Genipin ameliorates hypertension-induced renal damage via the angiotensin II-TLR/MyD88/MAPK pathway

Comprehensive Metabolite Identification of Genipin in Rats Using Ultra-High-Performance Liquid Chromatography Coupled with High Resolution Mass Spectrometry

Genipin, an aglycone of geniposide, is a rich iridoid component in the fruit of Gardenia jasminoides Ellis and has numerous biological activities. However, its metabolic profiles in vivo and vitro remain unclear. In this study, an effective analytical strategy based on ultra-high-performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS) in positive and negative ion modes was developed to analyze and identify genipin metabolites in rat urine, blood, feces, and fecal fermentation in combination with many methods including post-collection data mining methods, high-resolution extracted ion chromatography (HREIC), and multiple mass defect filtering (MMDF). Simultaneously, the metabolites of genipin in vivo were verified by fecal fermentation of SD rats at different times. Finally, based on information such as reference substances, chromatographic retention behavior, and accurate mass determination, a total of 50 metabolites (including prototypes) were identified in vivo. Among them, 7, 31 and 28 metabolites in vivo were identified in blood, urine, and feces, respectively. Our results showed that genipin could generate different metabolites that underwent multiple metabolic reactions in vivo including methylation, hydroxylation, dehydroxylation, hydrogenation, sulfonation, glucuronidation, demethylation, and their superimposed reactions. Forty-six metabolites were verified in vitro. Meanwhile, 2 and 19 metabolites identified in blood and urine were also verified in fecal fermentation at different times. These results demonstrated that metabolites were produced in feces and reabsorbed into the body. In conclusion, the newly discovered metabolites of genipin can provide a new perspective for understanding its pharmacological effects and build the foundation for thee toxicity and safety evaluations of genipin.

Patchouli alcohol against renal fibrosis of spontaneously hypertensive rats via Ras/Raf-1/ERK1/2 signalling pathway

OBJECTIVES

The present study was designed to obverse the protection of patchouli alcohol (PA) ameliorates hypertensive nephropathy in spontaneously hypertensive rats (SHR) and reveals potential mechanism.

METHODS

Briefly, the adult spontaneously hypertensive rats (SHR) or Wistar-Kyoto (WKY) rats (half male and half female) were intragastric gavaged or not with PA (80, 40 and 20 mg/kg) for 8 weeks. Body weight, blood pressure (BP), renal weight, renal function and renal morphology were measured. Further, western blotting and immunohistochemical analysis were used to study the underlying mechanism.

KEY FINDINGS

Compared with the WKY group, plasmatic levels of renin, angiotensin II (Ang-II), transforming growth factor beta 1(TGF-β1), plasminogen activator inhibitor-1(PAI-1), creatinine (Cr), blood urea nitrogen (BUN), renal index, mRNA levels of ERK1/2 and α-SMA were significantly increased in SHR. Histology results showed that renal tubular injury and tubulointerstitial fibrosis occurred in SHR. After administration, SBP of captopril group decreased at each week after administration, especially at 3, 5, 6 7 and 8 weeks (P < 0.05 or P < 0.01). There is no significant effect was assessed in the olive oil group. Decreased plasma Cr, Renin, Ang-II, TGF-β1, PAI-1, SCFAs and Renin, TGF-β1, PAI-1 in renal tissues were observed significantly in captopril (P <0.05 or P < 0.01). Plasma BUN, Ang-II, TGF-β1 and PAI-1 in renal tissues decreased in the olive oil group significantly (P <0.05 or P < 0.01). PA (80, 40 and 20 mg/kg) lowered BP and plasmatic levels of Renin, Ang-II, TGF-β1 and PAI-1. Treatment with PA (40, 20 mg/kg) decreased levels of Cr, BUN and suppressed of activation of pro-fibrosis cytokines including TGF-β1 in kidney. There is no ameliorative change in the olive oil group and the captopril group (P > 0.05) while PA treatment alleviated renal tubular injury and produced dramatic collagen fibre area reductions in mesangial membrane, basement membrane, and renal interstitium obviously (P < 0.05 or P < 0.01). Treatment of SHR with PA-inhibited MFB activation and downregulated mRNA of α-SMA. Treatment with PA suppressed excessive production of the extracellular matrix (ECM) via decreasing Col I, III and FN, downregulating mRNA of tissue inhibitor of TIMP-1 along with upregulating mRNA of MMP-9. The expression of Col III and MMP-9 mRNA-reduced in the captopril group (P < 0.05). In addition, the expression of ERK1/2 and pERK1/2 also reduced in the captopril group significantly (P < 0.05 or P < 0.01). Treatment with PA (20 mg/kg) downregulated proteins expression of Raf-1, ERK1/2 and pERK1/2 and mRNA expression of Ras, Raf-1 and ERK1/2.

