The FGF family: biology, pathophysiology and therapy

Autophagy-targeting modulation to promote peripheral nerve regeneration

Nerve regeneration following traumatic peripheral nerve injuries and neuropathies is a complex process modulated by diverse factors and intricate molecular mechanisms. Past studies have focused on factors that stimulate axonal outgrowth and myelin regeneration. However, recent studies have highlighted the pivotal role of autophagy in peripheral nerve regeneration, particularly in the context of traumatic injuries. Consequently, autophagy-targeting modulation has emerged as a promising therapeutic approach to enhancing peripheral nerve regeneration. Our current understanding suggests that activating autophagy facilitates the rapid clearance of damaged axons and myelin sheaths, thereby enhancing neuronal survival and mitigating injury-induced oxidative stress and inflammation. These actions collectively contribute to creating a favorable microenvironment for structural and functional nerve regeneration. A range of autophagy-inducing drugs and interventions have demonstrated beneficial effects in alleviating peripheral neuropathy and promoting nerve regeneration in preclinical models of traumatic peripheral nerve injuries. This review delves into the regulation of autophagy in cell types involved in peripheral nerve regeneration, summarizing the potential drugs and interventions that can be harnessed to promote this process. We hope that our review will offer novel insights and perspectives on the exploitation of autophagy pathways in the treatment of peripheral nerve injuries and neuropathies.

Fibroblast growth factor receptor signaling in metabolic dysfunction-associated fatty liver disease: Pathogenesis and therapeutic targets

Metabolic dysfunction-associated fatty liver disease (MAFLD) has emerged as a significant hepatic manifestation of metabolic syndrome, with its prevalence increasing globally alongside the epidemics of obesity and diabetes. MAFLD represents a continuum of liver damage, spanning from uncomplicated steatosis to metabolic dysfunction-associated steatohepatitis (MASH). This condition can advance to more severe outcomes, including fibrosis and cirrhosis. Fibroblast growth factor receptors (FGFRs) are a family of four receptor tyrosine kinases (FGFR1-4) that interact with both paracrine and endocrine fibroblast growth factors (FGFs). This interaction activates the phosphorylation of tyrosine kinase residues, thereby triggering downstream signaling pathways, including RAS-MAPK, JAK-STAT, PI3K-AKT, and PLCγ. In the context of MAFLD, paracrine FGF-FGFR signaling is predominantly biased toward the development of liver fibrosis and carcinogenesis. In contrast, endocrine FGF-FGFR signaling is primarily biased toward regulating the metabolism of bile acids, carbohydrates, lipids, and phosphate, as well as maintaining the overall balance of energy metabolism in the body. The interplay between these biased signaling pathways significantly influences the progression of MAFLD. This review explores the critical functions of FGFR signaling in MAFLD from three perspectives: first, it examines the primary roles of FGFRs relative to their structure; second, it summarizes FGFR signaling in hepatic lipid metabolism, elucidating mechanisms underlying the occurrence and progression of MAFLD; finally, it highlights recent advancements in drug development aimed at targeting FGFR signaling for the treatment of MAFLD and its associated diseases.

Organoid Vascularization: Strategies and Applications

Organoids provide 3D structures that replicate native tissues in biomedical research. The development of vascular networks within organoids enables oxygen and nutrient delivery while facilitating metabolic waste removal, which supports organoid growth and maturation. Recent studies demonstrate that vascularized organoid models offer insights into tissue interactions and promote tissue regeneration. However, the current limitations in establishing functional vascular networks affect organoid growth, viability, and clinical translation potential. This review examines the development of vascularized organoids, including the mechanisms of angiogenesis and vasculogenesis, construction strategies, and biomedical applications. The approaches are categorized into in vivo and in vitro methods, with analysis of their specific advantages and limitations. The review also discusses emerging techniques such as bioprinting and gene editing for improving vascularization and functional integration in organoid-based therapies. Current developments in organoid vascularization indicate potential applications in modeling human diseases and developing therapeutic strategies, contributing to advances in translational research.

FGF1ΔHBS ameliorates DSS-induced ulcerative colitis by reducing neutrophil recruitment through the MAPK pathway

BACKGROUND AND PURPOSE

Inflammatory bowel diseases (IBDs) constitute chronic inflammatory disease of the gastrointestinal tract, with escalating global prevalence. There is a pressing demand for safe and effective treatments for IBDs. Fibroblast growth factor 1 (FGF1) variant FGF1ΔHBS, characterised by reduced mitogenic capacity, has shown promising therapeutic potential in various inflammatory conditions, including obesity and diabetic nephropathy. Hence, exploring the therapeutic impact of FGF1ΔHBS on colitis is warranted.

EXPERIMENTAL APPROACH

The protective role of FGF1ΔHBS was evaluated using a dextran sulphate sodium (DSS)-induced colitis model in mice. RNA-seq analysis was performed on colonic tissues. Inflammatory factor expression was examined by quantitative real-time polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay. Flow cytometry and immunofluorescence staining were employed to confirm the inhibitory effect of FGF1ΔHBS on neutrophil recruitment. Western blotting was performed to explore the mitogen-activated protein kinase (MAPK) signalling pathway.

KEY RESULTS

FGF1ΔHBS significantly alleviated DSS-induced colitis, as indicated by reduced Disease Activity Index scores and less histological injury to the colon. Additionally, FGF1ΔHBS decreased the expression of pro-inflammatory factors. Mechanistically, FGF1ΔHBS inhibited neutrophil-associated chemokine expression in intestinal epithelial cells by suppressing the MAPK signalling pathway, thereby reducing neutrophil recruitment and attenuating neutrophil-mediated intestinal inflammation.

CONCLUSION AND IMPLICATIONS

FGF1ΔHBS protects against DSS-induced colitis in mice by inhibiting neutrophil recruitment through MAPK activity suppression, suggesting a potential therapeutic strategy for preventing IBDs.

Hypoxia-regulated miR-103-3p/FGF2 axis in adipose-derived stem cells promotes angiogenesis by vascular endothelial cells during ischemic tissue repair

BACKGROUND

Identifying factors mediating adipose-derived stem cells (ADSCs)-induced endothelial cell angiogenesis in hypoxic skin flap tissue is critical for reconstruction. While the paracrine action of VEGF by adipose-derived stem cells (ADSCs) is established in promoting endothelial cell angiogenesis, the role of FGF2 and its regulatory mechanisms in ADSCs paracrine secretion remains unclear.

METHODS

We induced hypoxia and examined the expression level of FGF2 in ADSCs using ELISA, qRT-PCR, and western blotting. Proliferation of ADSCs under hypoxia was assessed using a CCK-8 assay. Co-culture experiments of hypoxia-induced ADSCs with vascular endothelial cells were conducted, and migration and tube formation abilities were evaluated through wound healing assays, transwell cell migration, and tube formation experiments.

RESULTS

Hypoxia treatment induced significant upregulation of FGF2 expression in ADSCs, along with enhanced cell proliferation. Co-culture of hypoxia-induced ADSCs with vascular endothelial cells showed increased migration and tube formation abilities of endothelial cells. Knockdown of FGF2 inhibited these processes, while overexpression of miR-103-3p mimics in ADSCs suppressed endothelial cell migration and tube formation. FGF2 is a direct target of miR-103-3p in ADSCs. miR-103-3p/FGF2 axis regulates ADSCs on the biological activity of co-cultured vascular endothelial cells. Moreover, in the ischemic skin flap nude mouse model, ADSCs injection showed increased blood vessel formation and reduced flap necrosis, with the most significant improvement observed with ADSCs of miR-103-3p inhibitor overexpressed.

