High Mobility Group Box 1 mRNA Research Articles

Bone marrow-derived mesenchymal stem cell-derived exosome-loaded miR-129-5p targets high-mobility group box 1 attenuates neurological-impairment after diabetic cerebral hemorrhage

BACKGROUND Diabetic intracerebral hemorrhage (ICH) is a serious complication of diabetes. The role and mechanism of bone marrow mesenchymal stem cell (BMSC)-derived exosomes (BMSC-exo) in neuroinflammation post-ICH in patients with diabetes are unknown. In this study, we investigated the regulation of BMSC-exo on hyperglycemia-induced neuroinflammation. AIM To study the mechanism of BMSC-exo on nerve function damage after diabetes complicated with cerebral hemorrhage. METHODS BMSC-exo were isolated from mouse BMSC media. This was followed by transfection with microRNA-129-5p (miR-129-5p). BMSC-exo or miR-129-5p-overexpressing BMSC-exo were intravitreally injected into a diabetes mouse model with ICH for in vivo analyses and were cocultured with high glucose-affected BV2 cells for in vitro analyses. The dual luciferase test and RNA immunoprecipitation test verified the targeted binding relationship between miR-129-5p and high-mobility group box 1 (HMGB1). Quantitative polymerase chain reaction, western blotting, and enzyme-linked immunosorbent assay were conducted to assess the levels of some inflammation factors, such as HMGB1, interleukin 6, interleukin 1β, toll-like receptor 4, and tumor necrosis factor α. Brain water content, neural function deficit score, and Evans blue were used to measure the neural function of mice. RESULTS Our findings indicated that BMSC-exo can promote neuroinflammation and functional recovery. MicroRNA chip analysis of BMSC-exo identified miR-129-5p as the specific microRNA with a protective role in neuroinflammation. Overexpression of miR-129-5p in BMSC-exo reduced the inflammatory response and neurological impairment in comorbid diabetes and ICH cases. Furthermore, we found that miR-129-5p had a targeted binding relationship with HMGB1 mRNA. CONCLUSION We demonstrated that BMSC-exo can reduce the inflammatory response after ICH with diabetes, thereby improving the neurological function of the brain.

Bone marrow-derived mesenchymal stem cell-derived exosome-loaded miR-129-5p targets high-mobility group box 1 attenuates neurological-impairment after diabetic cerebral hemorrhage.

Diabetic intracerebral hemorrhage (ICH) is a serious complication of diabetes. The role and mechanism of bone marrow mesenchymal stem cell (BMSC)-derived exosomes (BMSC-exo) in neuroinflammation post-ICH in patients with diabetes are unknown. In this study, we investigated the regulation of BMSC-exo on hyperglycemia-induced neuroinflammation. To study the mechanism of BMSC-exo on nerve function damage after diabetes complicated with cerebral hemorrhage. BMSC-exo were isolated from mouse BMSC media. This was followed by transfection with microRNA-129-5p (miR-129-5p). BMSC-exo or miR-129-5p-overexpressing BMSC-exo were intravitreally injected into a diabetes mouse model with ICH for in vivo analyses and were cocultured with high glucose-affected BV2 cells for in vitro analyses. The dual luciferase test and RNA immunoprecipitation test verified the targeted binding relationship between miR-129-5p and high-mobility group box 1 (HMGB1). Quantitative polymerase chain reaction, western blotting, and enzyme-linked immunosorbent assay were conducted to assess the levels of some inflammation factors, such as HMGB1, interleukin 6, interleukin 1β, toll-like receptor 4, and tumor necrosis factor α. Brain water content, neural function deficit score, and Evans blue were used to measure the neural function of mice. Our findings indicated that BMSC-exo can promote neuroinflammation and functional recovery. MicroRNA chip analysis of BMSC-exo identified miR-129-5p as the specific microRNA with a protective role in neuroinflammation. Overexpression of miR-129-5p in BMSC-exo reduced the inflammatory response and neurological impairment in comorbid diabetes and ICH cases. Furthermore, we found that miR-129-5p had a targeted binding relationship with HMGB1 mRNA. We demonstrated that BMSC-exo can reduce the inflammatory response after ICH with diabetes, thereby improving the neurological function of the brain.

