[Ligusticum cycloprolactam inhibits IL-1ß-induced apoptosis and inflammation of rat chondrocytes via HMGB1/TLR4/NF-κB signaling pathway].

Chondrocytes are unique resident cells in the articular cartilage, and the pathological changes of them can lead to the occurrence of osteoarthritis(OA). Ligusticum cycloprolactam(LIGc) are derivatives of Z-ligustilide(LIG), a pharmacodynamic marker of Angelica sinensis, which has various biological functions such as anti-inflammation and inhibition of cell apoptosis. However, its protective effect on chondrocytes in the case of OA and the underlying mechanism remain unclear. This study conducted in vitro experiments to explore the molecular mechanism of LIGc in protecting chondrocytes from OA. The inflammation model of rat OA chondrocyte model was established by using interleukin-1ß(IL-1ß) to induce. LIGc alone and combined with glycyrrhizic acid(GA), a blocker of the high mobility group box-1 protein(HMGB1)/Toll-like receptor 4(TLR4)/nuclear factor-kappa B(NF-κB) signaling pathway, were used to intervene in the model, and the therapeutic effects were systematically evaluated. The viability of chondrocytes treated with different concentrations of LIGc was measured by the cell counting kit-8(CCK-8), and the optimal LIGc concentration was screened out. Annexin V-FITC/PI apoptosis detection kit was employed to examine the apoptosis of chondrocytes in each group. The enzyme-linked immunosorbent assay(ELISA) was employed to measure the expression of cyclooxygenase-2(COX-2), prostaglandin-2(PGE2), and tumor necrosis factor-alpha(TNF-α) in the supernatant of chondrocytes in each group. Western blot was employed to determine the protein levels of B-cell lymphoma-2(Bcl-2), Bcl-2-associated X protein(Bax), caspase-3, HMGB1, TLR4, and NF-κB p65. The mRNA levels of HMGB1, TLR4, NF-κB p65, and myeloid differentiation factor 88(MyD88) in chondrocytes were determined by real-time fluorescent quantitative PCR(RT-qPCR). The safe concentration range of LIGc on chondrocytes was determined by CCK-8, and then the optimal concentration of LIGc for exerting the effect was clarified. Under the intervention of IL-1ß, the rat chondrocyte model of OA was successfully established. The modeled chondrocytes showed increased apoptosis rate, promoted expression of COX-2, PGE2, and TNF-α, up-regulated protein levels of Bax, caspase-3, HMGB1, TLR4, and NF-κB p65 and mRNA levels of HMGB1, TLR4, NF-κB p65, and MyD88, and down-regulated protein level of Bcl-2. However, LIGc reversed the IL-1ß-induced changes of the above factors. Moreover, LIGc combined with GA showed more significant reversal effect than LIGc alone. These fin-dings indicate that LIGc extracted and derived from the traditional Chinese medicine A. sinensis can inhibit the inflammatory response of chondrocytes and reduce the apoptosis of chondrocytes, and this effect may be related to the HMGB1/TLR4/NF-κB signaling pathway. The pharmacological effect of LIGc on protecting chondrocytes has potential value in delaying the progression of OA and improving the clinical symptoms of patients, and deserves further study.

Icariin attenuates vascular endothelial dysfunction by inhibiting inflammation through GPER/Sirt1/HMGB1 signaling pathway in type 1 diabetic rats.

Icariin, a flavonoid glycoside, is extracted from Epimedium. This study aimed to investigate the vascular protective effects of icariin in type 1 diabetic rats by inhibiting high-mobility group box 1 (HMGB1)-related inflammation and exploring its potential mechanisms. The impact of icariin on vascular dysfunction was assessed in streptozotocin (STZ)-induced diabetic rats through vascular reactivity studies. Western blotting and immunofluorescence assays were performed to measure the expressions of target proteins. The release of HMGB1 and pro-inflammation cytokines were measured by enzyme-linked immunosorbent assay (ELISA). The results revealed that icariin administration enhanced acetylcholine-induced vasodilation in the aortas of diabetic rats. It also notably reduced the release of pro-inflammatory cytokines, including interleukin-8 (IL-8), IL-6, IL-1ß, and tumor necrosis factor-alpha (TNF-α) in diabetic rats and high glucose (HG)-induced human umbilical vein endothelial cells (HUVECs). The results also unveiled that the pro-inflammatory cytokines in the culture medium of HUVECs could be increased by rHMGB1. The increased release of HMGB1 and upregulated expressions of HMGB1-related inflammatory factors, including advanced glycation end products (RAGE), Toll-like receptor 4 (TLR4), and phosphorylated p65 (p-p65) in diabetic rats and HG-induced HUVECs, were remarkably suppressed by icariin. Notably, HMGB1 translocation from the nucleus to the cytoplasm in HUVECs under HG was inhibited by icariin. Meanwhile, icariin could activate G protein-coupled estrogen receptor (GPER) and sirt1. To explore the role of GPER and Sirt1 in the inhibitory effect of icariin on HMGB1 release and HMGB-induced inflammation, GPER inhibitor and Sirt1 inhibitor were used in this study. These inhibitors diminished the effects of icariin on HMGB1 release and HMGB1-induced inflammation. Specifically, the GPER inhibitor also negated the activation of Sirt1 by icariin. These findings suggest that icariin activates GPER and increases the expression of Sirt1, which in turn reduces HMGB1 translocation and release, thereby improving vascular endothelial function in type 1 diabetic rats by inhibiting inflammation.

