Expression Of Hepatocyte Growth Factor Research Articles

Deletion of TP signaling in macrophages delays liver repair following APAP-induced liver injury by reducing accumulation of reparative macrophage and production of HGF

BackgroundAcetaminophen (APAP)-induced liver injury is the most common cause of acute liver failure. Macrophages are key players in liver restoration following APAP-induced liver injury. Thromboxane A2 (TXA2) and its receptor, thromboxane prostanoid (TP) receptor, have been shown to be involved in tissue repair. However, whether TP signaling plays a role in liver repair after APAP hepatotoxicity by affecting macrophage function remains unclear.MethodsMale TP knockout (TP−/−) and C57BL/6 wild-type (WT) mice were treated with APAP (300 mg/kg). In addition, macrophage-specific TP-knockout (TP△mac) and control WT mice were treated with APAP. We explored changes in liver inflammation, liver repair, and macrophage accumulation in mice treated with APAP.ResultsCompared with WT mice, TP−/− mice showed aggravated liver injury as indicated by increased levels of alanine transaminase (ALT) and necrotic area as well as delayed liver repair as indicated by decreased expression of proliferating cell nuclear antigen (PCNA). Macrophage deletion exacerbated APAP-induced liver injury and impaired liver repair. Transplantation of TP-deficient bone marrow (BM) cells to WT or TP−/− mice aggravated APAP hepatotoxicity with suppressed accumulation of macrophages, while transplantation of WT-BM cells to WT or TP−/− mice attenuated APAP-induced liver injury with accumulation of macrophages in the injured regions. Macrophage-specific TP−/− mice exacerbated liver injury and delayed liver repair, which was associated with increased pro-inflammatory macrophages and decreased reparative macrophages and hepatocyte growth factor (HGF) expression. In vitro, TP signaling facilitated macrophage polarization to a reparative phenotype. Transfer of cultured BM-derived macrophages from control mice to macrophage-specific TP−/− mice attenuated APAP-induced liver injury and promoted liver repair. HGF treatment mitigated APAP-induced inflammation and promoted liver repair after APAP-induced liver injury.ConclusionsDeletion of TP signaling in macrophages delays liver repair following APAP-induced liver injury, which is associated with reduced accumulation of reparative macrophages and the hepatotrophic factor HGF. Specific activation of TP signaling in macrophages may be a potential therapeutic target for liver repair and regeneration after APAP hepatotoxicity.

HGF Facilitates the Repair of Spinal Cord Injuries by Driving the Chemotactic Migration of MSCs Through the β-Catenin/TCF4/Nedd9 Signaling Pathway.

Transplanted mesenchymal stem cells (MSCs) can significantly aid in repairing spinal cord injuries (SCI) by migrating to and settling at the injury site. However, this process is typically inefficient, as only a small fraction of MSCs successfully reach the target lesion area. During SCI, the increased expression and secretion of hepatocyte growth factor (HGF) act as a chemoattractant that guides MSC migration. Nonetheless, the precise mechanisms by which HGF influences MSC migration are not fully understood. This study focused on unraveling the molecular pathways that drive MSC migration towards the SCI site in response to HGF. It was found that HGF can activate β-catenin signaling in MSCs either by phosphorylating LRP6 or by suppressing GSK3β phosphorylation through the AKT and ERK1/2 pathways, or by enhancing the expression and nuclear translocation of TCF4. This activation leads to elevated Nedd9 expression, which promotes focal adhesion formation and F-actin polymerization, facilitating chemotactic migration. Transplanting MSCs during peak HGF expression in injured tissues substantially improves nerve regeneration, reduces scarring, and enhances hind limb mobility. Additionally, prolonging HGF release can further boost MSC migration and engraftment, thereby amplifying regenerative outcomes. However, inhibiting HGF/Met or interfering with β-catenin or Nedd9 signaling significantly impairs MSC engraftment, obstructing tissue repair and functional recovery. Together, these findings provide a theoretical basis and practical strategy for MSC transplantation therapy in SCI, highlighting the specific molecular mechanisms by which HGF regulates β-catenin signaling in MSCs, ultimately triggering their chemotactic migration.

Microvesicles derived from mesenchymal stem cells inhibit acute respiratory distress syndrome-related pulmonary fibrosis in mouse partly through hepatocyte growth factor.

