BRF1 ameliorates LPS-induced inflammation through autophagy crosstalking with MAPK/ERK signaling

BRF1 promotes the odontogenic differentiation of dental pulp stem cells in pulpitis by inducing autophagy

Objective

While post-transcriptional modifications play a pivotal role in the autophagy regulation, studies on dental pulp disease are limited. This study investigated the effect of BRF1 on autophagy in inflamed pulp tissue and human dental pulp stem cells (hDPSCs).

Methods

Immunohistochemical analysis was used to examine BRF1 expression, autophagy levels, and dentinogenic markers in normal and inflamed pulp. The presence of autophagosomes was observed by transmission electron microscopy. Primary hDPSCs were treated with 1 μg/mL lipopolysaccharide (LPS) for different lengths of time. The expression of BRF1 and autophagy makers was determined by Western blotting. BRF1 knockdown and 3 MA treatment were employed to assess changes in autophagy and dentinogenic differentiation. Double immunofluorescence staining was performed to co-localize BRF1 with LC3B in pulp tissue.

Results

The expressions of BRF1, LC3, DMP1, and DSP were significantly elevated in the inflamed pulp. LPS enhanced the protein production of IL-6, BRF1, LC3, and Beclin-1 from 6 h to 24 h after the treatment. BRF1 knockdown reduced the ratio of LC3-II/LC3-I and the differentiation ability of hDPSCs, while 3 MA inhibited LPS-mediated dentinogenic differentiation. Double-labeling revealed that BRF1 co-localized with LC3B in inflamed pulp.

Conclusion

This study demonstrated that BRF1 promoted autophagy activation and odontogenic differentiation in pulpitis.

2,5-Dihydroxyacetophenone attenuates acute kidney injury induced by intra-abdominal infection in rats

AIMS

As one of the most serious complications of sepsis, acute kidney injury (AKI) is pathologically associated with excessive inflammation. 2,5-Dihydroxyacetophenone (DHAP) is isolated from Radix rehmanniae praeparata and exhibit potent anti-inflammatory property. This research aimed at determining the role of DHAP in sepsis-associated AKI (SA-AKI) and the underlying mechanism.

METHODS

Plasma creatinine (Cre), blood urea nitrogen (BUN), tumour necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) levels of SA-AKI patients were detected to evaluate their clinical characteristics. SA-AKI rat models were established by using caecum ligation puncture (CLP) surgery. CLP-induced rats were administered via oral gavage with 20 or 40 mg DHAP after 2 h of CLP surgery. Subsequently, survival rates, serum indexes, histopathological changes, inflammatory factors, renal function indexes and extracellular regulated protein kinases (ERK) and nuclear factor-κB (NF-κB) signalling pathways were detected.

RESULTS

SA-AKI patients exhibited markedly higher levels of plasma Cre, BUN, TNF-α and IL-1β than healthy people. Compared with sham rats, CLP-induced septic rats showed significantly decreased survival rate, increased serum lactate dehydrogenase activity and serum lactate level, obvious renal histopathological injury, upregulated TNF-α, IL-1β and TGF-β1 levels, elevated serum creatinine, BUN and serum cystatin C concentrations, serum neutrophil gelatinase-associated lipocalin and kidney injury molecule-1 levels and reduced renal artery blood flow. All the above CLP-induced changes in septic rats were mitigated after DHAP administration. Additionally, CLP-induced elevation in phosphorylated-ERK1/2 and nuclear NF-κB p65 protein levels was inhibited by DHAP treatment.

CONCLUSION

DHAP hinders SA-AKI progression in rat models by inhibiting ERK and NF-κB signalling pathways.

Recent advances of mechanosensitive genes in vascular endothelial cells for the formation and treatment of atherosclerosis

Atherosclerotic cardiovascular disease and its complications are a high-incidence disease worldwide. Numerous studies have shown that blood flow shear has a huge impact on the function of vascular endothelial cells, and it plays an important role in gene regulation of pro-inflammatory, pro-thrombotic, pro-oxidative stress, and cell permeability. Many important endothelial cell mechanosensitive genes have been discovered, including KLK10, CCN gene family, NRP2, YAP, TAZ, HIF-1α, NF-κB, FOS, JUN, TFEB, KLF2/KLF4, NRF2, and ID1. Some of them have been intensively studied, whereas the relevant regulatory mechanism of other genes remains unclear. Focusing on these mechanosensitive genes will provide new strategies for therapeutic intervention in atherosclerotic vascular disease. Thus, this article reviews the mechanosensitive genes affecting vascular endothelial cells, including classical pathways and some newly screened genes, and summarizes the latest research progress on their roles in the pathogenesis of atherosclerosis to reveal effective therapeutic targets of drugs and provide new insights for anti-atherosclerosis.