Pingchuanning Decotion Alleviates Bronchial Asthma Airway Inflammation Through ROS/HMGB1/Beclin-1 Mediated Cell Autophagy.

Objective: Bronchial asthma is a prevalent respiratory disorder characterized by airway inflammation. This study aimed to investigate the protective effect of Pingchuanning decoction (PCN) on airway inflammation in bronchial asthma, focusing on the role of autophagy and its underlying molecular mechanism. Methods: Using an in vitro lipopolysaccharide (LPS)-induced inflammatory damage model of human airway epithelial cells (16HBE), we assessed the effect of PCN. Various experiments were performed to evaluate the expression of autophagy-related genes, autophagosome and vesicle counts, and reactive oxygen species (ROS) levels. Results: First, PCN reduced LPS-induced cellular inflammation. Second, PCN decreased the number of autophagosomes and autophagic vesicles. And third, PCN significantly reduced reactive oxygen species (ROS) levels. Most importantly, PCN also down-regulated LPS-induced expression of HMGB1, Beclin-1, and autophagy-related gene 5 (ATG5) while enhancing the expression of B-cell lymphoma 2 (Bcl-2), which further reduced the LC3II/I ratio. Conclusion: PCN reduces the 16HBE inflammatory response by inhibiting the overexpression of ROS/HMGB1/Beclin-1 mediated cell autophagy. Therefore, it may serve as a potential drug for treating bronchial asthma.

Catapol attenuates the aseptic inflammatory response to hepatic I/R injury in vivo and in vitro by inhibiting the HMGB1/TLR-4/NF-κB signaling pathway via the microRNA-410-3p.

BACKGROUND: Hepatic ischemia-reperfusion (I/R) injury involves inflammatory necrosis of liver cells as a significant pathological mechanism. Catapol possesses anti-inflammatory activity that is extracted from the traditional Chinese medicine, Rehmannia glutinosa. METHODS: The liver function and histopathology, Oxidative stress, and aseptic inflammatory responses were assessed in vivo, and the strongest dose group was selected. For mechanism, the expression of miR-410-3p, HMGB1, and TLR-4/NF-κB signaling pathways was detected. The dual luciferase assay can verify the targeting relationship between miR-410-3p and HMGB1. Knockdown of miR-410-3p in L02 cells is applied in interference experiments. RESULTS: CAT pre-treatment significantly decreased the liver function markers alanine and aspartate aminotransferases and reduced the areas of hemorrhage and necrosis induced by hepatic I/R injury. Additionally, it reduced the aseptic inflammatory response and oxidative stress, with the strongest protective effect observed in the high-dose CAT group. Mechanistically, CAT downregulates HMGB1, inhibits TLR-4/NF-κB signaling pathway activation, and reduces inflammatory cytokines TNF-α, and IL-1ß. In addition, the I/R-induced downregulation of microRNA-410-3p was inhibited by CAT pre-treatment in vivo and in vitro. HMGB1 was identified as a potential target of microRNA-410-3p using a dual-luciferase reporter assay. Knockdown of microRNA-410-3p abolished the inhibitory effect of CAT on HMGB1, p-NF-κB, and p-IκB-α protein expression. CONCLUSIONS: Our study showed that CAT pre-treatment has a protective effect against hepatic I/R injury in rats. Specifically, CAT attenuates the aseptic inflammatory response to hepatic I/R injury in vivo and in vitro by inhibiting the HMGB1/TLR-4/NF-κB signaling pathway via the microRNA-410-3p.

Puerarin Alleviates Oxidized Oil-Induced Oxidative Injury and Inflammation via Inhibition of the Nrf2/Keap1 and HMGB1/TLR4/MAPK Signaling Pathways: An Investigation in a Chicken Model.

SCOPE: Puerarin has possessed a wide range of pharmacological activities. However, little is known about the protective effects of puerarin on the oxidized oil-induced injury. Here, the antioxidant and anti-inflammatory effects of puerarin are described using a chicken model. METHODS AND RESULTS: A total of 360 broilers are arranged in four treatments. Diets include two types of soybean oil (fresh or oxidized) and two levels of puerarin (0 or 750 mg kg-1 ). Results show that puerarin alleviates oxidized soybean oil-induced hepatic and thymic oxidative injury. This effect is observed by increasing the SOD activity and the expressions of Nrf2 signaling pathway-related genes and reducing the MDA content in the liver and thymus. Moreover, puerarin supplementation decreases the concentrations and mRNA levels of pro-inflammatory factors in the liver and thymus. The potential mechanism responsible for this is the decrease in the mRNA or protein levels of HMGB1, TLR4, MyD88, and p65 in the liver or thymus. Western blotting results indicate that puerarin also decreases the phosphorylation of JNK1/2, ERK1/2, and p38 in the liver and thymus. CONCLUSION: This study demonstrates puerarin may be a potential nutrient supplement in the treatment of oxidized oil-induced damage, and the Nrf2/Keap1 and HMGB1/TLR4/MAPK signaling pathways might be its important target.