Glucocorticoids induce HMGB1 release in primary cultured rat cortical microglia

Stress, a risk factor for major depressive disorder and Alzheimer disease, leads to the release of high-mobility group box-1 (HMGB1) protein, which in turn causes neuroinflammation. The mechanism underlying stress-induced HMGB1 release is unknown, but stress-associated glucocorticoids could be involved. Primary cultured rat cortical microglia and neurons were treated with corticosterone, a stress-associated glucocorticoid, and HMGB1 release was measured by ELISA and western blotting to test this hypothesis. With corticosterone treatment, significant HMGB1 was released in microglia but not in neuronal cell cultures. HMGB1 mRNA expression and HMGB1 protein expression in microglia were not affected by corticosterone treatment. Thus, the source of extracellular HMGB1 released into the medium is likely to be existing nuclear HMGB1 rather than newly synthesized HMGB1. Corticosterone-induced HMGB1 release in microglia culture was significantly attenuated by blocking glucocorticoid receptors but not mineralocorticoid receptors. Dexamethasone, a selective glucocorticoid receptor agonist, and dexamethasone-bovine serum albumin (BSA), a membrane-impermeable glucocorticoid receptor agonist used to confirm the membrane receptor-mediated effects of glucocorticoids, increased the release of HMGB1. Immunocytochemistry showed that HMGB1 translocated from the nucleus to the cytoplasm following dexamethasone or dexamethasone-BSA treatment through glucocorticoid receptors. The present findings suggest that glucocorticoids stimulate microglial membrane glucocorticoid receptors and trigger cytoplasmic translocation and extracellular release of nuclear HMGB1. Thus, under stress conditions, glucocorticoids induce microglial HMGB1 release, leading to a neuroinflammatory state that could mediate neurological disorders.

CircMYO1C silencing alleviates chondrocytes inflammation and apoptosis through m6A/HMGB1 axis in osteoarthritis.

Circular RNAs (circRNAs) are involved in osteoarthritis (OA) progression. This study aimed to investigate the role and molecular mechanisms of circMYO1C in OA. CircMYO1C was upregulated in OA- and interleukin-1β (IL-1β)-exposed chondrocytes. The results indicated that circMYO1C knockdown repressed the inflammatory factors (tumor necrosis factor alpha [TNF-α], interleukin-6 [IL-6], interleukin-8 [IL-8], etc.) and apoptosis of chondrocytes following IL-1β exposure. CircMYO1C was an N6-methyladenosine (m6A)-modified circRNA with m6A characteristics. High mobility group box 1 (HMGB1) was a target of circMYO1C. IL-1β exposure increased the stability and half-life (t1/2) of HMGB1 mRNA, while silencing circMYO1C reduced HMGB1 mRNA stability. Taken together, circMYO1C targets the m6A/HMGB1 axis to promote chondrocyte apoptosis and inflammation. The present study demonstrates that the circMYO1C/m6A/HMGB1 axis is essential for OA progression, highlighting a novel potential therapeutic target for clinical OA.

LncRNA AA465934 Improves Podocyte Injury by Promoting Tristetraprolin-Mediated HMGB1 DownRegulation in Diabetic Nephropathy.

Although LncRNA AA465934 expression is reduced in high glucose (HG)-treated podocytes, its role in HG-mediated podocyte injury and diabetic nephropathy (DN) remains unknown. Herein, we investigated the role of AA465934 in HG-mediated podocyte injury and DN using a spontaneous type II diabetic nephropathy (T2DN) model. The model was created by injecting AA465934 overexpressed adeno-associated virus (AAV) or control into mice. The levels of renal function, proteinuria, renal structural lesions, and podocyte apoptosis were then examined. Furthermore, AA465934 and autophagy levels, as well as tristetraprolin (TTP) and high mobility group box 1 (HMGB1) expression changes were detected. We also observed podocyte injury and the binding ability of TTP to E3 ligase proviral insertion in murine lymphomas 2 (PIM2), AA465934, or HMGB1. According to the results, AA465934 improved DN progression and podocyte damage in T2DN mice. In addition, AA465934 bound to TTP and inhibited its degradation by blocking TTP-PIM2 binding. Notably, TTP knock-down blocked the ameliorating effects of AA465934 and TTP bound HMGB1 mRNA, reducing its expression. Overexpression of HMGB1 inhibited the ability of AA465934 and TTP to improve podocyte injury. Furthermore, AA465934 bound TTP, inhibiting TTP-PIM2 binding, thereby suppressing TTP degradation, downregulating HMGB1, and reversing autophagy downregulation, ultimately alleviating HG-mediated podocyte injury and DN. Based on these findings, we deduced that the AA465934/TTP/HMGB1/autophagy axis could be a therapeutic avenue for managing podocyte injury and DN.