CONCLUSION

Hypoxia induces paracrine secretion of FGF2 from ADSCs, which enhances endothelial cell angiogenesis. FGF2 expression is regulated by miR-103-3p in ADSCs. The miR-103-3p/FGF2 axis induces endothelial cell migration and angiogenesis and finally modulates ischemic skin flap repair in nude mice in vivo.

Angiogenesis: Biological Mechanisms and In Vitro Models

The translation of biomedical devices and drug research is an expensive and long process with a low probability of receiving FDA approval. Developing physiologically relevant in vitro models with human cells offers a solution to not only improving the odds of FDA approval but also to expand our ability to study complex in vivo systems in a simpler fashion. Animal models remain the standard for pre-clinical testing; however, the data from animal models is an unreliable extrapolation when anticipating a human response in clinical trials, thus contributing to the low rates of translation. In this review, we focus on in vitro vascular or angiogenic models because of the incremental role that the vascular system plays in the translation of biomedical research. The first section of this review discusses the most common angiogenic cytokines that are used in vitro to initiate angiogenesis, followed by angiogenic inhibitors where both initiators and inhibitors work to maintain vascular homeostasis. Next, we evaluate previously published in vitro models, where we evaluate capturing the physical environment for biomimetic in vitro modeling. These topics provide a foundation of parameters that must be considered to improve and achieve vascular biomimicry. Finally, we summarize these topics to suggest a path forward with the goal of engineering human in vitro models that emulate the in vivo environment and provide a platform for biomedical device and drug screening that produces data to support clinical translation.

Colonic epithelial-derived FGF1 drives intestinal stem cell commitment toward goblet cells to suppress inflammatory bowel disease

Understanding the molecular mechanisms that regulate intestinal epithelial cell (IEC) renewal provides potential targets for inflammatory bowel disease (IBD). Growing evidence has highlighted the importance of epithelial signals in regulating intestinal stem cell (ISC) differentiation. However, it remains unclear which IEC-derived cytokines can precisely regulate ISC commitment toward specific mature cells. Here we systematically analyze all fibroblast growth factors (FGFs) expression and find that colonic FGF1 levels are inversely correlated with the severity of IBD in mouse models and patients. IEC-specific Fgf1 deletion leads to impaired goblet cell differentiation and exacerbated colitis, while pharmacological administration of recombinant FGF1 (rFGF1) alleviates colitis by enhancing goblet cell differentiation and improving colonic epithelial integrity. Mechanistic studies reveal that rFGF1 directs ISC differentiation toward goblet cells via FGFR2-TCF4-ATOH1 signaling axis. In conclusion, our study identifies an epithelial niche-derived FGF1 that regulates ISC commitment toward goblet cells, shedding light on strategies for treating IBD.

Wnt signaling pathways in biology and disease: mechanisms and therapeutic advances

The Wnt signaling pathway is critically involved in orchestrating cellular functions such as proliferation, migration, survival, and cell fate determination during development. Given its pivotal role in cellular communication, aberrant Wnt signaling has been extensively linked to the pathogenesis of various diseases. This review offers an in-depth analysis of the Wnt pathway, detailing its signal transduction mechanisms and principal components. Furthermore, the complex network of interactions between Wnt cascades and other key signaling pathways, such as Notch, Hedgehog, TGF-β, FGF, and NF-κB, is explored. Genetic mutations affecting the Wnt pathway play a pivotal role in disease progression, with particular emphasis on Wnt signaling's involvement in cancer stem cell biology and the tumor microenvironment. Additionally, this review underscores the diverse mechanisms through which Wnt signaling contributes to diseases such as cardiovascular conditions, neurodegenerative disorders, metabolic syndromes, autoimmune diseases, and cancer. Finally, a comprehensive overview of the therapeutic progress targeting Wnt signaling was given, and the latest progress in disease treatment targeting key components of the Wnt signaling pathway was summarized in detail, including Wnt ligands/receptors, β-catenin destruction complexes, and β-catenin/TCF transcription complexes. The development of small molecule inhibitors, monoclonal antibodies, and combination therapy strategies was emphasized, while the current potential therapeutic challenges were summarized. This aims to enhance the current understanding of this key pathway.

Strategies to Overcome Resistance to Osimertinib in EGFR-Mutated Lung Cancer

Non-small-cell lung cancer (NSCLC) represents the most common type of lung cancer. The majority of patients with lung cancer characterized by activating mutations in the epidermal growth factor receptor (EGFR), benefit from therapies entailing tyrosine kinase inhibitors (TKIs). In this regard, osimertinib, a third-generation EGFR TKI, has greatly improved the outcome for patients with EGFR-mutated lung cancer. The AURA and FLAURA trials displayed the superiority of the third-generation TKI in both first- and second-line settings, making it the drug of choice for treating patients with EGFR-mutated lung cancer. Unfortunately, the onset of resistance is almost inevitable. On-target mechanisms of resistance include new mutations (e.g., C797S) in the kinase domain of EGFR, while among the off-target mechanisms, amplification of MET or HER2, mutations in downstream signaling molecules, oncogenic fusions, and phenotypic changes (e.g., EMT) have been described. This review focuses on the strategies that are currently being investigated, in preclinical and clinical settings, to overcome resistance to osimertinib, including the use of fourth-generation TKIs, PROTACs, bispecific antibodies, and ADCs, as monotherapy and as part of combination therapies.

Understanding Neovascularization in Glioblastoma: Insights from the Current Literature

Glioblastomas (GBMs), among the most aggressive and resilient brain tumors, characteristically exhibit high angiogenic potential, leading to the formation of a dense yet aberrant vasculature, both morphologically and functionally. With these premises, numerous expectations were initially placed on anti-angiogenic therapies, soon dashed by their limited efficacy in concretely improving patient outcomes. Neovascularization in GBM soon emerged as a complex, dynamic, and heterogeneous process, hard to manage with the classical standard of care. Growing evidence has revealed the existence of numerous non-canonical strategies of angiogenesis, variously exploited by GBM to meet its ever-increasing metabolic demand and differently involved in tumor progression, recurrence, and escape from treatments. In this review, we provide an accurate description of each neovascularization mode encountered in GBM tumors to date, highlighting the molecular players and signaling cascades primarily involved. We also detail the key architectural and functional aspects characteristic of the GBM vascular compartment because of an intricate crosstalk between the different angiogenic networks. Additionally, we explore the repertoire of emerging therapies against GBM that are currently under study, concluding with a question: faced with such a challenging scenario, could combined therapies, tailored to the patient's genetic signatures, represent an effective game changer?

Synthesis of Sulfated Carbohydrates - Glycosaminoglycans

Glycosaminoglycans (GAG) are polysaccharides that are ubiquitous on the surface of all mammalian cells, interacting with a multitude of proteins and orchestrating essential physiological and pathological processes. Among various GAG structures, heparan sulfate (HS) stands out for its intricate structure, positioning it as a significant cell-surface molecule capable of regulating wide range of cellular functions. Consequently, investigating the structure-activity relationships (SARs) with well-defined HS ligands emerges as an attractive avenue advancing drug discovery and biosensors. This chapter outlines a modular divergent strategy for synthesizing HS oligosaccharides to elucidate SARs. Here, we provide a literature overview on the synthesis of disaccharide building blocks, employing different orthogonal protecting groups, promoters, and optimization conditions to improve their suitability for subsequent oligosaccharide synthesis. Further, we highlight the synthesis of universal disaccharide building blocks derived from natural polysaccharides. We also provide insights of one-pot method and automated solid-phase synthesis of HS oligosaccharides. Finally, we review the status of SARs of popular heparan sulfate binding proteins (HSBPs).