[Compound Tinglizi Decoction intervenes COPD-associated pulmonary hypertension through regulation of HMGB1-mediated pyroptosis and immune imbalance].

This paper aimed to investigate the effects of high mobility group box 1(HMGB1)-mediated pulmonary artery smooth muscle cell pyroptosis and immune imbalance on chronic obstructive pulmonary disease-associated pulmonary hypertension(COPD-PH) in rats and the intervening mechanism of Compound Tinglizi Decoction. Ninety rats were randomly divided into a normal group, a model group, low-dose, medium-dose, and high-dose Compound Tinglizi Decoction groups, and a simvastatin group. The rat model of COPD-PH was established by fumigation combined with lipopolysaccharide(LPS) intravascular infusion, which lasted 60 days. Rats in the low, medium, and high-dose Compound Tinglizi Decoction groups were given 4.93, 9.87, and 19.74 g·kg~(-1) Compound Tinglizi Decoction by gavage, respectively. Rats in the simvastatin group were given 1.50 mg·kg~(-1) simvastatin by gavage. After 14 days, the lung function, mean pulmonary artery pressure, and arterial blood gas of rats were analyzed. Lung tissues of rats were collected for hematoxylin-eosin(HE) staining to observe the pathological changes. Real-time fluorescent quantitative polymerase chain reaction(qRT-PCR) was used to determine the expression of related mRNA in lung tissues, Western blot(WB) was used to determine the expression of related proteins in lung tissues, and enzyme linked immunosorbent assay(ELISA) was used to determine the levels of inflammatory factors in the lung tissues of rats. The ultrastructure of lung cells was observed by transmission electron microscope. The forced vital capacity(FVC), forced expiratory volume in 0.3 second(FEV_(0.3)), FEV_(0.3)/FVC, peek expiratory flow(PEF), respiratory dynamic compliance(Cdyn), arterial partial pressure of oxygen(PaO_2), and arterial oxygen saturation(SaO_2) were increased, and resistance of expiration(Re), mean pulmonary arterial pressure(mPAP), right ventricular hypertrophy index(RVHI), and arterial partial pressure of carbon dioxide(PaCO_2) were decreased by Compound Tinglizi Decoction in rats with COPD-PH. Compound Tinglizi Decoction inhibited the protein expression of HMGB1, receptor for advanced glycation end products(RAGE), pro caspase-8, cleaved caspase-8, and gasdermin D(GSDMD) in lung tissues of rats with COPD-PH, as well as the mRNA expression of HMGB1, RAGE, and caspase-8. Pulmonary artery smooth muscle cell pyroptosis was inhibited by Compound Tinglizi Decoction. Interferon-γ(IFN-γ) and interleukin-17(IL-17) were reduced, and interleukin-4(IL-4) and interleukin-10(IL-10) were incresead by Compound Tinglizi Decoction in lung tissues of rats with COPD-PH. In addition, the lesion degree of trachea, alveoli, and pulmonary artery in lung tissues of rats with COPD-PH was improved by Compound Tinglizi Decoction. Compound Tinglizi Decoction had dose-dependent effects. The lung function, pulmonary artery pressure, arterial blood gas, inflammation, trachea, alveoli, and pulmonary artery disease have been improved by Compound Tinglizi Decoction, and its mechanism is related to HMGB1-mediated pulmonary artery smooth muscle cell pyroptosis and helper T cell 1(Th1)/helper T cell 2(Th2), helper T cell 17(Th17)/regulatory T cell(Treg) imbalance.

[Effects of electroacupuncture pretreatment on long-term postoperative cognitive dysfunction and neuron-inflammation in aged rats].

OBJECTIVE: To observe the effects of electroacupuncture pretreatment on postoperative cognitive dysfunction (POCD), neuronal apoptosis and neuron-inflammation in aged rats. METHODS: Thirty-six male SD rats aged 20 months were randomly divided into sham operation group, model group and electroacupuncture (EA) group, with 12 rats in each group. The POCD rats model was prepared by internal fixation of left tibial fracture. Five days before modeling, EA stimulation (2 Hz/15 Hz, 1 mA, 30 min) was applied to "Zusanli" (ST36), "Hegu" (LI4) and "Neiguan" (PC6) on the unaffected side of rats in the EA group, once a day for consecutive 5 d. The learning and memory abilities of rats were evaluated by water maze test 31-35 days after operation. The apoptosis of hippocampal neurons was observed by Tunel/NeuN double staining. The expressions of high mobility group protein B1 (HMGB1) and phosphorylated (p)-nuclear factor (NF)-κB in microglia cells in hippocampal dentate gyrus were detected by immunofluorescence staining. The expression levels of interleukin (IL)-6 and IL-1ß in the hippocampus were detected by Western blot. RESULTS: Compared with the sham operation group, the escape latency was prolonged (P<0.05); the frequency of crossing the original platform, ratio of the swimming distance and the time in the target quadrant of the Morris water maze were significantly decreased (P<0.05); the apoptosis rate of hippocampal neurons was significantly increased (P<0.05); the expressions of HMGB1 and p-NF-κB in microglia cells in the dentate gyrus and the expression levels of IL-6 and IL-1ß in hippocampus were increased (P<0.05) in the model group. Compared with the model group, the results of the above indexes were all opposite (P<0.05) in the EA group. CONCLUSION: EA preconditioning can regulate hippocampal inflammatory response, alleviate neuronal apoptosis rate and long-term cognitive dysfunction in aged rats with POCD, the mechanisms may be related to the inhibition of microglia HMGB1/NF-κB pathway in hippocampal dentate gyrus.

