Hepatocyte growth factor enhances the inflammation-alleviating effect of umbilical cord–derived mesenchymal stromal cells in a bronchiolitis obliterans model

The MSC-EV-microRNAome: A Perspective on Therapeutic Mechanisms of Action in Sepsis and ARDS

Mesenchymal stromal cells (MSCs) and MSC-derived extracellular vesicles (EVs) have emerged as innovative therapeutic agents for the treatment of sepsis and acute respiratory distress syndrome (ARDS). Although their potential remains undisputed in pre-clinical models, this has yet to be translated to the clinic. In this review, we focused on the role of microRNAs contained in MSC-derived EVs, the EV microRNAome, and their potential contribution to therapeutic mechanisms of action. The evidence that miRNA transfer in MSC-derived EVs has a role in the overall therapeutic effects is compelling. However, several questions remain regarding how to reconcile the stochiometric issue of the low copy numbers of the miRNAs present in the EV particles, how different miRNAs delivered simultaneously interact with their targets within recipient cells, and the best miRNA or combination of miRNAs to use as therapy, potency markers, and biomarkers of efficacy in the clinic. Here, we offer a molecular genetics and systems biology perspective on the function of EV microRNAs, their contribution to mechanisms of action, and their therapeutic potential.

Effect of Expansion Media on Functional Characteristics of Bone Marrow-Derived Mesenchymal Stromal Cells

The therapeutic efficacy of mesenchymal stromal cells (MSCs) has been shown to rely on their immunomodulatory and regenerative properties. In order to obtain sufficient numbers of cells for clinical applications, MSCs have to be expanded ex vivo. Expansion media with xenogeneic-free (XF) growth-promoting supplements like human platelet lysate (PL) or serum- and xenogeneic-free (SF/XF) formulations have been established as safe and efficient, and both groups provide different beneficial qualities. In this study, MSCs were expanded in XF or SF/XF media as well as in mixtures thereof. MSCs cultured in these media were analyzed for phenotypic and functional properties. MSC expansion was optimal with SF/XF conditions when PL was present. Metabolic patterns, consumption of growth factors, and secretome of MSCs differed depending on the type and concentration of supplement. The lactate per glucose yield increased along with a higher proportion of PL. Many factors in the supernatant of cultured MSCs showed distinct patterns depending on the supplement (e.g., FGF-2, TGFβ, and insulin only in PL-expanded MSC, and leptin, sCD40L PDGF-AA only in SF/XF-expanded MSC). This also resulted in changes in cell characteristics like migratory potential. These findings support current approaches where growth media may be utilized for priming MSCs for specific therapeutic applications.

Menstrual blood-derived endometrial stem cells inhibit neuroinflammation by regulating microglia through the TLR4/MyD88/NLRP3/Casp1 pathway

Neuroinflammation is a common response in various neurological disorders. Mesenchymal stem cell-based treatment has become a promising therapy for neuroinflammation-associated diseases. However, the effects of mesenchymal stem cells are controversial, and the underlying mechanism is incompletely understood. In the present study, menstrual blood-derived endometrial stem cells were intravenously transplanted into a mouse model of neuroinflammation established by peripheral injection of lipopolysaccharide. Microglial cells challenged with lipopolysaccharide were cultured with conditioned medium from endometrial stem cells. The levels of cytokines were detected by enzyme-linked immunosorbent assay. Cell proliferation and death were detected by Cell Counting Kit 8 and flow cytometry, respectively. The expression levels of Toll-like receptor 4 (TLR4), myeloid differentiation primary response gene 88 (MyD88), NLR family pyrin domain containing 3 (NLRP3) and caspase 1 (Casp1) were evaluated by western blotting. The results showed that intravenous transplantation of endometrial stem cells downregulated proinflammatory factors and upregulated anti-inflammatory factors in the brain of mice with neuroinflammation. Conditioned medium suppressed the inflammatory reaction and hyperactivation of microglial cells and protected microglial cells from cell death induced by lipopolysaccharide in vitro. The expression of TLR4, MyD88, NLRP3 and Casp1 in the brain of mice with neuroinflammation and in lipopolysaccharide-stimulated microglial cells was downregulated by endometrial stem cells and conditioned medium, respectively. These data suggested that menstrual blood-derived endometrial stem cells may suppress neuroinflammatory reactions partially by regulating microglia through the TLR4/MyD88/NLRP3/Casp1 signalling pathway. Our findings may be very useful for the development of an alternative stem cell-based therapy for neuroinflammation-associated disorders.