Pulmonary fibrosis is one of the main reasons for the high mortality rate among acute respiratory distress syndrome (ARDS) patients. Mesenchymal stromal cell-derived microvesicles (MSC-MVs) have been shown to exert antifibrotic effects in lung diseases. To investigate the effects and mechanisms of MSC-MVs on pulmonary fibrosis in ARDS mouse models. MSC-MVs with low hepatocyte growth factor (HGF) expression (siHGF-MSC-MVs) were obtained via lentivirus transfection and used to establish the ARDS pulmonary fibrosis mouse model. Following intubation, respiratory mechanics-related indicators were measured via an experimental small animal lung function tester. Homing of MSC-MVs in lung tissues was investigated by near-infrared live imaging. Immunohistochemical, western blotting, ELISA and other methods were used to detect expression of pulmonary fibrosis-related proteins and to compare effects on pulmonary fibrosis and fibrosis-related indicators. The MSC-MVs gradually migrated and homed to damaged lung tissues in the ARDS model mice. Treatment with MSC-MVs significantly reduced lung injury and pulmonary fibrosis scores. However, low expression of HGF (siHGF-MSC-MVs) significantly inhibited the effects of MSC-MVs (P < 0.05). Compared with the ARDS pulmonary fibrosis group, the MSC-MVs group exhibited suppressed expression of type I collagen antigen, type III collagen antigen, and the proteins transforming growth factor-β and α-smooth muscle actin, whereas the siHGF-MVs group exhibited significantly increased expression of these proteins. In addition, pulmonary compliance and the pressure of oxygen/oxygen inhalation ratio were significantly lower in the MSC-MVs group, and the effects of the MSC-MVs were significantly inhibited by low HGF expression (all P < 0.05). MSC-MVs improved lung ventilation functions and inhibited pulmonary fibrosis in ARDS mice partly via HGF mRNA transfer.

Prognostic significance of hepatocyte growth factor in non-metastatic colorectal cancer

Hepatocyte growth factor (HGF), produced by mesenchymal cells, stimulates mitogenesis and angiogenesis in tumor cells. Tumor cells of some solid tumors do not secrete HGF. The aim of the study was to evaluate the prognostic significance of HGF expression in tumor tissue in colorectal cancer (CRC). The study included 50 patients with stage II-III colorectal cancer; they underwent radical surgical treatment, followed by adjuvant chemotherapy according to the FOLFOX/XELOX regimen. In primary tumor samples, quantitative PCR was used to assess the level of HGF expression. Statistical processing of the obtained data was carried out using STATISTICA 13.0, BioStat v.7.1., and Jamovi 1.6.8 software. The study aims to study a new marker. Comparison of characteristics in the case of non-normal distribution was carried out using the nonparametric Mann–Whitney U test. Cox and Kaplan–Meier linear regression tests were used to analyze progression-free survival. When discussing the results, we used our previously obtained data on the level of expression of TGF-β and CXCL8 in the tumor tissue. As a result of the studies, it was found that in 60% of tumor samples HGF was not expressed, but it was significantly higher than in the resection line samples. Analysis of relapse-free survival in patients with CRC according to the level of HGF expression (predicted level by proportional hazards assessment – 0.7) showed that the median survival in groups 1 (HGF expression more than 0.7) and 2 (HGF expression less than 0.7) was 23.3 and 62.9 months, respectively (long rank test p = 0.215). It was shown that the level of HGF mRNA in CRC tumors does not depend on age, stage of the disease, and sensitivity to FOLFOX/XELOX chemotherapy. The expression level is significantly reduced in tumors with a KRAS mutation and increased in those with a BRAF mutation, in poorly differentiated tumors. Using the level of HGF expression in the tumor tissue of patients with non-metastatic CRC before the start of chemotherapy to assess the prognosis of the relapse-free period is only possible in conjunction with the expression of TGF-β, CXCL8 in the tissue and the level of CEA in the blood of these patients.

Activation of Hepatocyte Growth Factor/MET Signaling as a Mechanism of Acquired Resistance to a Novel YAP1/TEAD Small Molecule Inhibitor.

Many tumor types harbor alterations in the Hippo pathway, including mesothelioma, where a high percentage of cases are considered YAP1/TEAD dependent. Identification of autopalmitoylation sites in the hydrophobic palmitate pocket of TEADs, which may be necessary for YAP1 protein interactions, has enabled modern drug discovery platforms to generate compounds that allosterically inhibit YAP1/TEAD complex formation and transcriptional activity. We report the discovery and characterization of a novel YAP1/TEAD inhibitor MRK-A from an aryl ether chemical series demonstrating potent and specific inhibition of YAP1/TEAD activity. In vivo, MRK-A showed a favorable tolerability profile in mice and demonstrated pharmacokinetics suitable for twice daily oral dosing in preclinical efficacy studies. Importantly, monotherapeutic targeting of YAP1/TEAD in preclinical models generated regressions in a mesothelioma CDX model; however, rapid resistance to therapy was observed. RNA-sequencing of resistant tumors revealed mRNA expression changes correlated with the resistance state and a marked increase of hepatocyte growth factor (HGF) expression. In vitro, exogenous HGF was able to fully rescue cytostasis induced by MRK-A in mesothelioma cell lines. In addition, co-administration of small molecule inhibitors of the MET receptor tyrosine kinase suppressed the resistance generating effect of HGF on MRK-A induced growth inhibition. In this work, we report the structure and characterization of MRK-A, demonstrating potent and specific inhibition of YAP1/TAZ-TEAD-mediated transcriptional responses, with potential implications for treating malignancies driven by altered Hippo signaling, including factors resulting in acquired drug resistance.