A Novel Recombinant Human FGF21 Analog with High Glycosylation Has a Prolonged Half-Life and Affects Glycemic and Body Weight Control

Fibroblast growth factor 21 (FGF21), a hormone-like protein, plays a crucial role in enhancing glucose and lipid metabolism, offering promising therapeutic avenues for conditions such as nonalcoholic steatohepatitis and severe hypertriglyceridemia. Despite its potential, this protein's limited stability and brief half-life pose significant challenges for its use in clinical settings. In this study, we created an FGF21 analog (named FGF21-164) that is a mutant of FGF21 and fused it with the tandem repeat sequence of human CD164. FGF21-164, characterized by extensive glycosylation and sialylation, exhibits enhanced pharmacokinetic properties, particularly in terms of its significantly longer half-life compared to its native form. The in vitro efficacy of FGF21-164 was evaluated using 3T3-L1-induced adipocytes. The protein demonstrated a dose-dependent increase in glucose uptake and effectively decreased lipid droplet accumulation surrounding the adipocytes. The in vivo activity of FGF21-164 was evaluated in leptin-deficient (ob/ob) and diet-induced obesity (DIO) mice. A single subcutaneous dose of FGF21-164 led to a rapid decrease in blood glucose levels and sustained normal fasting glucose levels for up to 28 days. Additionally, repeated dosing of FGF21-164 significantly curbed weight gain and reduced hepatic fat accumulation in DIO mice.

β-sitosterol suppresses fibroblast growth factor and epidermal growth factor receptors to induce apoptosis and inhibit migration in lung cancer: an in vitro study

β-Sitosterol (BS), is a significant bioactive component of phytosterols found in plants, foods, and dietary supplements. Its nutritional benefits include lowering of cholesterol levels, boost immune system as well as reduce inflammation. Previous studies have demonstrated its significant anticancer effects across various human cancers. However, the specific mechanisms of action of BS in lung cancer remain unclear. This study aimed to investigate the mechanisms through which BS exerts its anticancer properties in human lung cancer cells, focusing on its anti-proliferative, apoptotic, cytotoxic, and anti-migratory effects. We conducted an in vitro study to assess the effects of BS on lung cancer cell lines A549 and H1975. We used a range of assays, including MTT, western blot, wound healing, transwell migration, immunofluorescence, TUNEL, and cell survival assays, to evaluate the impact of BS on cell proliferation, apoptosis, cytotoxicity, and migration. Our findings indicate that BS inhibits the proliferation of lung cancer cells in a time- and dose-dependent manner. It significantly promotes apoptosis and impairs both cancer cell migration and survival. Additionally, BS suppresses the expression of both fibroblast growth factor receptor-1 (FGFR1) and epidermal growth factor (EGFR), leading to the downregulation of the PI3K/AKT/mTOR/CD1 signaling pathway. BS demonstrates significant anticancer potential in lung cancer cells by inhibiting proliferation, inducing apoptosis, and reducing cell migration. These effects are likely mediated by the concurrent downregulation of FGFR1 and EGFR, leading to the inhibition of the PI3K/AKT/mTOR/CD1 signaling pathway, thereby warranting further investigation of BS as a potential therapeutic agent for lung cancer.

Receptor tyrosine kinases CAD96CA and FGFR1 function as the cell membrane receptors of insect juvenile hormone

Juvenile hormone (JH) is important to maintain insect larval status; however, its cell membrane receptor has not been identified. Using the lepidopteran insect Helicoverpa armigera (cotton bollworm), a serious agricultural pest, as a model, we determined that receptor tyrosine kinases (RTKs) cadherin 96ca (CAD96CA) and fibroblast growth factor receptor homologue (FGFR1) function as JH cell membrane receptors by their roles in JH-regulated gene expression, larval status maintaining, rapid intracellular calcium increase, phosphorylation of JH intracellular receptor MET1 and cofactor Taiman, and high affinity to JH III. Gene knockout of Cad96ca and Fgfr1 by CRISPR/Cas9 in embryo and knockdown in various insect cells, and overexpression of CAD96CA and FGFR1 in mammalian HEK-293T cells all supported CAD96CA and FGFR1 transmitting JH signal as JH cell membrane receptors.

Breastfeeding and Future Cardiovascular, Kidney, and Metabolic Health-A Narrative Review

The benefits of breastfeeding for both mother and infant are generally recognized; however, the connections between breast milk, lactation, and long-term offspring health and disease remain incompletely understood. Cardiovascular-kidney-metabolic syndrome (CKMS) has become a major global public health challenge. Insufficient breast milk supply, combined with various early-life environmental factors, markedly increases the future risk of CKMS, as highlighted by the developmental origins of health and disease (DOHaD) concept. Given its richness in nutrients and bioactive components essential for infant health, this review focuses on reprogramming strategies involving breast milk to improve offspring's cardiovascular, kidney, and metabolic health. It also highlights recent experimental advances in understanding the mechanisms driving CKMS programming. Cumulatively, the evidence suggests that lactational impairment heightens the risk of CKMS development. In contrast, early interventions during the lactation period focused on animal models that leverage breast milk components in response to early-life cues show potential in improving cardiovascular, kidney, and metabolic outcomes-an area warranting further investigation and clinical translation.

Biological Activity of Biomarkers Associated With Metastasis in Osteosarcoma Cell Lines

INTRODUCTION

Osteosarcoma, a highly aggressive bone cancer primarily affecting children and young adults, remains a significant challenge in clinical oncology. Metastasis stands as the primary cause of mortality in osteosarcoma patients. However, the mechanisms driving this process remain incompletely understood. Clarifying the molecular pathways involved in metastasis is essential for enhancing patient prognoses and facilitating the development of targeted therapeutic strategies.

METHODS

RNA sequencing (RNA-Seq) analysis was employed to compare three conditions, hFOB1.19 versus Saos-2, hFOB1.19 versus SJSA-1, and Saos-2 versus SJSA-1, involving non-cancer osteoblasts (hFOB1.19) and highly metastatic osteosarcoma cell lines (Saos-2 and SJSA-1). Additionally, ENA datasets of RNA-Seq from osteosarcoma biopsies were included. Differentially expressed genes (DEGs) were identified and analyzed through enrichment pathway analysis and protein-protein interaction (PPI) networks. Additionally, for gene candidates, a biochemical evaluation was performed.

RESULTS

DEGs associated with biological functions pertinent to migration, invasion, and metastasis in osteosarcoma were identified. Notably, matrix metalloproteinase-2 (MMP-2) emerged as a promising candidate. Both canonical or full-length (FL-mmp-2) and N-terminal truncated (NTT-mmp-2) isoforms were discerned in biopsies. Moreover, MMP-2's activity was characterized in cell lines. Additionally, mRNA expression of voltage-gated sodium channels (NaVs) and voltage-gated potassium channels (KVs) was detected, and their functional expression was validated using patch clamp techniques. Evaluation of cell line migration and invasion capacities revealed their reduction in the presence of ion channel blockers (TTX and TEA) and MMP inhibitor (GM6001).

CONCLUSIONS

The gene functional enrichment analysis of DEGs enabled the identification of interaction networks in osteosarcoma, thereby revealing potential biomarkers. Moreover, the elucidated co-participation of TTX-sensitive NaVs and MMP-2 in facilitating migration and invasion suggests their suitability as novel prognostic biomarkers for osteosarcoma. Additionally, this study introduces a model delineating the potential interaction mechanism among ion channels, MMP-2, and other crucial factors in the metastatic cascade of osteosarcoma.

Repression of the ERRγ-CYP2E1 pathway by FGF4 mitigates alcohol-associated liver injury

BACKGROUND AND AIMS

Alcohol-associated liver disease (ALD) represents a critical global health challenge characterized by liver damage resulting from excessive alcohol consumption. Early detection and timely intervention are essential for optimizing patient outcomes. However, the mechanisms underlying alcohol-induced liver injury have not been fully elucidated. Fibroblast growth factor 4 (FGF4) has been implicated in the progression of various liver diseases. This study aims to elucidate the role of FGF4 in the pathogenesis of ALD.

