Curcumol inhibits KLF5-dependent angiogenesis by blocking the ROS/ERK signaling in liver sinusoidal endothelial cells

ROS-responsive injectable hydrogels loaded with exosomes carrying miR-4500 reverse liver fibrosis

The reversal of liver fibrosis requires effective strategies to reduce oxidative stress and inhibition of hepatic stellate cell (HSC) activation. MiR-4500 regulates pathological angiogenesis and collagen mRNA stability, with the potential to inhibit fibrosis. Herein, we explored the inhibition of HSC activation in vitro by exosomes (Exos) carrying miR-4500 and encapsulated ExosmiR-4500 in an intelligent injectable hydrogel with biological activity and reactive oxygen species (ROS) responsiveness for application in oxidative stress environments. Briefly, reversible boronic ester bonds were integrated into gelatin-based hydrogels through dynamic crosslinking of quaternized chitosan (QCS) and 4-carboxyphenylboronic acid (CPBA)-modified gelatin. The QCS-CPBA-Gelatin (QCG) hydrogel scavenged excess ROS from the local microenvironment and released ExosmiR-4500 through the dissociation of boronic ester bonds, providing a favorable microenvironment and in situ sustained-release drug delivery system for ExosmiR-4500. The results showed that QCG@ExosmiR-4500 hydrogel has biocompatibility, biodegradability, and slow-release ability, which could effectively clear ROS and inhibit HSC activation and pathological angiogenesis in vitro and in vivo. Furthermore, transcriptome analysis suggests that the pharmacological mechanism of the QCG@ExosmiR-4500 hydrogel is mainly related to anti-oxidation, anti-angiogenesis, anti-fibrosis processes, and signaling pathways. Thus, our study demonstrates that an intelligently responsive ExosmiR-4500 delivery system based on injectable hydrogels is a promising strategy for the treatment of liver fibrosis.

Network pharmacology provides new insights into the mechanism of traditional Chinese medicine and natural products used to treat pulmonary hypertension

BACKGROUND

Pulmonary hypertension (PH) is a rare cardiovascular disease with high morbidity and mortality rates. It is characterized by increased pulmonary arterial pressure. Current research into relevant therapeutic drugs and targets for PH, however, is insufficient still. Traditional Chinese medicine (TCM) and natural products have a long history as therapeutics for PH. Network pharmacology is an approach that integrates drug-target interactions and signaling pathways based on biomarkers information obtained from drug and disease databases. The concept of network pharmacology shows many similarities with the TCM philosophy. Network pharmacology help elucidate the mechanisms of TCM in PH. This review presents representative applications of network pharmacology in the study of the mechanisms of TCM and natural products for the treatment of PH.

METHODS

In this review, we used ("pulmonary hypertension" OR "pulmonary arterial hypertension" OR "chronic thromboembolic pulmonary hypertension") AND ("network pharmacology" OR "systematic pharmacology") as keywords to search for reports from PubMed, Web of Science, and Google Scholar databases from ten years ago. The studies were screened and those chosen are summarized here. The TCM and natural products inPH and their corresponding targets and signaling pathways are described. Additionally, we discuss the application of network pharmacology in the study of TCM in PH to provide insights for future application strategies.

RESULTS

Network pharmacology have shown that AKT-related pathways, HIF-1 signaling pathway, MAPK signaling pathway, TGF-β-Smad pathway, cell cycle-related pathways and inflammation-related pathways are the main signaling pathways enriched in the PH targets of TCM. Reservatrol, curcumol, genistin, formononetin, wogonin, luteolin, baicalein, berberine, triptolide and tanshinone llA are active ingredients specific for PH treatment. A number of databases and tools specific for the treatment of PH are used in network pharmacology and natural product research.

CONCLUSION

Through the reasonable combination of molecular docking, omics technology and bioinformatics technology, the mechanism of multi-targets can be explained more comprehensively. Analyzing the complex mechanism of TCM from the clinical perspective may be a potential development trend of network pharmacology. Combination of predicted targets and traditional pharmacology improves efficiency of drug development.