Agomelatine improves memory and learning impairments in a rat model of LPS-induced neurotoxicity by modulating the ERK/SorLA/BDNF/TrkB pathway

The mutual interplay between neuroinflammation, synaptic plasticity, and autophagy has piqued researchers' interest, particularly when it comes to linking their impact and relationship to cognitive deficits. Being able to reduce inflammation and apoptosis, melatonin has shown to have positive neuroprotective effects; that is why we thought to check the possible role of agomelatine (AGO) as a promising candidate that could have a positive impact on cognitive deficits. In the current study, AGO (40 mg/kg/day, p.o., 7 days) successfully ameliorated the cognitive and learning disabilities caused by lipopolysaccharide (LPS) in rats (250 μg/kg/day, i.p., 7 days). This positive impact was supported by improved histopathological findings and improved spatial memory as assessed using Morris water maze. AGO showed a strong ability to control BACE1 activity and to rein in the hippocampal amyloid beta (Aβ) deposition. Also, it improved neuronal survival, neuroplasticity, and neurogenesis by boosting BDNF levels and promoting its advantageous effects and by reinforcing the pTrkB expression. In addition, it upregulated the pre- and postsynaptic neuroplasticity biomarkers resembled in synapsin I, synaptophysin, and PSD-95. Furthermore, AGO showed a modulatory action on Sortilin-related receptor with A-type repeats (SorLA) pathway and adjusted autophagy. It is noteworthy that all of these actions were abolished by administering PD98059 a MEK/ERK pathway inhibitor (0.3 mg/kg/day, i.p., 7 days). In conclusion, AGO administration significantly improves memory and learning disabilities associated with LPS administration by modulating the ERK/SorLA/BDNF/TrkB signaling pathway parallel to its capacity to adjust the autophagic process.

Sesquiterpene from Artemisia argyi seed extracts: A new anti-acute peritonitis agent that suppresses the MAPK pathway and promotes autophagy

To find novel anti-inflammatory drugs, we screened anti-inflammatory compounds from 18 different types of Artemisia argyi seed extracts. The in vitro and in vivo anti-inflammatory activities of the screened compounds and their mechanisms were characterized. We first detected the cytotoxic effect of the compounds on RAW264.7 cells and the inhibitory effect on LPS-induced NO release. It was found that sesquiterpenoids CA-2 and CA-4 had low cytotoxic and strong NO inhibitory activity with an IC50 of 4.22 ± 0.61 μM and 2.98 ± 0.23 μM for NO inhibition, respectively. Therefore, compound CA-4 was studied in depth. We found that compound CA-4 inhibited LPS-induced pro-inflammatory factor production and M1 macrophage differentiation in RAW264.7 cells. Additionally, CA-4 inhibited the expression of p-ERK1/2, p-JNK, iNOS, and COX-2 by blocking the MAPK signaling pathway. CA-4 also promoted the expression of autophagy-related proteins such as LC3 II and Beclin-1 by inhibiting activation of the PI3K/AKT/mTOR signaling pathway, and promoted the generation of autophagosomes. Finally, CA-4 significantly inhibited the degree of inflammation in mice with acute peritonitis, showing good anti-inflammatory activity in vivo. Consequently, compound CA-4 may be a promising drug for the treatment of acute inflammatory diseases and provide new ideas for the synthesis of novel anti-inflammatory compounds.

[Dihydromyricetin alleviates pyroptosis and necroptosis in mice with MPTP-induced chronic Parkinson's disease by inducing autophagy]

OBJECTIVE

To investigate the effect of 8-week dihydromyricetin (DHM) treatment on motor ability of mice with MPTP/probenecid-induced Parkinson's disease (PD) and explore the molecular mechanism.

