Hepatocyte growth factor in physiology and infectious diseases

Elevated cytokine levels in the central nervous system of cluster headache patients in bout and in remission

BACKGROUND

Cluster headache is characterized by activation of the trigeminovascular pathway with subsequent pain signalling in the meningeal vessels, and inflammation has been suggested to play a role in the pathophysiology. To further investigate inflammation in cluster headache, inflammatory markers were analysed in patients with cluster headache and controls.

METHODS

We performed a case-control study, collecting cerebrospinal fluid and serum samples from healthy controls, cluster headache patients in remission, active bout, and during an attack to cover the dynamic range of the cluster headache phenotype. Inflammatory markers were quantified using Target 48 OLINK cytokine panels.

RESULTS

Altered levels of several cytokines were found in patients with cluster headache compared to controls. CCL8, CCL13, CCL11, CXCL10, CXCL11, HGF, MMP1, TNFSF10 and TNFSF12 levels in cerebrospinal fluid were comparable in active bout and remission, though significantly higher than in controls. In serum samples, CCL11 and CXCL11 displayed decreased levels in patients. Only one cytokine, IL-13 was differentially expressed in serum during attacks.

CONCLUSION AND INTERPRETATION

Our data shows signs of possible neuroinflammation occurring in biological samples from cluster headache patients. Increased cerebrospinal fluid cytokine levels are detectable in active bout and during remission, indicating neuroinflammation could be considered a marker for cluster headache and is unrelated to the different phases of the disorder.

Mechanisms of Postischemic Stroke Angiogenesis: A Multifaceted Approach

Ischemic stroke constitutes a significant global health care challenge, and a comprehensive understanding of its recovery mechanisms is imperative for the development of innovative therapeutic strategies. Angiogenesis, a pivotal element of ischemic tissue repair, facilitates the restoration of blood flow to damaged regions, thereby promoting neuronal regeneration and functional recovery. Nevertheless, the mechanisms underlying postischemic stroke angiogenesis remain incompletely elucidated. This review meticulously examines the constituents of the neurovascular unit, ion channels, molecular mediators, and signaling pathways implicated in angiogenesis following stroke. Furthermore, it delves into prospective therapeutic strategies informed by these factors. Our objective is to provide detailed and exhaustive information on the intricate mechanisms governing postischemic stroke angiogenesis, thus providing a robust scientific foundation for the advancement of novel neurorepair therapies.

Emerging mRNA Technology for Liver Disease Therapy

Liver diseases have consistently posed substantial challenges to global health. It is crucial to find innovative methods to effectively prevent and treat these diseases. In recent times, there has been an increasing interest in the use of mRNA formulations that accumulate in liver tissue for the treatment of hepatic diseases. In this review, we start by providing a detailed introduction to the mRNA technology. Afterward, we highlight types of liver diseases, discussing their causes, risks, and common therapeutic strategies. Additionally, we summarize the latest advancements in mRNA technology for the treatment of liver diseases. This includes systems based on hepatocyte growth factor, hepatitis B virus antibody, left-right determination factor 1, human hepatocyte nuclear factor α, interleukin-12, methylmalonyl-coenzyme A mutase, etc. Lastly, we provide an outlook on the potential of mRNA technology for the treatment of liver diseases, while also highlighting the various technical challenges that need to be addressed. Despite these difficulties, mRNA-based therapeutic strategies may change traditional treatment methods, bringing hope to patients with liver diseases.

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

BACKGROUND AND OBJECTIVE

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.

METHODS

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.

RESULTS

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.

CONCLUSION

HGF plays divergent effects in the progression of experimental periodontitis and accelerates osteoclastic activity and bone destruction in the late stage of inflammation.

Unlocking c-MET: A comprehensive journey into targeted therapies for breast cancer

Breast cancer is the most common malignancy among women, posing a formidable health challenge worldwide. In this complex landscape, the c-MET (cellular-mesenchymal epithelial transition factor) receptor tyrosine kinase (RTK), also recognized as the hepatocyte growth factor (HGF) receptor (HGFR), emerges as a prominent protagonist, displaying overexpression in nearly 50% of breast cancer cases. Activation of c-MET by its ligand, HGF, secreted by neighboring mesenchymal cells, contributes to a cascade of tumorigenic processes, including cell proliferation, metastasis, angiogenesis, and immunosuppression. While c-MET inhibitors such as crizotinib, capmatinib, tepotinib and cabozantinib have garnered FDA approval for non-small cell lung cancer (NSCLC), their potential within breast cancer therapy is still undetermined. This comprehensive review embarks on a journey through structural biology, multifaceted functions, and intricate signaling pathways orchestrated by c-MET across cancer types. Furthermore, we highlight the pivotal role of c-MET-targeted therapies in breast cancer, offering a clinical perspective on this promising avenue of intervention. In this pursuit, we strive to unravel the potential of c-MET as a beacon of hope in the fight against breast cancer, unveiling new horizons for therapeutic innovation.

Control of muscle satellite cell function by specific exercise-induced cytokines and their applications in muscle maintenance

Exercise is recognized to play an observable role in improving human health, especially in promoting muscle hypertrophy and intervening in muscle mass loss-related diseases, including sarcopenia. Recent rapid advances have demonstrated that exercise induces the release of abundant cytokines from several tissues (e.g., liver, muscle, and adipose tissue), and multiple cytokines improve the functions or expand the numbers of adult stem cells, providing candidate cytokines for alleviating a wide range of diseases. Muscle satellite cells (SCs) are a population of muscle stem cells that are mitotically quiescent but exit from the dormancy state to become activated in response to physical stimuli, after which SCs undergo asymmetric divisions to generate new SCs (stem cell pool maintenance) and commit to later differentiation into myocytes (skeletal muscle replenishment). SCs are essential for the postnatal growth, maintenance, and regeneration of skeletal muscle. Emerging evidence reveals that exercise regulates muscle function largely via the exercise-induced cytokines that govern SC potential, but this phenomenon is complicated and confusing. This review provides a comprehensive integrative overview of the identified exercise-induced cytokines and the roles of these cytokines in SC function, providing a more complete picture regarding the mechanism of SC homeostasis and rejuvenation therapies for skeletal muscle.

Associations between anthropometric parameters and immune-phenotypical characteristics of circulating Tregs and serum cytokines

OBJECTIVE

To investigate the associations between several anthropometric parameters and regulatory T cells (Tregs) and circulating cytokines in a population-based cohort.

METHODS

Between 2018 and 2021, a total of 238 participants were examined up to three times within the scope of the MEGA study in Augsburg, Germany. Tregs were analyzed using flow cytometry and the serum concentrations of 52 cytokines were determined. Anthropometric parameters were measured, using also bioelectrical impedance analysis: body mass index (BMI), relative total body fat, relative visceral adipose tissue (rVAT), waist circumference (WC), waist-to-hip ratio (WHR) and body fat distribution. Associations were analyzed using linear mixed models with random intercept (Tregs) and conventional linear regression models (cytokines).

RESULTS

WC and WHR were inversely associated with the general Treg subset. Four parameters (BMI, rVAT, WC, and WHR) were inversely associated with the conventional Treg population. Three cytokines showed a particularly strong association with several anthropometric parameters: the cutaneous T-cell attracting chemokine was inversely associated with anthropometric parameters, while hepatocyte growth factor and interleukine-18 showed positive associations.