Liver sinusoidal endothelial cell: An important yet often overlooked player in the liver fibrosis

Liver sinusoidal endothelial cells (LSECs) are liver-specific endothelial cells with the highest permeability than other mammalian endothelial cells, characterized by the presence of fenestrae on their surface, the absence of diaphragms and the lack of basement membrane. Located at the interface between blood and other liver cell types, LSECs mediate the exchange of substances between the blood and the Disse space, playing a crucial role in maintaining substance circulation and homeostasis of multicellular communication. As the initial responders to chronic liver injury, the abnormal LSEC activation not only changes their own physicochemical properties but also interrupts their communication with hepatic stellate cells and hepatocytes, which collectively aggravates the process of liver fibrosis. In this review, we have comprehensively updated the various pathways by which LSECs were involved in the initiation and aggravation of liver fibrosis, including but not limited to cellular phenotypic change, the induction of capillarization, decreased permeability and regulation of intercellular communications. Additionally, the intervention effects and latest regulatory mechanisms of anti-fibrotic drugs involved in each aspect have been summarized and discussed systematically. As we studied deeper into unraveling the intricate role of LSECs in the pathophysiology of liver fibrosis, we unveil a promising horizon that pave the way for enhanced patient outcomes.

Curcumol ameliorates neuroinflammation after cerebral ischemia-reperfusion injury via affecting microglial polarization and Treg/Th17 balance through Nrf2/HO-1 and NF-κB signaling

Neuroinflammation caused by microglia and other immune cells plays pivotal role in cerebral ischemia/reperfusion injury and recovery. Modulating microglial polarization or Treg/Th17 balance from pro-inflammatory phenotype to anti-inflammatory phenotype are promising strategies for the treatment of cerebral ischemia. Curcumol has potential to fight against oxidative stress and inflammation, but whether it has protective effect in cerebral ischemia is uncertain. In the present study, cerebral ischemia was induced in C57BL/6 mice via middle cerebral artery occlusion (MCAO). MCAO mice were treated with curcumol for 7 days, then post-stroke ischemic injury, neurological deficits, microglial polarization and brain leukocyte infiltration were evaluated by TTC staining, behavioural tests, flow cytometry, western blot and immunofluorescence. We found that poststroke administration of curcumol reduced infarct volume, attenuated neuronal damage and inflammation, and improved motor function recovery of MCAO mice. Curcumol skewed microglial polarization toward anti-inflammatory phenotype in MCAO mice in vivo or after oxygen-glucose deprivation and reoxygenation (OGD/R) in vitro. In addition, curcumol reduced local T cell infiltration in ischemic brain of MCAO mice and impaired Treg/Th17 balance. Curcumol inhibited ROS production and regulated Nrf2/HO-1 and NF-κB signaling in microglia. Finally, inhibiting Nrf2/HO-1 signaling or activating NF-κB signaling abrogated the influence of curcumol on microglial polarization. In conclusion, curcumol treatment reduced brain damage and neuroinflammation via modulating anti-inflammatory microglial polarization and Treg/Th17 balance through Nrf2/HO-1 and NF-κB signaling. Curcumol might be a promising treatment strategy for stroke patients.

Curcumol: a review of its pharmacology, pharmacokinetics, drug delivery systems, structure-activity relationships, and potential applications