Overexpression of HMGB1 in hepatocytes accelerates PTEN inactivation-induced liver cancer.

Liver cancer is increasing due to the rise in metabolic dysfunction-associated steatohepatitis (MASH). High-mobility group box-1 (HMGB1) is involved in the pathogenesis of chronic liver disease, but its role in MASH-associated liver cancer is unknown. We hypothesized that an increase in hepatocyte-derived HMGB1 in a mouse model of inactivation of PTEN that causes MASH could promote MASH-induced tumorigenesis. We analyzed publicly available transcriptomics datasets, and to explore the effect of overexpressing HMGB1 in cancer progression, we injected 1.5-month-old Pten∆Hep mice with adeno-associated virus serotype-8 (AAV8) vectors to overexpress HMGB1-EGFP or EGFP, and sacrificed them at 3, 9 and 11 months of age. We found that HMGB1 mRNA increases in human MASH and MASH-induced hepatocellular carcinoma (MASH-HCC) compared to healthy livers. Male and female Pten∆Hep mice overexpressing HMGB1 showed accelerated liver tumor development at 9 and 11 months, respectively, with increased tumor size and volume, compared to control Pten∆Hep mice. Moreover, Pten∆Hep mice overexpressing HMGB1, had increased incidence of mixed HCC-intrahepatic cholangiocarcinoma (iCCA). All iCCAs were positive for nuclear YAP and SOX9. Male Pten∆Hep mice overexpressing HMGB1 showed increased cell proliferation and F4/80+ cells at 3 and 9 months. Overexpression of HMGB1 in hepatocytes accelerates liver tumorigenesis in Pten∆Hep mice, enhancing cell proliferation and F4/80+ cells to drive MASH-induced liver cancer.

Sirtuin 1 alleviates alcoholic liver disease by inhibiting HMGB1 acetylation and translocation.

Alcoholic liver disease (ALD) encompasses a spectrum of liver disorders resulting from prolonged alcohol consumption and is influenced by factors such as oxidative stress, inflammation, and apoptosis. High Mobility Group Box 1 (HMGB1) plays a pivotal role in ALD due to its involvement in inflammation and immune responses. Another key factor, Sirtuin 1 (SIRT1), an NAD+-dependent deacetylase, is known for its roles in cellular stress responses and metabolic regulation. Despite individual studies on HMGB1 and SIRT1 in ALD, their specific molecular interactions and combined effects on disease advancement remain incompletely understood. Alcohol-induced liver injury (ALI) models were established using HepG2 cells and male C57BL/6 mice. HMGB1 and SIRT1 expressions were assessed at the mRNA and protein levels usingreverse transcription-quantitative polymerase chain reaction, western blot, and immunofluorescence staining. The physical interaction between HMGB1 and SIRT1 was investigated using co-immunoprecipitation and immunofluorescence co-expression analyses. Cellular viability was evaluated using the CCK-8 assay. In patients with clinical ALI, HMGB1 mRNA levels were elevated, while SIRT1 expression was reduced, indicating a negative correlation between the two. ALI models were successfully established in cells and mice, as evidenced by increased markers of cellular and liver damage. HMGB1 acetylation and translocation were observed in both ALI cells and mouse models. Treatment with the SIRT1 agonist, SRT1720, reversed the upregulation of HMGB1 acetylation, nuclear translocation, and release in the ethyl alcohol (EtOH) group. Furthermore, SIRT1 significantly attenuated ALI. Importantly, in vivo binding was confirmed between SIRT1 and HMGB1. SIRT1 alleviates HMGB1 acetylation and translocation, thereby ameliorating ALI.

MicroRNA-181a-5p alleviates acute liver failure in mice by inhibiting HMGB1.