Mechanism of Paeoniae Radix Rubra and Aconiti Lateralis Radix Praeparata herbal pair in promoting hepatocellular regeneration in chronic acute liver failure based on HGF/PI3K/Akt signaling axis

Based on the hepatocyte growth factor(HGF)/phosphatidylinositol 3-kinase(PI3K)/protein kinase B(Akt) signaling axis, this study investigated the therapeutic effect of Paeoniae Radix Rubra and Aconiti Lateralis Radix Praeparata(PRR-ALRP) her-bal pair on acute-on-chronic liver failure(ACLF) rats and its impact on hepatocellular regeneration. The rat model of ACLF was constructed by subcutaneous and tail vein injection of bovine serum albumin combined with intraperitoneal injection of lipopolysaccharides(LPS)+D-galactosamine(D-GalN). The rats were divided into normal control(NC) group, model(vehicle) group, PRR-ALRP(5.85 g·kg~(-1)) group, and hepatocyte growth factor granules(HGFG, 4.05 g·kg~(-1)) group. Hematoxylin-eosin(HE) staining was used to observe pathological changes in rat liver tissues. Serum alanine aminotransferase(ALT), aspartate transaminase(AST), and total bilirubin(TBIL) were detected using an automatic biochemical analyzer. The levels of interleukin-1β(IL-1β) and tumor necrosis factor-α(TNF-α) inflammatory factors were detected by ELISA. Immunofluorescence staining was used to detect the positive expression of proliferating cell nuclear antigen(PCNA), antigen identified by monoclonal antibody(Ki67), and cell cycle protein B1(CyclinB1). Real-time fluorescence-based quantitative polymerase chain reaction(RT-qPCR) and Western blot were used to detect the mRNA and protein expression levels of HGF, growth factor receptor-bound protein 1(Gab1), PI3K, Akt, phosphorylated PI3K(p-PI3K), and phosphorylated Akt(p-Akt). The results showed that compared with the vehicle group, the PRR-ALRP group had reduced liver tissue pathological scores, improved liver function, and reduced inflammatory response, with enhanced PCNA, Ki67, and CyclinB1 fluorescence expression. Furthermore, compared with the model group, the PRR-ALRP group showed upregulated expression of HGF and Gab1 proteins, as well as activation of PI3K and Akt phosphorylation. These findings suggest that PRR-ALRP herbal pair exerts anti-liver failure effects by alleviating hepatocyte inflammatory damage and promoting hepatocellular regeneration, and its specific regulatory mechanism may be related to the activation of the HGF/PI3K/Akt signaling pathway.

Poly (I:C) increases the expression of galectin 1, 3, 9 and HGF genes in exosomes isolated from human Wharton's jelly mesenchymal stem cells

BackgroundMesenchymal stem cells (MSCs) are commonly employed as a powerful tool for the treatment of immune-mediated problems owing to their capacity to regulate the immune system and differentiate into different tissues. Researchers use mesenchymal stem cell products given the limitations associated with the application of MSCs. Exosomes are nanometer vesicles derived from MSCs that are used in cell-free therapy. Inflammatory environmental conditions, such as stimulation of Toll-like receptor 3 (TLR-3), has the ability to adjust the immune-regulating properties and anti-inflammatory function of mesenchymal stem cells and their exosomes. Galectins and hepatocyte growth factor (HGF) are known as immunomodulatory factors in mesenchymal stem cells. This study was designed to examine the expression of galectin-1, galectin-3, galectin-9, and HGF genes in exosomes isolated from human Wharton's jelly mesenchymal stem cells (hWJ-MSCs) after stimulation with Poly (I:C) (Polyinosinic:polycytidylic acid sodium salt). MethodsTo begin, the explant technique was used to extract mesenchymal stem cells from human umbilical cord Wharton's jelly. Then, the stem cells were stimulated using Poly (I:C) at three time intervals of 12, 24 and 48 h. Exosomes secreted from the supernatant of cells were extracted and exosome confirmation tests, including Scanning electron microscopy (SEM), Dynamic light scattering (DLS) and Flow cytometry were performed. Finally, the expression of galectin-1, galectin-3, galectin-9, and HGF genes in exosomes was evaluated by Real-Time PCR at three time intervals of 12, 24 and 48 h after stimulation. ResultsThe findings of our study indicated that following stimulation with Poly (I:C), the expression of galectin-9 and HGF (P < 0.05) genes was markedly higher than in the control group after 12 h. After 24 h, the expression of galectin-9 (P < 0.01), galectin-3 and HGF (P < 0.05) increased; the expression of galectin-1, galectin-3, (P < 0.05), galectin-9 and HGF genes (p < 0.01) significantly increased compared to the control group after 48 h. ConclusionTLR3 stimulation can increase the expression of galectins and HGF genes in exosomes derived from hWJ-MSCs and may be improve the immunosuppressive abilities of exosomes.