APPROACH AND RESULTS

We analyzed human liver specimens and observed significant upregulation of FGF4 mRNA and protein levels in patients with ALD. Consistent findings were noted in mouse models subjected to a Lieber-DeCarli liquid diet. Importantly, hepatic FGF4 expression exhibited a positive correlation with ALD severity in both human subjects and murine models. Hepatocyte-specific deletion of Fgf4 ( Fgf4 -LKO) exacerbated alcohol-induced liver injury through increased oxidative stress, inflammation, and apoptosis. Specifically, Fgf4 -LKO mice demonstrated heightened susceptibility to ethanol plus CCl 4 -induced fibrosis and liver injury. However, treatment with the ERRγ inverse agonist GSK5182 and CYP2E1 inhibitor chlormethiazole (CMZ) mitigated the exacerbated liver injury associated with Fgf4 deficiency. Mechanistic investigations revealed that FGFR4 phosphorylates ERRγ, promoting its ubiquitination and degradation in hepatocytes. Hepatic-specific knockout of Fgfr4 intensified alcohol-induced liver injury and nullified the protective conferred of recombinant FGF4 △NT .

CONCLUSIONS

Our study identifies FGF4 as a stress-responsive regulator in liver pathophysiology, operating through an FGFR4-mediated ERRγ-CYP2E1 signaling pathway. These results underscore the potential of FGF4 and its downstream pathways as therapeutic targets for ALD treatment.

aFGF gene-modified adipose-derived mesenchymal stem cells promote healing of full-thickness skin defects in diabetic rats

BACKGROUND

Chronic diabetic wounds pose a significant clinical challenge due to the limited efficacy of current treatments. This study aimed to investigate the role and potential mechanisms of adipose-derived mesenchymal stem cells (ADSCs) overexpressing acidic fibroblast growth factor (aFGF) in diabetic wound healing in a rat model.

METHODS

ADSCs were genetically modified to achieve stable overexpression of aFGF. Varying doses of aFGF-ADSCs (1 × 106, 2 × 106, 3 × 106, 4 × 106) were injected into the muscular tissue surrounding diabetic rat wounds. We assessed aFGF expression and its impact on various stages of wound healing, including angiogenesis, inflammatory response, epithelialization, and collagen deposition. Transcriptomic sequencing was performed to explore the underlying mechanisms driving enhanced wound healing.

RESULTS

Lentiviral transduction successfully induced stable aFGF overexpression in ADSCs. In vivo experiments revealed that varying doses of aFGF-ADSCs markedly enhanced wound healing in diabetic rats in a dose-dependent manner. The dose of 3 × 10⁶ aFGF-ADSCs demonstrated the most significant effect. In the 3 × 106 aFGF-ADSCs group, expression levels of aFGF, CD31, and CD163 were significantly higher than in other groups (p < 0.05), while CD86 expression was significantly lower (p < 0.05).

CONCLUSION

Single doses of aFGF-ADSCs comprehensively improved various aspects of wound repair in diabetic rats, offering a potential new approach for treating chronic diabetic wounds. The mechanism of action involves promoting angiogenesis, modulating inflammatory responses, accelerating epithelialization, and optimizing collagen deposition.

Shared interactions of six neurotropic viruses with 38 human proteins: a computational and literature-based exploration of viral interactions and hijacking of human proteins in neuropsychiatric disorders

INTRODUCTION

Viral infections may disrupt the structural and functional integrity of the nervous system, leading to acute conditions such as encephalitis, and neuropsychiatric conditions as mood disorders, schizophrenia, and neurodegenerative diseases. Investigating viral interactions of human proteins may reveal mechanisms underlying these effects and offer insights for therapeutic interventions. This study explores molecular interactions of virus and human proteins that may be related to neuropsychiatric disorders.

METHODS

Herpes Simplex Virus-1 (HSV-1), Cytomegalovirus (CMV), Epstein-Barr Virus (EBV), Influenza A virus (IAV) (H1N1, H5N1), and Human Immunodeficiency Virus (HIV1&2) were selected as key viruses. Protein structures for each virus were accessed from the Protein Data Bank and analyzed using the HMI-Pred web server to detect interface mimicry between viral and human proteins. The PANTHER classification system was used to categorize viral-human protein interactions based on function and cellular localization.

RESULTS

Energetically favorable viral-human protein interactions were identified for HSV-1 (467), CMV (514), EBV (495), H1N1 (3331), H5N1 (3533), and HIV 1&2 (62425). Besides immune and apoptosis-related pathways, key neurodegenerative pathways, including those associated with Parkinson's and Huntington's diseases, were frequently interacted. A total of 38 human proteins, including calmodulin 2, Ras-related botulinum toxin substrate 1 (Rac1), PDGF-β, and vimentin, were found to interact with all six viruses.

CONCLUSION

The study indicates a substantial number of energetically favorable interactions between human proteins and selected viral proteins, underscoring the complexity and breadth of viral strategies to hijack host cellular mechanisms. Further in vivo and in vitro validation is required to understand the implications of these interactions.

Mechanisms of nebivolol-mediated effects on bFGF-induced vascular smooth muscle cell proliferation and migration

Background

Nebivolol is a β-adrenergic receptor antagonist that has intrinsic activity on β3-adrenergic receptors (β3-ARs). Previous studies suggest that nebivolol inhibits bFGF-induced vascular smooth muscle cell (VSMC) proliferation and migration and vascular injury-induced neointima formation through activation of β3-ARs. However, our recently published data shown that activation of β3-ARs produced the opposite results, suggesting that the mechanisms of nebivolol-mediated effects are not fully understood. The current project was to study the mechanisms of nebivolol's effects on bFGF-induced VSMC proliferation and migration by comparing to the selective β3-AR agonist, CL316,243.

Methods

VSMCs isolated from Sprague Dawley rat aortas were pretreated with nebivolol or CL316,243 followed by stimulation with bFGF. Cell proliferation and migration and phosphorylation of ERK and AKT were measured.

Results

We found that pretreatment of VSMCs with nebivolol produced biphasic effects on bFGF-induced VSMC proliferation, manifested as potentiation at lower concentrations and inhibition at the higher concentration. The effects of low concentrations of nebivolol on bFGF-induced VSMC proliferation was blocked by the selective β3-AR antagonist, SR59230A. Nebivolol inhibited bFGF-induced cell migration at all concentrations tested. In addition, only higher concentrations of nebivolol significantly inhibited bFGF-induced AKT phosphorylation but not ERK phosphorylation whereas CL316,243 at all concentrations tested significantly enhanced bFGF-induced VSMC proliferation and migration and higher concentrations of CL316,243 not only enhanced bFGF-induced AKT phosphorylation but also ERK phosphorylation.

Conclusion

Our data suggest that the effect of nebivolol on bFGF-induced cell proliferation is concentration-dependent. The enhancement on bFGF-induced cell proliferation at lower concentrations appears to be mainly mediated by activation of β3-ARs but the inhibitory effects on bFGF-mediated cell proliferation as well as migration may occur through different mechanisms. AKT signaling is only involved in high concentrations of nebivolol-mediated effects.