MicroRNAs (miRNAs) control liver diseases, but the role of microRNA-181a-5p in acute liver failure (ALF) is unclear. In this study, the ALF model was generated by injection of D-galactosamine (D-GalN) and lipopolysaccharide (LPS). The levels of miRNAs were assessed by microarray and qRT-PCR. The expression of caspase 3 was detected as the marker of cell apoptosis in ALF by immunohistochemistry and western blot. The targeting of microRNA-181a-5p on the high mobility group box 1 (HMGB1) was verified by dual luciferase assay. The impact of microRNA-181a-5p and HMGB1 was explored by flow cytometry. Results showed that microRNA-181a-5p was significantly down-regulated by D-GalN/LPS in vivo and in vitro, while the level of HMGB1 was up-regulated after the challenge. Furthermore, microRNA-181a-5p overexpression attenuated cell apoptosis in D-GalN/TNF-treated BNLCL2 cells. MicroRNA-181a-5p could directly target HMGB1 mRNA and repress its expressions, in further HMGB1 is involved in microRNA-181a-5p effect on cell apoptosis of ALF. In conclusion, these findings demonstrate that microRNA-181a-5p regulates hepatocyte apoptosis via HMGB1 in the development of ALF, which may provide potential therapeutic targets for ALF. However, the precise underlying mechanism that connects microRNA-181a-5p and HMGB1 remains to be explored.

HMGB1 induces macrophage pyroptosis in chronic endometritis

BackgroundChronic endometritis (CE) reflects the local imbalance in the endometrial immune microenvironment after inflammation. High mobility group box 1 (HMGB1) is highly involved in both immunity and inflammation. In this study, we aimed to explore the roles of HMGB1 in the endometrium of patients with CE. MethodsEndometrium and uterine fluid HMGB1 were tested in a cohort of infertile patients with or without CE. Expression levels of the pyroptosis marker, gasdermin D (GSDMD)-N-terminal (NT), in the human endometrium of patients with CE and controls were determined. Next, the role of HMGB1 as a driver of macrophage pyroptosis was investigated using human THP-1 cells in vitro and a CE mouse model in vivo. ResultsHigh expression levels of HMGB1 in biopsied endometrial tissue and uterine fluid were confirmed in a cohort of patients with CE. Positive correlation between the number of CD138+ cells and HMGB1 mRNA expression level were detected (rs = 0.592, P < 0.001). Meanwhile, we found that GSDMD-NT expression was significantly increased in the CE endometrium at both the transcriptional and translational levels. Moreover, co-localization of GSDMD-NT and macrophages was confirmed via the double immunostaining of GSDMD-NT and CD68. In vitro experiments revealed that macrophage pyroptosis was induced by HMGB1 in human THP-1-derived macrophages. Treatment with glycyrrhizic acid, an inhibitor of HMGB1, significantly suppressed endometrial pyroptosis and inflammation in the CE mouse model. ConclusionsHMGB1 effectively induced macrophage pyroptosis in the human endometrium, suggesting that its inhibition may serve as a novel treatment option for CE.

Effect of Vitamin D on the HMGB1/RAGE Pathway and Adipokines Levels in Obese Asthmatic Mice.

Compared to common asthma, obese asthma is difficult to control. Previous studies have shown that vitamin D (Vit D) has a therapeutic effect on asthma. Nevertheless, the action mechanism of Vit D for obese asthma are not well known. In this study, we, therefore, induced obesity and established an obese asthma mouse model using ovalbumin (OVA) stimulation and applied treatment with Vit D (100 ng/kg). Accordingly, thirty mice were randomly divided into 5 equal groups of normal control, asthma, obese asthma, asthma+Vit D, and obese asthma+ Vit D. The levels of inflammatory factors and adipokines were measured by the ELISA assay; then the quantitative reverse transcription PCR (qRT-PCR) method was used to evaluate the expression of high mobility group box 1(HMGB1) and receptor for advanced glycation end products [RAGE] genes.T he results showed that OVA sensitization significantly increased airway resistance, the levels of inflammatory cytokines, and HMGB and RAGE expression in asthmatic and obese asthmatic mice, as compared to the control group. Also, these changes in the obese asthmatic group were notably higher than those in the asthmatic one. In addition, the treatment of asthmatic and obese asthmatic mice with Vit D significantly reduced the raw, serum and BALF levels of inflammatory cytokines, as well as the expression of HMGB1 and RAGE mRNA. To conclude, the present study showed that vitamin D might attenuate lung injury by up-regulating HMGB1 and RAGE expression. Our findings, thus, may offer new concepts and approaches for the treatment and prevention of obese asthma.