CONCLUSIONS

Anthropometric measures are associated with Tregs and serum cytokine concentrations revealing new important interconnections between obesity and the adaptive immune system.

α-Fetoprotein contributes to the malignant biological properties of AFP-producing gastric cancer

This study aimed to investigate whether α-fetoprotein (AFP) could affect the malignant behavior of AFP-producing gastric cancer (AFP-GC) and to explore the relationship between AFP and mesenchymal-epithelial transition factor (c-Met) in AFP-GC. In this study, 23 patients with AFP-GC (AFP[+]) and 18 patients with common gastric cancer (AFP[-]) were evaluated for the c-Met expression using immunohistochemical analysis. The AFP-GC cell line, GCIY, was used. The AFP endoribonuclease-prepared small interfering RNA (siRNA) and eukaryotic AFP overexpression vector were used to increase/knockdown the expression of AFP. Afterward, the c-Met expression was evaluated by polymerase chain reaction and western blot. The proliferation, migration, and invasion of GCIY cells were estimated before and after the AFP overexpression/knockdown. The c-Met expression in both groups was the same (p > 0.05), and AFP[+] group had a higher positive incidence of the c-Met expression than the AFP[-] group (p < 0.01). Furthermore, the c-Met expression frequency was decreased by AFP knockdown and increased by AFP overexpression (p < 0.01). The cell counting kit-8 cell proliferation assay, cell invasion, and migration assays confirmed that the AFP could affect the malignant biological behavior of AFP-GC. These findings suggest that AFP contributes to the malignant biological properties of AFP-GC and the high expression of c-Met in AFP-GC.

Liver tissue changes induced by biological and chemical silver nanoparticles in trained male Wistar rats

INTRODUCTION

Despite the widespread use of chemical and biological nano-silver are in industry, their side effects on hepatocytes have been less studied. On the other hand, different types of physical activities may increase liver resistance to toxins. Therefore, the aim of this study was to evaluate the resistance of hepatocytes to receiving chemical versus biological silver nanoparticles in aerobic and anaerobic pre-conditioned rats.

MATERIALS AND METHODS

45 male Wistar rats with similar average range of age (8-12 weeks) and weight (180-220 g), were randomly divided normally into 9 groups, including Control (C), Aerobic (A), Anaerobic (AN), Biological nano-silver (BNS), Chemical nano-silver (CNS), Biological nano-silver + Aerobic (BNS+A), Biological nano-silver + Anaerobic (BNS+AN), Chemical nano-silver + Aerobic (CNS+A) and Chemical nano-silver + Anaerobes (CNS+AN). Prior to injection, rats trained on a rodent treadmill, 10 weeks, 3 sessions per week, according to aerobic and anaerobic protocols.Then, 48 h after the last training session, the rats received 10 % of their body weight, chemical and biological nanosilver intraperitoneally. Liver enzymes (ALT, AST, and ALP) and liver tissue were sent to the relevant laboratories for further evaluation.

RESULTS

Results showed that the weight of rats in all groups of physical pre-conditioning, decreased comparison to the control and non-exercise groups, and this decrease was much greater in the anaerobic group (p-value=0.045). Also, the distance traveled in the progressive endurance running a test on a rodent treadmill, increased significantly in the training groups compared to the nano-exercise and control groups (p-value=0.001). Also, the results showed that the level of ALT in chemical nano-silver (p-value=0.004) and biological nano-silver (p-value=0.044), increased significantly compared to other groups. Also, histopathological results showed that nano-silver injection affects the structure of the liver of male Wistar rats and causes inflammation, hyperemia and destruction of liver cells, especially in chemical nano-silver.

CONCLUSION

The results of the present study showed that chemical silver nanoparticles cause liver damage more than comparison biological ones. Also, physical pre-conditioning increases hepatocyte resistance to toxic nanoparticle doses and aerobic preparation appears to be more effective than anaerobic.

Emerging roles of tyrosine kinases in hepatic inflammatory diseases and therapeutic opportunities

Inflammation has been convicted of causing and worsening many liver diseases like acute liver failure, fibrosis, cirrhosis, fatty liver and liver cancer. Pattern recognition receptors (PRRs) like TLRs 4 and 9 localized on resident or recruited immune cells are well known cellular detectors of pathogen and damage-associated molecular patterns (PAMPs/DAMPs). Stimulation of these receptors generates the sterile and non-sterile inflammatory responses in the liver. When these responses are repeated, there will be a sustained liver injury that may progress to fibrosis and its outcomes. Crosstalk between inflammatory/fibrogenic-dependent streams and certain tyrosine kinases (TKs) has recently evolved in the context of hepatic diseases. Because of TKs increasing importance, their role should be elucidated to highlight effective approaches to manage the diverse liver disorders. This review will give a brief overview of types and functions of some TKs like BTK, JAKs, Syk, PI3K, Src and c-Abl, as well as receptors for TAM, PDGF, EGF, VEGF and HGF. It will then move to discuss the roles of these TKs in the regulation of the proinflammatory, fibrogenic and tumorigenic responses in the liver. Lastly, the therapeutic opportunities for targeting TKs in hepatic inflammatory disorders will be addressed. Overall, this review sheds light on the diverse TKs that have substantial roles in hepatic disorders and potential therapeutics modulating their activity.

The Impaired Wound Healing Process Is a Major Factor in Remodeling of the Corneal Epithelium in Adult and Adolescent Patients With Keratoconus

Purpose

Keratoconus (KTCN) is the most common corneal ectasia, characterized by pathological cone formation. Here, to provide an insight into the remodeling of the corneal epithelium (CE) during the course of the disease, we evaluated topographic regions of the CE of adult and adolescent patients with KTCN.

Methods

The CE samples from 17 adult and 6 adolescent patients with KTCN, and 5 control CE samples were obtained during the CXL and PRK procedures, respectively. Three topographic regions, central, middle, and peripheral, were separated toward RNA sequencing and MALDI-TOF/TOF Tandem Mass Spectrometry. Data from transcriptomic and proteomic investigations were consolidated with the morphological and clinical findings.

Results

The critical elements of the wound healing process, epithelial-mesenchymal transition, cell-cell communications, and cell-extracellular matrix interactions were altered in the particular corneal topographic regions. Abnormalities in pathways of neutrophils degranulation, extracellular matrix processing, apical junctions, IL, and IFN signaling were revealed to cooperatively disorganize the epithelial healing. Deregulation of the epithelial healing, G2M checkpoints, apoptosis, and DNA repair pathways in the middle CE topographic region in KTCN explains the presence of morphological changes in the corresponding doughnut pattern (a thin cone center surrounded by a thickened annulus). Despite similar morphological characteristics of CE samples in adolescents and adults with KTCN, their transcriptomic features were different. Values of the posterior corneal elevation differentiated adults with KTCN from adolescents with KTCN and correlated with the expression of TCHP, SPATA13, CNOT3, WNK1, TGFB2, and KRT12 genes.

Conclusions

Identified molecular, morphological, and clinical features indicate the effect of impaired wound healing on corneal remodeling in KTCN CE.