METHODS

Sixty C57BL/6 mice were randomized into the control group, PD model group, PD+DHM group and PD+NEC-1 group (n=15). In the latter 3 groups, the mice were treated with 25 mg·kg-1·d-1 MPTP and 250 mg·kg-1·d-1 probenecid twice a week for 5 weeks to establish PD models; DHM (100 mg·kg-1·d-1) was administered 5 times a week via gavage for 8 weeks and NEC-1 (6.25 mg·kg-1·d-1, twice a week) via intraperitoneal injection for 5 weeks. The changes in motor function of the mice were assessed, and the expressions of TH, GFAP and Iba-1 in the substantia nigra were detected with immunofluorescence assay; serum levels of IL-1β and LDH were detected using ELISA. The mRNA expressions of TNF-α and IL-6 were determined with RT-PCR, and the expressions of TH and proteins associated with pyroptosis, neuroinflammation, necroptosis and autophagy in the striatum were detected using Western blotting. MPP +-activated Bv-2 cells were treated with different concentrations of DHM or 3-MA, and the expressions of proteins associated with autophagy and NLRP3 were detected using Western blotting; PI staining was used to detect cell necroptosis.

RESULTS

The PD mouse models showed significantly reduced TH-positive cells and TH protein expression (P < 0.001). DHM obviously ameliorated motor deficits and TH loss in PD mice, increased TH expression (P=0.0023), decreased α-syn levels (P < 0.001), lowered the protein expressions of GFAP (P=0.045) and Iba-1 (P < 0.001) and the mRNA and protein levels of TNF-α (P=0.0015) and IL-6 (P < 0.001), and increased IL-4 level (P < 0.001). The 8-week DHM treatment significantly suppressed pyroptosis and necroptosis and activated autophagy in the striatum of the PD mice. In MPP +-induced Bv-2 cells, DHM treatment effectively reversed autophagy impairment and inhibited NLRP3 and TNF-α, IL-6 and IL-1β release, and the anti--inflammatory effects of DHM was obviously blunted by 3-MA.

CONCLUSION

DHM can improve motor function of PD mice probably by activating autophagy to inhibit pyroptosis and necroptosis and reduce neuroinflammation.

Purification and characterization of Se-enriched Grifola frondosa glycoprotein, and evaluating its amelioration effect on As3+ -induced immune toxicity

BACKGROUND

Selenium (Se)-enriched glycoproteins have been a research highlight for the role of both Se and glycoproteins in immunoregulation. Arsenic (As) is a toxicant that is potentially toxic to the immune function and consequently to human health. Several reports suggested that Se could reduce the toxicity of heavy metals. Moreover, more and more nutrients in food had been applied to relieve As-induced toxicity. Hence glycoproteins were isolated and purified from Se-enriched Grifola frondosa, and their preliminary characteristics as well as amelioration effect and mechanism on As³⁺ -induced immune toxicity were evaluated.

RESULTS

Four factions, namely Se-GPr11 (electrophoresis analysis exhibited one band: 14.32 kDa), Se-GPr22 (two bands: 20.57 and 31.12 kDa), Se-GPr33 (three bands: 15.08, 20.57 and 32.78 kDa) and Se-GPr44 (three bands: 16.73, 32.78 and 42.46 kDa), were obtained from Se-enriched G. frondosa via DEAE-52 and Sephacryl S-400 column. In addition, Se-GPr11 and Se-GPr44 are ideal proteins that contain high amounts of almost all essential amino acids. Thereafter, the RAW264.7 macrophage model was adopted to estimate the effect of Se-GPr11 and Se-GPr44 on As³⁺ -induced immune toxicity. The results showed that the pre-intervention method was the best consequent and the potential mechanisms were, first, by improving the oxidative stress state (enhancing the activity of superoxide dismutase and glutathione peroxidase, decreasing the levels of reactive oxygen species and malondialdehyde); secondly, through nuclear factor-κB and mitogen-activated protein kinase-mediated upregulation cytokines (interleukin-2 and interferon-γ) secretion induced by As³⁺ .

CONCLUSION

The results suggested Se-enriched G. frondosa may be a feasible supplement to improve health level of the As³⁺ pollution population. © 2021 Society of Chemical Industry.

Novel insights into antidepressant mechanism of Kai Xin San formula: Inhibiting NLRP3 inflammasome activation by promoting autophagy

BACKGROUND

Kai Xin San (KXS) was widely applied for the treatment of depression for thousands of years. However, the underlying antidepressant mechanism of KXS remains not clear.