Functional enhancement strategies to potentiate the therapeutic properties of mesenchymal stromal cells for respiratory diseases

Respiratory diseases remain a major health concern worldwide because they subject patients to considerable financial and psychosocial burdens and result in a high rate of morbidity and mortality. Although significant progress has been made in understanding the underlying pathologic mechanisms of severe respiratory diseases, most therapies are supportive, aiming to mitigate symptoms and slow down their progressive course but cannot improve lung function or reverse tissue remodeling. Mesenchymal stromal cells (MSCs) are at the forefront of the regenerative medicine field due to their unique biomedical potential in promoting immunomodulation, anti-inflammatory, anti-apoptotic and antimicrobial activities, and tissue repair in various experimental models. However, despite several years of preclinical research on MSCs, therapeutic outcomes have fallen far short in early-stage clinical trials for respiratory diseases. This limited efficacy has been associated with several factors, such as reduced MSC homing, survival, and infusion in the late course of lung disease. Accordingly, genetic engineering and preconditioning methods have emerged as functional enhancement strategies to potentiate the therapeutic actions of MSCs and thus achieve better clinical outcomes. This narrative review describes various strategies that have been investigated in the experimental setting to functionally potentiate the therapeutic properties of MSCs for respiratory diseases. These include changes in culture conditions, exposure of MSCs to inflammatory environments, pharmacological agents or other substances, and genetic manipulation for enhanced and sustained expression of genes of interest. Future directions and challenges in efficiently translating MSC research into clinical practice are discussed.

Enhanced secretion of hepatocyte growth factor in human umbilical cord mesenchymal stem cells ameliorates pulmonary fibrosis induced by bleomycin in rats

Umbilical cord mesenchymal stem cells (UCMSCs) are a reportedly promising choice in the treatment of irreversible pulmonary fibrosis and lethal interstitial lung disease with limited drug treatment options. In this study, we investigated the therapeutic efficacy of UCMSCs overexpressing hepatocyte growth factor (HGF), which is considered one of the main anti-fibrotic factors secreted by MSCs. Adenovirus vector carrying the HGF gene was transfected into UCMSCs to produce HGF-modified UCMSCs (HGF-UCMSCs). Transfection promoted the proliferation of UCMSCs and did not change the morphology, and differentiation ability, or biomarkers. Rats were injected with HGF-UCMSCs on days 7 and 11 after intratracheal administration of bleomycin (10 mg/kg). We performed an analysis of histopathology and lung function to evaluate the anti-fibrotic effect. The results showed that HGF-UCMSCs decreased the Ashcroft scores in hematoxylin and eosin-stained sections, the percentage positive area in Masson trichrome-stained sections, and the hydroxyproline level in lungs. Forced expiratory volume in the first 300 m/forced vital capacity was also improved by HGF-UCMSCs. To explore the possible therapeutic mechanism of HGF-UCMSCs, we detected inflammatory factors in the lungs and performed mRNA sequencing in UCMSCs and HGF-UCMSCs. The data indicated that inhibition of interleukin-17 in the lung may be related to the anti-fibrosis of HGF-UCMSCs, and overexpressed HGF probably played a primary role in the treatment. Collectively, our study findings suggested that the overexpression of HGF may improve the anti-fibrotic effect of UCMSCs through directly or indirectly interacting with interleukin-17-producing cells in fibrotic lungs.

Hepatocyte Growth Factor Promotes Differentiation Potential and Stress Response of Human Stem Cells from Apical Papilla