Association between fatigue and cytokine profiles in patients with ischemic stroke

Background

Chronic fatigue is a common symptom after a stroke. Studies suggested that chronic fatigue is caused by inflammatory or immunological processes but data are limited and contradictory. Thus, the present study aimed to identify specific biomarkers associated with fatigue in post-stroke patients and replicated the findings in a population-based study.

Methods

We investigated associations between 39 circulating biomarkers of inflammation and fatigue in 327 patients after an ischemic stroke included in the Stroke Cohort Augsburg (SCHANA) study and the "Metabolism, Nutrition and Immune System in Augsburg" (MEIA) study (n = 140). The Fatigue Assessment Scale (FAS) was used to assess the severity of fatigue. The serum concentrations of the biomarkers were measured using the Bio-Plex Pro™ Human Cytokine Screening Panel (Bio-Rad, USA). Multiple linear regression models adjusted for possible confounders were used to examine associations.

Results

In patients with stroke, SCGFb was inversely associated [-1.67, 95% confidence interval (CI) (-3.05; -0.29) p = 0.018], and in healthy subjects, G-CSF was positively associated [1.56, 95% CI (0.26; 2.87), p = 0.020] with an increasing FAS-score, while SCF was positively related in both samples [1.84, 95% CI (0.27; 3.42), p = 0.022 and 1.40, 95% CI (0.29; 2.52), p = 0.015]. However, after correction for multiple testing, all of these associations lost statistical significance.

Conclusion

The present findings suggested an association between the growth factor SCF and fatigue. Future research on cytokines as possible markers of fatigue should focus on a longitudinal design including a sufficiently large number of study participants to enable testing associations between certain cytokines and sub-groups of chronic fatigue.

Marburg and Ebola Virus Infections Elicit a Complex, Muted Inflammatory State in Bats

The Marburg and Ebola filoviruses cause a severe, often fatal, disease in humans and nonhuman primates but have only subclinical effects in bats, including Egyptian rousettes, which are a natural reservoir of Marburg virus. A fundamental question is why these viruses are highly pathogenic in humans but fail to cause disease in bats. To address this question, we infected one cohort of Egyptian rousette bats with Marburg virus and another cohort with Ebola virus and harvested multiple tissues for mRNA expression analysis. While virus transcripts were found primarily in the liver, principal component analysis (PCA) revealed coordinated changes across multiple tissues. Gene signatures in kidney and liver pointed at induction of vasodilation, reduction in coagulation, and changes in the regulation of iron metabolism. Signatures of immune response detected in spleen and liver indicated a robust anti-inflammatory state signified by macrophages in the M2 state and an active T cell response. The evolutionary divergence between bats and humans of many responsive genes might provide a framework for understanding the differing outcomes upon infection by filoviruses. In this study, we outline multiple interconnected pathways that respond to infection by MARV and EBOV, providing insights into the complexity of the mechanisms that enable bats to resist the disease caused by filoviral infections. The results have the potential to aid in the development of new strategies to effectively mitigate and treat the disease caused by these viruses in humans.

Discovery of anticancer agents with c-Met inhibitory potential by virtual and experimental screening of a chemical library

c-Met receptor tyrosine kinase has recently emerged as an important target with therapeutic implications in pancreatic cancer. In this study, we carried out a docking virtual screening on an in-house library of 441 synthesized compounds and selected the compounds with the best interactions with the c-Met protein to be subjected to experimental tests. Ten compounds belonging to 3 different classes of chemical structures were selected for this purpose and their antiproliferative effects were studied against 4 pancreatic ductal adenocarcinoma (PDAC) cell lines including AsPC-1, Suit-2, Panc-1 and Mia-Paca-2 cells, primary PDAC cells and also c-Met amplified EBC-1 cell line by sulforhodamine-B assay. Apoptosis induction was examined by Hoechst 33258 staining and annexin V-FITC/propidium iodide flow cytometric assay. The best compound was also assayed in three-dimensional cultures of AsPC-1 cells and its c-Met inhibitory potential was studied by immunoblotting and a homogenous time resolved fluorescence (HTRF) assay. The compound with a phenanthrotriazine hydrazinyl scaffold bearing nitrophenyl pendant (PhTH) was the most active derivative, with IC50 values in the range of 5-8 μM. This compound exerted antiproliferative effect against AsPC-1 cells also in the presence of hepatocyte growth factor (HGF). PhTH induced apoptosis, dose-dependently inhibited spheroid growth, inhibited c-Met activity in cell-free HTRF assay and also inhibited the phosphorylation of c-Met and its downstream effector ERK1/2 in AsPC-1 cells. Molecular docking and dynamics simulation and MM-PBSA analysis confirmed close interactions of PhTH with c-Met kinase domain. Some of the tested compounds in this study seem to be potential c-Met inhibitors with promising activities against PDAC cells.

The Role of Growth Factors in the Pathogenesis of Dengue: A Scoping Review

Growth factors (GFs) have a role in tissue repair and in the modulation of the expression of inflammatory cells in damage caused by pathogens. This study aims to systematize the evidence on the role of GFs in the pathogenesis of dengue. This scoping review considered all published peer-reviewed studies in the MEDLINE and Embase databases. Ultimately, 58 studies that analyzed GFs in dengue patients, published between 1998 and 2021, were included. DENV-2 infection and secondary infection were more frequent in the patients studied. ELISA and multiplex immunoassay (Luminex) were the most used measurement techniques. Increased levels of vascular endothelial growth factor, granulocyte-macrophage colony-stimulating factor, granulocyte colony-stimulating factor, transforming growth factor beta, and hepatocyte growth factor as well as reduced levels of platelet-derived growth factor and epidermal growth factor were observed in severe dengue in most studies. Vascular endothelial growth factor and hepatocyte growth factor were identified as biomarkers of severity. In addition, there is evidence that the dengue virus can use the growth factor pathway to facilitate its entry into the cell and promote its viral replication. The use of tyrosine kinase inhibitors is an alternative treatment for dengue that is being studied.

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.

Changes in Cell Biology under the Influence of Low-Level Laser Therapy

Low-level laser therapy (LLLT) has become an important part of the therapeutic process in various diseases. However, despite the broad use of LLLT in everyday clinical practice, the full impact of LLLT on cell life processes has not been fully understood. This paper presents the current state of knowledge concerning the mechanisms of action of LLLT on cells. A better understanding of the molecular processes occurring within the cell after laser irradiation may result in introducing numerous novel clinical applications of LLLT and potentially increases the safety profile of this therapy.

The Cerebellar Involvement in Autism Spectrum Disorders: From the Social Brain to Mouse Models

Autism spectrum disorders (ASD) are pervasive neurodevelopmental disorders that include a variety of forms and clinical phenotypes. This heterogeneity complicates the clinical and experimental approaches to ASD etiology and pathophysiology. To date, a unifying theory of these diseases is still missing. Nevertheless, the intense work of researchers and clinicians in the last decades has identified some ASD hallmarks and the primary brain areas involved. Not surprisingly, the areas that are part of the so-called “social brain”, and those strictly connected to them, were found to be crucial, such as the prefrontal cortex, amygdala, hippocampus, limbic system, and dopaminergic pathways. With the recent acknowledgment of the cerebellar contribution to cognitive functions and the social brain, its involvement in ASD has become unmistakable, though its extent is still to be elucidated. In most cases, significant advances were made possible by recent technological developments in structural/functional assessment of the human brain and by using mouse models of ASD. Mouse models are an invaluable tool to get insights into the molecular and cellular counterparts of the disease, acting on the specific genetic background generating ASD-like phenotype. Given the multifaceted nature of ASD and related studies, it is often difficult to navigate the literature and limit the huge content to specific questions. This review fulfills the need for an organized, clear, and state-of-the-art perspective on cerebellar involvement in ASD, from its connections to the social brain areas (which are the primary sites of ASD impairments) to the use of monogenic mouse models.

