Baicalin clears inflammation by enhancing macrophage efferocytosis via inhibition of RhoA/ROCK signaling pathway and regulating macrophage polarization

Clearing the Path: Exploring Apoptotic Cell Clearance in Inflammatory and Autoimmune Disorders for Therapeutic Advancements

Inflammatory and autoimmune disorders, characterized by dysregulated immune responses leading to tissue damage and chronic inflammation, present significant health challenges. This review uniquely focuses on efferocytosis-the phagocyte-mediated clearance of apoptotic cells-and its pivotal role in these disorders. We delve into the intricate mechanisms of efferocytosis' four stages and their implications in disease pathogenesis, distinguishing our study from previous literature. Our findings highlight impaired efferocytosis in conditions like atherosclerosis and asthma, proposing its targeting as a novel therapeutic strategy. We discuss the therapeutic potential of efferocytosis in modulating immune responses and resolving inflammation, offering a new perspective in treating inflammatory disorders.

Dipotassium glycyrrhizate and hinokitiol enhance macrophage efferocytosis by regulating recognition, uptake, and metabolism of apoptotic cells in vitro

BACKGROUND AND OBJECTIVE

Efferocytosis is a process whereby macrophages remove apoptotic cells, such as neutrophils, that have accumulated in tissues, which is required for resolution of inflammation. Efferocytosis is impaired in individuals with increasing age and in those with various systemic diseases. Recently, efferocytosis has been reported to be related to the pathogenesis and progression of periodontitis, and enhancement of efferocytosis, especially in the subjects with impaired efferocytosis, was suggested to lead to periodontitis prevention and care. Various anti-inflammatory ingredients are used in oral care products, but their effect on efferocytosis is unclear. Here, we aimed to identify ingredients contained in oral care products that are effective for efferocytosis regulation.

METHODS

The ability of dead cells to induce inflammation in human gingival fibroblast (HGF) cells were evaluated by measuring IL-6 secretion. Six ingredients in oral care products used as anti-inflammatory agents were evaluated for their effect on efferocytosis using flow cytometry. The expression of various efferocytosis-related molecules, such as MERTK and LRP1 involved in recognition, and LXRα and ABCA1 that function in metabolism, were measured in RAW264.7 cells with or without ingredient treatment. Rac1 activity, which is related to the uptake of dead cells, was measured using the G-LISA kit.

RESULTS

Dead cells elicited IL-6 secretion in HGF cells. Among the six ingredients, GK2 and hinokitiol enhanced efferocytosis activity. GK2 and hinokitiol significantly increased the expression of MERTK and LRP1, and also enhanced LXRα and ABCA1 expression after efferocytosis. Furthermore, they increased Rac1 activity in the presence of dead cells.

CONCLUSION

Among the six ingredients tested, GK2 and hinokitiol promoted efferocytosis by regulating apoptotic cell recognition, uptake, and metabolism-related molecules. Efferocytosis upregulation may be one of the mechanisms of GK2 and hinokitiol in the treatment of inflammatory diseases, such as periodontitis.

The Efficacy of Chaihu-Guizhi-Ganjiang Decoction on Chronic Non-Atrophic Gastritis with Gallbladder Heat and Spleen Cold Syndrome and Its Metabolomic Analysis: An Observational Controlled Before-After Clinical Trial

Purpose

The aim of this study was to verify the effectiveness and explore the mechanism of Chaihu-Guizhi-Ganjiang decoction (CGGD) in the treatment of chronic non-atrophic gastritis (CNAG) with gallbladder heat and spleen cold syndrome (GHSC) by metabolomics based on UHPLC-Q-TOF/MS.

Patients and Methods

An observational controlled before-after study was conducted to verify the effectiveness of CGGD in the treatment of CNAG with GHSC from January to June 2023, enrolling 27 patients, who took CGGD for 28 days. 30 healthy volunteers were enrolled as the controls. The efficacy was evaluated by comparing the traditional Chinese medicine (TCM) syndrome and CNAG scores, and clinical parameters before and after treatment. The plasma levels of hormones related to gastrointestinal function were collected by ELISA. The mechanisms of CGGD in the treatment of CNAG with GHSC were explored using a metabolomic approach based on UHPLC-Q-TOF/MS.

Results

Patients treated with CGGD experienced a statistically significant improvement in TCM syndrome and CNAG scores (p < 0.01). CGGD treatment evoked the concentration alteration of 15 biomarkers, which were enriched in the glycerophospholipid metabolism, and branched-chain amino acids biosynthesis pathways. Moreover, CGGD treatment attenuated the abnormalities of the gastrointestinal hormone levels and significantly increased the pepsinogen level.

Conclusion

It was the first time that this clinical trial presented detailed data on the clinical parameters that demonstrated the effectiveness of CGGD in the treatment of CNAG with GHSC patients. This study also provided supportive evidence that CNAG with GHSC patients were associated with disturbed branched-chain amino acid metabolism and glycerophospholipid levels, suggesting that CNAG treatment based on TCM syndrome scores was reasonable and also provided a potential pharmacological mechanism of action of CGGD.