[Effect of acupuncture at "Houxi" (SI3) and"Huantiao" (GB30) on high mobility group box 1 protein in spinal nerve trunk of rats with lumbar disc herniation].

OBJECTIVE: To observe the effect of acupuncture at "Houxi"(SI3) and "Huantiao"(GB30) on high mobility group box 1(HMGB1) protein and mRNA in spinal nerve trunk(SNT) of rats with lumbar disc herniation(LDH), so as to explore the mechanisms of acupuncture at this paired points on the treatment for LDH. METHODS: SD rats were randomly divided into sham operation, model, conventional acupuncture(CA) and paired points(PP) groups (with 8 rats in each group). The LDH model was established by injection of autologous suspension made from rats' own nucleus pulsus into the epidural space. Rats in the CA group received acupuncture treatment at bilateral "Weizhong"(BL40), "Dachangshu"(BL25) and "Shenshu"(BL23), while rats in the PP group received acupuncture at bilateral SI3 and GB30, 30 min each time, once daily for 14 consecutive days. The thermal pain threshold of bilateral hind feet of rats was detected by thermal pain stimulator. The contents of serum IL-1ß, IL-6 and IL-8 of rats were detected by ELISA. Western blot and immunofluorescence were used to detect the expression of HMGB1 protein in the lumbar(L)5 SNT of rats. The relative expression of HMGB1 mRNA in L5 SNT was determined by qPCR. HE staining was used to observe the morphological changes of L5 SNT. RESULTS: Compared with the sham operation group, the thermal pain threshold of bilateral hind feet in the model group was decreased (P<0.05); compared with the model group, the thermal pain threshold of bilateral hind feet in the CA group and the PP group were increased (P<0.05). The expressions of HMGB1 protein and mRNA in L5 SNT, and the contents of serum IL-1ß, IL-6 and IL-8 of rats in the model group were significantly increased(P<0.000 1, P<0.001) in contrast to the sham operation group. The expressions of HMGB1 protein and mRNA in L5 SNT, and the levels of serum IL-1ß, IL-6 and IL-8 were significantly decreased (P<0.01, P<0.000 1, P<0.001, P<0.05) in the CA and PP group, in comparison with those of the model group. Compared with the CA group, the above indexes of rats in the PP group recovered more significantly (P<0.05,P<0.001, P<0.01,P<0.000 1). The histomorphological results showed scattered and various-sized nerve fibers, vacuolation, a large number of disintegrating myelin sheath and lysed Schwann cells in the model group. Myelin sheaths regeneration, regularly-arranged nerve fibers were seen in the CA group and the PP group, with more obvious histopathological recovery observed in the PP group than the CA group. CONCLUSION: Acupuncture intervention inhibites the expressions of HMGB1 protein and mRNA in rats with LDH, and further reduces the production of IL-1ß, IL-6 and IL-8, which is beneficial to inflammatory response inhibition and pain alleviation. The therapeutic effect of the PP group is more obvious than that of the CA group.

Mechanisms involved in the HMGB1 modulation of tumor multidrug resistance (Review).

Tumor multidrug resistance (MDR) remains one of the most challenging barriers to successful cancer treatment. Several previous studies have suggested that high mobility group box 1 (HMGB1) may be a promising therapeutic target for overcoming cancer drug resistance. Emerging evidence has indicated that HMGB1 functions as a 'double­edged sword' that plays both pro­ and anti­tumor roles in the development and progression of multiple types of cancer. HMGB1 has also been found to be a key regulator of several cell death and signaling pathways, and is involved in MDR by mediating cell autophagy and apoptosis, ferroptosis, pyroptosis and multiple signaling pathways. Additionally, HMGB1 is regulated by a variety of non­coding RNAs (ncRNAs), such as microRNAs, long ncRNAs and circular RNAs that are involved in MDR. Thus far, studies have been conducted to identify strategies with which to overcome HMGB1­mediated MDR by the targeted silencing of HMGB1 and the targeted interference of HMGB1 expression using drugs and ncRNAs. Therefore, HMGB1 is closely associated with tumor MDR and is a promising therapeutic target.

[Protective effect of Shenfu Injection on rats with chronic heart failure based on HMGB1/TLR4/NF-κB signaling pathway].