Primitive macrophages enable long-term vascularization of human heart-on-a-chip platforms

The intricate anatomical structure and high cellular density of the myocardium complicate the bioengineering of perfusable vascular networks within cardiac tissues. Invivo neonatal studies highlight the key role of resident cardiac macrophages in post-injury regeneration and angiogenesis. Here, we integrate human pluripotent stem-cell-derived primitive yolk-sac-like macrophages within vascularized heart-on-chip platforms. Macrophage incorporation profoundly impacted the functionality and perfusability of microvascularized cardiac tissues up to 2weeks of culture. Macrophages mitigated tissue cytotoxicity and the release of cell-free mitochondrial DNA (mtDNA), while upregulating the secretion of pro-angiogenic, matrix remodeling, and cardioprotective cytokines. Bulk RNA sequencing (RNA-seq) revealed an upregulation of cardiac maturation and angiogenesis genes. Further, single-nuclei RNA sequencing (snRNA-seq) and secretome data suggest that macrophages may prime stromal cells for vascular development by inducing insulin like growth factor binding protein 7 (IGFBP7) and hepatocyte growth factor (HGF) expression. Our results underscore the vital role of primitive macrophages in the long-term vascularization of cardiac tissues, offering insights for therapy and advancing heart-on-a-chip technologies.

Transient growth factor expression via mRNA in lipid nanoparticles promotes hepatocyte cell therapy in mice

Primary human hepatocyte (PHH) transplantation is a promising alternative to liver transplantation, whereby liver function could be restored by partial repopulation of the diseased organ with healthy cells. However, currently PHH engraftment efficiency is low and benefits are not maintained long-term. Here we refine two male mouse models of human chronic and acute liver diseases to recapitulate compromised hepatocyte proliferation observed in nearly all human liver diseases by overexpression of p21 in hepatocytes. In these clinically relevant contexts, we demonstrate that transient, yet robust expression of human hepatocyte growth factor and epidermal growth factor in the liver via nucleoside-modified mRNA in lipid nanoparticles, whose safety was validated with mRNA-based COVID-19 vaccines, drastically improves PHH engraftment, reduces disease burden, and improves overall liver function. This strategy may overcome the critical barriers to clinical translation of cell therapies with primary or stem cell-derived hepatocytes for the treatment of liver diseases.

The inhibitory effect and mechanisms of Diwu Yanggan on hepatic precancerous lesions in a 2-AAF/PH rat model

Diwu Yanggan (DWYG) is a medicinal food formula that has demonstrated in vivo hepatoprotective properties. However, the mechanisms underlying DWYG's effects against hepatic precancerous lesions have not yet been elucidated. In this study, we aimed to investigate the potential role of DWYG in alleviating pre-cancerous liver lesions and explore the associated mechanisms using a rat model of 2-acetylaminofluorene/partial hepatectomy (2-AAF/PH) induced hepatic precancerous lesions. Our results demonstrated that treatment with Diwu Yanggan significantly reduced the levels of alanine transaminase (ALT) and aspartate transaminase (AST) in the liver compared to the model group. Additionally, alkaline phosphatase (ALP) levels approached those observed in the control group. Meanwhile, the expression of interleukin-6 (IL-6) and hepatocyte growth factor (HGF) was also decreased in the DWYG group. Collectively, our findings suggest that DWYG exhibits significant inhibitory effects on hepatic precancerous lesions in the 2-AAF/PH rat model through modulation of the IL-6/HGFsignaling system.

Hepatocyte growth factor (HGF) gene: molecular characterisation of complete coding sequence and expression profile in Tarim red deer (Cervus hanglu yarkandensis) antlers

Context The cDNA sequence of hepatocyte growth factor (HGF) gene in Tarim red deer has not been reported yet. Aims This study aims to obtain the full-length cDNA sequence of HGF and analyse its expression in different parts of developing antler tissues. The result provides foundational data for understanding the potential role of HGF in regulating antler growth and development. Methods Rapid amplification of cDNA ends was used to obtain the full-length cDNA sequence of Tarim red deer HGF. The pET28a (+) vector was constructed for prokaryotic expression of the recombinant protein in E. coli BL21 (DE3). The expression of HGF in different antler tissues was detected using real-time quantitative polymerase chain reaction and immunohistochemistry. Key results The full-length cDNA of Tarim red deer HGF was found to consist of a 156 bp 5’untranslated region (UTR), a 112 bp 3’UTR, and a 2193 bp open reading frame encoding a protein of 730 amino acids. The recombinant HGF protein expressed in prokaryotic cells formed inclusion bodies. HGF and its receptor c-Met were expressed in all four different antler tissues, with the highest expression level in velvet skin, followed by bone, cartilage, and the lowest in the mesenchyme. Conclusions The study successfully obtained the full-length cDNA sequence of Tarim red deer HGF and identified the expression profile of HGF and c-Met in different antler tissues. HGF is a candidate gene that may play a role in regulating the growth and development of deer antler. Implications These findings provide fundamental data for further investigations into the role of HGF in antler development. Understanding the function of HGF in antler development could have implications for elucidating the mechanism of antler regeneration.