PURPOSE

This study aimed to investigate whether NLRP3 inflammasome and autophagy are involved in inflammation-induced depression and antidepressant mechanism of KXS.

METHODS

Wistar rats were exposed to chronic unpredictable mild stress (CUMS) for 6 weeks, and KXS (3, 5, and 10 g/kg/d) was administrated during the last 2 weeks of CUMS procedure. The effects of KXS on depressive-like behaviors, neuroinflammation, NLRP3 inflammasome activation, and autophagy were investigated in CUMS rats. Rat astrocytes were employed to further explore the potential mechanism of KXS in regulating NLRP3 inflammasome and autophagy. Autophagy inhibitor 3-methyladenine (3-MA, 5 mM) was used in vitro to elucidate the role of autophagy in the antidepressant mechanism of KXS.

RESULTS

In vivo, KXS improved depressive-like behaviors of CUMS rats in sucrose preference test, open field test and forced swimming test. Moreover, KXS inhibited the neuroinflammation induced by CUMS and promoted autophagy in prefrontal cortex of rats. The results in vitro further validated the anti-inflammatory and proautohapgic effects of KXS. More importantly, autophagy inhibitor 3-MA diminished the inhibitory effect of KXS on NLRP3 inflammasome activation in rat astrocytes.

CONCLUSION

KXS ameliorated CUMS-induced depressive behaviors in rats and inhibited the NLRP3 inflammasome-mediated inflammation in vivo and in vitro. These effects might be regulated by KXS-induced autophagy.

Pentoxifylline Can Reduce the Inflammation Caused by LPS after Inhibiting Autophagy in RAW264.7 Macrophage Cells

Pentoxifylline (PTX), as a methylxanthine derivative and nonspecific phosphodiesterase inhibitor, has the characteristics of anti-inflammatory and partial inflammatory process inhibition. However, the regulatory effect of PTX on inflammatory cytokines is unclear. Autophagy can regulate the activation of inflammasomes and then inhibit inflammation as previously described. Our study attempts to explore the relationship between autophagy and PTX-mediated regulation of inflammasome suppression. Macrophage-like RAW264.7 cells were studied as the in vitro macrophage model. We investigated the anti-inflammatory effect caused by PTX with time and dose response against the LPS-induced inflammatory factors (TNF-α, IL-1β). Western blot detected the levels of autophagy-related proteins Beclin-1 and LC3, as well as the signal pathways of AMPK and p-AMPK. Fluorescence microscope and transmission electron microscope were used to observe the autophagy bodies in cells influenced by PTX. The autophagy in cells inhibited by PTX exhibited dose- and time-dependent effects, and PTX alleviated LPS-induced inflammation caused by retarded autophagy. Furthermore, in RAW264.7 macrophage cells, our data indicated that AMPK signaling perhaps functioned importantly in repressed autophagy. In addition, in RAW264.7 macrophages, our data suggested that AMPK signaling might play an important role in inhibiting autophagy during the process of PTX ameliorating LPS-mediated inflammation.

Mechanisms of the lipopolysaccharide-induced inflammatory response in alveolar epithelial cell/macrophage co-culture

The interaction between alveolar epithelial cells (EpCs) and macrophages (MPs) serves an important role in initiating and maintaining inflammation in chronic pulmonary diseases. The aim of the present study was to investigate the molecular mechanisms of the inflammatory response in co-cultured EpCs and MPs. Briefly, a co-culture system of A549 (EpCs) and THP-1 (monocyte/MPs) cells was established in a filter-separated Transwell plate to evaluate the inflammatory response. Following lipopolysaccharide (LPS) treatment, cytokine levels were measured using ELISAs, NF-κB transcription factor activity was detected using EMSA and protein expression levels were analyzed using Western blot assays subsequently in EpCs and MPs. Co-cultured EpCs/MPs were found to secrete increased levels of interleukin (IL)-6, IL-1β, IL-8 and tumor necrosis factor (TNF)-α following LPS exposure for 6, 12, 24 and 48 h compared with either EpC or MP monocultures. Concurrently, NF-κB was revealed to be activated in MPs at 6 and 12 h, and in EpCs at 24 h. NF-κB DNA binding, Toll-like receptor 4 expression levels and the p65 phosphorylation status were also increased, which may contribute to the inflammatory response in the EpC/MP co-cultures. Notably, cytokine levels decreased following the inhibition of NF-κB expression with pyrrolidinedithiocarbamate. In conclusion, the present study successfully established an EpC/MP co-culture system using LPS, which may be a useful model for studying chronic inflammation in vitro.