The study aimed to explore the mechanism and targets of Shenfu Injection in the regulation of inflammatory injury in chronic heart failure rats based on the high mobility group box-1/Toll like receptor 4/nuclear factor kappa-B(HMGB1/TLR4/NF-κB) signaling pathway. The rat model of chronic heart failure was established using isoproterenol. The modeled rats were divided into three groups by random number table: the model group, Shenfu group and glycopyrrolate group, and the normal group was also set. The rats were administrated for 15 consecutive days, and on the following day after the last administration, they were sacrificed for sample collection. The cardiac mass index and left ventricular mass index of the rats in each group were measured, and the echocardiogram was used to analyze the cardiac function indices, and ELISA to test the inflammatory indices in rat serum. The pathological morphology and fibrosis status of rat heart tissues were observed by HE staining and Masson staining, respectively. The content of HMGB1 was determined by immunofluorescence staining. The protein and mRNA expression of HMGB1/TLR4/TLR4 signaling pathway was detected by Western blot and RT-qPCR, respectively. The results showed that the chronic heart failure rat model was successfully prepared. The rats in the model group had reduced cardiac function, increased levels of HMGB1 and inflammatory factors(P<0.05), and elevated protein and mRNA expression of HMGB1, TLR4, MyD88, and NF-κB P65 in myocardial tissue(P<0.05), with fibrous connective tissue hyperplasia, inflammatory cell infiltration and severe fibrosis. Shenfu Injection improved cardiac function, decreased the levels of HMGB1 and inflammatory factors(P<0.05) and the protein and mRNA expression of HMGB1, TLR4, MyD88, and NF-κB P65 in myocardial tissue(P<0.05), ameliorated interstitial fibrous connective tissue hyperplasia and inflammatory cell infiltration, and reduced fibrosis. In conclusion, Shenfu Injection can reduce inflammatory damage and improve cardiac function in chronic heart failure rats by regulating the HMGB1/TLR4/NF-κB signaling pathway.

Rutin prevents seizures in kainic acid-treated rats: evidence of glutamate levels, inflammation and neuronal loss modulation.

Rutin, a naturally derived flavonoid molecule with known neuroprotective properties, has been demonstrated to have anticonvulsive potential, but the mechanism of this effect is still unclear. The current study aimed to investigate the probable antiseizure mechanisms of rutin in rats using the kainic acid (KA) seizure model. Rutin (50 and 100 mg kg-1) and carbamazepine (100 mg kg-1) were administered daily by oral gavage for 7 days before KA (15 mg kg-1) intraperitoneal (i.p.) injection. Seizure behavior, neuronal cell death, glutamate concentration, excitatory amino acid transporters (EAATs), glutamine synthetase (GS), glutaminase, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor subunits GluA1 and GluA2, N-methyl-D-aspartate (NMDA) receptor subunits GluN2A and GluN2B, activated astrocytes, and inflammatory and anti-inflammatory molecules in the hippocampus were evaluated. Supplementation with rutin attenuated seizure severity in KA-treated rats and reversed KA-induced neuronal loss and glutamate elevation in the hippocampus. Decreased glutaminase and GluN2B, and increased EAATs, GS, GluA1, GluA2 and GluN2A were observed with rutin administration. Rutin pretreatment also suppressed activated astrocytes, downregulated the protein levels of inflammatory molecules [interleukin-1ß (IL-1ß), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), high mobility group Box 1 (HMGB1), interleukin-1 receptor 1 (IL-1R1), and Toll-like receptor-4 (TLR-4)] and upregulated anti-inflammatory molecule interleukin-10 (IL-10) protein expression. Taken together, the results indicate that the preventive treatment of rats with rutin attenuated KA-induced seizures and neuronal loss by decreasing glutamatergic hyperactivity and suppressing the IL-1R1/TLR4-related neuroinflammatory cascade.

Inhibitory Activities of Rare Ginsenoside Rg4 on Cecal Ligation and Puncture-Induced Sepsis.

Sepsis is an uncontrolled response to inflammatory infection and is associated with high levels of mortality and morbidity. Rg4 is a rare ginsenoside mainly found in the leaves of Panax ginseng C. A. Meyer and the major protopanaxatriol-type ginsenoside of black ginseng. In this study, we determined whether Rg4 affects cecal ligation and puncture (CLP)-induced sepsis. Animals were separated into the following six groups: control group, CLP-operated group, CLP plus maslinic acid (MA), and CLP plus Rg4 (5, 10, or 15 mg/kg). Survival rate, body weight changes, inflammatory cytokines, and histological analyses were assessed. Human endothelial cells were activated with the high-mobility group box 1 (HMGB1) protein and Rg4. Cell viability was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Enzyme-linked immunosorbent assay (ELISA) and Western blot analysis were used to assess inflammation and gene expression, respectively. After CLP surgery, the Rg4-administered group exhibited a higher survival rate and body weight compared with the untreated control group. Rg4 treatment reduced cytokine levels, including tumor necrosis factor (TNF)-α and interleukin (IL)-1ß, as well as nitric oxide (NO) levels and renal inflammation. After Rg4 treatment of HMGB1-activated cells, the expressions of toll-like receptor (TLR) 4 and TNF-α were decreased, and the activation of phosphoinositide 3-kinase (PI3K)/AKT signaling increased cell viability. In summary, Rg4 inhibited inflammation and exhibited a protective effect against CLP-induced sepsis, thereby reinforcing cell survival against septic responses.