Harsh local microenvironment, such as hypoxia and lack of instructive clues for transplanted stem cells, presents the serious obstacle for stem cell therapies' efficacy. Therefore, continued efforts have been taken to improve stem cells' viability and plasticity. Hepatocyte growth factor (HGF) has previously been reported to mitigate the complications of various human diseases in animal model studies and in some clinical trials. Besides, human stem cells from the root apical papilla (SCAP) are deemed a better resource of mesenchymal stem cells due to derived stem cells holding greater amplification ability in vitro compared with those from other dental resources. To move forward, evaluating effects and understanding underlying molecular mechanisms of HGF on SCAP for periodontal regeneration are needed. In this study, HGF was transgenically expressed in SCAP, and it was found that HGF enhanced osteo/dentinogenic differentiation capacity of SCAP compared with those of non-treated control in an ectopic mineralization model. Moreover, HGF reduced the apoptosis of SCAP under both normoxic and hypoxic conditions, whereas the combination of HGF and hypoxia exposure had inhibitory effects on cell proliferation during an 8-day in vitro culture period. Transcriptome analysis further revealed that suppressed cell cycle progression and activated BMP/TGFβ, Hedgehog, WNT, FGF, HOX, and other morphogen family members result upon HGF overexpression, which may render SCAP recapitulate part of neural crest stem cell characteristics. Moreover, strengthened stress response modulation such as unfolded protein response, macroautophagy, and anti-apoptotic molecules might explain the increased viability of SCAP. In all, our results imply that these potential mechanisms underlying HGF-promoting SCAP differentiation could be further elucidated and harnessed to improve periodontal tissue regeneration.

Recent advances in the therapeutic efficacy of hepatocyte growth factor gene-modified mesenchymal stem cells in multiple disease settings

Mesenchymal stem cell (MSC) therapy is considered a new treatment for a wide range of diseases and injuries, but challenges remain, such as poor survival, homing and engraftment rates, thus limiting the therapeutic efficacy of the transplanted MSCs. Many strategies have been developed to enhance the therapeutic efficacy of MSCs, such as preconditioning, co-transplantation with graft materials and gene modification. Hepatocyte growth factor (HGF) is secreted by MSCs, which plays an important role in MSC therapy. It has been reported that the modification of the HGF gene is beneficial to the therapeutic efficacy of MSCs, including diseases of the heart, lung, liver, urinary system, bone and skin, lower limb ischaemia and immune-related diseases. This review focused on studies involving HGF/MSCs both in vitro and in vivo. The characteristics of HGF/MSCs were summarized, and the mechanisms of their improved therapeutic efficacy were analysed. Furthermore, some insights are provided for HGF/MSCs' clinical application based on our understanding of the HGF gene and MSC therapy.

Application of Mesenchymal Stem Cells During Machine Perfusion: An Emerging Novel Strategy for Organ Preservation

Although solid organ transplantation remains the definitive management for patients with end-stage organ failure, this ultimate treatment has been limited by the number of acceptable donor organs. Therefore, efforts have been made to expand the donor pool by utilizing marginal organs from donation after circulatory death or extended criteria donors. However, marginal organs are susceptible to ischemia-reperfusion injury (IRI) and entail higher requirements for organ preservation. Recently, machine perfusion has emerged as a novel preservation strategy for marginal grafts. This technique continually perfuses the organs to mimic the physiologic condition, allows the evaluation of pretransplant graft function, and more excitingly facilitates organ reconditioning during perfusion with pharmacological, gene, and stem cell therapy. As mesenchymal stem cells (MSCs) have anti-oxidative, immunomodulatory, and regenerative properties, mounting studies have demonstrated the therapeutic effects of MSCs on organ IRI and solid organ transplantation. Therefore, MSCs are promising candidates for organ reconditioning during machine perfusion. This review provides an overview of the application of MSCs combined with machine perfusion for lung, kidney, liver, and heart preservation and reconditioning. Promising preclinical results highlight the potential clinical translation of this innovative strategy to improve the quality of marginal grafts.

Anti-inflammatory effect of HGF responses to oral traumatic ulcers using an HGF-Tg mouse model

Hepatocyte growth factor (HGF) has been implicated in inhibiting diverse types of inflammation. Oral traumatic ulceration (OTU) is a common disease of the oral mucosa, and inflammation is the main process for ulcer healing. This study aimed to explore the expression of HGF in oral ulcers and its role in ulcer inflammation. The saliva of 14 recurrent alphous stomatitis (RAS) patients, 18 OTU patients and 17 healthy controls was collected. Traumatic ulcers of the left mucosa were observed in 42 wild-type (WT) and 42 HGF-overexpressing transgenic (HGF-Tg) mice. Histological scores, inflammatory cell expression and serum cytokine expression were measured and analyzed on the 5th day. The HGF protein level in ulcer-affected human saliva was 9.3-fold higher than that in healthy saliva. The HGF protein levels in RAS and OTU saliva were 14- and 5.7-fold higher, respectively, than those in healthy saliva. Traumatic ulcers enhanced HGF expression in ulcer-affected oral mucosa and in the blood of C57BL/6 mice by 1.21- and 1.40-fold, respectively. In HGF-Tg mouse traumatic ulcers, HGF expression was 1.34-fold higher than that in wild-type mice. HGF-Tg mice had lower weight loss, less ulcer area and lower histopathology scores than WT mice. The results from immunohistochemistry, flow cytometry and serum cytokine analysis showed that HGF-Tg animals presented fewer Ly6G-positive neutrophils and higher levels of circulating inflammatory cytokines. HGF overexpression alleviated weight loss, ulcer area and inflammation, suggesting the role of HGF in promoting the healing of oral ulcers.