Curcumol (Cur), a guaiane-type sesquiterpenoid hemiketal, is an important and representative bioactive component extracted from the essential oil of the rhizomes of Curcumae rhizoma which is also known as "Ezhu" in traditional Chinese medicine. Recently, Cur has received considerable attention from the research community due to its favorable pharmacological activities, including anti-cancer, hepatoprotective, anti-inflammatory, anti-viral, anti-convulsant, and other activities, and has also exerted therapeutic effect on various cancers, liver diseases, inflammatory diseases, and infectious diseases. Pharmacokinetic studies have shown that Cur is rapidly distributed in almost all organs of rats after intragastric administration with high concentrations in the small intestine and colon. Several studies focusing on structure-activity relationship (SAR) of Cur have shown that some Cur derivatives, chemically modified at C-8 or C-14, exhibited more potent anti-cancer activity and lower toxicity than Cur itself. This review aims to comprehensively summarize the latest advances in the pharmacological and pharmacokinetic properties of Cur in the last decade with a focus on its anti-cancer and hepatoprotective potentials, as well as the research progress in drug delivery system and potential applications of Cur to date, to provide researchers with the latest information, to highlighted the limitations of relevant research at the current stage and the aspects that should be addressed in future research. Our results indicate that Cur and its derivatives could serve as potential novel agents for the treatment of a variety of diseases, particularly cancer and liver diseases.

Curcumol reduces lower limb arteriosclerosis in rats by inhibiting human arterial smooth muscle cell activity

Cardiovascular diseases, particularly those involving arterial stenosis and smooth muscle cell proliferation, pose significant health risks. This study aimed to investigate the therapeutic potential of curcumol in inhibiting platelet-derived growth factor-BB (PDGF-BB)-induced human aortic smooth muscle cell (HASMC) proliferation, migration and autophagy. Using cell viability assays, 5-ethynyl-2'-deoxyuridine (EdU) incorporation assays and Western Blot analyses, we observed that curcumol effectively attenuated PDGF-BB-induced HASMC proliferation and migration in a concentration-dependent manner. Furthermore, curcumol mitigated PDGF-BB-induced autophagy, as evidenced by the downregulation of LC3-II/LC3-I ratio and upregulation of P62. In vivo experiments using an arteriosclerosis obliterans model demonstrated that curcumol treatment significantly ameliorated arterial morphology and reduced stenosis. Additionally, curcumol inhibited the activity of the KLF5/COX2 axis, a key pathway in vascular diseases. These findings suggest that curcumol has the potential to serve as a multi-target therapeutic agent for vascular diseases.

Downregulation of KLF5 by EBER1 via the ERK signaling pathway in EBV-positive nasopharyngeal carcinoma cells: implications for latent EBV infection

Nasopharyngeal carcinoma (NPC) carcinogenesis and malignant transformation are intimately associated with Epstein-Barr virus (EBV) infection. A zinc-fingered transcription factor known as Krüppel-like factor 5 (KLF5) has been shown to be aberrantly expressed in a number of cancer types. However, little is known about the regulatory pathways and roles of KLF5 in EBV-positive NPC. Our study found that KLF5 expression was significantly lower in EBV-positive NPC than in EBV-negative NPC. Further investigation revealed that EBER1, which is encoded by EBV, down-regulates KLF5 via the extracellular signal-regulated kinase (ERK) signalling pathway. This down-regulation of KLF5 by EBER1 contributes to maintaining latent EBV infection in NPC. Furthermore, we uncovered the biological roles of KLF5 in NPC cells. Specifically, KLF5 may influence the cell cycle, prevent apoptosis, and encourage cell migration and proliferation - all of which have a generally pro-cancer impact. In conclusion, these findings offer novel strategies for EBV-positive NPC patients' antitumour treatment.

CD62E- and ROS-Responsive ETS Improves Cartilage Repair by Inhibiting Endothelial Cell Activation through OPA1-Mediated Mitochondrial Homeostasis