Astragalus membranaceus Injection Suppresses Production of Interleukin-6 by Activating Autophagy through the AMPK-mTOR Pathway in Lipopolysaccharide-Stimulated Macrophages

Astragalus membranaceus (AM), used in traditional Chinese medicine, has been shown to enhance immune functions, and recently, its anti-inflammatory effects were identified. However, the mechanisms of action remain unclear. Most studies have shown that autophagy might be involved in the immune response of the body, including inflammation. Here, we developed an inflammatory model by stimulating macrophages with lipopolysaccharides (LPS) to explore the anti-inflammatory effect and mechanisms of AM injection from the perspective of the regulation of autophagy. Immunoblot, immunofluorescence, and ELISA were used to determine the effects of AM injection on the production of interleukin-6 (IL-6) and alterations of autophagy markers. It was found that AM injection reduced the expression of IL-6 in LPS-stimulated macrophages and reversed the LPS-induced inhibition of cellular autophagy. After treatment with inhibitors of signaling pathways, it was shown that LPS downregulated autophagy and upregulated the production of IL-6 in macrophages via the protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway. AM injection reversed the effects of LPS by activating the AMP-activated protein kinase (AMPK) instead of inhibiting Akt. These results were further confirmed by testing activators and siRNA silencing of AMPK. Hence, these 2 distinct signaling molecules appear to exert opposite effects on mTOR, which integrates information from multiple upstream signaling pathways, negatively regulating autophagy. In addition, we demonstrated that autophagy might play a key role in regulating the production of IL-6 by testing activators and inhibitors of autophagy and siRNA silencing of ATG5. These findings showed that AM injection might enhance autophagy by activating AMPK and might further play a repressive effect on the LPS-stimulated expression of IL-6. This study explored the relationship between autophagy, signaling pathways, and the production of inflammatory factors in a model of endotoxin infection and treatment with AM injection.

Osteopontin inhibits osteoarthritis progression via the OPN/CD44/PI3K signal axis

Chondrocyte degeneration and extracellular matrix component loss are the primary causes of osteoarthritis (OA). OA can be treated by inhibiting chondrocyte degeneration and increasing extracellular matrix component secretion. Osteopontin (OPN), a multifunctional protein, has gained immense attention with regard to its involvement in OA. This study aimed to explore the therapeutic value and mechanism of action of OPN in OA treatment. Results of the histomorphological analysis revealed a worn-off OA cartilage tissue surface, cartilage matrix layer deterioration, and calcium salt deposition. Compared to that in normal chondrocytes, in OA chondrocytes, the OPN, CD44, and PI3K protein and mRNA expression was upregulated. Further, siOPN, rhOPN, and rhOPN plus LS-C179404 interfered with OA chondrocytes. As verified in mice, OPN directly inhibited the expression level of PI3K in OA chondrocytes by binding with CD44. Morphological analysis of the knee joints demonstrated that OPN effectively inhibited OA progression via the OPN/CD44/PI3K signal axis. In conclusion, OPN activates intracellular PI3K signaling molecules by binding to CD44 on the cell surface to cause downstream cascading effects, thereby delaying chondrocyte degeneration and reducing cartilage matrix component loss; therefore, OPN is a potential therapeutic agent for OA.

α7nAChR Deletion Aggravates Myocardial Infarction and Enhances Systemic Inflammatory Reaction via mTOR-Signaling-Related Autophagy