Mechanisms behind the Immunoregulatory Dialogue between Mesenchymal Stem Cells and Th17 Cells

Mesenchymal stem cells (MSCs) exhibit potent immunoregulatory abilities by interacting with cells of the adaptive and innate immune system. In vitro, MSCs inhibit the differentiation of T cells into T helper 17 (Th17) cells and repress their proliferation. In vivo, the administration of MSCs to treat various experimental inflammatory and autoimmune diseases, such as rheumatoid arthritis, type 1 diabetes, multiple sclerosis, systemic lupus erythematosus, and bowel disease showed promising therapeutic results. These therapeutic properties mediated by MSCs are associated with an attenuated immune response characterized by a reduced frequency of Th17 cells and the generation of regulatory T cells. In this manuscript, we review how MSC and Th17 cells interact, communicate, and exchange information through different ways such as cell-to-cell contact, secretion of soluble factors, and organelle transfer. Moreover, we discuss the consequences of this dynamic dialogue between MSC and Th17 well described by their phenotypic and functional plasticity.

Strategies to Enhance Mesenchymal Stem Cell-Based Therapies for Acute Respiratory Distress Syndrome

Acute respiratory distress syndrome (ARDS) is a multifaced disease characterized by the acute onset of hypoxemia, worsened pulmonary compliance, and noncardiogenic pulmonary edema. Despite over five decades of research, specific treatments for established ARDS are still lacking. MSC-based therapies have the advantage of targeting nearly all pathophysiological components of ARDS by means of a variety of secreted trophic factors, exerting anti-inflammatory, antioxidative, immunomodulatory, antiapoptotic, and proangiogenic effects, resulting in significant structural and functional recovery following ARDS in various preclinical models. However, the therapeutic efficacy of transplanted MSCs is limited by their poor engraftment and low survival rate in the injured tissues, major barriers to clinical translation. Accordingly, several strategies have been explored to improve MSC retention in the lung and enhance the innate properties of MSCs in preclinical models of ARDS. To provide a comprehensive and updated view, we summarize a large body of experimental evidence for a variety of strategies directed towards strengthening the therapeutic potential of MSCs in ARDS.

Losartan suppresses the inflammatory response in collagen-induced arthritis by inhibiting the MAPK and NF-κB pathways in B and T cells

The angiotensin II type 1 receptor (AT1R) antagonist losartan has been confirmed to have a moderate anti-inflammatory effect in vitro and in vivo. However, how it affects immune cells in Rheumatoid Arthritis (RA) is still unknown. We found that in human synovial tissues, AT1R is significantly expressed on T cells and B cells. Treatment with losartan (15 mg/kg) alone and in combination with a low dose of methotrexate (MTX 0.25 mg/kg/3 days) significantly suppressed the progression of CIA. Secondary paw swelling, joint destruction and the presence of pro-inflammatory cytokines (TNF-α and IFN-γ) in the serum were alleviated after treatment. The therapeutic effects of losartan were based on reduced T-cell and B-cell activation, specifically by decreased cell vitality and pro-inflammatory cytokine production. In addition, losartan combined with a low dose of MTX achieved a similar therapeutic effect, while protecting liver and kidney from MTX damage. Mechanistically, losartan inhibits the production of pro-inflammatory mediators, reduces the phosphorylation of p38, ERK, and p65, p50 nuclear transposition in T cells and B cells. Phosphorylation of JNK is not affected by losartan in the CIA rat model. losartan can be used as an effective RA treatment, which exhibits anti-arthritic effects potentially through down-regulating the phosphorylation of p38, ERK and signaling through NF-κB. While achieving similar anti-rheumatic effects, a combination therapy of losartan with a low dose of MTX, can protect from liver and renal damage caused by giving a high dose of MTX.