Microglial Autophagic Dysregulation in Traumatic Brain Injury: Molecular Insights and Therapeutic Avenues

Traumatic brain injury (TBI) is a complex and multifaceted condition that can result in cognitive and behavioral impairments. One aspect of TBI that has received increasing attention in recent years is the role of microglia, the brain-resident immune cells, in the pathophysiology of the injury. Specifically, increasing evidence suggests that dysfunction in microglial autophagy, the process by which cells degrade and recycle their own damaged components, may contribute to the development and progression of TBI-related impairments. Here, we unravel the pathways by which microglia autophagic dysregulation predisposes the brain to secondary damage and neurological deficits following TBI. An overview of the role of autophagic dysregulation in perpetuation and worsening of the inflammatory response, neuroinflammation, and neuronal cell death in TBI follows. Further, we have evaluated several signaling pathways and processes that contribute to autophagy dysfunction-mediated inflammation, neurodegeneration, and poor outcome in TBI. Additionally, a discussion on the small molecule therapeutics employed to modulate these pathways and mechanisms to treat TBI have been presented. However, additional research is required to fully understand the processes behind these underlying pathways and uncover potential therapeutic targets for restoring microglial autophagic failure in TBI.

Shc1 cooperates with Frs2 and Shp2 to recruit Grb2 in FGF-induced lens development

Fibroblast growth factor (FGF) signaling elicits multiple downstream pathways, most notably the Ras/MAPK cascade facilitated by the adaptor protein Grb2. However, the mechanism by which Grb2 is recruited to the FGF signaling complex remains unresolved. Here we showed that genetic ablation of FGF signaling prevented lens induction by disrupting transcriptional regulation and actin cytoskeletal arrangements, which could be reproduced by deleting the juxtamembrane region of the FGF receptor and rescued by Kras activation. Conversely, mutations affecting the Frs2-binding site on the FGF receptor or the deletion of Frs2 and Shp2 primarily impact later stages of lens vesicle development involving lens fiber cell differentiation. Our study further revealed that the loss of Grb2 abolished MAPK signaling, resulting in a profound arrest of lens development. However, removing Grb2's putative Shp2 dephosphorylation site (Y209) neither produced a detectable phenotype nor impaired MAPK signaling during lens development. Furthermore, the catalytically inactive Shp2 mutation (C459S) only modestly impaired FGF signaling, whereas replacing Shp2's C-terminal phosphorylation sites (Y542/Y580) previously implicated in Grb2 binding only caused placental defects, perinatal lethality, and reduced lacrimal gland branching without impacting lens development, suggesting that Shp2 only partially mediates Grb2 recruitment. In contrast, we observed that FGF signaling is required for the phosphorylation of the Grb2-binding sites on Shc1 and the deletion of Shc1 exacerbates the lens vesicle defect caused by Frs2 and Shp2 deletion. These findings establish Shc1 as a critical collaborator with Frs2 and Shp2 in targeting Grb2 during FGF signaling.

Design, synthesis, and biological evaluation of Ponatinib-based N-Phenylpyrimidine-2-amine derivatives as novel fibroblast growth factor receptor 4 (FGFR4) selective inhibitors

Fibroblast growth factor receptor 4 (FGFR4) has been proven to be a promising target for FGFR-driven HCC therapy. Great efforts have been devoted to the discovery of FGFR4 inhibitors. In this article, a new class of Ponatinib-based N-phenylpyridine-2-amine derivatives was designed and synthesized as covalent and irreversible FGFR4 selective inhibitors through a rational drug design strategy. The representative compound 10f displayed significant FGFR4 inhibition and reasonable selectivity. Meanwhile, compound 10f strongly suppressed the proliferation of FGFR4 dependent HCC cells both in vitro and in vivo by inhibiting the FGFR4 signaling pathway. Moreover, the irreversible binding to Cys552 in FGFR4 of compound 10f was also characterized by LC-MS/MS. These results provide evidence of 10f as a potential lead compound targeting FGFR4 for anti-HCC agent development.

Molecular mechanisms and pathological implications of unconventional protein secretion in human disease: from cellular stress to therapeutic targeting

Unconventional protein secretion (UcPS) encompasses diverse non-canonical cellular export mechanisms that operate independently of the classical secretory pathway, representing a crucial cellular response to various physiological and pathological conditions. This comprehensive review synthesizes current understanding of UcPS mechanisms, particularly focusing on their roles in disease pathogenesis and progression. Recent advances in proteomics and cellular biology have revealed that UcPS facilitates the secretion of various biomedically significant proteins, including inflammatory mediators, growth factors, and disease-associated proteins, through multiple pathways such as membrane translocation, secretory lysosomes, and membrane-bound organelles. Notably, dysregulation of UcPS mechanisms has been implicated in various pathological conditions, including chronic inflammation, neurodegenerative disorders, and malignant transformation. We critically evaluate the molecular machinery governing UcPS, its regulation under cellular stress, and its contribution to disease mechanisms. Furthermore, we examine emerging therapeutic strategies targeting UcPS pathways, highlighting both opportunities and challenges in developing novel interventional approaches.

Circulating plasma protein identified as a therapeutic target for intracranial aneurysm through Mendelian Randomization analysis

BACKGROUND

Intracranial aneurysms are the main cause of subarachnoid hemorrhage (SAH), a severe stroke with devastating effects. However, there are no existing medications for intracranial aneurysms (IAs) and novel therapeutic targets are required.

METHODS

We performed a summary data-based Mendelian Randomization (MR) analysis to explore the causal association between circulating plasma proteins and the risk of IAs and SAH. Colocalization analysis was conducted to identify shared causal variants between circulating plasma proteins and IAs, as well as SAH. Finally, mediation MR analyses were conducted to clarify the role of potential plasma proteins in aneurysm formation.

RESULTS

Proteome-wide MR analysis showed that FGF5 (fibroblast growth factor 5) had a causal effect on IA and SAH risk (Pfdr < 0.05). Moreover, genetic variants affecting FGF5 expression levels showed strong evidence of colocalization with IA risk (PPH4 = 0.993) and SAH risk (PPH = 0.988), suggesting that this protein represents a potential direct target for IA intervention. Mediation analysis using two-step MR showed that systolic blood pressure and diastolic blood pressure mediate the effects of FGF5 on IA and SAH.

CONCLUSION

Our investigation identified a causal connection between FGF5 and IAs.

Environmental high temperature induced cartilage damage through triggering programmed necrosis mediated by producing left-handed DNA

Amid global climate warming, rising temperatures are becoming a major challenge for public health worldwide. At present, many places in the world frequently encounter extreme high temperature weather, which directly leads to frequent occurrence of heat stroke (HS). Heat stroke may lead to significant organ damage and potentially result in death. However, the impact of heat stroke (HS) on cartilage and osteoarthritis has not been fully revealed, which is an urgent scientific issue to be explored. In the current study, we first established an in vitro chondrocyte model and then explored the toxicological effects of HS on chondrocytes. Experimental data indicate that HS significantly reduces the proliferative activity of chondrocytes. HS triggers oxidative stress and inflammation in chondrocytes. Further biochemical experiments showed that HS caused chondrocytes senescence by detecting a series of senescence marker molecules, such as p21, p16, and p53. We further studied the molecular mechanism of HS-induced cell damage. We found that HS induced genomic damage, generating substantial Z-DNA (left-handed DNA) and activating ZBP-1-mediated programmed cell necrosis, which subsequently released various inflammatory factors. In contrast, inhibition of Z-DNA-mediated activation of ZBP-1 can significantly alleviate aging damage. In in-vivo experiments using a gene-knockout mouse model, our team found that HS induced cartilage aging. Additionally, HS aggravated osteoarthritis in vivo. On this basis, we observed that the expression of FGF1 was reduced under HS conditions. Therefore, we explored the effect of FGF1 on the damage of chondrocytes caused by HS. The experimental data showed that FGF1 activates the AMPK signaling pathway, which effectively alleviating the aging caused by HS. This work lays a solid foundation for further exploration into cartilage damage induced by HS. Our study also simultaneously indicates that FGF1 may be a very promising agent for the treatment of HS causing cartilage damage.