CONCLUSIONS

Overall, PA restored normal BP, alleviated renal dysfunction and renal fibrosis, possibly by suppressing Ang II and TGF-β1-mediated Ras/Raf-1/ERK1/2 signalling pathway.

Effects of TLR9/NF-κB on oxidative stress and inflammation in IPEC-J2 cells

BACKGROUND

Oxidative stress is one of the most important factors affecting large-scale breeding, especially the performance of pigs. Oxidative stress plays a role by affecting various genes in pigs, which can cause serious body damage, functional degradation and reduce production performance.

OBJECTIVE

The purpose of this study was to investigate the effect of Toll like receptor 9 (TLR9) pathway on IPEC-J2 cells under oxidative stress and to provide reference for the growth development of Dapulian pigs.

METHODS

In this study, Diquat was used as a source of oxidative stress to study the effects on Dapulian pigs by detecting relevant indicators. Then the IPEC-J2 cells were selected to verify the TLR9 signaling pathway in oxidative stress.

RESULTS

Compared with the control group, superoxide dismutase (SOD) in experimental group decreased significantly, malondialdehyde (MDA) was significantly increased, accompanied by inflammatory reaction, and inflammatory factors were significantly increased in the experimental group. Oxidative stress model was constructed by H2O2 incubating IPEC-J2 cells. The interference and overexpression vectors of TLR9 and myeloid differentiation primary response protein 88 (MyD88) were constructed to detect the activity of antioxidant enzymes and related proteins. The results showed that overexpression of TLR9 enhanced the activity of antioxidant enzymes, decreased the secretion of inflammatory factors, and decreased the activity of MDA，reactive oxygen species (ROS); the results were opposite after TLR9 interference. This study also showed that H₂O₂ can activate the nuclear factor-κB (NF-κB) pathway and promote the translocation of NF-κB into the nucleus. After co-transfection with TLR9 and MyD88, the results showed that TLR9 regulated the expression of NF-κB through MyD88.

CONCLUSION

The study showed that TLR9 pathway had a significant positive effect on antioxidant.

Protection of Toll-Like Receptor 9 Against Lipopolysaccharide-Induced Inflammation and Oxidative Stress of Pulmonary Epithelial Cells via MyD88-Mediated Pathways

Acute lung injury (ALI) caused by lipopolysaccharide (LPS) is a common, severe clinical syndrome. Injury caused by inflammation and oxidative stress in vascular endothelial and alveolar epithelial cells is a vital process in the pathogenesis of ALI. Toll-like receptor 9 (TLR9) is highly expressed in LPS-induced ALI rats. In this study, Beas-2B human pulmonary epithelial cells and A549 alveolar epithelial cells were stimulated by LPS, resulting in the upregulation of TLR9 in a concentration-dependent manner. Furthermore, TLR9 overexpression and interference vectors were transfected before LPS administration to explore the role of TLR9 in LPS-induced ALI in vitro. The findings revealed that inhibition of TLR9 reduced inflammation and oxidative stress while suppressing apoptosis of LPS-induced Beas-2B and A549 cells, whereas TLR9 overexpression aggravated these conditions. Moreover, TLR9 inhibition resulted in downregulated protein expression of myeloid differentiation protein 88 (MyD88) and activator activator protein 1 (AP-1), as well as phosphorylation of nuclear factor-B (NF-B), c-Jun N terminal kinase (JNK), and p38 mitogen-activated protein kinase (MAPK). The phosphorylation of extracellular-regulated protein kinases 1/2 was upregulated compared to that of cells subjected to only LPS administration, and this was reversed by TLR9 overexpression. These results indicate that inhibition of TLR9 plays a protective role against LPS-induced inflammation and oxidative stress in Beas-2B and A549 cells, possibly via the MyD88/NF-B and MyD88/MAPKs/AP-1 pathways.

