a therapy should they prove effective.

GSK3: A Kinase Balancing Promotion and Resolution of Inflammation

GSK3 has been implicated for years in the regulation of inflammation and addressed in a plethora of scientific reports using a variety of experimental (disease) models and approaches. However, the specific role of GSK3 in the inflammatory process is still not fully understood and controversially discussed. Following a detailed overview of structure, function, and various regulatory levels, this review focusses on the immunoregulatory functions of GSK3, including the current knowledge obtained from animal models. Its impact on pro-inflammatory cytokine/chemokine profiles, bacterial/viral infections, and the modulation of associated pro-inflammatory transcriptional and signaling pathways is discussed. Moreover, GSK3 contributes to the resolution of inflammation on multiple levels, e.g., via the regulation of pro-resolving mediators, the clearance of apoptotic immune cells, and tissue repair processes. The influence of GSK3 on the development of different forms of stimulation tolerance is also addressed. Collectively, the role of GSK3 as a kinase balancing the initiation/perpetuation and the amelioration/resolution of inflammation is highlighted.

Calves Infected with Virulent and Attenuated Mycoplasma bovis Strains Have Upregulated Th17 Inflammatory and Th1 Protective Responses, Respectively

Mycoplasma bovis is a critical bovine pathogen, but its pathogenesis remains poorly understood. Here, the virulent HB0801 (P1) and attenuated HB0801-P150 (P150) strains of M. bovis were used to explore the potential pathogenesis and effect of induced immunity from calves’ differential transcriptomes post infection. Nine one-month-old male calves were infected with P1, P150, or mock-infected with medium and euthanized at 60 days post-infection. Calves in P1 group exhibited other clinical signs and pathological changes compared to the other two groups. Transcriptome profiles of peripheral blood mononuclear cells revealed seven and 10 hub differentially expressed genes (DEGs) in P1 and P150 groups compared with mock-infected group, respectively. Then, P1-induced pathogenesis was predicted to be associated with enhanced Th17, and P150-induced immunity with Th1 response and expression of ubiquitination-associated enzymes. Association analysis showed that 14 and 11 DEGs were positively and negatively correlated with pathological changes, respectively. Furthermore, up-regulated expression in molecules critical to differentiation of pathogenic Th17 cells in lung and peripheral blood mononuclear cells in P1 group was validated at RNA and protein levels. The results confirmed virulent and attenuated strains might be associated with biased differentiation of pro-inflammatory pathogenic Th17 and Th1 subsets respectively.

SU5416 attenuated lipopolysaccharide-induced acute lung injury in mice by modulating properties of vascular endothelial cells

Background and aim: A potent and selective vascular endothelial growth factor receptor (VEGFR) inhibitor SU5416, has been developed for the treatment of solid human tumors. The binding of VEGF to VEGFR plays a crucial role in the pathophysiology of respiratory disorders. However, the impact of SU5416 on lipopolysaccharide (LPS)-induced acute lung injury (ALI) remains unclear. Thus, this study aimed to illuminate the biofunction of SU5416 in the mouse model of ALI.

Methods: Wild-type (WT) and toll-like receptor 4 (TLR4)-deficient (TLR4^−/-) C57BL/6 mice were used to establish LPS-induced ALI model. The primary pulmonary microvascular endothelial cell (PMVEC) was extracted for detection of endothelial barrier function.

Results: LPS significantly increased the number of inflammatory cells and inflammatory cytokines in bronchoalveolar lavage fluid (BALF). In addition, LPS increased alveolar epithelial cells injury, inflammation infiltration and vascular permeability of PMVEC in WT and TLR4^−/- mice. Western blotting experiment indicated VEGF/VEGFR and TLR4/NF-κB pathways were involved in the progression of LPS-stimulated ALI. Consistent with previous research, dexamethasone treatment appeared to be an effective therapeutic for mice with ALI. Moreover, treatment with SU5416 dramatically attenuated LPS-induced immune responses in mice lung tissues via inhibiting VEGF/VEGFR and TLR4/NF-κB pathways. Finally, SU5416 also decreased vascular permeability of PMVEC in vitro.

Conclusion: SU5416 ameliorated alveolar epithelial cells injury and histopathological changes in mice lung via inhibiting VEGF/VEGFR and TLR4/NF-κB signaling pathways. We also confirmed that SU5416 could restrain vascular permeability in PMVEC through improving the integrity of endothelial cell. These findings suggested that SU5416 may serve as a potential agent for the treatment of patients with ALI.

Cell therapy in acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is driven by a severe pro-inflammatory response resulting in lung damage, impaired gas exchange and severe respiratory failure. There is no specific treatment that effectively improves outcome in ARDS. However, in recent years, cell therapy has shown great promise in preclinical ARDS studies. A wide range of cells have been identified as potential candidates for use, among these are mesenchymal stromal cells (MSCs), which are adult multi-lineage cells that can modulate the immune response and enhance repair of damaged tissue. The therapeutic potential of MSC therapy for sepsis and ARDS has been demonstrated in multiple in vivo models. The therapeutic effect of these cells seems to be due to two different mechanisms; direct cellular interaction, and paracrine release of different soluble products such as extracellular vesicles (EVs)/exosomes. Different approaches have also been studied to enhance the therapeutic effect of these cells, such as the over-expression of anti-inflammatory or pro-reparative molecules. Several clinical trials (phase I and II) have already shown safety of MSCs in ARDS and other diseases. However, several translational issues still need to be addressed, such as the large-scale production of cells, and their potentiality and variability, before the therapeutic potential of stem cells therapies can be realized.