Alpha7 nicotinic acetylcholine receptor (α7nAChR) has been previously reported to play an alleviative role in myocardial infarction (MI). In this study, we investigated its specific mechanism. α7nAChR^-/- mice and its control (α7nAChR^+/+) were used for the study of α7nAChR. Left anterior descending coronary artery occlusion was conducted for the creation of mice MI model and lipopolysaccharide (LPS) was used as inflammatory stressor in murine peritoneal macrophages. Triphenyltetrazolium chloride (TTC) staining and echocardiography was used for the detection of infarct size and cardiac function, respectively. Western blot was conducted for the testing of autophagy-related proteins and enzyme-linked immunosorbent assay (ELISA) and real-time polymerase chain reaction (RT-PCR) was used for the testing of proinflammatory cytokines. Rapamycin was used for the induction of autophagy through inhibiting mammalian target of rapamycin (mTOR)-related signaling. We found that knocking out α7nAChR enhanced the cardiac infarct size and damaged cardiac function in MI. α7nAChR deficiency increased the levels of several proinflammatory cytokines in serum and spleen from MI mice as well as murine macrophages under inflammatory stress. α7nAChR deletion decreased the level of autophagy in spleen from MI mice and macrophages under inflammatory stress. Rapamycin alleviated the cardiac function and systemic inflammatory reaction in MI mice as well as inflammatory reaction in macrophages under inflammatory stress, which was attenuated by knocking out α7nAChR. Our current study investigated the mechanism of α7nAChR-mediated cardio-protective and anti-inflammatory effect related to mTOR-related autophagy, which might provide a novel insight in the treatment of MI.

Antidepressant effects of a polysaccharide from okra (Abelmoschus esculentus (L) Moench) by anti-inflammation and rebalancing the gut microbiota

The present study aimed to evaluate the antidepressant-like effect of a polysaccharide (OP), which is isolated from okra (Abelmoschus esculentus (L) Moench), in CUMS-induced mice and its possible mechanisms. OPT, FST and TST were employed to examine the anxiety and depressive behavior in CUMS-induced mice and fecal microbiota transplantation (FMT) CUMS-induced mice, while proinflammatory cytokines, TLR4/NF-κB pathway and MAPKs signaling were detected in both CUMS-induced mice and LPS-induced BV2 cells. The results showed that anxiety- and depressive-like behaviors, gut microbiota dysbiosis and changes of SCFAs, and activation of inflammatory reactions in the colon, serum, and hippocampus of CUMS-induced mice, as well as activation of inflammatory reactions in BV2 cells, could be alleviated by the treatment of OP. The mice that were colonized by OP microbiota showed improved anxiety and depressive behaviors and lower inflammatory response. Furthermore, OP inhibited the expression of TLR4, the nuclear translocation of NF-κB and high levels of proinflammatory cytokines, and enhanced the MAPKs signaling, these effects of OP also observed in LPS-induced BV2 cells. Above all, suggested that the potential mechanism of the antidepressant-like effects of OP was closely correlated with the bidirectional communication of microbiota-gut-brain axis via regulation of inflammation response.

Red Ginseng Reduces Inflammatory Response via Suppression MAPK/P38 Signaling and p65 Nuclear Proteins Translocation in Rats and Raw 264.7 Macrophage

Lipopolysaccharides (LPS) cause systemic inflammatory responses, which are characterized by high mortality and multiple signs, including metabolic disturbances, respiratory acidosis, hypotension, and vital organs disorder. Cytokines secretion and oxidative stress are the main features of the disease. Diagnosis and treatment of systemic inflammation (SI) remain a challenge. Korean Red Ginseng (RG) is one of medicinal herbs that showed a potent anti-oxidant effect. We aimed to study the protective effects of RG on systemic inflammatory response in rats and RAW 264.7 macrophage cells induced by LPS. The rats were treated with water and alcohol extracts of RG for four weeks to prevent the inflammatory response. The result showed that LPS toxin increased morbidity and mortality, and induced liver, kidney, and lung injuries manifested by deteriorated biomarkers. Hypotension, hypomagnesemia, acidosis, and oxidative stress were observed in septic rats. However, RG extracts attenuated liver, kidney, and lung enzymes and metabolites in treated groups via its anti-inflammatory and anti-oxidant properties. Furthermore, RG improved magnesium and blood pressure in the treated groups. RAW 264.7 macrophage cells exposed to LPS disturbance in translocation of p65 and MAPK/p38. Nevertheless, RG-pretreated cells did not significantly alter. In conclusion, RG reduced the rates of mortality and morbidity of treated rats - liver, kidney, and lung injuries were protected in the treated groups through the potentiation of anti-oxidant defense. RG was able to conserve mitochondrial function, inhibiting the activation of MAPK/p38 signaling and suppressing NF-κB p65 cytoplasm-nucleus transport. Further studies are needed to examine the effects on chronic conditions in animal models and human.

iRoot BP Plus promotes osteo/odontogenic differentiation of bone marrow mesenchymal stem cells via MAPK pathways and autophagy

BACKGROUND

iRoot BP Plus is a novel bioceramic endodontic material. Recently, it has been considered as an alternative to MTA which is the most popular scaffold cover during regenerative endodontic therapy. This study aimed to evaluate the effects of iRoot BP Plus on the osteo/odontogenic capacity of bone marrow mesenchymal stem cells (BMMSCs), including the underlying mechanisms.