Novel Findings regarding the Bioactivity of the Natural Blue Pigment Genipin in Human Diseases

Genipin is an important monoterpene iridoid compound isolated from Gardenia jasminoides J.Ellis fruits and from Genipa americana fruits, or genipap. It is a precursor of a blue pigment which may be attractive alternative to existing food dyes and it possesses various potential therapeutic properties such as anti-cancer, anti-diabetic and hepatoprotective activity. Biomedical studies also show that genipin may act as a neuroprotective drug. This review describes new aspects of the bioactivity of genipin against various diseases, as well as its toxicity and industrial applications, and presents its potential mechanism of action.

Study on Toll-Like Receptor 2-Mediated Inflammation-Induced Familial Hypertension Combined with Hyperlipemia and Its Mechanism

According to the latest clinical data, cardiovascular diseases have ranked first in prone diseases, causing 40% of the premature deaths of China's population. This study aimed to investigate the influence of Toll-like receptor 2- (TLR2-) mediated inflammation on the occurrence and development of familial hypertension combined with hyperlipemia and its related mechanism. Blood specimens from 66 patients undergoing coronary atherosclerosis were collected and grouped, including 22 patients into the control group, 25 into the familial hypertension group, and 19 into familial hypertension combined with hyperlipemia group. In this study, ELISA was conducted for determining the levels of four inflammatory factors of TLR2 and IL-1β, IL-6, TNF-ɑ, and CCL2 in serum and the levels of relevant indicators in mice. C57Bl/6j and genetically engineered C.129(B6)-Tlr2tm1Kir/J mice were given subcutaneous injection of normal saline (wild-saline group), 8-week 40% high-fat diet (wild-high-fat group), and subcutaneous Alzet-implanted angiotensin II micropump supplemented with the research diet (wild-high fat-Ang II group, Tlr2 ^-/- -high fat-Ang II group). Blood pressure in mice was recorded consecutively with a noninvasive hemopiezometer for eight weeks. TLR2 and IL-1β, IL-6, TNF-ɑ, and CCL2 in serum of patients with familial hypertension combined with hyperlipemia and the hypertension combined with hyperlipemia mouse model were higher than those in the normal group. Under combined intervention of Ang II and the research diet, mRNA expression related to blood pressure, blood lipid, and fat metabolism in Tlr2 ^-/- genetically engineering mice was significantly lower than that in the wild-high fat-Ang II group. The phosphorylation levels of AKT, IKK, and p65 in mice with hypertension combined with hyperlipidemia were significantly higher than those in normal group. The levels of blood pressure and blood lipid in mice after blocking the AKT or NF-κB pathway were significantly downregulated compared with those in the wild-high fat-Ang II group, with statistically significant differences (both P < 0.05). In conclusion, TLR2 regulates inflammation through Akt-NF-κB pathway, thus inducing the occurrence and development of familial hypertension combined with hyperlipemia.

Potassium Alginate Oligosaccharides Alter Gut Microbiota, and Have Potential to Prevent the Development of Hypertension and Heart Failure in Spontaneously Hypertensive Rats