Abstract IA16: Creation and preliminary analyses of a full spectrum of breast cancers initiated de novo from normal human mammary cells

Abstract Human breast cancers (BCs) are well recognized for the diagnostic and treatment challenges posed by their extensive and continuously evolving genetic and biologic heterogeneity. Although much progress has been made in identifying features that may serve as new targets, most of these have not been found to be usefully applied to metastatic BCs characterized by a lack of cellular expression of ER, PR, HER2 and a high proliferative activity. Accordingly, these generally incurable BCs, thus identified as “triple-negative” (TNBCs) are in particular need of strategies to model their development in ways that could facilitate the design and testing of effective treatments. Given the drawbacks historically encountered in using cell lines, mouse models, and patient-derived xenografts for this purpose, we launched experiments to assess the potential of creating a useful human model of TNBC de novo. We first discovered that forced expression of KRASG12D (K) alone is sufficient to produce low grade, but persistent human tumors in transplanted immunodeficient NRG mice from 2 of the 3 cell types that constitute and maintain the normal adult human female mammary gland. Histologically, these YB-1-dependent K–induced tumors were classified as variably human ER-, PR- and HER2-positive, invasive ductal carcinomas, also able to produce derivative small tumors in secondary hosts. Subsequent experiments to test whether the indolent properties of these tumors can be modified (i.e., by additional forced expression of human hepatocyte growth factor, or maintenance of transplanted mice on an obesity-inducing diet) showed that neither of these treatments enhance the growth of the K-induced tumors. However, in sharp contrast, transplantation of female NRG mice with the same types of freshly isolated normal adult female mammary cells transduced with lentivirally-encoded BMI1, MYC and TP53R273C and K (KBMT) produced growths containing an increased frequency of Ki67+ cells within a week, and subsequently, produced still YB-1-elevated, but continuously expanding TNBCs. Interestingly, K was required in addition to all 3 of these oncogenes to obtain aggressively expanding TNBCs and, when any one of the BMI1, MYC, or TP53R273C oncogenes was omitted, variably diminished outputs were obtained. FACS analyses showed the surface marker phenotypes of the cells present in any of the more rapidly growing tumors to be remarkably homogeneous with features of normal basal cells. In addition, despite any gross evidence of metastatic capability, cells isolated from all KBMT-induced tumors tested could be expanded in vitro and generated fast growing tumors in transplanted secondary mice. Taken together, these findings demonstrate the feasibility of rapidly and reproducibly creating a model of human TNBC de novo from initially normal human mammary cells, thus offering a new and powerful platform for potentially developing novel prevention, diagnostic, as well as treatment approaches applicable to this disease. Citation Format: Susanna Tan, Davide Pellacani, Sylvain Lefort, Amal El-Naggar, Shengsen Ding, Poul H Sorensen, Martin Hirst, Connie Eaves. Creation and preliminary analyses of a full spectrum of breast cancers initiated de novo from normal human mammary cells [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Breast Cancer Research; 2023 Oct 19-22; San Diego, California. Philadelphia (PA): AACR; Cancer Res 2024;84(3 Suppl_1):Abstract nr IA16.

LNP-RNA-engineered adipose stem cells for accelerated diabetic wound healing

Adipose stem cells (ASCs) have attracted considerable attention as potential therapeutic agents due to their ability to promote tissue regeneration. However, their limited tissue repair capability has posed a challenge in achieving optimal therapeutic outcomes. Herein, we conceive a series of lipid nanoparticles to reprogram ASCs with durable protein secretion capacity for enhanced tissue engineering and regeneration. In vitro studies identify that the isomannide-derived lipid nanoparticles (DIM1T LNP) efficiently deliver RNAs to ASCs. Co-delivery of self-amplifying RNA (saRNA) and E3 mRNA complex (the combination of saRNA and E3 mRNA is named SEC) using DIM1T LNP modulates host immune responses against saRNAs and facilitates the durable production of proteins of interest in ASCs. The DIM1T LNP-SEC engineered ASCs (DS-ASCs) prolong expression of hepatocyte growth factor (HGF) and C-X-C motif chemokine ligand 12 (CXCL12), which show superior wound healing efficacy over their wild-type and DIM1T LNP-mRNA counterparts in the diabetic cutaneous wound model. Overall, this work suggests LNPs as an effective platform to engineer ASCs with enhanced protein generation ability, expediting the development of ASCs-based cell therapies.

Hepatocyte growth factor is protective in early stage but bone-destructive in late stage of experimental periodontitis.