Combined treatment with sinomenine and acupuncture on collagen-induced arthritis through the NF-κB and MAPK signaling pathway

Sinomenine is a monomer extracted from the traditional Chinese medicine plant Sabia japonica, which possesses several pharmacological properties including prominent abirritation, mitigation, anti-inflammation, immune suppression, cough relief, stimulation of histamine release, decrease in blood pressure and antiarrhythmia. Sinomenine is clinically employed to treat rheumatic disease. To investigate the impact of combined sinomenine treatment with acupuncture on the progression of arthritis and explore the potential underlying molecular mechanisms, the present study analyzed a collagen-induced arthritis model. Results from the combined curative (CC) treatment group (combined treatment with sinomenine and acupuncture) demonstrated a decrease in volume changes and arthritis score changes within rat paws, and increased the overall body weight in arthritic rats. CC treatment significantly decreased tumor necrosis factor α, interleukin (IL)-6, IL-1β and IL-8 serum levels in arthritic rats. CC treatment significantly increased superoxide dismutase and inhibited malondialdehyde levels in arthritic rats. The protein expression of cyclooxygenase-2, inducible nitric oxide synthase, matrix metalloproteinase (MMP)2 and MMP9 in arthritic rats was suppressed owing to CC treatment. Finally, nuclear factor κB and phosphorylated p38 mitogen-activated protein kinase (MAPK) protein expression in arthritic rats were also suppressed following CC treatment. The results indicate that the combined treatment of sinomenine and acupuncture on collagen-induced arthritis takes effect through the nuclear factor κB and MAPK signaling pathway.

Hepatocyte growth factor (HGF) optimizes oral traumatic ulcer healing of mice by reducing inflammation

OBJECTIVE

To evaluate the influence of overexpression HGF on the healing of traumatic ulcer of oral mucosa of mice.

MATERIAL AND METHODS

Mice were divided into two groups: wild type C57BL6(WT) and HGF high expression transgenic (HGF-Tg) mice. Traumatic ulcer of all mice were made by number 15 scalpel blade. Mice were sacrificed after 5days and the inflammation score and expression of TNFα, IFNγ, c-Met, apoptosis (TUNEL) and 40 serum inflammation cytokines were estimated.

RESULTS

HGF-Tg mice presented a lower inflammation score (p=0.011), Serum TNFα expression in HGF-Tg ulcers is 1.3 times than WT ulcer and the difference is statistical significance (t test, p=0.003). Serum c-Met protein in HGF-Tg mice were significantly higher than WT mice (t test, p=0.004). No statistical difference was observed in the serum IFNγ between WT ulcer and HGF-Tg ulcer (t test, p=0.268). TNFα positive cytoplasm expression cells in connective tissue of HGF-Tg mice is significantly lower than that of WT group (t test, p=0.029). C-Met positive cytoplasm expression cells in both epithelium and connective tissue of HGF-Tg group is significantly higher than that of WT group (t test, p=0.040, p=0.000). Samples in HGF-Tg group showed a lower number of positive cells of epithelium TUNEL staining compared with that in the WT group (t test, p=0.035).

CONCLUSIONS

HGF exhibited anti-inflammatory potential in oral traumatic ulcer through the reduction of epithelial apoptosis, connective tissue TNFα expression and induction of c-Met expression.

Human adipose-derived mesenchymal stem cells alleviate obliterative bronchiolitis in a murine model via IDO

Background

Long-term survival of lung transplantation is hindered by the development of obliterative bronchiolitis (OB). Adipose-derived stem cells (ASCs) were documented to have more potent immunosuppressive ability than mesenchymal stem cells (MSCs) from bone marrow and placenta. The goal of our study is to evaluate the effect of repeated administration of ASCs on OB and the involvement of indoleamine 2,3-dioxygenase (IDO) mediating the protective effect of ASCs in a heterotopic tracheal transplantation (HTT) model.

Methods

For studies in vitro, ASCs were treated with interferon-γ (IFN-γ). For in vivo study, tracheas from BALB/c or C57BL/6 donors were transplanted into C57BL/6 recipients to create a HTT model. On days 0, 1, 3, 5, 8, 12, 15, 20 and 25 post-transplant, the allogeneic recipient mice were administered intravenously with phosphate buffered saline, 1 × 10⁶ human ASCs, or 1 × 10⁶ human ASCs plus 1-methyltryptophan (1-MT), an IDO inhibitor. On days 3, 7, 14 and 28, serum, trachea and spleen samples were harvested for analysis.