Food-derived oligosaccharides show promising therapeutic potential in lowering blood pressure (BP), but the mechanism is poorly understood. Recently, the potential role of gut microbiota (GM) in hypertension has been investigated, but the specific GM signature that may participate in hypertension remains unclear. To test the potassium alginate oligosaccharides (PAO) mechanism in lowering BP and specific microbial signature changes in altering GM, we administered various dosages of PAO in 40 spontaneously hypertensive rats for a duration of six weeks. We analyzed BP, sequenced the 16S ribosomal DNA gene in the cecum content, and gathered RNA-seq data in cardiac tissues. We showed that the oral administration of PAO could significantly decrease systolic BP and mean arterial pressure. Transcriptome analyses demonstrated that the protective effects of developing heart failure were accompanied by down-regulating of the Natriuretic Peptide A gene expression and by decreasing the concentrations of angiotensin II and atrial natriuretic peptide in plasma. In comparison to the Vehicle control, PAO could increase the microbial diversity by altering the composition of GM. PAO could also decrease the ratio of Firmicutes to Bacteroidetes by decreasing the abundance of Prevotella and Phascolarctobacterium bacteria. The favorable effect of PAO may be added to the positive influence of the abundance of major metabolites produced by Gram-negative bacteria in GM. We suggest that PAO caused changes in GM, and thus, they played an important role in preventing the development of cardiovascular disease.

Benzoylaconine Modulates LPS-Induced Responses Through Inhibition of Toll-Like Receptor-Mediated NF-κB and MAPK Signaling in RAW264.7 Cells

Previous studies have shown that benzoylaconine (BAC), a representative monoester alkaloid, has a potential anti-inflammatory effect. This study investigated the underlying molecular mechanisms using the mode of LPS-activated RAW264.7 macrophage cells. Our findings showed that BAC significantly suppressed the release of pro-inflammatory cytokines and mediators, including IL-6, TNF-α, IL-1β, ROS, NO, and PGE₂. BAC treatment also effectively downregulated the elevated protein levels of iNOS and COX-2 induced by LPS in a dose-dependent manner. In this study, we found that BAC inhibited LPS-induced NF-κB activation by reducing the phosphorylation and degradation of IκBα by western blotting and blocking the nuclear translocation of p65 using an immunofluorescence assay. The elevated protein levels of JNK, p38, and ERK phosphorylation after LPS stimulation were restored effectively by BAC treatment. The protein expression of Toll-like receptor 4 (TLR4) and LPS-induced phosphorylation of TAK1, which is a crucial upstream regulatory factor of TLR-induced MAPK and NF-κB signaling, were inhibited by BAC in activated RAW264.7 macrophages. Moreover, BAC decreased the levels of TAK1 phosphorylation and pro-inflammatory cytokines and mediators associated with MAPK and NF-κB activation, similar to TLR4 inhibitor TAK-242. These findings demonstrated that BAC exhibited an anti-inflammatory effect by the inhibition of TLR-induced MAPK and NF-κB pathways, indicating that it could potentially be used for treating inflammatory diseases.

Toll-Like Receptors Regulate the Development and Progression of Renal Diseases

Background

Stimulated by both microbial and endogenous ligands, toll-like receptors (TLRs) play an important role in the development and progression of renal diseases.

Summary

As a highly conserved large family, TLRs have 11 members in humans (TLR1∼TLR11) and 13 members in mouse (TLR1∼TLR13). It has been widely reported that TLR2 and TLR4 signaling, activated by both exogenous and endogenous ligands, promote disease progression in both renal ischemia-reperfusion injury and diabetic nephropathy. TLR4 also vitally functions in CKD and infection-associated renal diseases such as pyelonephritis induced by urinary tract infection. Stimulation of intracellular TLR7/8 and TLR9 by host-derived nucleic acids also plays a key role in systemic lupus erythematosus. Given that certain microRNAs with GU-rich sequence have recently been found to be able to serve as TLR7/8 ligands, these microRNAs may initiate pro-inflammatory signal via activating TLR signal. Moreover, as microRNAs can be transferred across different organs via cell-secreted exosomes or protein-RNA complex, the TLR signaling activated by the miRNAs released by other injured organs may also result in renal dysfunction.

Key Messages

In this review, we sum up the recent progress in the role of TLRs in various forms of glomerulonephritis and discuss the possible prevention or therapeutic strategies for clinic treatment to renal diseases.