Aristolochic acid I induces proximal tubule injury through ROS/HMGB1/mt DNA mediated activation of TLRs.

Aristolochic acids (AAs) are extracted from certain plants as folk remedies for centuries until their nephrotoxicity and carcinogenicity were recognized. Aristolochic acid I (AAI) is one of the main pathogenic compounds, and it has nephrotoxic, carcinogenic and mutagenic effects. Previous studies have shown that AAI acts mainly on proximal renal tubular epithelial cells; however, the mechanisms of AAI-induced proximal tubule cell damage are still not fully characterized. We exposed human kidney proximal tubule cells (PTCs; HK2 cell line) to AAI in vitro at different time/dose conditions and assessed cell proliferation, reactive oxygen species (ROS) generation, nitric oxide (NO) production, m-RNA/ protein expressions and mitochondrial dysfunction. AAI exposure decreased proliferation and increased apoptosis, ROS generation / NO production in PTCs significantly at 24 h. Gene/ protein expression studies demonstrated activation of innate immunity (TLRs 2, 3, 4 and 9, HMGB1), inflammatory (IL6, TNFA, IL1B, IL18, TGFB and NLRP3) and kidney injury (LCN2) markers. AAI also induced epithelial-mesenchymal transition (EMT) and mitochondrial dysfunction in HK2 cells. TLR9 knock-down and ROS inhibition were able to ameliorate the toxic effect of AAI. In conclusion, AAI treatment caused injury to PTCs through ROS-HMGB1/mitochondrial DNA (mt DNA)-mediated activation of TLRs and inflammatory response.

Tanreqing Injection Attenuates Macrophage Activation and the Inflammatory Response via the lncRNA-SNHG1/HMGB1 Axis in Lipopolysaccharide-Induced Acute Lung Injury.

The etiology of acute lung injury (ALI) is not clear, and the treatment of ALI presents a great challenge. This study aimed to investigate the pathogenesis and potential therapeutic targets of ALI and to define the target gene of Tanreqing (TRQ), which is a traditional Chinese medicine formula composed of five medicines, scutellaria baicalensis, bear bile powder, goat horn powder, honeysuckle and forsythia. Macrophage activation plays a critical role in many pathophysiological processes, such as inflammation. Although the regulation of macrophage activation has been extensively investigated, there is little knowledge of the role of long noncoding RNAs (lncRNAs) in this process. In this study, we found that lncRNA-SNHG1 expression is distinctly regulated in differently activated macrophages in that it is upregulated in LPS. LncRNA-SNHG1 knockdown attenuates LPS-induced M1 macrophage activation. The SNHG1 promoter was bound by NF-κB subunit p65, indicative of SNHG1 being a direct transcriptional target of LPS-induced NF-κB activation. SNHG1 acts as a proinflammatory driver that leads to the production of inflammatory cytokines and the activation of macrophages and cytokine storms by physically interacting with high-mobility group box 1 (HMGB1) in ALI. TRQ inhibited NF-κB signaling activation and binding of NF-κB to the SNHG1 promoter. In conclusion, this study defined TRQ target genes, which can be further elucidated as mechanism(s) of TRQ action, and provides insight into the molecular pathogenesis of ALI. The lncRNA-SNHG1/HMGB1 axis is an ideal therapeutic for ALI treatment.

Co-treatment with natural HMGB1 inhibitor Glycyrrhizin exerts neuroprotection and reverses Parkinson's disease like pathology in Zebrafish.

ETHNOPHARMACOLOGICAL RELEVANCE: Parkinson's disease (PD) is the second most devastating age-related neurodegenerative diseases after Alzheimer diseases (AD) and is characterized by the loss of dopaminergic (DA) neurons in the substantia nigra (SN) and aggregation of α-synuclein (α-syn). The precise etiology of PD is not yet fully understood and lacks the disease-modifying therapeutic strategies that could reverse the ongoing neurodegeneration. In the quest of exploring novel disease modifying therapeutic strategies, natural compounds from plant sources have gained much attention in recent days. Glycyrrhizin (GL) is the main active ingredient of the roots and rhizomes of licorice (Glycyrrhiza glabra L), which are generally used in the treatment of inflammatory diseases or as a tonifying herbal medicine. In Persia, GL is a conventional neuroprotective agent that are used to treat neurological disorders. The traditional use of GL in Japan is to treat chronic hepatitis B. In addition, GL is a natural inhibitor of high mobility group box 1 (HMGB1) which has exerted neuroprotective effect against several HMGB1 mediated pathological conditions. AIM OF THE STUDY: The study is aimed to evaluate therapeutic effect of GL against PD in zebrafish. MATERIAL AND METHODS: PD in zebrafish larvae is induced by administration of neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Apoptosis was assessed with TUNEL assay. Gene expression was performed to assess the modulation in genes related to neuroinflammatory and autophagy. RESULTS: We observed that GL co-treatment increased the length of DA neurons, decreased the number of apoptotic cells in zebrafish brain, and inhibited the loss of vasculature and disorganized vasculature induced by MPTP. GL co-treatment relieved the MPTP-induced locomotor impairment in zebrafish. GL co-treatment suppressed MPTP-induced upregulated mRNA expression of inflammatory markers such as hmgb1a, tlr4b, nfκb, il1ß, and il6. GL co-treatment suppressed the autophagy related genes α-syn and atg5 whereas increased the mRNA expression level of parkin and pink1. In addition, molecular docking study reveals that GL has binding interaction with HMGB1, TLR4, and RAGE. CONCLUSION: Hence, the effect of GL co-treatment on MPTP-induced PD-like condition in zebrafish is to alleviate apoptosis and autophagy, as well as suppress inflammatory responses.