Clinical studies found high levels of hepatocyte growth factor (HGF) expression in patients with periodontitis. Studies suggest that HGF plays an important role in periodontitis, is involved in inflammation, and modulates alveolar bone integrity in periodontitis. This study aims to investigate the effects and mechanisms of HGF in the progression of experimental periodontitis. We used silk thread ligation to induce periodontitis in HGF-overexpressing transgenic (HGF-Tg) and wild-type C57BL/6J mice. The effects of HGF overexpression on alveolar bone destruction were assessed by microcomputed tomography imaging at baseline and on days 7, 14, 21, and 28. We analyzed the cytokines (IL-6 and TNF-α) and lymphocytes in periodontitis tissues by enzyme-linked immunosorbent assay and flow cytometry. The effects of HGF on alveolar bone destruction were further tested by quantifying the systemic bone metabolism markers CTXI and PINP and by RNA sequencing for the signaling pathways involved in bone destruction. Western blotting and immunohistochemistry were performed to further elucidate the involved signaling pathways. We found that experimental periodontitis increased HGF production in periodontitis tissues; however, the effects of HGF overexpression were inconsistent with disease progression. In the early stage of periodontitis, periodontal inflammation and alveolar bone destruction were significantly lower in HGF-Tg mice than in wild-type mice. In the late stage, HGF-Tg mice showed higher inflammatory responses and progressively aggravated bone destruction with continued stimulation of inflammation. We identified the IL-17/RANKL/TRAF6 pathway as a signaling pathway involved in the HGF effects on the progression of periodontitis. HGF plays divergent effects in the progression of experimental periodontitis and accelerates osteoclastic activity and bone destruction in the late stage of inflammation.

Human mesenchymal stem cell secretome increases hepatocyte growth factor expression and promotes liver regeneration in Wistar rats with cholestasis

Globally, the annual mortality rate due to liver cirrhosis is 2.2%, which ranks 12th as the cause of death in the United States. Human mesenchymal stem cell secretome (Hu-MSC-S) is known to reduce liver injury and inflammation. Thus, the present study aims to determine the effect of Hu-MSC-S on hepatocyte growth factor (HGF) expression and liver regeneration in cholestatic rats after choledochal duct ligation receiving standard ursodeoxycholic acid (UDCA) therapy. A randomized experimental study was conducted on 24 male Wistar rats. All rats were randomly assigned into four groups such as control, UDCA, Hu-MSC-S, and UDCA+Hu-MSC-S. The expression of HGF and mitotic index as markers of liver regeneration were evaluated using histopathologic examination. Both HGF expression and the mitotic index were significantly higher in the UDCA and Hu-MSC-S groups (P &lt; 0.05) compared to the control group. The combined administration of UDCA and Hu-MSC-S resulted in significantly higher HGF expression and mitotic index than the individual intervention (P &lt; 0.05). The additional administration of Hu-MSC-S increased HGF expression and mitotic index in rat model of hepatic cholestasis. In conclusion, HuMSC-S administration could be considered as a therapy in patients who received standard UDCA therapy for liver regeneration.

Development of multifunctional pyrrole-imidazole polyamides that increase hepatocyte growth factor and suppress transforming growth factor-β1

PurposeThe DNA recognition peptide compounds pyrrole-imidazole (PI) polyamides bind to the minor groove and can block the binding of transcription factors to target sequences. To develop more PI polyamides as potential treatments for fibrotic diseases, including chronic renal failure, we developed multifunctional PI polyamides that increase hepatocyte growth factor (HGF) and decrease transforming growth factor (TGF)-β1. MethodsWe designed seven PI polyamides (HGF-1 to HGF-7) that bind to the chicken ovalbumin upstream promoter transcription factor-1 (COUP-TF1) binding site of the HGF promoter sequence. We selected PI polyamides that increase HGF and suppress TGF-β1 in human dermal fibroblasts (HDFs). FindingsGel shift assays showed that HGF-2 and HGF-4 bound the appropriate dsDNAs. HGF-2 and HGF-4 significantly inhibited the TGF-β1 mRNA expression in HDFs stimulated by phorbol 12-myristate 13-acetate. HGF-2 and HGF-4 significantly inhibited the TGF-β1 protein expression in HDFs with siRNA targeting HGF, indicating that HGF-2 and HGF-4 directly inhibited the expression of TGF-β1. ConclusionThe designed and synthetic HGF PI polyamides targeting the HGF promoter, which increased the expression of HGF and suppressed the expression of TGF-β, will be a potential practical medicine for fibrotic diseases, including progressive renal diseases.