Lipoaspirate Shows In Vitro Potential for Wound Healing

Mesenchymal stem cells (MSCs) are a promising therapy in wound healing, although extensive time and manipulation are necessary for their use. In our previous study on cartilage regeneration, we demonstrated that lipoaspirate acts as a natural scaffold for MSCs and gives rise to their spontaneous outgrowth, together with a paracrine effect on resident cells that overcome the limitations connected to MSC use. In this study, we aimed to investigate in vitro whether the microfragmented adipose tissue (lipoaspirate), obtained with Lipogems^® technology, could promote and accelerate wound healing. We showed the ability of resident cells to outgrow from the clusters of lipoaspirate encapsulated in a 3D collagen substrate as capability of repopulating a culture of human skin. Moreover, we demonstrated that the in vitro lipoaspirate paracrine effect on fibroblasts and keratinocytes proliferation, migration, and contraction rate is mediated by the release of trophic/reparative proteins. Finally, an analysis of the paracrine antibacterial effect of lipoaspirate proved its ability to secrete antibacterial factors and its ability to modulate their secretion in culture media based on a bacterial stimulus. The results suggest that lipoaspirate may be a promising approach in wound healing showing in vitro regenerative and antibacterial activities that could improve current therapeutic strategies.

Overview of First-Line and Second-Line Pharmacotherapies for Osteoarthritis with Special Focus on Intra-Articular Treatment

Osteoarthritis (OA) can be defined as the result of pathological processes of various etiologies leading to damage to the articular structures. Although the mechanism of degenerative changes has become better understood due to the plethora of biochemical and genetic studies, the drug that could stop the degenerative cascade is still unknown. All available forms of OA therapy are based on symptomatic treatment. According to actual guidelines, comprehensive treatment of OA should always include a combination of various therapeutic options aimed at common goals, which are pain relief in the first place, and then the improvement of function. Local treatment has become more common practice, which takes place between rehabilitation and pharmacological treatment in the hierarchy of procedures. Only in the case of no improvement and the presence of advanced lesions visible in imaging tests, should surgery be considered. Currently, an increasing number of studies are being published suggesting that intra-articular injections may be as effective or even more effective than non-steroidal anti-inflammatory drugs (NSAIDs) and result in fewer systemic adverse events. The most commonly used preparations are hyaluronic acid (HA), glucocorticosteroids (GS), and also platelet-rich plasma (PRP) in recent years. This review aims to present the mechanism of action and clinical effectiveness of different pharmacological options in relieving pain and improving functions in OA as well as the emerging approach in intra-articular treatment with PRP.

Cytokine Interaction With Cancer-Associated Fibroblasts in Esophageal Cancer

Esophageal cancer (EC) is a highly aggressive cancer with poor outcomes under current treatment regimens. More recent findings suggest stroma elements, specifically cancer-associated fibroblasts (CAFs), play a role in disease occurrence and progression. Cancer-associated fibroblasts are largely the product of converted fibroblasts, but a variety of other local cell types including epithelial cells, endothelial cells, and mesenchymal cells have also been shown to transform to CAFs under the correct conditions. Cancer-associated fibroblasts primarily function in the communication between the tumor microenvironment and cancer cells via cytokine and chemokine secretions that accentuate immunosuppression and cancer growth. Cancer-associated fibroblasts also pose issues for EC treatment by contributing to resistance of current chemotherapeutics like cisplatin. Targeting this cell type directly proves difficult given the heterogeneity between CAFs subpopulations, but emerging research provides hope that treatment is on the horizon. This review aims to unravel some of the complexities surrounding CAFs’ impact on EC growth and therapy.

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.

Correlations between Salivary Immuno-Biochemical Markers and HbA1c in Type 2 Diabetes Subjects before and after Dental Extraction

Dental extraction can trigger certain sequences of complex processes that involve both hard (alveolar bone) and soft tissue (periodontal ligament, gingiva) remodeling. Type 2 diabetes is a serious risk factor for many oral pathologies, both in terms of progression and severity, but also regarding subsequent rehabilitation possibilities. The aim of this study was to establish whether certain molecules: osteoprotegerin (OPG), kappa B nuclear factor receptor activator ligand (RANKL), hepatocyte growth factor (HGF), tumor necrosis factor-α (TNF-α), interleukin 18 (IL-18), matrix metalloproteinase 9 (MMP-9) and oxidative stress markers-total oxidant status (TOS), total antioxidant capacity (TAC)-evaluated in saliva are modified post-extraction in type 2 diabetes mellitus subjects and whether there is a correlation with HbA1c levels. The aforementioned markers plus HbA1c were investigated in a group of systemically healthy subjects (n = 45) and in a type 2 diabetes mellitus group (n = 41) before and three months after a tooth extraction. Diabetes patients' recorded increased levels of OPG, RANKL, TNF-α, MMP-9, IL-18 and TOS compared to controls both pre- and post-extraction. In both study groups, the average OPG, HGF and TAC level recorded an upward trend three months post-extraction. TNF-α registered a statistically significant decrease only in the diabetes group after dental extraction, together with a decrement of mean HbA1c levels in the diabetes group. By plotting the ROC (receiver operating characteristic) curve, at baseline RANKL, TNF-α, IL-18, MMP-9, TOS and OPG were good predictors of HbA1c levels. Post-extraction, there was a significant correlation between HbA1c and oxidative status biomarkers, however the linear regression model indicated the influence of all studied salivary markers in HbA1c determinism, in a considerable proportion. In conclusion, our study demonstrated that several oxidative status markers and proinflammatory biomarkers are modified in the saliva of diabetic patients and they correlate to HbA1c levels, thus being potential indicators of the post-extraction healing status in the oral cavity.

Associations of the cerebrospinal fluid hepatocyte growth factor with Alzheimer's disease pathology and cognitive function

Background

Hepatocyte growth factor (HGF) plays a role in neuronal survival and development, and has been implicated in neurodegenerative diseases. We sought to examine the associations of the CSF HGF with Alzheimer’s disease (AD) pathology and cognitive function.

Methods

A total of 238 participants (including 90 cognitively normal (CN) and 148 mild cognitive impairment (MCI)) who had measurements of CSF HGF were included from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) database. Multiple linear regression models were utilized to explore the cross-sectional associations of CSF HGF with AD biomarkers (including Aβ42, pTau, and tTau proteins) in non-demented participants. Moreover, linear mixed-effects regression models were utilized to explore the longitudinal associations of HGF subgroups with cognitive function. Mediation analyses were utilized to explore the mediation effects of AD markers.

Results

MCI individuals had significantly increased CSF HGF compared with the CN individuals. Results of multiple linear regressions showed significant correlations of CSF HGF with CSF Aβ42, pTau, and tTau in non-demented participants. Higher level of baseline CSF HGF was associated with faster cognitive decline. Influences of the baseline CSF HGF on cognition were partially mediated by Aβ42, pTau, and tTau pathologies.