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

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. 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-1β, 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. 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-1β, 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-1β, 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. Acupuncture intervention inhibites the expressions of HMGB1 protein and mRNA in rats with LDH, and further reduces the production of IL-1β, 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.

The effects of etomidate on expression of high mobility group box 1 via the nuclear factor kappa B pathway in rat model of sepsis

ABSTRACT Etomidate is an anesthetic agent used in hemodynamically unstable patients, but its use has been controversial in septic patients. The response of high-mobility group box 1 (HMGB1), a late-phase lethal cytokine in sepsis, to etomidate has not been reported. This study investigated the effects of etomidate on the expression and release of HMGB1 and the underlying mechanism using a cecal ligation and puncture (CLP) model. Thirty-six male Sprague–Dawley rats were divided into sham, CLP, and Etomi groups. Sepsis was induced in the CLP and Etomi groups, and intravenous etomidate (4 mg/kg) was infused for 40 min immediately after operation in the Etomi group. Serum creatinine, alanine aminotransferase (ALT), tumor necrosis factor (TNF)-α, interleukin (IL)-6, and HMGB1 levels were measured 6 and 24 hours after surgery. Activation of nuclear factor (NF)-ĸB and HMGB1 mRNA expression in the liver, lung, kidney, and ileum tissues were measured, and immunohistochemical staining of HMGB1 was implemented. Increases of the TNF-α level 6 h after CLP and ALT and IL-6 levels 24 h after CLP were significantly inhibited by etomidate treatment. Etomidate treatment also significantly attenuated the increase in serum HMGB1 level at 6 and 24 h after CLP and suppressed the NF-ĸB and HMGB1 mRNA in multiple organs 24 h after CLP. Immunohistochemical staining also revealed that etomidate treatment inhibited HMGB1 expression. Etomidate inhibited the systemic release of HMGB1 and its expression in various organs. The mechanism may be associated with the inhibitory effects of etomidate on pro-inflammatory cytokine release and NF-ĸB activity.

CircRTN1 stimulates HMGB1 to regulate the malignant progression of papillary thyroid cancer by sponging miR-101-3p.

The important role played by circular RNA (circRNA) in promoting the progression of papillary thyroid cancer (PTC) is attracting ever more attention among medical researchers. However, what the precise contribution is of circRTN1 in PTC progression remains unclear. The study was designed to analyze the role and mechanism of circRTN1 in regulating PTC progression. Human PTC cell lines (TPC-1 and IHH-4) and human thyroid normal cells (Nthy-ori 3-1) were used for in vitro assays. mRNA or protein expression of circRTN1, miR-101-3p, and high mobility group box 1 (HMGB1) were detected by quantitative real-time polymerase chain reaction or western blot. Cell proliferation was investigated by cell counting kit-8 assay, cell colony formation assay, and 5-ethynyl-2'-deoxyuridine assay. Wound-healing assay and transwell invasion assay were conducted to evaluate cell migration and invasion. Dual-luciferase reporter assay and RNA immunoprecipitation assay were applied to verify the target relations between circRTN1, miR-101-3p, and HMGB1. A xenograft tumor model was established to demonstrate the effect of circRTN1 on tumor formation in vivo. An immunohistochemistry assay was used to detect protein expression of HMGB1, ki-67, E-cadherin, and vimentin. In comparison with healthy thyroid tissues and cells, PTC tissues and cells displayed high circRTN1 RNA expression and high HMGB1 mRNA and protein expression but low miR-101-3p expression. Silencing of circRTN1 suppressed PTC cell proliferation, migration, and invasion in vitro. MiR-101-3p was a target of circRTN1, and the knockdown of miR-101-3p relieved circRTN1 absence-mediated suppressive effects on PTC cell malignancy. HMGB1 was identified as a target gene of miR-101-3p, and overexpressed HMGB1 almost reverted the inhibitory impacts induced by miR-101-3p mimic in PTC cells. Moreover, circRTN1 silencing hampered tumor formation in vivo. CircRTN1 depletion impeded PTC cell malignancy via the miR-101-3p/HMGB1 pathway, which provided a possible circRNA-targeted therapeutic strategy for PTC.