Hepatocyte-Derived FGF1 Alleviates Isoniazid and Rifampicin-Induced Liver Injury by Regulating HNF4α-Mediated Bile Acids Synthesis

Isoniazid and rifampicin co-therapy are the main causes of anti-tuberculosis drug-induced liver injury (ATB-DILI) and acute liver failure, seriously threatening human health. However, its pathophysiology is not fully elucidated. Growing evidences have shown that fibroblast growth factors (FGFs) play a critical role in diverse aspects of liver pathophysiology. The aim of this study is to investigate the role of FGFs in the pathogenesis of isoniazid (INH) and rifampicin (RIF)-induced liver injury. Through systematic screening, this study finds that hepatic FGF1 expression is significantly downregulated in both mouse model and human patients challenged with INH and RIF. Hepatocyte-specific Fgf1 deficiency exacerbates INH and RIF-induced liver injury resulted from elevated bile acids (BAs) synthases and aberrant BAs accumulation. Conversely, pharmacological administration of the non-mitogenic FGF1 analog - FGF1ΔHBS significantly alleviated INH and RIF-induced liver injury via restoring BAs homeostasis. Mechanically, FGF1 repressed hepatocyte nuclear factor 4α (Hnf4α) transcription via activating FGF receptor 4 (FGFR4)-ERK1/2 signaling pathway, thus reducing BAs synthase. The findings demonstrate hepatic FGF1 functions as a negative regulator of BAs biosynthesis to protect against INH and RIF-induced liver injury via normalizing hepatic BAs homeostasis, providing novel mechanistic insights into the pathogenesis of ATB-DILI and potential therapeutic strategies for treatment of ATB-DILI.

FGF-based drug discovery: advances and challenges

The fibroblast growth factor (FGF) family comprises 15 paracrine-acting and 3 endocrine-acting polypeptides, which govern a multitude of processes in human development, metabolism and tissue homeostasis. Therapeutic endocrine FGFs have recently advanced in clinical trials, with FGF19 and FGF21-based therapies on the cusp of approval for the treatment of primary sclerosing cholangitis and metabolic syndrome-associated steatohepatitis, respectively. By contrast, while paracrine FGFs were once thought to be promising drug candidates for wound healing, burns, tissue repair and ischaemic ailments based on their potent mitogenic and angiogenic properties, repeated failures in clinical trials have led to the widespread perception that the development of paracrine FGF-based drugs is not feasible. However, the observation that paracrine FGFs can exert FGF hormone-like metabolic activities has restored interest in these FGFs. The recent structural elucidation of the FGF cell surface signalling machinery and the formulation of a new threshold model for FGF signalling specificity have paved the way for therapeutically harnessing paracrine FGFs for the treatment of a range of metabolic diseases.

Circulating fibroblast growth factor 21 levels in gestational diabetes mellitus and preeclampsia: a systematic review and meta-analysis

BACKGROUND

The connection between fibroblast growth factor 21 (FGF21) and the likelihood of gestational diabetes mellitus (GDM) or preeclampsia (PE) has received more attention recently. Based on published articles, meta-analysis were conducted to explore the differences in FGF21 levels in GDM or PE compared to control groups.

METHODS

Articles published before April 5, 2024 were searched across four databases: PubMed, Web of Science, Embase, and Cochrane Library, and studies exploring the association of FGF21 levels and GDM or PE were collected. Additionally, ClinicalTrials.gov was also searched for completed and ongoing trials. (Prospero Registration CRD42024504738). The standardized mean differences (SMDs) and 95% confidence intervals (CIs) were utilized to determine FGF21 levels among different groups.

RESULTS

This analysis incorporated a total of 16 articles, with 714 GDM and 701 non-GDM in the control group. The GDM-affected pregnant women had greater levels of circulating FGF21 than the control group (SMD = 0.529, 95% CI: 0.168 ~ 0.890, p = 0.004). Moreover, the PE case group covered 120 while the control group contained 134. The findings indicated that pregnant women with PE had significantly greater levels of circulating FGF21 than healthy expectant mothers (SMD = 0.743, 95% CI: 0.527 ~ 0.958, p = 0.000).

CONCLUSIONS

Our study found that FGF21 has the potential to serve as a diagnostic marker for GDM or PE. However, due to the limited number of studies and the fact that most data were from the second and third trimesters of pregnancy, more large-scale prospective studies are needed to validate these conclusions, investigate the potential of FGF21 in enabling early diagnosis, and further examine the role of FGF21 in the development and progression of GDM/PE.

TRIAL REGISTRATION

Not applicable.

Hepatic FXR-FGF4 is required for bile acid homeostasis via an FGFR4-LRH-1 signal node under cholestatic stress

Bile acid (BA) homeostasis is vital for various physiological processes, whereas its disruption underlies cholestasis. The farnesoid X receptor (FXR) is a master regulator of BA homeostasis via the ileal fibroblast growth factor (FGF)15/19 endocrine pathway, responding to postprandial or abnormal transintestinal BA flux. However, the de novo paracrine signal mediator of hepatic FXR, which governs the extent of BA synthesis within the liver in non-postprandial or intrahepatic cholestatic conditions, remains unknown. We identified hepatic Fgf4 as a direct FXR target that paracrinally signals to downregulate Cyp7a1 and Cyp8b1. The effect of FXR-FGF4 is mediated by an uncharted intracellular FGF receptor 4 (FGFR4)-LRH-1 signaling node. This liver-centric pathway acts as a first-line checkpoint for intrahepatic and transhepatic BA flux upstream of the peripheral FXR-FGF15/19 pathway, which together constitutes an integral hepatoenteric control mechanism that fine-tunes BA homeostasis, counteracting cholestasis and hepatobiliary damage. Our findings shed light on potential therapeutic strategies for cholestatic diseases.

Bone Tissue Engineering: From Biomaterials to Clinical Trials

Bone tissue engineering is a promising field that aims to rebuild the bone tissue using biomaterials, cells, and signaling molecules. Materials like natural and synthetic polymers, inorganic materials, and composite materials are used to create scaffolds that mimic the hierarchical microstructure of bone. Stem cells, particularly mesenchymal stem cells (MSCs), play a crucial role in bone tissue engineering by promoting tissue regeneration and modulating the immune response. Growth factors like bone morphogenetic proteins (BMPs), vascular endothelial growth factor (VEGF), and platelet-derived growth factor (PDGF) are utilized to accelerate bone regeneration. Clinical applications include treating nonunion and mal-union fractures, osteonecrosis, orthopedic surgery, dental applications, and spinal cord injuries. Recent advances in the field include nanotechnology, 3D printing, bioprinting techniques, gene editing technologies, and microfluidic devices for drug testing. However, challenges remain, such as standardization of protocols, large-scale biomaterial production, personalized medicine approaches, cost-effectiveness, and regulatory issues. Current clinical trials are investigating the safety and efficacy of various bone tissue engineering approaches, with the potential to modernize patient care by providing more adequate treatments for bone defects and injuries.