Conclusions

High concentrations of HGF in CSF may be related to faster cognitive decline. The cognitive consequences of higher CSF HGF partly stem from AD pathology, which suggests that the CSF HGF may be an attractive biomarker candidate to track AD progression.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-021-02356-9.

Understanding the Renal Fibrotic Process in Leptospirosis

Leptospirosis is a neglected infectious disease caused by pathogenic species of the genus Leptospira. The acute disease is well-described, and, although it resembles other tropical diseases, it can be diagnosed through the use of serological and molecular methods. While the chronic renal disease, carrier state, and kidney fibrosis due to Leptospira infection in humans have been the subject of discussion by researchers, the mechanisms involved in these processes are still overlooked, and relatively little is known about the establishment and maintenance of the chronic status underlying this infectious disease. In this review, we highlight recent findings regarding the cellular communication pathways involved in the renal fibrotic process, as well as the relationship between renal fibrosis due to leptospirosis and CKD/CKDu.

Association between the HGF/c‑MET signaling pathway and tumorigenesis, progression and prognosis of hepatocellular carcinoma (Review)

Hepatocellular carcinoma (HCC) is one of the most aggressive and lethal malignancies with a rising incidence, and is characterized by rapid progression, frequent metastasis, late diagnosis, high postoperative recurrence and poor prognosis. Therefore, novel treatment strategies for HCC, particularly advanced HCC, are urgently required. The hepatocyte growth factor (HGF)/c‑mesenchymal‑epithelial transition receptor (c‑MET) axis is a key signaling pathway in HCC and is strongly associated with its highly malignant features. Available treatments based on HGF/c‑MET inhibition may prolong the lifespan of patients with HCC; however, they do not achieve the desired therapeutic effects. The aim of the present article was to review the basic knowledge regarding the role of the HGF/c‑MET signaling pathway in HCC, and examine the association between the HGF/c‑MET signaling pathway and the tumorigenesis, progression and prognosis of HCC.

Serum hepatocyte growth factor as a predictor of disease severity and future exacerbations in patients with non-cystic fibrosis bronchiectasis

BACKGROUND

Serum biomarkers associated with the severity of non-cystic fibrosis (CF) bronchiectasis are insufficient. This study determined the association of serum hepatocyte growth factor (HGF), osteopontin, and pentraxin-3 levels with disease severity and exacerbation in patients with non-CF bronchiectasis.

METHODS

Serum levels of HGF, osteopontin, and pentraxin-3 were measured in patients with clinically stable non-CF bronchiectasis (n = 61). The correlation between the biomarkers and bronchiectasis severity index (BSI) and FACED score was assessed using univariate and multivariate linear regression analyses. Predictive variables associated with exacerbation were analyzed using a Cox proportional hazards model and the time to first exacerbation in high and low HGF groups during the observation period was compared using Kaplan-Meier survival curves.

RESULTS

The BSI showed significant correlation with HGF (r = 0.423; p = 0.001) and pentraxin-3 (r = 0.316; p = 0.013). The FACED score was significantly correlated with HGF (r = 0.406; p = 0.001). Univariate and multivariate linear regression analysis revealed that serum level of HGF was independently associated with both scoring systems. The high HGF group showed a significantly shorter time to first exacerbation (Log-rank test, p = 0.014). Multivariate Cox proportional hazards regression analysis revealed that high serum HGF level and colonization with non-pseudomonas organisms were independent predictors of future exacerbations (HR 2.364; p = 0.024 and HR 2.438; p = 0.020, respectively).

CONCLUSION

Serum level of HGF is a potential biomarker that is closely associated with disease severity and future risk of exacerbations in patients with non-CF bronchiectasis.

Hepatocyte growth factor protects PC12 cells against OGD/R-induced injury by reducing iron

In the light of hepatocyte growth factor (HGF) the inhibiting role on the expression of hepcidin, we hypothesized that HGF might be able to reduce cell and tissue iron by increasing ferroportin 1 (Fpn1) content and Fpn1-mediated iron release from cells and tissues. The hypothesized ability of HGF to reduce iron might be one of the mechanisms associated with its neuroprotective action under the conditions of ischemia/reperfusion (I/R). Here, we investigated the effects of HGF on the expression of hepcidin as well as transferrin receptor 1 (TfR1), divalent metal transporter 1 (DMT1), Fpn1, ferritin and iron regulatory proteins (IRPs) in oxygen-glucose deprivation and reoxygenation (OGD/R)-treated PC12 cells by real-time PCR and Western blot analysis. We demonstrated that HGF could completely reverse the OGD/R-induced reduction in Fpn1 and IRP1 expression and increase in ferritin light chain protein and hepcidin mRNA levels in PC12 cells. It was concluded that HGF protects PC12 cells against OGD/R-induced injury mainly by reducing cell iron contents via the up-regulation of Fpn1 and increased Fpn1-mediated iron export from cells. Our findings suggested that HGF may also be able to ameliorate OGD/R or I/R-induced overloading of brain iron by promoting Fpn1 expression.

Sevoflurane preconditioning activates HGF/Met-mediated autophagy to attenuate hepatic ischemia-reperfusion injury in mice

Sevoflurane (SEV) preconditioning plays a protective effect against liver ischemia reperfusion (IR) injury, while the role of autophagy in SEV-mediated hepatoprotection and the precise mechanism is unclear. In the current study, mice were pretreated with SEV or autophagy inhibitor before liver IR injury. In vitro, primary rat hepatocytes were pretreated with SEV and then exposed to hypoxia/reoxygenation (H/R). Liver function was measured by biochemical and histopathological examinations, and markers associated with inflammation, oxidation, apoptosis and autophagy were subsequently measured. We found that SEV preconditioning dramatically reduced hepatic damage, alleviated cell inflammatory response, oxidative stress and apoptosis in mice suffering hepatic IR injury, whereas these protective effects were abolished by the autophagy inhibitor 3-MA. In addition, pretreatment with SEV markedly activated HGF/Met signaling pathway regulation. Besides, pretreatment with an hepatocyte growth factor (HGF) inhibitor or knocking down HGF expression significantly downregulated phosphorylated met (p-met) and autophagy levels, and abolished the protective effects of SEV against hepatic IR or hepatocyte H/R injury. Conversely, HGF overexpression efficiently increased the p-met and autophagy levels and strengthened the protective effects of SEV. These results indicated that sevoflurane preconditioning ameliorates hepatic IR injury by activating HGF/Met-mediated autophagy.

Expression of Estrogen Receptor α by Decidual Macrophages in Preeclampsia

Preeclampsia is a gestation-associated hypertensive syndrome that threatens the life and health of the mother and the child. The condition is presumably caused by systemic failure with a strong involvement of innate immunity. In particular, it has been associated with flexible phenotypes of macrophages, which depend on the molecules circulating in the blood and tissue fluid, such as cytokines and hormones. This study aimed at a comparative evaluation of pro-inflammatory (TNFα) and anti-inflammatory (CD206, MMP9, HGF) markers, as well as the levels of estrogen receptor α, expressed by decidual macrophages in normal pregnancy and in patients with early- and late-onset preeclampsia. The tissue samples of decidua basalis were examined by immunohistochemistry and Western blotting. Isolation of decidual macrophages and their characterization were performed using cultural methods, flow cytometry and real-time PCR. Over 50% of the isolated decidual macrophages were positive for the pan-macrophage marker CD68. In the early-onset preeclampsia group, the levels of estrogen receptor α in decidua were significantly decreased. Furthermore, significantly decreased levels of HGF and CD206 were observed in both preeclampsia groups compared with the control group. The observed downregulation of estrogen receptor α, HGF and CD206 may contribute to the balance of pro- and anti-inflammatory macrophages and thereby to pathogenesis of preeclampsia.