[Influence of electroacupuncture on locomotor function and expression of spinal HMGB1 and TLR4 in mice with spinal cord injury].

OBJECTIVE: To observe the effect of electroacupuncture(EA)on locomotor activity and the expression of high-mobility group box-1(HMGB1) and Toll-like receptor 4(TLR4) in mice with spinal cord injury(SCI), so as to explore its mechanisms underlying improvement of SCI at the acute stage. METHODS: Forty-eight female C57BL/6 mice were equally randomized into 3 groups: sham operation, model and EA. The SCI model was established by clamping the spinal cord with a serrefine after laminectomy at the 1st lumbar vertebra(L1). EA (1.5 Hz/7.5 Hz, 1.0 mA) was applied to "Jiaji"(EXH-B2) for 10 min, once a day for 5 and 14 days, separately. The hindlimb locomotor function was assessed by Basso, Beattie, Bresnahan Locomotor Rating Scale (BBB). Histopathological changes of the injured area of the spinal cord were determined by H.E. staining. The expression levels of spinal HMGB1, TLR4, ionized calcium binding adaptor molecule 1(Iba1) proteins were detected by Western blot, and the Iba1-positive microglial cells and HMGB1 and Iba1 co-labelled microglia were displayed by immunofluorescence staining. RESULTS: After SCI, the BBB scores on day 5 and 14 were obviously decreased (P<0.05), and the expression of HMGB1 on day 14, TLR4 on day 5 and 14, the number of Iba1-positive microglia as well as the co-expressed HMGB1/Iba1-positive microglia on day 5 and 14 were significantly increased in the model group relevant to the sham operation group (P<0.05, P<0.01). In the EA intervention group, SCI-induced reduction of BBB scores on day 5 and 14, and increases of the expression of HMGB1 and Iba1 on day 14, and TLR4 on day 5 and 14, and the number of Iba1-positive cells as well as the co-expressed HMGB1/Iba1-positive microglia on day 14 were reversed relevant to the model group (P<0.05,P<0.01). H.E. staining showed a structural disorder with lots of cavities, severe inflammatory infiltration with a large quantity of inflammatory cells, and a reduction of normal neurons in the injured spinal cord tissue in the model group， which was relatively milder, with lower activation of microglia in the EA group. CONCLUSION: EA can significantly improve locomotor function in SCI mice, which is associated with its effects in suppressing the expression of inflammatory factors such as HMGB1, TLR4, Iba1 and the over-activation of microglia.

[Electroacupuncture at "Ganshu" (BL18) and "Yanglingquan" (GB34) alleviates hepatic ischemia-reperfusion injury by inhibiting translocation and release of high mobility group protein 1 in rats].

OBJECTIVE: To explore the protective effect of electroacupuncture (EA) on hepatic ischemia-reperfusion injury (HIRI) and the expression of high mobility group protein 1 (HMGB1) in liver tissues in rats. METHODS: A total of 40 male SD rats were randomly divided into 4 groups, namely sham control, HIRI model, "Ganshu"(BL18) -"Yanglingquan"(GB34) and non-acupoint group, with 10 rats in each group. The HIRI model was induced by blocking the arteries, veins and bile ducts supplying the middle and left lobes of the liver for 1 h, and reperfusion for 4 h to induce an area of about 70% HIRI. EA was applied to bila-teral BL18 and GB34, or non-acupoints about 6-8 mm to the bilateral BL18 for 30 min before modeling. Serum alanine transaminase (ALT) and aspartate aminotransferase (AST) levels were measured by using an automatic biochemical analyzer. Serum tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and HMGB1 levels were assayed by ELISA. Hematoxylin - eosin (H.E.) staining was used to observe histopathological changes of the liver tissue by using tissue injury scaling (0-3 scores). The expression of HMGB1 protein in liver tissues was detected by immunohistochemical staining, Western blot and PCR, separately. RESULTS: Following modeling and compared with the sham group, the levels of serum ALT, AST, TNF-α, IL-6, and HMGB1 contents, the number of HMGB1 immunoreaction (IR)-positive cells, and HMGB1 protein and mRNA were significantly increased (P＜0.01). After the treatment, the contents of serum ALT, AST, TNF-α, IL-6, and HMGB1, liver HMGB1 IR-positive cells, protein and mRNA were considerably down-regulated in the BL18-GB34 group (P<0.05), rather than in the non-acupoint group (P>0.05) in contrast to the model group. H.E. stain showed a higher liver injury score in the model group than in the sham group (P<0.01), and a lower liver injury score in the BL18-GB34 group (not the non-acupoint group) relevant to the model group (P<0.05). CONCLUSION: EA of BL18 and GB34 points has a protective effect on ischemic liver injury in rats with HIRI, which may be associated with its functions in inhibiting the migration and release of HMGB1 from the nucleus to the cytoplasm and in down-regulating the expression of inflammatory factors.