Mechanism of herbal medicine on hypertensive nephropathy (Review)

Hypertensive nephropathy is the most common complication of hypertension, and is one of the main causes of end-stage renal disease (ESRD) in numerous countries. The basic pathological feature of hypertensive nephropathy is arteriolosclerosis followed by renal parenchymal damage. The etiology of this disease is complex, and its pathogenesis is mainly associated with renal hemodynamic changes and vascular remodeling. Despite the increased knowledge on the pathogenesis of hypertensive nephropathy, the current clinical treatment methods are still not effective in preventing the development of the disease to ESRD. Herbal medicine, which is used to relieve symptoms, can improve hypertensive nephropathy through multiple targets. Since there are few clinical studies on the treatment of hypertensive nephropathy with herbal medicine, this article aims to review the progress on the basic research on the treatment of hypertensive nephropathy with herbal medicine, including regulation of the renin angiotensin system, inhibition of sympathetic excitation, antioxidant stress and anti-inflammatory protection of endothelial cells, and improvement of obesity-associated factors. Herbal medicine with different components plays a synergistic and multi-target role in the treatment of hypertensive nephropathy. The description of the mechanism of herbal medicine in the treatment of hypertensive nephropathy will contribute towards the progress of modern medicine.

Bioinformatic analysis reveals novel hub genes and pathways associated with hypertensive nephropathy

AIM

Hypertensive nephropathy (HTN) is one of the leading causes of end-stage renal disease and is closely associated with inflammation and tubule-interstitial fibrosis. The molecular mechanism underlying HTN remains unclear. This study used bioinformatic analysis to identify the novel gene targets for HTN.

METHODS

We downloaded the microarray data of GSE99325 and GSE32591 from Gene Expression Omnibus. The dataset comprised 20 HTN and 15 normal samples. The differentially expressed genes (DEG) were identified, and then gene ontology (GO) enrichment was performed, and a GO tree was constructed by using clusterProfiler and ClueGO. In addition, a protein-protein interaction network was established using the Search Tool for the Retrieval of Interacting Genes database and visualized by Cytoscape. The novel hub genes were validated in in vitro experiments.

RESULTS

A total of 267 genes (117 up-regulated and 150 down-regulated genes) were identified as DEG. GO analysis and the GO tree indicated that the DEG were mainly associated with steroid hormone response and the extracellular matrix. Based on the protein-protein interaction network, we screened out several novel hub genes. Considering the findings and the literature review, we focused on and validated the dual specificity phosphatase 1, tissue inhibitor of matrix metalloproteinases 1, fos proto-oncogene and jun proto-oncogenes, which may play significant roles in the pathogenesis of HTN. These findings were consistent with the bioinformatic results for the in vitro validation.

CONCLUSION

This study identified for the first time novel hub genes with microarray data in HTN by using bioinformatic analysis and provided novel evidence and clues for future works.

Genipin protects against H2O2-induced oxidative damage in retinal pigment epithelial cells by promoting Nrf2 signaling

Oxidative stress serves a vital function in the pathogenesis of age-related macular degeneration (AMD); genipin (GP) possesses antioxidative properties. The present study aimed to investigate the effects of GP on retinal pigment epithelial (RPE) cells induced by H₂O₂ and the underlying mechanism. ARPE-19 cells were subjected to H₂O₂ treatment to induce oxidative damage. Cell viability was determined via an MTT assay. Reactive oxygen species (ROS) levels and cell apoptosis were detected by flow cytometry. Nuclear factor-erythroid 2-related factor-2 (Nrf2) signaling-associated and the expression of apoptosis-associated factors were measured using reverse transcription-quantitative polymerase chain reaction assay and western blotting. The results revealed that 200 µM H₂O₂ and 30 µM GP were determined to be the optimal concentrations for subsequent experimentation. GP reversed the inhibitory effects of H₂O₂ by promoting cell viability, attenuating ROS accumulation and cell apoptosis, and increased the expression of Nrf2, heme oxygenase-1 (HO-1) and NAD(P)H: Quinine oxidoreductase 1 (NQO1); Nrf2 silencing inhibited HO-1 and NQO1 expression. In addition, Nrf2 silencing enhanced the effects of H₂O₂ by promoting ROS production and cell apoptosis. Compared with H₂O₂, Nrf2 silencing further decreased the expression levels of B-cell lymphoma-2 (Bcl-2), but increased that of Bcl-2-associated X protein and cleaved-caspase-3. The results of the present study revealed that Nrf2 silencing attenuated the protective effects of GP on H₂O₂-induced injury in ARPE-19 cells by promoting apoptosis and oxidation. Collectively, GP attenuated oxidative damage induced by H₂O₂ in ARPE-19 cells. Furthermore, the molecular mechanism may be associated with the Nrf2 signaling pathway. The findings of the present study nay provide insight into a potential therapeutic agent for the treatment of AMD.