Multi-Biomarker Prediction Models for Multiple Infection Episodes Following Blunt Trauma

Severe trauma predisposes patients to multiple independent infection episodes (MIIEs), leading to augmented morbidity and mortality. We developed a method to identify increased MIIE risk before clinical signs appear, which is fundamentally different from existing approaches entailing infections' detection after their establishment. Applying machine learning algorithms to genome-wide transcriptome data from 128 adult blunt trauma patients' (42 MIIE cases and 85 non-cases) leukocytes collected ≤48 hr of injury and ≥3 days before any infection, we constructed a 15-transcript and a 26-transcript multi-biomarker panel model with the least absolute shrinkage and selection operator (LASSO) and Elastic Net, respectively, which accurately predicted MIIE (Area Under Receiver Operating Characteristics Curve [AUROC] [95% confidence intervals, CI]: 0.90 [0.84–0.96] and 0.92 [0.86–0.96]) and significantly outperformed clinical models. Gene Ontology and network analyses found various pathways to be relevant. External validation found our model to be generalizable. Our unique precision medicine approach can be applied to a wide range of patient populations and outcomes.

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We describe a method for predicting multiple independent infection episodes (MIIEs).

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We applied machine learning algorithms to transcriptome data to develop models

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The biomarker prediction models significantly outperformed clinical models

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External validation in another trauma cohort found evidence of generalizability

Age-related changes in the immunomodulatory effects of human dental pulp derived mesenchymal stem cells on the CD4+ T cell subsets

Mesenchymal stem cells (MSCs) are powerful immunomodulatory cells. The effects of the aging on these abilities of MSCs have not been adequately clarified. In this study, alterations in immunomodulatory abilities of MSCs caused by aging were investigated. For this, dental pulp (DP) MSCs and peripheral blood mononuclear cells (PBMCs) of elderly and young donors were co-cultured age-matched and cross. We detected that the effects of DP-MSCs on Th1 and Th2 cells and their specific cytokines IFN-γ and IL-4 are not affected by aging. However, we observed that young and elderly DP-MSCs have different effects on Th17 and Treg cells. Th17 frequencies of young and elderly PBMCs were significantly increased only by young DP-MSCs, in contrast, Treg frequencies were significantly increased by elderly DP-MSCs. IL-6, IL-17a and HGF levels of both young and elderly PBMCs showed a significant increase only by young DP-MSCs, but TGF-β levels were significantly increased only by elderly DP-MSCs. The oral cavity is home to a rich microflora. The interactions of dental tissues with this microflora can lead them to acquire different epigenetic modifications. Aging can affect the microflora composition of the oral cavity and change this process in different directions. According to our findings, DP-MSCs are effective cells in the regulation of CD4⁺ T cells, and their effects on Th1 and Th2 cells were not affected by aging. However, pleiotropic molecules IL-6 and HGF expressions, which are important in dental and bone tissue regeneration, decreased significantly in elderly DP-MSCs. This situation may have indirectly made a difference in the modulation effects of young and elderly DP-MSCs on the Th17 and Treg cells.

Cyclic Peptide-Based Biologics Regulating HGF-MET

Using a random non-standard peptide integrated discovery system, we obtained cyclic peptides that bind to hepatocyte growth factor (HGF) or mesenchymal-epithelial transition factor. (MET) HGF-inhibitory peptide-8 (HiP-8) selectively bound to two-chain active HGF, but not to single-chain precursor HGF. HGF showed a dynamic change in its molecular shape in atomic force microscopy, but HiP-8 inhibited dynamic change in the molecular shape into a static status. The inhibition of the molecular dynamics of HGF by HiP-8 was associated with the loss of the ability to bind MET. HiP-8 could selectively detect active HGF in cancer tissues, and active HGF probed by HiP-8 showed co-localization with activated MET. Using HiP-8, cancer tissues with active HGF could be detected by positron emission tomography. HiP-8 seems to be applicable for the diagnosis and treatment of cancers. In contrast, based on the receptor dimerization as an essential process for activation, the cross-linking of the cyclic peptides that bind to the extracellular region of MET successfully generated an artificial ligand to MET. The synthetic MET agonists activated MET and exhibited biological activities which were indistinguishable from the effects of HGF. MET agonists composed of cyclic peptides can be manufactured by chemical synthesis but not recombinant protein expression, and thus are expected to be new biologics that are applicable to therapeutics and regenerative medicine.

Resina Draconis Reduces Acute Liver Injury and Promotes Liver Regeneration after 2/3 Partial Hepatectomy in Mice

Aim

To investigate the protective effects and possible mechanisms of action of resina draconis (RD) on acute liver injury and liver regeneration after 2/3 partial hepatectomy (PH) in mice.

Methods

2/3 PH was used to induce acute liver injury. Mice were divided into three groups: sham, vehicle + 2/3 PH, and RD + 2/3 PH. Resina draconis was administered intragastrically after 2/3 PH into the RD + 2/3 PH group, and the same volume of vehicle (1% sodium carboxymethyl cellulose) was injected into the vehicle + 2/3 PH group and sham group mice. The index of liver to body weight (ILBW) and proliferating cell nuclear antigen (PCNA) were assayed to evaluate liver regeneration. Blood and liver tissues were collected for serological and western blotting analysis.

Results

Resina draconis protected against 2/3 PH-induced acute severe liver injury and promoted liver regeneration as shown by significantly increased ILBW compared with that of controls. 2/3 PH increased serum AST and ALT levels, which were significantly decreased by RD treatment, while 2/3 PH decreased serum TP and ALB, which were increased by RD treatment. In the RD + 2/3 PH group, PCNA expression was significantly increased compared with the 2/3 PH group. Further, hepatocyte growth factor (HGF), TNFα, and EGFR levels were increased in the RD group at postoperative days 2 and 4 compared with the those in the 2/3 PH group.

Conclusion

Our results suggest that RD ameliorates acute hepatic injury and promotes liver cell proliferation, liver weight restoration, and liver function after 2/3 PH, probably via HGF, TNFα, and EGFR signaling.