Background: In the environment of cartilage injury, the activation of vascular endothelial cell (VEC), marked with excessive CD62E and reactive oxygen species (ROS), can affect the formation of hyaluronic cartilage. Therefore, we developed a CD62E- and ROS-responsive drug delivery system using E-selectin binding peptide, Thioketal, and silk fibroin (ETS) to achieve targeted delivery and controlled release of Clematis triterpenoid saponins (CS) against activated VEC, and thus promote cartilage regeneration. Methods: We prepared and characterized ETS/CS and verified their CD62E- and ROS-responsive properties in vitro. We investigated the effect and underlying mechanism of ETS/CS on inhibiting VEC activation and promoting chondrogenic differentiation of bone marrow stromal cells (BMSCs). We also analyzed the effect of ETS/CS on suppressing the activated VEC-macrophage inflammatory cascade in vitro. Additionally, we constructed a rat knee cartilage defect model and administered ETS/CS combined with BMSC-containing hydrogels. We detected the cartilage differentiation, the level of VEC activation and macrophage in the new tissue, and synovial tissue. Results: ETS/CS was able to interact with VEC and inhibit VEC activation through the carried CS. Coculture experiments verified ETS/CS promoted chondrogenic differentiation of BMSCs by inhibiting the activated VEC-induced inflammatory cascade of macrophages via OPA1-mediated mitochondrial homeostasis. In the rat knee cartilage defect model, ETS/CS reduced VEC activation, migration, angiogenesis in new tissues, inhibited macrophage infiltration and inflammation, promoted chondrogenic differentiation of BMSCs in the defective areas. Conclusions: CD62E- and ROS-responsive ETS/CS promoted cartilage repair by inhibiting VEC activation and macrophage inflammation and promoting BMSC chondrogenesis. Therefore, it is a promising therapeutic strategy to promote articular cartilage repair.

Interfering with Dusp2 alleviates high glucose-induced vascular endothelial cell dysfunction by promoting p38 MAPK pathway activation

BACKGROUND

Hyperglycemia-induced vascular endothelial cell dysfunction is a major factor contributing to diabetic lower extremity ischemia. We intend to investigate the role of Dusp2 in hyperglycemia-induced vascular endothelial cell dysfunction and related mechanisms.

METHODS

The human umbilical vein endothelial cells (HUVECs) were treated with high glucose (HG) as the cell model. Streptozotocin injection was performed to induce diabetes and femoral artery ligation was to induce hind limb ischemia in mice. The levels of Dusp2, p-p38 MAPK, E2F4, and p38 MAPK were evaluated by Western blot or quantitative real-time PCR. The laser Doppler perfusion imaging was conducted to measure blood flow recovery. The cell counting kit-8, transwell, and tube formation assay were performed to evaluate cell proliferation, migration, and angiogenesis, respectively. CD31 immunohistochemical staining was carried out to detect the capillary density of gastrocnemius. The dual-luciferase reporter gene assay and Chromatin immunoprecipitation assay were executed to explore the interaction between E2F4 and Dusp2.

RESULTS

Dusp2 was highly expressed in HG-induced HUVECs and diabetic lower extremity ischemia model mice. Interference with Dusp2 promoted cell proliferation, migration, and angiogenesis, as well as alleviated mouse diabetic hindlimb ischemia. Dusp2 knockdown up-regulated p-p38 MAPK levels. We verified the binding between E2F4 and Dusp2. Overexpressing E2F4 suppressed Dusp2 levels and promoted cell proliferation, migration, and angiogenesis, co-overexpression of Dusp2 reversed the results.

CONCLUSIONS

Overexpressing E2F4 promotes endothelial cell proliferation, migration, and angiogenesis by inhibiting Dusp2 expression and activating p38 MAPK to alleviate vascular endothelial cell dysfunction under HG stimulation.

Knockdown of KLF5 ameliorates renal fibrosis in MRL/lpr mice via inhibition of MX1 transcription

OBJECTIVE

This study aims to elucidate the role of Kruppel-like factor (KLF5) and myxovirus resistance 1 (MX1) in the progression of renal fibrosis in lupus nephritis (LN).