TMIC-01. PERICYTES ORCHESTRATE A TUMOR-SUPPRESSIVE MICROENVIRONMENT BY IMPINGING ON THE CROSSTALK BETWEEN MACROPHAGES AND TUMOR-INITIATING CELLS IN GLIOBLASTOMA MULTIFORME

Abstract Glioblastoma multiforme (GBM) is characterized by fast progression, infiltrative growth pattern and a high rate of relapse. A defining feature of GBM is the existence of spatially and functionally distinct cellular niches, i.e. a hypoxic niche, a leading-edge niche, and a peri-vascular niche, in which malignant cells engage in paracrine crosstalk with cell types comprising the tumor microenvironment, including immune cells, astrocytes, and vascular cells. Here, by analysis of single-cell transcriptomic data of human GBM and transgenic mouse models of GBM, we unexpectedly identified pericytes intimately associated with the endothelium as the most active paracrine signaling hub within the tumor parenchyma. Exclusive signaling axes emanating from pericytes were received by endothelial cells, malignant cells, astrocytes, and immune cells. Depletion of pericytes through genetic engineering in several different transgenic and orthotopic mouse models of GBM demonstrated accelerated tumor progression, a disrupted blood-brain-barrier, and premature death of pericyte-poor mice. Mechanistic studies revealed that pericyte deficiency altered the cellular composition of GBM, remodeled the endothelium, and impacted on the immune cell landscape. Specifically, endothelial cells deprived of pericyte association upregulated Colony Stimulating Factor (CSF)-1, which in turn attracted peri-vascular tumor-associated macrophages polarized towards an immune-suppressive phenotype. In the absence of pericytes, the recruited macrophages expressed Hepatocyte Growth Factor (HGF), which reinforced activation of its receptor tyrosine kinase c-Met on a subset of GBM cells harboring an extreme mesenchymal-like state. Indeed, orthotopic implantation of isolated c-Met-expressing GBM cells corroborated their superior tumor-initiating capability and invasive phenotype, compared to cells negative for c-Met. Taken together, we infer that the pericyte represents a critical modulator of GBM development by orchestrating a tumor-suppressive microenvironment; our findings thus highlight the importance of pericyte preservation in the face of current and future GBM therapies.

HGF Regulation in the Tumor-Supportive Microenvironment Combined with Pan-PIM Kinases Inhibition in Malignant Cells As a Multi-Target Approach for Acute Myeloid Leukemia

Background: In acute myeloid leukemia (AML), persistent clonal proliferation of malignant myeloid cells results in high severity and low cure potential. Resistance to currently available chemotherapeutics and disease relapse remains an important concern worldwide. Several molecular targets play key roles in impairing therapeutic response, including PIM-kinases, a serine/threonine kinase family associated with the progression of hepatocyte growth factor (HGF)-driven cancers through its receptor, MET. We reported that enhanced HGF secretion by bone marrow (BM) mesenchymal stromal cells (MSC) correlated with low levels of the serine protease inhibitor kunitz-type2 (SPINT2) in AML (Roversi et al., 2019), which are affected by immunosuppressive properties of the tumor microenvironment (TME). However, the interplay between SPINT2, HGF, and PIM-kinases in the TME is yet to be elucidated and could represent an important multi-target therapeutic strategy in hematological cancers. Aims: Given the importance of HGF to AML prognosis and progression, we analyzed the interplay between SPINT2, HGF, and pan-PIM kinases by evaluating the gene expression and the effects of a novel pan-PIM kinase inhibitor, PIM447 (Novartis), in leukemia cells and in the TME. Methods: SPINT2, HGF, PIM1, PIM2 and PIM3 mRNA expression data were obtained from OHSU (2018) AML study and TCGA (cBio Portal). Correlation analysis was obtained by Spearman's coefficient (r). A total of 5 healthy donors (HD) and 5 de novo AML patients BMMSC (CD90+CD105+CD73+CD45-CD34-CD31-HLA-DR-) were treated with 5-Azacitidine (Aza), and evaluated for SPINT2 gene expressions. Myeloid (OCI-AML3, MOLM13, U937) and lymphoblastic (RS4;11, Jurkat) leukemia cells were treated with increasing concentrations of PIM447, and the 101nd apoptosis rates were determined. Peripheral blood and BM mononuclear cells (PBMC/BMMC) from HD were tested for cytotoxicity. Leukemia cells were also examined for reactive oxygen species (ROS), nitric oxide (NO) production, and mitochondrial membrane potential (ΔΨm). To verify PIM447 action onto an immunosuppressive TME, cocultures of leukemia cells and monocytes or monocyte-derived macrophages (MDMs) were performed. To understand the interplay between SPINT2 and PIM-kinases, cocultures of SPINT2-overexpressed MSC and leukemia cells, were performed. Statistical analyzes were performed using Kruskal Wallis, ANOVA or Mann-Whitney tests ( P&amp;lt;.05). Results: The analysis of gene expression performed in MC from 188 AML patients (age median: 57.5 years [range: 18-88]) showed that levels of HGF correlated positively with PIM1, PIM2, and PIM3 ((r) =.8727;.9094;.9093, respectively, P&amp;lt;.0001) and negatively with SPINT2 (r=-.06402). We also verified that SPINT2 mRNA expression was upregulated in AML-BMMSC ( P&amp;lt;.05) after Aza treatment when compared to HD-BMMSC, suggesting that this gene is methylated in AML. Our in vitro results showed PIM447 treatment (2-20μM) yielded reduced cell viability and increased apoptosis in leukemia cells [IC50 range: 12.2-22.2μM, P&amp;lt;.01] without affecting HD cells. PIM447 reduced ROS, NO production, and ΔΨm (all P&amp;lt;.0001) in all cell lines. PIM447 treatment of macrophages differentiated from HD-PBMC revealed a shorter population of M2 macrophages (HLA-DR-CD206+) ( P&amp;lt;.001) and an increased population of M1 macrophages (HLA-DR+CD80+) ( P&amp;lt;.05). Moreover, PIM447 promoted apoptosis of leukemia cells co-cultured with MDMs ( P&amp;lt;.0001). Interestingly, co-culture analyses of SPINT2-overexpressed MSC enhanced PIM447 cytotoxic activity towards leukemia cells (P&amp;lt;.05) and reduced cell-cell adhesion by diminishing CD49b, CD49d, and CD49e (P&amp;lt;.05), suggesting an interplay between SPINT2 and pan-PIM kinases Conclusion: Collectively, our data identify a novel pan-PIM kinase inhibitor, PIM447, which effectively induces leukemia cell apoptosis through reducing MET receptor activation as well as acts on their tumor-supportive microenvironment by inducing a phenotypic shift from immunosuppressive M2 to anti-tumor M1 macrophages. PIM447 also interplays with SPINT2/HGF pathway in the TME, reducing AML progression. These findings suggest that a pivotal strategy to treat AML could be a multi-target therapy, acting both on leukemia cells and in the tumor microenvironment. Funding: FAPESP #2017/21801-2, #2019/25247-5, #2021/05320-0; CNPq #303405/2018-0.