Electric Field-Based Cancer Therapy Induces the Expression of HMGB1 and PD-L1 mRNA Genes on Breast Tumor of Female Rats

Electro Capacitive Cancer Therapy (ECCT) is an electric field-based cancer therapy method using intermediate frequency (150 kHz) and low intensity (18 Vpp). High Mobility Group Box 1 (HMGB1) is a cytokine related to damage-associated molecular patterns (DAMPs) secreted by dead cells. The expression of Programmed Death Ligand 1 (PD-L1) is ligand present on the surface of tumor cells and its expression is associated with the increase in the number CD8+ T lymphocytes. This study aims to examine the effect of ECCT exposure on the expression of HMGB1 and PD-L1 genes on the breast tumor, brain, and liver tissues of Rattus norvegicus (Berkenhout, 1769). The tissues were obtained from the previous studies stored in RNAlater (-20˚C). Female rat tissues of the previous study from four treatment groups, namely the control group (NINT), non-DMBA-induction with therapy (NIT), DMBA-induction with non-therapy (INT), and DMBA-induction with therapy (IT). Gene expression was analyzed using the RT-qPCR. Statistical t-test with a p&lt;0.05 significance level was performed using GraphPad Prism 9.4.0 software. The result shows HMGB1 and PD-L1 mRNA genes were both significantly expressed in breast tumor samples. The liver and brain samples of normal rats did not show any significant changes in the activity of these genes after exposure to the electric field. This study indicates that exposure to electric fields may trigger the expression of HMGB1 and PD-L on the rat’s breast tumor samples. This study also provides information related to the safety of ECCT in healthy organs of female rats, especially the brain and liver.Keywords: ECCT, breast tumor, HMGB1, PD-L1, IFN- γ.

Glycyrrhizin ameliorates vascular endothelial cell senescence by inhibiting HMGB1 in HFD/STZ-induced diabetic rats and human umbilical vein endothelial cells

The senescence and dysfunction of vascular endothelial cells are important features of diabetic vascular disease. High mobility group box-1(HMGB1) may be involved in vascular injury in response to high glucose. Glycyrrhizin (GL) is an HMGB1 inhibitor that significantly reduces HMGB1. However, the relationship between HMGB1 and vascular ageing in diabetes is not clear, the protective mechanism of GL against vascular injury in type 2 diabetes mellitus (T2DM) is unclear too. This study aims to examine the role of HMGB1 in vascular endothelial cell senescence and the protective effects of GL on vascular aging in high fat diet/streptozotocin (HFD/STZ) induce type 2 diabetic rats.After induction of diabetes, GL (150 mg/kg/d) was treated by gavage for 4 weeks. Results showed that compared with the Control group, the serum level of HMGB1 was increased in rats with type 2 diabetes, while the expression of HMGB1 mRNA and protein in the thoracic aorta was upregulated, with a decrease in endothelium-dependent vasodilation function and an increase in aging degree in the thoracic aorta. However, the above indicators were significantly improved after GL treatment. In HUVECs, we found that treated with HMGB1 (50, 100 and 200 ng/ml) for 48 h induced cells senescence and GL (50, 100 mg/L) significantly inhibited high-glucose-induced endothelial cell senescence, meanwhile GL (50, 100 mg/L) significantly inhibited the high-glucose-induced HMGB1 release and upregulated p53 expression. In conclusion, GL as an HMGB1 inhibitor, attenuates endothelium-dependent relaxation impairment and vascular ageing in an animal model of diabetes and high-glucose-induced endothelial cell senescence.

Abstract 552: Sustained Inhibition Of High Mobility Box 1 By Antisense Oligonucleotide