Baicalin and baicalein in modulating tumor microenvironment for cancer treatment: A comprehensive review with future perspectives

Cancer is a leading cause of death worldwide. The burden of cancer incidence and mortality is increasing rapidly. New approaches to cancer prevention and treatment are urgently needed. Natural products are reliable and powerful sources for anticancer drug discovery. Baicalin and baicalein, two major flavones isolated from Scutellaria baicalensis Georgi, a multi-purpose traditional medicinal plant in China, exhibit anticancer activities against multiple cancers. Of note, these phytochemicals exhibit extremely low toxicity to normal cells. Besides their cytotoxic and cytostatic activities toward diverse tumor cells, recent studies demonstrated that baicalin and baicalein modulate a variety of tumor stromal cells and extracellular matrix (ECM) in the tumor microenvironment (TME), which is essential for tumorigenesis, cancer progression and metastasis. In this review, we summarize the therapeutic potential and the mechanism of action of baicalin and baicalein in the regulation of tumor microenvironmental immune cells, endothelial cells, fibroblasts, and ECM that reshape the TME and cancer signaling, leading to inhibition of tumor angiogenesis, progression, and metastasis. In addition, we discuss the biotransformation pathways of baicalin and baicalein, related therapeutic challenges and the future research directions to improve their bioavailability and clinical anticancer applications. Recent advances of baicalin and baicalein warrant their continued study as important natural ways for cancer interception and therapy.

Macrophage neogenin deficiency exacerbates myocardial remodeling and inflammation after acute myocardial infarction through JAK1-STAT1 signaling

Immune response plays a crucial role in post-myocardial infarction (MI) myocardial remodeling. Neogenin (Neo1), a multifunctional transmembrane receptor, plays a critical role in the immune response; however, whether Neo1 participates in pathological myocardial remodeling after MI is unclear. Our study found that Neo1 expression changed significantly after MI in vivo and after LPS + IFN-γ stimulation in bone marrow-derived macrophages (BMDMs) in vitro. Neo1 functional deficiency (using a neutralizing antibody) and macrophage-specific Neo1 deficiency (induced by Neo1flox/flox;Cx3cr1cre mice) increased infarction size, enhanced cardiac fibrosis and cardiomyocyte apoptosis, and exacerbated left ventricular dysfunction post-MI in mice. Mechanistically, Neo1 deficiency promoted macrophage infiltration into the ischemic myocardium and transformation to a proinflammatory phenotype, subsequently exacerbating the inflammatory response and impairing inflammation resolution post-MI. Neo1 deficiency regulated macrophage phenotype and function, possibly through the JAK1-STAT1 pathway, as confirmed in BMDMs in vitro. Blocking the JAK1-STAT1 pathway with fludarabine phosphate abolished the impact of Neo1 on macrophage phenotype and function, inflammatory response, inflammation resolution, cardiomyocyte apoptosis, cardiac fibrosis, infarction size and cardiac function. In conclusion, Neo1 deficiency aggravates inflammation and left ventricular remodeling post-MI by modulating macrophage phenotypes and functions via the JAK1-STAT1 signaling pathway. These findings highlight the anti-inflammatory potential of Neo1, offering new perspectives for therapeutic targets in MI treatment. Neo1 deficiency aggravated inflammation and left ventricular remodeling after MI by modulating macrophage phenotypes and functions via the JAK1-STAT1 signaling pathway.

Baicalin Attenuates Panton-Valentine Leukocidin (PVL)-Induced Cytoskeleton Rearrangement via Regulating the RhoA/ROCK/LIMK and PI3K/AKT/GSK-3β Pathways in Bovine Mammary Epithelial Cells

Pore-forming toxins (PFTs) exert physiological effects by rearrangement of the host cell cytoskeleton. Staphylococcus aureus-secreted PFTs play an important role in bovine mastitis. In the study, we examined the effects of recombinant Panton-Valentine leukocidin (rPVL) on cytoskeleton rearrangement, and identified the signaling pathways involved in regulating the process in bovine mammary epithelial cells (BMECs) in vitro. Meanwhile, the underlying regulatory mechanism of baicalin for this process was investigated. The results showed that S. aureus induced cytoskeleton rearrangement in BMECs mainly through PVL. S. aureus and rPVL caused alterations in the cell morphology and layer integrity due to microfilament and microtubule rearrangement and focal contact inability. rPVL strongly induced the phosphorylation of cofilin at Ser3 mediating by the activation of the RhoA/ROCK/LIMK pathway, and resulted in the activation of loss of actin stress fibers, or the hyperphosphorylation of Tau at Ser396 inducing by the inhibition of the PI3K/AKT/GSK-3β pathways, and decreased the microtubule assembly. Baicalin significantly attenuated rPVL-stimulated cytoskeleton rearrangement in BMECs. Baicalin inhibited cofilin phosphorylation or Tau hyperphosphorylation via regulating the activation of RhoA/ROCK/LIMK and PI3K/AKT/GSK-3β signaling pathways. These findings provide new insights into the pathogenesis and potential treatment in S. aureus causing bovine mastitis.