[Neonatal Malnutrition Impacts Fibroblast Growth Factor 21-induced Neurite Outgrowth and Growth Hormone-releasing Hormone Secretion in Neonatal Mouse Brain]

Neonatal malnutrition has been suggested as a factor contributing to neurological and other disorders. However, the details of this mechanism remain unclear. We focused on fibroblast growth factor 21 (FGF21), an endocrine factor produced in the liver during lactation-the main source of nutrition during the neonatal period- and analyzed its role in the brain. From the RNA-seq analysis of mouse brains, we analyzed the genes whose expression was regulated by FGF21 and their respective functions. We found that FGF21 has two functions in the neonatal brain; FGF21 induces the production of growth hormone-releasing hormone (GHRH) in the hypothalamus and is involved in isoform determination of Kalirin, a Ras homologous guanine nucleotide exchange factor, and promotes neurite outgrowth in the brain. Furthermore, the above mechanism is regulated by SH2-containing tyrosine phosphatase (SHP2) activity downstream of the FGF receptor. Additionally, the conserved intron of the SHP2 gene, Ptpn11, shows altered activity in malnourished mouse brains. In summary, FGF21 functions in neurite outgrowth and GHRH production in the neonatal mouse brain, with the mechanism being regulated by SHP2. However, SHP2 activity depends on nutritional status. Our goal was to elucidate the mechanisms by which FGF21 is involved in the maintenance of the central nervous system during the neonatal period. This study provides new insights into the role of FGF21 in diseases caused by dysfunction due to malnutrition.

A Promising Paradigm Shift in Cancer Treatment with FGFR Inhibitors

FGFR have been demonstrated to perform a crucial role in biological processes but their overexpression has been perceived as the operator component in the occurrence and progression of different types of carcinoma. Out of all the interest around cancer, FGFR inhibitors have assembled pace over the past few years. Therefore, FGFR inhibitors are one of the main fundamental tools to reverse drug resistance, tumor growth, and angiogenesis. Currently, many FGFR inhibitors are under the development stage or have been developed. Due to great demand and hotspots, different pharmacophores were approached to access structurally diverse FGFR inhibitors. Here, we have selected to present several representative examples such as Naphthyl, Pyrimidine, Pyridazine, Indole, and Quinoline derivatives that illustrate the diversity and advances of FGFR inhibitors in medicinal chemistry. This review focuses on the SAR study of FGFR inhibitors last five years which will be a great future scope that influences the medicinal chemist to work towards more achievements in this area.

Impaired Fibroblast Growth Factor 21 (FGF21) Associated with Visceral Adiposity Leads to Insulin Resistance: The Core Defect in Diabetes Mellitus

The Central nervous system (CNS) is the prime regulator of signaling pathways whose function includes regulation of food intake (consumption), energy expenditure, and other metabolic responses like glycolysis, gluconeogenesis, fatty acid oxidation, and thermogenesis that have been implicated in chronic inflammatory disorders. Type 2 diabetes mellitus (T2DM) and obesity are two metabolic disorders that are linked together and have become an epidemic worldwide, thus raising significant public health concerns. Fibroblast growth factor 21 (FGF21) is an endocrine hormone with pleiotropic metabolic effects that increase insulin sensitivity and energy expenditure by elevating thermogenesis in brown or beige adipocytes, thus reducing body weight and sugar intake. In contrast, during starvation conditions, FGF21 induces its expression in the liver to initiate glucose homeostasis. Insulin resistance is one of the main anomalies caused by impaired FGF21 signaling, which also causes abnormal regulation of other signaling pathways. Tumor necrosis factor alpha (TNF-α), the cytokine released by adipocytes and inflammatory cells in response to chronic inflammation, is regarded major factor that reduces the expression of FGF21 and modulates underlying insulin resistance that causes imbalanced glucose homeostasis. This review aims to shed light on the mechanisms underlying the development of insulin resistance in obese individuals as well as the fundamental flaw in type 2 diabetes, which is malfunctioning obese adipose tissue.

Circulating inflammatory cytokines and the risk of cerebral small vessel disease: a bidirectional Mendelian randomization analysis

BACKGROUND

A correlation between inflammation and cerebral small vessel disease (CSVD) has been hypothesized by earlier observational research, while this correlation has not been well established. Considering the significant clinical value of this causality determination, Mendelian randomization (MR) was implemented to investigate the causality between inflammatory cytokines and CSVD radiological lesions.

METHODS

Using the publicly available Genome-Wide Association Study (GWAS) datasets, a bidirectional two-sample MR analysis was employed to infer causality between 91 inflammatory cytokines and CSVD phenotypes [white matter hyperintensity (WHM), fractional anisotropy (FA), mean diffusivity (MD), cerebral microbleeds (CMBs), and lacunar stroke]. A set of methods was used for sensitivity analysis, including Cochran's Q test, MR-Egger intercept method, and MR pleiotropy residual sum and outlier (MR-PRESSO) global test. Furthermore, the strength of causality was assessed using the Bonferroni correction.

RESULTS

Our research discovered a mutually predictive bidirectional link between CSVD phenotypes and inflammatory cytokines. Following the application of the Bonferroni correction, fibroblast growth factor 21 (FGF-21) was significantly inversely correlated with an increased risk of CMBs (OR = 0.579, 95 % CI = 0.425-0.789, P = 0.00055). Using sensitivity analysis, heterogeneity, and horizontal pleiotropy were not detected.

CONCLUSION

In this investigation, we established the causality between CSVD and inflammatory cytokines, with FGF-21 in particular significantly reducing the risk of CMBs. With further validation, these findings may provide new targets for the prevention, detection, and intervention of CSVD.

Sulfated and Phosphorylated Agarose as Biomaterials for a Biomimetic Paradigm for FGF-2 Release

Cardiovascular diseases such as myocardial infarction or limb ischemia are characterized by regression of blood vessels. Local delivery of growth factors (GFs) involved in angiogenesis such as fibroblast blast growth factor-2 (FGF-2) has been shown to trigger collateral neovasculature and might lead to a therapeutic strategy. In vivo, heparin, a sulfated polysaccharide present in abundance in the extracellular matrix (ECM), has been shown to function as a local reservoir for FGF-2 by binding FGF-2 and other morphogens and it plays a role in the evolution of GF gradients. To access injectable biomaterials that can mimic such natural electrostatic interactions between soluble signals and macromolecules and mechanically tunable environments, the backbone of agarose, a thermogelling marine-algae-derived polysaccharide, was modified with sulfate, phosphate, and carboxylic moieties and the interaction and release of FGF-2 from these functionalized hydrogels was assessed by ELISA in vitro and CAM assay in ovo. Our findings show that FGF-2 remains active after release, and FGF-2 release profiles can be influenced by sulfated and phosphorylated agarose, and in turn, promote varied blood vessel formation kinetics. These modified agaroses offer a simple approach to mimicking electrostatic interactions experienced by GFs in the extracellular environment and provide a platform to probe the role of these interactions in the modulation of growth factor activity and may find utility as an injectable gel for promoting angiogenesis and as bioinks in 3D bioprinting.

The Complexity and Significance of Fibroblast Growth Factor (FGF) Signaling for FGF-Targeted Cancer Therapies

Fibroblast growth factors (FGFs) have diverse functions in the regulation of cell proliferation and differentiation in development, tissue maintenance, wound repair, and angiogenesis. The goal of this review paper is to (i) deliberate on the role of FGFs and FGF receptors (FGFRs) in different cancers, (ii) present advances in FGF-targeted cancer therapies, and (iii) explore cell signaling mechanisms that explain how FGF expression becomes dysregulated during cancer development. FGF is often mutated and overexpressed in cancer and the different FGF and FGFR isoforms have unique expression patterns and distinct roles in different cancers. Among the FGF members, the FGF 15/19 subfamily is particularly interesting because of its unique protein structure and role in endocrine function. The abnormal expression of FGFs in different cancer types (breast, colorectal, hepatobiliary, bronchogenic, and others) is examined and correlated with patient prognosis. The classification of FGF ligands based on their mode of action, whether autocrine, paracrine, endocrine, or intracrine, is illustrated, and an analysis of the binding specificity of FGFs to FGFRs is also provided. Moreover, the latest advances in cancer therapeutic strategies involving small molecules, ligand traps, and monoclonal antibody-based FGF inhibitors are presented. Lastly, we discuss how the dysregulation of FGF and FGFR expression affects FGF signaling and its role in cancer development.