Migrating Schwann cells direct axon regeneration within the peripheral nerve bridge

Schwann cells within the peripheral nervous system possess a remarkable regenerative potential. Current research shows that peripheral nerve-associated Schwann cells possess the capacity to promote repair of multiple tissues including peripheral nerve gap bridging, skin wound healing, digit tip repair as well as tooth regeneration. One of the key features of the specialized repair Schwann cells is that they become highly motile. They not only migrate into the area of damaged tissue and become a key component of regenerating tissue but also secrete signaling molecules to attract macrophages, support neuronal survival, promote axonal regrowth, activate local mesenchymal stem cells, and interact with other cell types. Currently, the importance of migratory Schwann cells in tissue regeneration is most evident in the case of a peripheral nerve transection injury. Following nerve transection, Schwann cells from both proximal and distal nerve stumps migrate into the nerve bridge and form Schwann cell cords to guide axon regeneration. The formation of Schwann cell cords in the nerve bridge is key to successful peripheral nerve repair following transection injury. In this review, we first examine nerve bridge formation and the behavior of Schwann cell migration in the nerve bridge, and then discuss how migrating Schwann cells direct regenerating axons into the distal nerve. We also review the current understanding of signals that could activate Schwann cell migration and signals that Schwann cells utilize to direct axon regeneration. Understanding the molecular mechanism of Schwann cell migration could potentially offer new therapeutic strategies for peripheral nerve repair.

A Systematic Review on Cornea Epithelial-Stromal Homeostasis

INTRODUCTION

This review aims to summarise the role of different cells, genes, proteins and lipid in regulating cornea epithelial-stromal homeostasis.

METHODS

We performed an Entrez PubMed literature search using keywords "human," "cornea," "epithelial," "stromal," "homeostasis," "fibrosis response," and "pathogenesis" on 24th of September 2019, resulting in 35 papers, of which 18 were chosen after filtering for "English language" and "published within 10 years" as well as curation for relevance by the authors.

RESULTS

The 18 selected papers showed that corneal epithelial cells, fibroblasts and telocytes, together with genes such as Klf4, Pax6 and Id found in the cells, play important roles in achieving homeostasis to maintain corneal integrity and transparency. Proteins classified as pro-fibrotic ligands and anti-fibrotic ligands are responsible for regulating cornea stromal fibrosis and extracellular matrix deposition, thus regulators of scar formation during wound healing. Anti-inflammatory ligands and wound repairing ligands are critical in eliciting protective inflammation and promoting epithelial healing, respectively. Protein receptors located on cellular membrane play a role in maintaining intercellular connections as well as corneal hydration.

DISCUSSION/CONCLUSION

These studies prompt development of novel therapeutic strategies such as tear drops or ointments that target certain proteins to maintain corneal homeostasis. However, more in vitro and in vivo studies are required to prove the effectiveness of exogenous administration of molecules in improving healing outcome. Hence, future investigations of the molecular pathways highlighted in this review will reveal novel therapeutic tools such as gene or cell therapy to treat corneal diseases.

Modern Trends for Peripheral Nerve Repair and Regeneration: Beyond the Hollow Nerve Guidance Conduit

Peripheral nerve repair and regeneration remains among the greatest challenges in tissue engineering and regenerative medicine. Even though peripheral nerve injuries (PNIs) are capable of some degree of regeneration, frail recovery is seen even when the best microsurgical technique is applied. PNIs are known to be very incapacitating for the patient, due to the deprivation of motor and sensory abilities. Since there is no optimal solution for tackling this problem up to this day, the evolution in the field is constant, with innovative designs of advanced nerve guidance conduits (NGCs) being reported every day. As a basic concept, a NGC should act as a physical barrier from the external environment, concomitantly acting as physical guidance for the regenerative axons across the gap lesion. NGCs should also be able to retain the naturally released nerve growth factors secreted by the damaged nerve stumps, as well as reducing the invasion of scar tissue-forming fibroblasts to the injury site. Based on the neurobiological knowledge related to the events that succeed after a nerve injury, neuronal subsistence is subjected to the existence of an ideal environment of growth factors, hormones, cytokines, and extracellular matrix (ECM) factors. Therefore, it is known that multifunctional NGCs fabricated through combinatorial approaches are needed to improve the functional and clinical outcomes after PNIs. The present work overviews the current reports dealing with the several features that can be used to improve peripheral nerve regeneration (PNR), ranging from the simple use of hollow NGCs to tissue engineered intraluminal fillers, or to even more advanced strategies, comprising the molecular and gene therapies as well as cell-based therapies.

Rosiglitazone Suppresses Calcium Oxalate Crystal Binding and Oxalate-Induced Oxidative Stress in Renal Epithelial Cells by Promoting PPAR-γ Activation and Subsequent Regulation of TGF-β1 and HGF Expression

Peroxisome proliferator-activated receptor- (PPAR-) γ is a ligand-dependent transcription factor, and it has become evident that PPAR-γ agonists have renoprotective effects, but their influence and mechanism during the development of calcium oxalate (CaOx) nephrolithiasis remain unknown. Rosiglitazone (RSG) was used as a representative PPAR-γ agonist in our experiments. The expression of transforming growth factor-β1 (TGF-β1), hepatocyte growth factor (HGF), c-Met, p-Met, PPAR-γ, p-PPAR-γ (Ser112), Smad2, Smad3, pSmad2/3, and Smad7 was examined in oxalate-treated Madin-Darby canine kidney (MDCK) cells and a stone-forming rat model. A CCK-8 assay was used to evaluate the effects of RSG on cell viability. In addition, intracellular reactive oxygen species (ROS) levels were monitored, and lipid peroxidation in renal tissue was detected according to superoxide dismutase and malondialdehyde levels. Moreover, the location and extent of CaOx crystal deposition were evaluated by Pizzolato staining. Our results showed that, both in vitro and in vivo, oxalate impaired PPAR-γ expression and phosphorylation, and then accumulative ROS production was observed, accompanied by enhanced TGF-β1 and reduced HGF. These phenomena could be reversed by the addition of RSG. RSG also promoted cell viability and proliferation and decreased oxidative stress damage and CaOx crystal deposition. However, these protective effects of RSG were abrogated by the PPAR-γ-specific inhibitor GW9662. Our results revealed that the reduction of PPAR-γ activity played a critical role in oxalate-induced ROS damage and CaOx stone formation. RSG can regulate TGF-β1 and HGF/c-Met through PPAR-γ to exert antioxidant effects against hyperoxaluria and alleviate crystal deposition. Therefore, PPAR-γ agonists may be expected to be a novel therapy for nephrolithiasis, and this effect is related to PPAR-γ-dependent suppression of oxidative stress.

HGF/MET Regulated Epithelial-Mesenchymal Transitions And Metastasis By FOSL2 In Non-Small Cell Lung Cancer

Background

HGF/MET has been found to be associated with non-small cell lung cancer (NSCLC). However, the underlying molecular mechanisms of HGF/MET involved in regulating the metastasis of NSCLC remain unclear.

Methods

The effect of HGF/MET and FOSL2 on cell migration and invasion were assessed by transwell and scratch assays. HGF/MET-induced phosphorylation and upregulation of FOSL2 was analyzed by RT-PCR and Western blotting. Regulatory effects of FOSL2 on SNAI2 transcription were detected by chromatin immunoprecipitation (ChIP) and dual-Luciferase reporter assays. The correlations of FOSL2 expression with clinical outcomes were assessed in 56 NSCLC patients.

Results

HGF/MET induced the phosphorylation and upregulation of FOSL2 by ERK1/2 kinase, FOSL2 promoted the transcription of SNAI2 by binding with the SNAI2 promoter, and SNAI2 subsequently promoted the epithelial-mesenchymal transition (EMT), invasion, and migration of NSCLC cells. According to the clinical correlation analysis in NSCLC, high expression of FOSL2 correlated with advanced tumor stage and metastasis.