Exploring the mechanism of Chaihujia Longgu Muli decoction in the treatment of epilepsy in rats based on the RhoA/ROCK signaling pathway

BACKGROUND

The Chinese herbal formula Chaihujia Longgu Muli Decoction (CD) has a good antiepileptic effect, but its mechanisms remain unclear. Therefore, in this study we explored the molecular mechanisms of CD against epilepsy.

METHODS

Twelve-day-old SD rats were randomly divided into a normal group, model group, valproic acid group, and CD high, medium, and low groups. Except for the normal group, the other groups were given an intraperitoneal injection of pentylenetetrazol (PTZ) to establish epilepsy models, and the Racine score was applied for model judgment. After 14 consecutive days of dosing, the Morris water maze test was performed. Then, hippocampal Nissl staining and immunofluorescence staining were performed, and synaptic ultrastructure was observed by transmission electron microscopy (TEM). RhoA/ROCK signaling pathway proteins were detected.

RESULTS

In PTZ model rats, the passing times were reduced, and the escape latency was prolonged in the Morris water maze test. Nissl staining showed that some hippocampal neurons swelled and ruptured, Nissl bodies in the cytoplasm were significantly reduced, and neurons were lost. Immunofluorescence detection revealed that the expression of PSD95 and SYP was significantly reduced. Electron microscopy results revealed that the number of synapses in hippocampal neurons was significantly reduced and the postsynaptic membrane length was significantly reduced. Western blot analysis showed that the RhoA/ROCK signaling pathway was activated, while SYP, SPD95, and PTEN expression was significantly decreased. After treatment with CD, neurobehavioral abnormalities and neuronal damage caused by epileptic seizures were improved.

CONCLUSION

CD exerted an antiepileptic effect by inhibiting the activation of the RhoA/ROCK signaling pathway.

Dysregulated B7H4/JAK2/STAT3 Pathway Involves in Hypertriglyceridemia Acute Pancreatitis and Is Attenuated by Baicalin

BACKGROUND

Patients with hypertriglyceridemia (HTG) are prone to develop more severe acute pancreatitis (AP). However, the specific molecular mechanism still has not been elaborated clearly, and effective drugs for treating HTG-AP are not yet readily available. Baicalin is an ingredient isolated from a natural product that with potential to attenuate inflammation and pain in AP.

AIMS

The aim of the present study was to explore the effect of baicalin on HTG-AP and the possible mechanism involved.

METHODS

A mouse model of HTG-AP was successfully established by administering Poloxamer 407 and L-arginine intraperitoneally. We analyzed pathological changes, and performed TUNEL staining, DHE staining, and western blot to detect apoptosis, inflammation, oxidative stress, and B7H4/JAK2/STAT3 signaling in the pancreas.

RESULTS

Treatment with baicalin decreased serum triglyceride, cholesterol, lipase, amylase levels, and attenuated pancreatic edema. After intervention with baicalin, apoptosis and inflammation in HTG-AP mice were alleviated, as indicated by the decrease of Bax, cleaved-caspase-3, IL-6, TNF-α, and IL-1β. Baicalin also alleviated oxidative stress by decreasing NOX2, increasing SOD2 protein expression, and regulating Nrf2/Keap1 signaling in HTG-AP mice. Furthermore, baicalin decreased the upregulated B7H4/JAK2/STAT3 pathway in HTG-AP.

CONCLUSIONS

In conclusion, our data suggested that baicalin could attenuate HTG-AP, possibly through regulating B7H4/JAK2/STAT3 signaling.

N-Acetylcysteine, an ROS Inhibitor, Alleviates the Pathophysiology of Hyperthyroidism-Induced Cardiomyopathy via the ROS/Ca2+ Pathway

Hyperthyroidism is common and can induce cardiomyopathy, but there is no effective therapeutic strategy. The purpose of this study was to investigate the molecular mechanism of hyperthyroidism-induced cardiomyopathy (HTC) and the effect of N-acetylcysteine (NAC), an ROS inhibitor, on the pathophysiology of HTC in vivo and in vitro. Compared with those in the control groups in vivo and in vitro, TT3 and TT4 were significantly increased, the structure of myocardial cells was enlarged and disordered, and interstitial fibrosis and the apoptosis of myocardial cells were markedly increased in the L-Thy group. The ROS and inflammatory response were increased in the hyperthyroidism group. In the NAC group, the contents of TT3 and TT4 were decreased, the myocardial cell structure was slightly disturbed, fibrosis and apoptosis were significantly reduced, and the ROS level and inflammatory response were significantly reduced. Interestingly, L-Thy decreased the viability of fibroblasts and H9c2 cells, suggesting that L-Thy-induced fibrosis was not caused by the proliferation of fibroblasts. The molecular mechanism of HTC could be explained by the fact that L-Thy could cause cardiac hypertrophy, inflammation, and fibrosis by regulating the Ca2+/calpain/Rcan1-dependent signalling pathway, the Ca2+/Rcan1/NF-κB/p65-dependent signalling pathway, and the Ca2+/ROS/Bcl-2/caspase-3-dependent signalling pathway. In conclusion, NAC can alleviate the pathophysiology of hyperthyroidism-induced cardiomyopathy, probably by regulating the ROS/Ca2+-dependent pathway.