Poly(ethylene glycol)-Based Hydrogel Microcarriers Alter Secretory Activity of Genetically Modified Mesenchymal Stromal Cells.

In order to scale up culture therapeutic cells, such as mesenchymal stromal cells (MSCs), culture in suspension bioreactors using microcarriers (μCs) is preferred. However, the impact of microcarrier type on the resulting MSC secretory activity has not been investigated. In this study, two poly(ethylene glycol) hydrogel formulations with different swelling ratios (named "stiffer" and "softer") were fabricated as μC substrates to culture MSCs and MSCs genetically modified to express the interleukin-1 receptor antagonist (IL-1Ra-MSCs). Changes in cell number, secretory and angiogenic activity, and changes in MAPK signaling were evaluated when cultured on hydrogel μCs, as well as on tissue culture plastic-based Synthemax μCs. We demonstrated that culture on stiffer μCs increased secretion of IL-1Ra compared to culture on Synthemax μCs by IL-1Ra-MSCs by 1.2- to 1.6-fold, as well as their in vitro angiogenic activity, compared to culture on Synthemax μCs, while culture on both stiffer and softer μCs altered the secretion of several other factors compared to culture on Synthemax μCs. Changes in angiogenic activity corresponded with increased gene expression and secretion of hepatocyte growth factor by MSCs cultured on softer μCs by 2.5- to 6-fold compared to MSCs cultured on Synthemax μCs. Quantification of phosphoprotein signaling with the MAPK pathway revealed broad reduction of pathway activation by IL-1Ra-MSCs cultured on both stiffer and softer μCs compared to Synthemax, where phosphorylated c-Jun, ATF2, and MEK1 were reduced specifically on softer μCs. Overall, this study showed that μC surfaces can influence the secretory activity of genetically modified MSCs and identified associated changes in MAPK pathway signaling, which is a known central regulator of cytokine secretion.

Transplantation of Chemical Compound-Induced Cells from Human Fibroblasts Improves Locomotor Recovery in a Spinal Cord Injury Rat Model.

The development of regenerative medicine using cell therapy is eagerly awaited for diseases such as spinal cord injury (SCI), for which there has been no radical cure. We previously reported the direct conversion of human fibroblasts into neuronal-like cells using only chemical compounds; however, it is unclear whether chemical compound-induced neuronal-like (CiN) cells are clinically functional. In this study, we partially modified the method of inducing CiN cells (termed immature CiN cells) and examined their therapeutic efficacy, in a rat model of SCI, to investigate whether immature CiN cells are promising for clinical applications. Motor function recovery, after SCI, was assessed using the Basso, Beattie, and Bresnahan (BBB) test, as well as the CatWalk analysis. We found that locomotor recovery, after SCI in the immature CiN cell-transplanted group, was partially improved compared to that in the control group. Consistent with these results, magnetic resonance imaging (MRI) and histopathological analyses revealed that nerve recovery or preservation improved in the immature CiN cell-transplanted group. Furthermore, transcriptome analysis revealed that immature CiN cells highly express hepatocyte growth factor (HGF), which has recently been shown to be a promising therapeutic agent against SCI. Our findings suggest that immature CiN cells may provide an alternative strategy for the regenerative therapy of SCI.