Background: High-mobility group box 1 (HMGB1), a highly conserved nonhistone DNA-binding nuclear protein, may contribute to vascular diseases including atherosclerosis, pulmonary hypertension, and abdominal aortic aneurysm. Since whole-body genetic deletion of HMGB1 is embryonic lethal, pharmacological approaches, such as neutralizing antibodies and functional inhibitors, have been used to manipulate HMGB1 in mice. However, it remains desirable to genetically manipulate HMGB1 for further understanding its role. In the current study, we assessed the efficacy of a novel antisense oligonucleotides (ASOs) approach to deplete HMGB1 in mice. Methods and Results: First, abundance of HMGB1 mRNA was assessed by qPCR in major organs and tissues of male C57BL/6J mice (N=6). Hmgb1 mRNA was expressed ubiquitously, but it was most highly abundant in the lung, while least abundant in the testes. Next, we examined the efficacy of ASOs to reduce HMGB1 protein abundance at selected intervals. Either ASOs (25 mg/kg/day) or phosphate-buffered saline (PBS) were injected intraperitoneally into male C57BL/6J mice (8-10-week-old) at day 0 and 3 in the initial week and then once a week during the remainder of the study. Mice were terminated at either 2, 6, or 12 weeks after the initial injection of ASOs (N=5/group). Subsequently, mRNA and protein abundance of HMGB1 were determined in the lungs. Since previous studies have shown that systemic administration of ASOs mainly targets kidney and liver, HMGB1 mRNA or protein abundance was also examined in these organs. We also assessed HMGB1 protein abundance in the heart. In lungs, kidney, and liver, ASO administration resulted in a consistent &gt;90% decrease of Hmgb1 mRNA abundance at 2 weeks of ASO injection (P&gt;0.001). The decreased Hmbg1 mRNA abundance was also consistent at both weeks 6 and 12 (P&gt;0.001). ASOs decreased HMGB1 protein abundance significantly at 6- and 12-week time intervals. Heart tissue also indicated a consistent Hmgb1 mRNA decrease in response to ASO administration. Conclusion: ASO approach decreased HMGB1 at mRNA and protein abundance for 12 weeks in the liver, kidney, lungs, and heart. This mode may provide more clear insights into understanding the biological functions of HMGB1.

Diacerein ameliorates acetaminophen hepatotoxicity in rats via inhibiting HMGB1/TLR4/NF-κB and upregulating PPAR-γ signal.

BackgroundAcetaminophen (APAP) is a worldwide antipyretic as well as an analgesic medication. It has been extensively utilized during the outbreak of coronavirus 2019 (COVID-19). APAP misuse would lead to liver injury. Diacerein (DIA), an anthraquinone derivative, has antioxidant and inflammatory properties. Hence, this study attempted to evaluate the impact of DIA treatment on liver injury induced by APAP and its influence on nuclear factor-κB (NF-κB) /toll-like receptor 4 (TLR4)/high mobility group box-1(HMGB-1) signaling as well as the expression of peroxisome proliferator-activated receptor-gamma (PPAR-γ) expression.MethodsMale albino rats received 25 as well as 50 mg/kg/day DIA orally for seven days. One hour after the last administration, rats received APAP (1gm/kg, orally). For histopathological analysis, liver tissues and blood were collected, immunohistochemical (IHC) assay, biochemical assay, as well as quantitative real-time polymerase chain reaction (qRT-PCR).ResultsDIA markedly reduced liver injury markers and ameliorated histopathological changes. Moreover, DIA dose-dependently alleviated oxidative stress status caused by APAP administration along with inflammatory markers, including the level of interleukin-1 beta (IL-1β), myeloperoxidase (MPO), tumor necrosis factor-alpha (TNF-α), and interleukin 6 (IL-6). Furthermore, DIA downregulated protein levels as well as mRNA of HMGB-1, TLR4, NF-κB p65 expression, and enhanced PPAR-γ expression. Moreover, DIA ameliorated apoptotic (Bax) and caspase-3 expressions and increased the anti-apoptotic (Bcl2) expression.ConclusionsThis study demonstrated that DIA exerts anti-apoptotic, anti-inflammatory, and antioxidant properties against liver injury induced by APAP that is attributed to inhibition of the HMGB1/TLR4/NF-κB pathway, besides upregulation of the expression of PPAR-γ.

Ethyl Pyruvate Alleviating Inflammatory Response after Diabetic Cerebral Hemorrhage.

This study's purpose is to investigate the neuroprotective role of ethyl pyruvate (EP) in the pathogenesis of diabetic intracerebral hemorrhage. The present study used a mouse model of collagenase-induced intracerebral hemorrhage (ICH) and streptozotocin-induced diabetes. The C57BL/6 mice were randomly divided into 3 groups: sham operation, diabetic cerebral hemorrhage, and diabetic cerebral hemorrhage with EP. The EP (80 mg/kg) and EP (50 mg/kg) were injected intraperitoneally one day and one hour before modeling. The protein expression levels of high mobility group box 1 (HMGB1) and NOD-like receptors 3 (NLRP3) were detected with western blot. The mRNA levels of HMGB1 and toll-like receptor 4 (TLR4) were measured by quantitative real-time polymerase chain reaction (PCR). Immunofluorescence and ELISA were performed to confirm some inflammatory factors. Compared to the normal diabetic intracerebral hemorrhage group, the mRNA and protein expression levels of HMGB1 and TLR4 were downregulated in the EP-affected group with diabetic cerebral hemorrhage, together with the downregulation of the expression of inflammasomes, including NLRP3, apoptosis-associated speck-like protein containing CARD (ASC), and caspase 1. EP can reduce the inflammatory response after diabetic intracerebral hemorrhage and may inhibit the activation of inflammasomes by the HMGB1/TLR4 pathway.