METHODS

First, the expression of KLF5 and MX1 was assessed in the peripheral blood of LN patients and healthy participants. Next, the pathological changes in renal tissues were evaluated and compared in BALB/c and MRL/lpr mice, by detecting the expression of fibrosis marker proteins (transforming growth factor-β [TGF-β] and CTGF) and α-SMA, the content of urine protein, and the levels of serum creatinine, blood urea nitrogen, and serum double-stranded DNA antibody. In TGF-β1-induced HK-2 cells, the messenger RNA levels of KLF5 and MX1 were tested by qRT-PCR, and the protein expression of α-SMA, type I collagen (Col I), fibronectin (FN), and matrix metalloproteinase 9 (MMP9) was measured by western blot analysis. Moreover, the relationship between KLF5 and MX1 was predicted and verified.

RESULTS

In renal tissues of MRL/lpr mice and the peripheral blood of LN patients, KLF5 and MX1 were highly expressed. Pearson analysis revealed that KLF5 was positively correlated with MX1. Furthermore, KLF5 bound to MX1 promoter and promoted its transcription level. MRL/lpr mice showed substantial renal injury, accompanied by increased expression of α-SMA, TGF-β, CTGF, Col I, FN, and MMP9. Injection of sh-KLF5 or sh-MX1 alone in MRL/lpr mice reduced renal fibrosis in LN, while simultaneous injection of sh-KLF5 and ad-MX1 exacerbated renal injury and fibrosis. Furthermore, we obtained the same results in TGF-β1-induced HK-2 cells.

CONCLUSION

Knockdown of KLF5 alleviated renal fibrosis in LN through repressing the transcription of MX1.

Blockade of KLF5/LDH-A feedback loop contributes to Curcumol inhibition of sinusoidal endothelial cell glycolysis and mitigation of liver fibrosis

BACKGROUND

LSECs (Liver sinusoidal endothelial cells) are the portal of liver, their pathological angiogenesis plays a constructive role in etiopathogenesis of liver fibrosis by affecting liver tissue repair and inflammatory drive. Although intervention in angiogenesis can effectively inhibit abnormal activation of LSEC, no effective drugs have been found to treat liver fibrosis.

PURPOSE

We investigated the effect of the natural compound Curcumol on LSEC angiogenesis and elucidated the novel underlying mechanism, expecting to provide a scientific basis for exploring potential therapeutic drugs for liver fibrosis.

METHODS

Various cellular and molecular assays, as well as genetic assays, were used to detect pathological angiogenesis and changes in glycolysis levels in cultured rat LSECs and mouse liver fibrosis models.

RESULTS

Transcription factor KLF5 is able to influence the angiogenic properties of LSEC by regulating the glycolytic process, and affect the expression of LDH-A by transcriptionally binding to its promoter. In our study, we were surprised to find that LDH-A (the final step of glycolysis) has a strong regulatory effect on the glycolytic process of LSEC. Through in-depth study, we found that LDH-A could affect the transcriptional activity of KLF5, thus forming a positive feedback loop. Curcumol could break this positive feedback loop and inhibit the glycolysis-dependent angiogenic nature of LSEC, thus alleviating liver fibrosis. Curcumol reduced extracellular matrix (ECM) deposition, attenuated pathological angiogenesis in LSEC, and decreased the level of CCl₄-induced liver fibrosis in mice.

CONCLUSION

Our results demonstrated the great utilization potentiality of KLF5 in liver fibrosis, and the innovative discovery that LDH-A regulates the glycolytic process and forms a malignant feedback loop by exerting non-enzymatic effects. It also reveals the prospect of Curcumol-regulated KLF5/LDH-A feedback loop in the treatment of liver fibrosis, providing a new option for the future medicine of liver fibrosis.