Therapeutic Potential and Effective Components of the Chinese Herb Gardeniae Fructus in the Treatment of Senile Disease

Gardeniae fructus (GF), an evergreen Rubiaceae shrub, is one of the most commonly used Chinese herbs in traditional Chinese medicine (TCM) and has been used for over a thousand years. It is usually prescribed for the treatment of brain aging, vascular aging, bone and joint aging, and other age-related diseases. It has been demonstrated that several effective compounds of GF, such as geniposide, genipin and crocin, have neuroprotective or related activities which are involved in senile disease treatment. These bioactivities include the mitochondrion dysfunction, antioxidative activity, apoptosis regulation and an anti-inflammatory activity, which related to multiple signaling pathways such as the nuclear factor-κB pathway, AMP-activated protein kinase signaling pathway, and the mitogen-activated protein kinase pathway. To lay the ground for fully elucidating the potential mechanisms of GF in treating age-related pathologies, we summarized the available research conducted in the last fifteen years about GF and its effective components, which have been studied in vivo and in vitro

Monoterpenes modulating cytokines - A review

Inflammatory response can be driven by cytokine production and is a pivotal target in the management of inflammatory diseases. Monoterpenes have shown that promising profile as agents which reduce the inflammatory process and also modulate the key chemical mediators of inflammation, such as pro and anti-inflammatory cytokines. The main interest focused on monoterpenes were to develop the analgesic and anti-inflammatory drugs. In this review, we summarized current knowledge on monoterpenes that produce anti-inflammatory effects by modulating the release of cytokines, as well as suggesting that which monoterpenoid molecules may be most effective in the treatment of inflammatory disease. Several different inflammatory markers were evaluated as a target of monoterpenes. The proinflammatory and anti-inflammatory cytokines were found TNF-α, IL-1β, IL-2, IL-5, IL-4, IL-6, IL-8, IL-10, IL-12 IL-13, IL-17A, IFNγ, TGF-β1 and IFN-γ. Our review found evidence that NF-κB and MAPK signaling are important pathways for the anti-inflammatory action of monoterpenes. We found 24 monoterpenes that modulate the production of cytokines, which appears to be the major pharmacological mechanism these compounds possess in relation to the attenuation of inflammatory response. Despite the compelling evidence supporting the anti-inflammatory effect of monoterpenes, further studies are necessary to fully explore their potential as anti-inflammatory compounds.

Vaccarin alleviates hypertension and nephropathy in renovascular hypertensive rats

The kidney is an important organ in the regulation of blood pressure, and it is also one of the primary target organs of hypertension. Kidney damage in response to hypertension eventually leads to renal insufficiency. The authors previously demonstrated that vaccarin exhibits a protective role in endothelial injury. However, the effects of vaccarin on the two-kidney, one clip (2K1C) renovascular hypertension model and subsequent kidney injury have yet to be fully elucidated. The present study was designed to investigate the roles and mechanisms of vaccarin in attenuating hypertension and whether vaccarin had beneficial effects on kidney injury. The 2K1C rats had greater fibrosis, apoptosis, reactive oxygen species production, inflammation, angiotensin II (Ang II) and angiotensin type 1 (AT1) receptors in the right kidney compared with normotensive rats, which were alleviated by a high dose of vaccarin and captopril. Vaccarin treatment attenuated hypertension, reduced fibrosis markers, NADPH oxidase (NOX)-2, NOX-4, 3-nitrotyrosine, tumor necrosis factor-α, interleukin 1β (IL-1β), and IL-6 protein levels and altered pro-apoptotic protein levels including caspase-3, anti-apoptosis protein B cell lymphoma (Bcl)-2 and Bcl-2 associated X, apoptosis regulator in the right kidney of 2K1C rats. These findings suggest that the protective effects of vaccarin on the right kidney in renovascular hypertension are possibly due to downregulation of fibrosis, inflammatory molecules, oxidative stress, Ang II, and AT1 receptor levels.