LncRNA OIP5-AS1 promotes the proliferation and migration of vascular smooth muscle cells via regulating miR-141-3p/HMGB1 pathway

BackgroundLong non-coding RNAs (lncRNAs) have been reported to play critical roles in the pathogenesis of cardiovascular diseases. However, whether lncRNA opa-interacting protein 5 antisense RNA 1 (OIP5-AS1) regulates the pathogenesis of atherosclerosis (AS) is still unknown. MethodsHuman vascular smooth muscle cells (VSMCs) were treated with oxidized low-density lipoprotein (ox-LDL). OIP5-AS1, miR-141-3p and HMGB1 mRNA expressions were determined using quantitative real-time polymerase chain reaction (qRT-PCR). The proliferation, migration, and apoptosis of VSMCs were measured using MTT method, Transwell assay and TUNEL assay, respectively. Dual-luciferase reporter gene assay, qRT-PCR, and Western blot were conducted to investigate the interactions among OIP5-AS1, miR-141-3p and high mobility group box 1 (HMGB1). ResultsOIP5-AS1 expression was markedly increased in serum samples of AS patients and VSMCs treated with ox-LDL. OIP5-AS1 over-expression remarkably promoted proliferation, migration and inhibited apoptosis of VSMCs while miR-141-3p exerted the opposite effects. Furthermore, the binding sites between OIP5-AS1 and miR-141-3p were identified. OIP5-AS1 indirectly increased HMGB1 expression in VSMCs by targeting miR-141-3p. ConclusionsOIP5-AS1 promotes the proliferation, migration and suppresses apoptosis of VSMCs through regulating miR-141-3p/HMGB1 axis.

CCCTC-binding factor-mediated microRNA-340-5p suppression aggravates myocardial injury in rats with severe acute pancreatitis through activation of the HMGB1/TLR4 axis

Background Severe acute pancreatitis (SAP) is a life-threatening disorder associated with multisystem organ failure. This study aimed to investigate the function of high mobility group box 1 (HMGB1) in SAP-induced myocardial injury. Methods A rat model with SAP was induced. The pathological changes in rat pancreatic and cardiac tissues were examined by HE staining. Cardiomyocyte apoptosis in rat cardiac tissues, and the serum levels of myocardial injury markers and pro-inflammatory cytokines were examined. Rat primary cardiomyocytes were treated with H2O2 for in vitro experiments. The regulatory molecules of HMGB1 were predicted by bioinformatics analysis. Altered expression of HMGB1, microRNA (miR)-340-5p and CCCTC-binding factor (CTCF) was introduced in rats or cells to investigate their roles in myocardial injury. Results CTCF and HMGB1 were highly expressed but miR-340-5p was poorly expressed in cardiac tissues of rats with SAP. HMGB1 silencing reduced toll-like receptor 4 (TLR4) expression to promote proliferation and reduce apoptosis of H2O2-treated cardiomyocytes. miR-340-5p targeted HMGB1 mRNA, while CTCF suppressed miR-340-5p transcription. CTCF upregulation or miR-340-5p downregulation blocked the effects of HMGB1 silencing on cardiomyocytes. In vivo, CTCF silencing alleviated injury in rat pancreatic and cardiac tissues and reduced the expression of creatine kinase-MB (CK-MB), lactic dehydrogenase, interleukin (IL)-1β, IL-6 and tumor necrosis factor-α (TNF-α) in rat serum. But further overexpression of HMGB1 or inhibition of miR-340-5p aggravated the symptoms in rats. Conclusion This study demonstrated that CTCF reduces transcription of miR-340-5p to promote HMGB1 expression, which activates TLR4 expression and promotes myocardial injury in rats with SAP.