Curcumol suppresses endothelial-to-mesenchymal transition via inhibiting the AKT/GSK3β signaling pathway and alleviates pulmonary arterial hypertension in rats

Endothelial dysfunction is essential in pulmonary arterial hypertension (PAH) pathogenesis and is considered to be a therapeutic target of PAH. Curcumol is a bioactive sesquiterpenoid with pharmacological properties including restoring endothelial cells damage. This study aimed to evaluate the effect of curcumol on PAH rats and investigate its possible mechanisms. PAH was induced by subcutaneous injection of 60 mg/kg monocrotaline (MCT) in male Sprague Dawley rats. Curcumol (12.5, 25, and 50 mg/kg/day) were administered by intragastric administration for 3 weeks. The results demonstrated that curcumol dose-dependently alleviated MCT-induced right ventricular hypertrophy and pulmonary arterial wall thickness. In addition, endothelial-to-mesenchymal transition (EndMT) in the pulmonary arteries of MCT-challenged rats was inhibited after curcumol treatment, as evidenced by the restored expressions of endothelial and myofibroblast markers. The possible pharmacological mechanisms of curcumol were analyzed using network pharmacology. After screening the common therapeutic targets of PAH and curcumol by searching related databases and comparison, pathway enrichment was performed and AKT/GSK3β was screened out as a possible signaling pathway which was relevant to the therapeutic mechanism of curcumol on PAH. Western blot analysis verified this in lung tissues. Moreover, combination of TNF-α, TGF-β1 and IL-1β-induced EndMT in primary rat pulmonary arterial endothelial cells were blocked by curcumol, and this effect was resembled by PI3K/AKT inhibitor LY294002. Above all, our study suggested that curcumol inhibited EndMT via inhibiting the AKT/GSK3β signaling pathway, which may contribute to its alleviated effect on PAH. Curcumol may be developed as a therapeutic for PAH in the future.

Analysis on internal mechanism of zedoary turmeric in treatment of liver cancer based on pharmacodynamic substances and pharmacodynamic groups

Zedoary tumeric (Curcumae Rhizoma, Ezhu in Chinese) has a long history of application and has great potential in the treatment of liver cancer. The antiliver cancer effect of zedoary tumeric depends on the combined action of multiple pharmacodynamic substances. In order to clarify the specific mechanism of zedoary tumeric against liver cancer, this paper first analyzes the mechanism of its single pharmacodynamic substance against liver cancer, and then verifies the joint anti liver cancer mechanism of its "pharmacodynamic group". By searching the research on the antihepatoma effect of active components of zedoary tumeric in recent years, we found that pharmacodynamic substances, including curcumol, zedoarondiol, curcumenol, curzerenone, curdione, curcumin, germacrone, β-elemene, can act on multi-target and multi-channel to play an antihepatoma role. For example, curcumin can regulate miR, GLO1, CD133, VEGF, YAP, LIN28B, GPR81, HCAR-1, P53 and PI3K/Akt/mTOR, HSP70/TLR4 and NF-κB. Wnt/TGF/EMT, Nrf2/Keap1, JAK/STAT and other pathways play an antihepatoma role. Network pharmacological analysis showed that the core targets of the "pharmacodynamic group" for anti-life cancer are AKT1, EGFR, MAPK8, etc, and the core pathways are neuroactive live receiver interaction, nitrogen metabolism, HIF-1 signaling pathway, etc. At the same time, by comparing and analyzing the relationship between the specific mechanisms of pharmacodynamic substance and "pharmacodynamic group", it is found that they have great reference significance in target, pathway, biological function, determination of core pharmacodynamic components, formation of core target protein interaction, in-depth research of single pharmacodynamic substance, increasing curative effect and so on. By analyzing the internal mechanism of zedoary tumeric pharmacodynamic substance and "pharmacodynamic group" in the treatment of liver cancer, this paper intends to provide some ideas and references for the deeper pharmacological research of zedoary tumeric and the relationship between pharmacodynamic substance and "pharmacodynamic group".