Paclitaxel alleviates the sepsis-induced acute kidney injury via lnc-MALAT1/miR-370-3p/HMGB1 axis.

AIMS: To investigate the effects of paclitaxel on lipopolysaccharide (LPS)-induced acute kidney injury (AKI) and its related mechanisms. MAIN METHODS: The sepsis-associated AKI was induced by LPS using HK-2 cells. Then the mRNA and protein expression levels of relevant genes in the serum of sepsis patients and HK-2 cells with LPS-induced AKI were detected by qRT-PCR and western blot analyses before and after paclitaxel treatment, respectively. Subsequently, the cell counting kit-8 (CCK-8) and flow cytometry assays were performed to estimate the effects of paclitaxel, lnc-MALAT1, miR-370-3p and HMGB1 on the proliferation and apoptosis of HK-2 cells injured by LPS. KEY FINDINGS: Lnc-MALAT1 was increased both in the serum of sepsis patients and cells injured by LPS, which could inhibit the cell proliferation, promote the cell apoptosis and increase the expression of TNF-α, IL-6 and IL-1ß caused by paclitaxel. Moreover, lnc-MALAT1 was sponged with miR-370-3p which had the inverse effects with lnc-MALAT1 in LPS induced HK-2 cells. What's more, miR-370-3p targeted HMGB1 which was induced in serum and cells of sepsis. Knockdown of miR-370-3p inhibited the expression of HMGB1 and suppressed the proliferation but promoted the apoptosis of HK-2 cells injured by LPS as well as the expression of TNF-α, IL-6 and IL-1ß. Besides, paclitaxel restrained the expression of HMGB1 via regulating lnc-MALAT1/miR-370-3p axis. SIGNIFICANCE: Paclitaxel could protect against LPS-induced AKI via the regulation of lnc-MALAT1/miR-370-3p/HMGB1 axis and the expression of TNF-α, IL-6 and IL-1ß, revealing that paclitaxel might act as a therapy drug in reducing sepsis-associated AKI.

Vitamin D attenuates HMGB1-mediated neointimal hyperplasia after percutaneous coronary intervention in swine.

Intracoronary stenting is a common procedure in patients with coronary artery disease (CAD). Stent deployment stretches and denudes the endothelial layer, promoting a local inflammatory response, resulting in neointimal hyperplasia. Vitamin D deficiency associates with CAD. In this study, we examined the association of vitamin D status with high mobility group box 1 (HMGB1)-mediated pathways (HMGB1, receptor for advanced glycation end products [RAGE], and Toll-like receptor-2 and -4 [TLR2 and TLR4]) in neointimal hyperplasia in atherosclerotic swine following bare metal stenting. Yucatan microswine fed with a high-cholesterol diet were stratified to receive vitamin D-deficient (VD-DEF), vitamin D-sufficient (VD-SUF), and vitamin D-supplemented (VD-SUP) diet. After 6 months, PTCA (percutaneous transluminal balloon angioplasty) followed by bare metal stent implantation was performed in the left anterior descending (LAD) artery of each swine. Four months following coronary intervention, angiogram and optical coherence tomography (OCT) were performed and swine euthanized. Histology and immunohistochemistry were performed in excised LAD to evaluate the expression of HMGB1, RAGE, TLR2, and TLR4. OCT analysis revealed the greatest in-stent restenosis area in the LAD of VD-DEF compared to VD-SUF or VD-SUP swine. The protein expression of HMGB1, RAGE, TLR2, and TLR4 was significantly higher in the LAD of VD-DEF compared to VD-SUF or VD-SUP swine. Vitamin D deficiency was associated with both increased in-stent restenosis and increased HMGB1-mediated inflammation noted in coronary arteries following intravascular stenting. Inversely, vitamin D supplementation was associated with both a decrease in this inflammatory profile and in neointimal hyperplasia, warranting further investigation for vitamin D as a potential adjunct therapy following coronary intervention.

Early effect of laser irradiation in signaling pathways of diabetic rat submandibular salivary glands.

Low-power laser irradiation (LPLI) is clinically used to modulate inflammation, proliferation and apoptosis. However, its molecular mechanisms are still not fully understood. This study aimed to describe the effects of LPLI upon inflammatory, apoptotic and proliferation markers in submandibular salivary glands (SMGs) in an experimental model of chronic disorder, 24h after one time irradiation. Diabetes was induced in rats by the injection of streptozotocin. After 29 days, these animals were treated with LPLI in the SMG area, and euthanized 24h after this irradiation. Treatment with LPLI significantly decreased diabetes-induced high mobility group box 1 (HMGB1) and tumor necrosis factor alpha (TNF-α) expression, while enhancing the activation of the transcriptional factor cAMP response element binding (CREB) protein. LPLI also reduced the expression of bax, a mitochondrial apoptotic marker, favoring the cell survival. These findings suggest that LPLI can hamper the state of chronic inflammation and favor homeostasis in diabetic rats SMGs.