METHODS

BMMSCs were collected by a whole marrow method and treated with iRoot BP Plus-conditioned medium (BP-CM). The proliferation ability was evaluated by cell counting kit 8 and flow cytometry. Complete medium was used as a blank control, and 2 mg/ml MTA-conditioned medium was served as a positive control. Alkaline phosphatase (ALP) activity assay, ALP staining, western blot, real-time RT-PCR, Alizarin Red S staining, and immunofluorescence staining were performed to explore the osteo/odontogenic potential and the involvement of MAPK pathways. Besides, autophagy was investigated by western blot, immunofluorescence staining, and transmission electron microscopy.

RESULTS

Allicin attenuates pathological cardiac hypertrophy by inhibiting autophagy via activation of PI3K/Akt/mTOR and MAPK/ERK/mTOR signaling pathways

BACKGROUND

Cardiac hypertrophy is an adaptive response of the myocardium to pressure or volume overload. Recent evidences indicate that allicin can prevent cardiac hypertrophy. However, it is not clear whether allicin alleviates cardiac hypertrophy by inhibiting autophagy.

PURPOSE

We aimed to investigate the effects of allicin on pressure overload-induced cardiac hypertrophy, and further to clarify the related mechanism.

STUDY DESIGN/METHODS

Cardiac hypertrophy was successfully established by abdominal aortic constriction (AAC) in rats, and cardiomyocytes hypertrophy was simulated by angiotensin II (Ang II) in vitro. Hemodynamic parameters were monitored by organism function experiment system in vivo. The changes of cell surface area were observed using HE and immunofluorescence staining in vivoand in vitro, respectively. The expressions of cardiac hypertrophy relative protein (BNP and β-MHC), autophagy marker protein (LC3-II and Beclin-1), Akt, PI3K and ERK were detected by western blot.

RESULTS

Allicin could improve cardiac function, and reduce cardiomyocytes size, and decrease BNP and β-MHC protein expressions. Further results showed that allicin could lower LC3-II and Beclin-1 protein expressions both in vivo and in vitro experiments. And pharmacological inhibitor of mTOR, rapamycin could antagonize the effects of allicin on Ang II-induced cardiac hypertrophy and autophagy. Simultaneously, allicin could promote the expressions of p-Akt, p-PI3K and p-ERK protein.

CONCLUSION

These findings reveal a novel mechanism of allicin attenuating cardiac hypertrophy which allicin could inhibit excessive autophagy via activating PI3K/Akt/mTOR and MAPK/ERK/mTOR signaling pathways.

Oxidative Stress-Induced HMGB1 Release from Melanocytes: A Paracrine Mechanism Underlying the Cutaneous Inflammation in Vitiligo

Vitiligo is a cutaneous depigmentation disorder caused by the destruction of epidermal melanocytes. The generation and the skin infiltration of autoreactive CD8⁺ cytotoxic T cells triggered by oxidative stress play a critical role in vitiligo. High-mobility group protein B1 (HMGB1) is a classic damage-associated molecular pattern molecule with strong proinflammatory effects in inflammatory reactions. A previous study reported an enhanced expression of HMGB1 in vitiligo lesions, but the role of HMGB1 in cutaneous inflammation of vitiligo is still unknown. In the present study, we initially found that HMGB1 was released from the nucleus of melanocytes in vitiligo perilesional skin. Furthermore, cultured normal human melanocytes could release HMGB1 under treatment with hydrogen peroxide. Moreover, HMGB1 facilitated the secretion of CXCL16 and IL-8 from keratinocytes by binding to the receptor for advanced glycation end products and activating NF-κB and extracellular signal-regulated kinase signaling pathways. Subsequently, HMGB1 led to the formation of chemotaxis for the migration of CD8⁺ T cells from patients with vitiligo by increasing the release of CXCL16 from keratinocytes. Additionally, HMGB1 promoted the maturation of dendritic cells from patients with vitiligo. Altogether, our study demonstrates that HMGB1 released from melanocytes contributes to the formation of oxidative stress-induced autoimmunity in vitiligo.