Effects of diet, BMP-2 treatment, and femoral skeletal injury on endothelial cells derived from the ipsilateral and contralateral limbs

Type 2 diabetes (T2D) results in physiological and structural changes in bone, contributing to poor fracture healing. T2D compromises microvascular performance, which can negatively impact bone regeneration as angiogenesis is required for new bone formation. We examined the effects of bone morphogenetic protein-2 (BMP-2) administered locally at the time of femoral segmental bone defect (SBD) surgery, and its angiogenic impacts on endothelial cells (ECs) isolated from the ipsilateral or contralateral tibia in T2D mice. Male C57BL/6 mice were fed either a low-fat diet (LFD) or high-fat diet (HFD) starting at 8 weeks. After 12 weeks, the T2D phenotype in HFD mice was confirmed via glucose and insulin tolerance testing and echoMRI, and all mice underwent SBD surgery. Mice were treated with BMP-2 (5 µg) or saline at the time of surgery. Three weeks postsurgery, bone marrow ECs were isolated from ipsilateral and contralateral tibias, and proliferation, angiogenic potential, and gene expression of the cells was analyzed. BMP-2 treatment increased EC proliferation by two fold compared with saline in LFD contralateral tibia ECs, but no changes were seen in surgical tibia EC proliferation. BMP-2 treatment enhanced vessel-like structure formation in HFD mice whereas, the opposite was observed in LFD mice. Still, in BMP-2 treated LFD mice, ipsilateral tibia ECs increased expression of CD31, FLT-1, ANGPT1, and ANGPT2. These data suggest that the modulating effects of T2D and BMP-2 on the microenvironment of bone marrow ECs may differentially influence angiogenic properties at the fractured limb versus the contralateral limb.

Histamine Deficiency Promotes Myofibroblasts Transformation from HDC-Expressing CD11b+ Myeloid Cells in Injured Hearts Post Myocardial Infarction

Myocardial infarction (MI) is a significant contributor to the development of heart failure. Histidine decarboxylase (HDC), the unique enzyme that converts L-histidine to histamine, is highly expressed in CD11b⁺ immature myeloid cells. However, the relationship between HDC-expressing macrophages and cardiac myofibroblasts remains to be explained. Here, we demonstrate that the GFP (green fluorescent protein)-labeled HDC⁺CD11b⁺ myeloid precursors and their descendants could differentiate into fibroblast-like cells in myocardial interstitium. Furthermore, we prove that CD11b⁺Ly6C⁺ monocytes/macrophages, but not CD11b⁺Ly6G⁺ granulocytes, are identified as the main cellular source for bone marrow-derived myofibroblast transformation, which could be regulated via histamine H1 and H2 receptor-dependent signaling pathways. Using HDC knockout mice, we find that histamine deficiency promotes myofibroblast transformation from Ly6C⁺ macrophages and cardiac fibrosis partly through upregulating the expression of Krüppel-like factor 5 (KLF5). Taken together, our data uncover a central role of HDC in regulating bone marrow-derived macrophage-to-myofibroblast transformation but also identify a histamine receptor (HR)-KLF5 related signaling pathway that mediates myocardial fibrosis post-MI. CD11b⁺Ly6C⁺ monocytes/macrophages are the main cellular source for bone marrow-derived myofibroblast transformation. Histamine inhibits myofibroblasts transformation via H1R and H2R-dependent signaling pathways, and ameliorates cardiac fibrosis partly through upregulating KLF5 expression.

Pharmacological properties of baicalin on liver diseases: a narrative review

Baicalin is the main active component of Scutellaria baicalensis, widely used in traditional Chinese medicine thanks to its various pharmacological effects, such as anti-tumor, anti-inflammatory, and antibacterial properties, as well as cardiovascular, hepatic, and renal protective effect. Recently, the protective effects of baicalin on liver disease have received much more attention. Several studies showed that baicalin protects against several types of liver diseases including viral hepatitis, fatty liver disease, xenobiotic induced liver injury, cholestatic liver injury, and hepatocellular carcinoma, with a variety of pharmacological mechanisms. A comprehensive understanding of the mechanism of baicalin can provide a valuable reference for its clinical use, but up to now, no narrative review is available that summarizes the pharmacological effects of baicalin to clarify its potential use in the treatment of liver diseases. Therefore, this review summarizes the progress of baicalin research and the underlying mechanism in the treatment of various liver diseases, to promote further research and its clinical application.