Conclusion

Our studies propose that the regulatory mechanisms of the HGF/MET-induced cascade pathway is mediated by FOSL2 in NSCLC metastasis and suggested that FOSL2 could potentially be employed as a prognostic biomarker and potential therapeutic target of NSCLC metastasis.

Hepatocyte growth factor enhances the clearance of a multidrug-resistant Mycobacterium tuberculosis strain by high doses of conventional chemotherapy, preserving liver function

Tuberculosis (TB) is one of the deadliest infectious diseases in humankind history. Although, drug sensible TB is slowly decreasing, at present the rise of TB cases produced by multidrug-resistant (MDR) and extensively drug-resistant strains is a big challenge. Thus, looking for new therapeutic options against these MDR strains is mandatory. In the present work, we studied, in BALB/c mice infected with MDR strain, the therapeutic effect of supra-pharmacological doses of the conventional primary antibiotics rifampicin and isoniazid (administrated by gavage or intratracheal routes), in combination with recombinant human hepatocyte growth factor (HGF). This high dose of antibiotics administered for 3 months, overcome the resistant threshold of the MDR strain producing a significant reduction of pulmonary bacillary loads but induced liver damage, which was totally prevented by the administration of HGF. To address the long-term efficiency of this combined treatment, groups of animals after 1 month of treatment termination were immunosuppressed by glucocorticoid administration and, after 1 month, mice were euthanized, and the bacillary load was determined in lungs. In comparison with animals treated only with a high dose of antibiotics, animals that received the combined treatment showed significantly lower bacterial burdens. Thus, treatment of MDR-TB with very high doses of primary antibiotics particularly administrated by aerial route can produce a very good therapeutic effect, and its hepatic toxicity can be prevented by the administration of HGF, becoming in a new treatment modality for MDR-TB.

Transplantation of Adipose Stromal Cell Sheet Producing Hepatocyte Growth Factor Induces Pleiotropic Effect in Ischemic Skeletal Muscle

Cell therapy remains a promising approach for the treatment of cardiovascular diseases. In this regard, the contemporary trend is the development of methods to overcome low cell viability and enhance their regenerative potential. In the present study, we evaluated the therapeutic potential of gene-modified adipose-derived stromal cells (ADSC) that overexpress hepatocyte growth factor (HGF) in a mice hind limb ischemia model. Angiogenic and neuroprotective effects were assessed following ADSC transplantation in suspension or in the form of cell sheet. We found superior blood flow restoration, tissue vascularization and innervation, and fibrosis reduction after transplantation of HGF-producing ADSC sheet compared to other groups. We suggest that the observed effects are determined by pleiotropic effects of HGF, along with the multifactorial paracrine action of ADSC which remain viable and functionally active within the engineered cell construct. Thus, we demonstrated the high therapeutic potential of the utilized approach for skeletal muscle recovery after ischemic damage associated with complex tissue degenerative effects.

Hepatoprotective Activity of InlB321/15, the HGFR Ligand of Bacterial Origin, in CCI4-Induced Acute Liver Injury Mice

HGF (hepatocyte growth factor)/HGFR (HGF receptor) signaling pathway is a key pathway in liver protection and regeneration after acute toxic damage. Listeria monocytogenes toxin InlB contains a HGFR-interacting domain and is a functional analog of HGF. The aim of this work was to evaluate the hepatoprotective activity of the InlB HGFR-interacting domain. The recombinant HGFR-interacting domain InlB321/15 was purified from E. coli. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) test was used to measure InlB321/15 mitogenic activity in HepG2 cells. Activation of MAPK- and PI3K/Akt-pathways was tracked with fluorescent microscopy, Western blotting, and ELISA. To evaluate hepatoprotective activity, InlB321/15 and recombinant human HGF (rhHGF) were intravenously injected at the same concentration of 2 ng·g⁻¹ to BALB/c mice 2 h before liver injury with CCl₄. InlB321/15 caused dose-dependent activation of MAPK- and PI3K/Akt-pathways and correspondent mitogenic effects. Both InlB321/15 and rhHGF improved macroscopic liver parameters (liver mass was 1.51, 1.27 and 1.15 g for the vehicle, InlB321/15 and rhHGF, respectively, p < 0.05), reduced necrosis (24.0%, 16.18% and 21.66% of the total area for the vehicle, InlB321/15 and rhHGF, respectively, p < 0.05). Obtained data suggest that InlB321/15 is a promising candidate for a tissue repair agent.

Cellular signaling and gene expression profiles evoked by a bivalent macrocyclic peptide that serves as an artificial MET receptor agonist

Non-native ligands for growth factor receptors that are generated by chemical synthesis are applicable to therapeutics. However, non-native ligands often regulate cellular signaling and biological responses in a different manner than native ligands. Generation of surrogate ligands comparable to native ligands is a challenging need. Here we investigated changes in signal transduction and gene expression evoked by a bivalent macrocyclic peptide (aMD5-PEG11) capable of high-affinity binding to the MET/hepatocyte growth factor (HGF) receptor. Binding of aMD5-PEG11 to the MET extracellular region was abolished by deletion of the IPT3−IPT4 domain, indicating the involvement of IPT3−IPT4 in the binding of aMD5-PEG11 to the MET receptor. aMD5-PEG11 induced dimerization and activation of the MET receptor and promoted cell migration that was comparable to induction of these activities by HGF. Signal activation profiles indicated that aMD5-PEG11 induced phosphorylation of intracellular signaling molecules, with a similar intensity and time dependency as HGF. In 3-D culture, aMD5-PEG11 as well as HGF induced epithelial tubulogenesis and up-regulated the same sets of functionally classified genes involved in multicellular organism development. Thus, a non-native surrogate ligand that consisted of a bivalent macrocyclic peptide can serve as an artificial MET receptor agonist that functionally substitutes for the native ligand, HGF.

MET Activation by a Macrocyclic Peptide Agonist that Couples to Biological Responses Differently from HGF in a Context-Dependent Manner

Non-native ligands for growth factor receptors with distinct chemical properties and different biological activities have the potential to become therapeutic applications. We previously generated MET/hepatocyte growth factor (HGF) receptor agonists using bivalent macrocyclic peptides. The highest MET-activating agonists exhibited biological activity that was indistinguishable from the effects of HGF. In this study, we investigated MET activation, signal characteristics, and biological responses induced by a macrocyclic peptide partial agonist known as aML5-PEG11. aML5-PEG11 induced weak tyrosine phosphorylation of MET while enhancing cell migration with potency comparable to HGF. aML5-PEG11 induced marked AKT (protein kinase B) and ERK (extracellular signal-regulated kinase) activation at a comparable potency and time-dependency to HGF, which suggests that enhancement of cell motility is attributable to activation of these molecules. In a 3-D culture of bile duct cancer cells in collagen gel, HGF induced robust activation of MET, ERK, and AKT, which was associated with enhanced expression of genes involved in bile duct development and subsequent branching of tubulogenesis. In contrast, aML5-PEG11 induced marginal activation of MET, ERK, and AKT (levels near the detection limits), which was associated with failure to enhance the expression of genes involved in bile duct development and a lack of tubulogenic response. Thus, MET activation by aML5-PEG11 couples to biological responses differently from HGF in an extracellular context-dependent manner.