Paeonol ameliorates imiquimod-induced psoriasis-like skin lesions in BALB/c mice by inhibiting the maturation and activation of dendritic cells

Paeonol, an active component derived from the traditional Chinese medicine Cortex Moutan, possesses anti-inflammatory, analgesic, antioxidant and anti-allergic properties. Psoriasis is a chronic, recurrent, inflammatory dermatosis accompanied by excessive activation of Toll-like receptors (TLRs) in dendritic cells (DCs), which are primarily responsible for initiating an immune response. We investigated the effect of paeonol on inflammation in an imiquimod (IMQ)-induced psoriasis-like mouse model and murine bone marrow-derived dendritic cells (BMDCs) stimulated by R848. Mice were intragastrically administered 100 mg/kg (high), 50 mg/kg (medium) and 25 mg/kg (low) paeonol, respectively. We evaluated inflammation of psoriasis-like lesions based on histological changes, protein levels of myeloid differentiation factor 88 (MyD88) and TLR8 in skin lesions by western blotting, and levels of CD11c⁺ DCs in skin by immunoassay and in spleens by flow cytometry. Inflammatory cytokines [interleukin (IL)-23, IL-12 and IL-1β] in skin lesions and BMDCs were also assessed by RT-PCR and ELISA. Application of paeonol decreased IMQ-induced keratinocyte proliferation, and infiltration of CD3⁺ cells, while the treatment ameliorated CD11c⁺ cells in the spleen and skin, and reduced MyD88 and TLR8 proteins in skin lesions. Paeonol inhibited IMQ-induced mRNA expression of IL-23, but not IL-12 and IL-1β in BMDCs, along with significantly lower levels of DCs expressing MHCII, CD80 and CD86 in vitro. These results indicate that paeonol suppresses the maturation and activation of DCs by decreasing MyD88 and TLR8 proteins in the TLR7/8 signaling pathway which finally alleviates psoriasis-like skin lesions. The TLR7/8 signaling pathway in DCs provides an important insight into the mechanism of psoriasis, and paeonol may be a potent therapeutic drug for psoriasis.

The interplay between Angiotensin II, TLR4 and hypertension

Hypertension is a multifactorial disease. Although a number of different underlying mechanisms have been learned from the various experimental models of the disease, hypertension still poses challenges for treatment. Angiotensin II plays an unquestionable role in blood pressure regulation acting through central and peripheral mechanisms. During hypertension, dysregulation of the Renin-Angiotensin System is associated with increased expression of pro-inflammatory cytokines and reactive oxygen species causing kidney damage, endothelial dysfunction, and increase in sympathetic activity, among other damages, eventually leading to decline in organ function. Recent studies have shown that these effects involve both the innate and the adaptive immune response. The contribution of adaptive immune responses involving different lymphocyte populations in various models of hypertension has been extensively studied. However, the involvement of the innate immunity mediating inflammation in hypertension is still not well understood. The innate and adaptive immune systems intimately interact with one another and are essential to an effectively functioning of the immune response; hence, the importance of a better understanding of the underlying mechanisms mediating innate immune system during hypertension. In this review, we aim to discuss mechanisms linking Angiotensin II and the innate immune system, in the pathogenesis of hypertension. The newest research investigating Angiotensin II triggering toll like receptor 4 activation in the kidney, vasculature and central nervous system contributing to hypertension will be discussed. Understanding the role of the innate immune system in the development of hypertension may bring to light new insights necessary to improve hypertension management.