Results

ASCs homed to heterotopic tracheal grafts after infusion. Multiple doses of ASCs significantly increased tracheal IDO levels in allografts. There were significant increases in graft and serum IFN-γ levels in allografts compared with isografts. IFN-γ elevated IDO expression and activity in ASCs in vitro. ASCs alleviated OB in allografts as evidenced by reduced epithelial loss, epithelial apoptosis, and intraluminal obstruction. The effects of ASCs on OB were blocked by 1-MT. 1-MT also blocked the alterations in pro and anti-inflammatory cytokines as well as CD3+ T cell infiltration induced by ASCs. ASCs induced not only splenic levels of CD4+CD25+Foxp3+ regulatory T cells (Treg) but also IL-10 and TGF-β-producing Treg. Furthermore, IDO inhibition abolished the changes of splenic Treg induced by ASCs. In addition, Treg reduction by cyclophosphamide treatment did not alter the effects of ASCs on tracheal IDO expression in allografts confirming Treg induction is downstream of IDO.

Conclusions

Repeated doses of ASCs are capable of ameliorating OB. ASCs act at least in part via elevating IDO expression. ASCs promote the generation of Treg and suppress T cell infiltration via an IDO-dependent mechanism.

Repeated systemic administration of adipose tissue-derived mesenchymal stem cells prevents tracheal obliteration in a murine model of bronchiolitis obliterans

OBJECTIVE

To investigate the effect of adipose tissue-derived mesenchymal stem cell (ASC) administered either systemically or locally in a murine model of bronchiolitis obliterans.

RESULTS

When compared to controls, systemic treatment with 10⁶ ASCs on D0 and a second dose on D7 significantly prevented tracheal obliteration 28 days after heterotopic tracheal transplantation (median of 94 vs. 16%; P < 0.01). A single dose tended towards less stenosis than controls, but did not reach statistical significance (28 vs. 94%; P = 0.054). On the contrary, repeated local injection was incapable of preventing tracheal obliteration when compared to a single injection or controls (37 vs. 71 vs. 87%). Two intravenous doses also tended to be better than two local injections (16 vs. 37%; P = 0.058), and were better than a single local dose (16 vs. 71%; P < 0.01).

CONCLUSION

A second dose of ASC, given systemically after 7 days, reduces luminal obliteration in a heterotopic tracheal transplantation model in mice, suggesting that ASC can be used to prevent obliterative bronchiolitis after lung transplantation.

N-Butylphthalide (NBP) ameliorated cerebral ischemia reperfusion-induced brain injury via HGF-regulated TLR4/NF-κB signaling pathway

N-Butylphthalide (NBP) has been known to have potential neuroprotective effects in Alzheimer's disease and stroke animal models. Hepatocyte-growth factor (HGF), with strong angiogenic properties, exerted protective role in brain injury. The present study was aimed to investigate the possible anti-inflammatory effects of NBP on the brain injury of rats with cerebral ischemia reperfusion (IR) and astrocytes activation induced by lipopolysaccharide (LPS) treatment. Our results showed that cerebral IR induced brain damage with down-regulation of HGF and astrocytes activation. NBP treatment significantly increased HGF expression and activated cMet/PI3K/AKT signaling pathway, stimulating mTOR activity and suppressing apoptosis in brain tissues. Also NBP inhibited pro-inflammatory cytokines expression, including IL-6, IL-1β, and TNFα, via TLR4/NF-κB suppression. Anti-HGF treatment enhanced TLR4 expression while HGF could suppress TLR4 activation and its down-streaming signals, attenuating inflammation finally. Notably, NBP up-regulated HGF and down-regulated TLR4 expression significantly in the astrocytes combined with the treatment of TLR4 inhibitor than the cells only treated with TLR4 inhibitor, suggesting that NBP could further suppress TLR4 activation, suggesting that NBP might impede TLR4 through up-regulating HGF expression. These results suggested that NBP treatment significantly ameliorated cerebral IR-induced brain injury by inhibiting TLR4/NF-κB-associated inflammation regulated by HGF.