Fibroblast Growth Factor 21 Confers Protection Against Asthma Through Inhibition of NLRP3 Inflammasome Activation

Fibroblast growth factor 21 (FGF21) modulates the inflammatory response in a range of pathological conditions. However, whether FGF21 modulates asthma remains unexplored. This study sought to investigate its function in asthma using an ovalbumin (OVA)-induced mouse model. Levels of FGF21 were observed to be elevated in mice exhibiting asthmatic symptoms. FGF21 knockout (KO) mice exhibited exacerbated asthmatic pathologies, marked by heightened infiltration of inflammatory cells and elevated release of inflammatory cytokine, compared to wild-type (WT) mice with OVA challenge. Adeno-associated virus (AAV)-mediated overexpression of FGF21 significantly reversed asthmatic pathologies in both WT and FGF21 KO mice. Activated NLRP3 inflammasome was observed in WT mice following OVA challenge, and this response was intensified in FGF21 KO mice, manifested by an upregulation of NLRP3, ASC, cleaved Caspase-1, cleaved Gasdermin D (GSDMD), IL-1β, and IL-18. Pharmacological suppression of NLRP3 ameliorated the aggravated asthmatic pathologies observed in FGF21 KO mice after OVA challenge. Overall, the present work underscores the pivotal function of FGF21 in the pathogenesis of asthma and suggests that FGF21 could serve as a potential target for therapeutic interventions.

Novel FGF21 analogues through structure-based optimization for therapeutic development

Fibroblast growth factor 21 (FGF21) plays a pivotal role in regulating metabolic processes and energy homeostasis, making it a promising therapeutic avenue for various obesity-related conditions. However, its therapeutic efficacy faces challenges due to its suboptimal pharmacokinetics and bioactivity. To overcome these limitations, we adapt a strategy in which key amino acid residues responsible for enhanced activity are pinpointed through sequence alignment and comparative analysis to develop long-acting FGF21 analogs. The mutant FGF21 analogs are fused with the Fc fragment. Here, we report the design, identification, and characterization of two distinct Fc-fused FGF21 analogs, Fc-FGF21(P119R) and Fc-FGF21(H125R), with significantly augmented potency. These findings hold promise for clinical applications, offering potential interventions for obesity-related metabolic disorders.

Mesenchymal Stem Cell Extract Promotes Skin Wound Healing

Recently, it has been reported that mesenchymal stem cell (MSC)-derived humoral factors promote skin wound healing. As these humoral factors are transiently stored in cytoplasm, we collected them as part of the cell extracts from MSCs (MSC-ext). This study aimed to investigate the effects of MSC-ext on skin wound healing. We examined the effects of MSC-ext on cell proliferation and migration. Additionally, the effect of MSC-ext on skin wound healing was evaluated using a mouse skin defect model. The MSC-ext enhanced the proliferation of dermal fibroblasts, epithelial cells, and endothelial cells. It also increased the number of migrating fibroblasts and epithelial cells. The skin defects treated with MSC-ext demonstrated rapid wound closure compared to those treated with phosphate-buffered saline. The MSC-ext group exhibited a thicker dermis, larger Picrosirius red-positive areas, and a higher number of Ki67-positive cells. Our results indicate that MSC-ext promotes the proliferation and/or migration of fibroblasts, epithelial cells, and endothelial cells, and enhances skin wound healing. This suggests the therapeutic potential of MSC-ext in treating skin defects as a novel cell-free treatment modality.

FGF20 Secreted From Dermal Papilla Cells Regulate the Proliferation and Differentiation of Hair Follicle Stem Cells in Fine-Wool Sheep

Wool traits determine the market value of fine-wool sheep, and wool fibre-breaking elongation (fibres can be stretched or elongated before they break) is one of the important wool traits. The interaction between hair follicle stem cells (HFSCs) and dermal papilla cells (DPCs) determines hair follicle development in fine wool sheep, thereby directly influencing wool traits. A genome-wide association study based on pre-sequencing data identified FGF20, which was significantly associated with wool fibre-breaking elongation. The study reveals that the regulatory mechanism of FGF20 secreted from DPCs affects the proliferation and differentiation of HFSCs through a co-culture system, to provide a new perspective for fine-wool sheep breeding. After knocking down FGF20 expression in DPCs, the results showed that the expression of fibroblast growth factor receptor 2 (FGFR2) and fibroblast growth factor receptor 3 (FGFR3) in DPCs and HFSCs was significantly decreased (p < 0.05), the number of EdU-positive cells and cell viability was significantly decreased (p < 0.01), and the apoptosis rate was significantly increased (p < 0.05). Meanwhile, the differentiation markers of SOX9, NOTCH1 and β-Catenin in HFSCs were also significantly reduced (p < 0.05). These findings indicate that FGF20-knockdown in DPCs of fine-wool sheep inhibits the proliferation and differentiation of HFSCs in the co-culture system, providing a theoretical basis for elucidating the regulatory mechanism of hair follicle self-renewal and differentiation of fine-wool sheep and providing a co-culture system for regenerative medicine.

Decoding FGF/FGFR Signaling: Insights into Biological Functions and Disease Relevance

Fibroblast Growth Factors (FGFs) and their cognate receptors, FGFRs, play pivotal roles in a plethora of biological processes, including cell proliferation, differentiation, tissue repair, and metabolic homeostasis. This review provides a comprehensive overview of FGF-FGFR signaling pathways while highlighting their complex regulatory mechanisms and interconnections with other signaling networks. Further, we briefly discuss the FGFs involvement in developmental, metabolic, and housekeeping functions. By complementing current knowledge and emerging research, this review aims to enhance the understanding of FGF-FGFR-mediated signaling and its implications for health and disease, which will be crucial for therapeutic development against FGF-related pathological conditions.

The role of FGF15/FGF19 in the development of the central nervous system, eyes and inner ears in vertebrates

Fibroblast growth factor 19 (FGF19), and its rodent ortholog FGF15, is a member of a FGF subfamily directly involved in metabolism, acting in an endocrine way. During embryonic development, FGF15/FGF19 also functions as a paracrine or autocrine factor, regulating key events in a large number of organs. In this sense, the Fgf15/Fgf19 genes control the correct development of the brain, eye, inner ear, heart, pharyngeal pouches, tail bud and limbs, among other organs, as well as muscle growth in adulthood. These growth factors show relevant differences according to molecular structures, signalling pathway and function. Moreover, their expression patterns are highly dynamic at different stages of development, in particular in the central nervous system. The difficulty in understanding the action of these genes increases when comparing their expression patterns and regulatory mechanisms between different groups of vertebrates. The present review will address the expression patterns and functions of the Fgf15/Fgf19 genes at different stages of vertebrate embryonic development, with special attention to the regulation of the early specification, cell differentiation, and morphogenesis of the central nervous system and some sensory organs such as eye and inner ear. The most relevant anatomical aspects related to the structures analysed have also been considered in detail to provide an understandable context for the molecular and cellular studies shown.

Analysis of cell signaling profiles induced by DNA aptamer-based FGFR1 agonist

DNA aptamers have attracted attention as an alternative modality for biomolecules due to their excellent target binding specificity and thermal stability, and they are also expected to be applied as artificial agonists for receptor proteins. DNA aptamer agonist TD0 targeting the receptor of fibroblast growth factor (FGFR), which plays an important role in the fields of wound healing and regenerative medicine, has been reported to induce cellular responses as well as its native ligands. However, it was also noted that there were some different responses upon long-term stimulation, suggesting that the intracellular signals induced by DNA aptamer agonist TD0 are different from those of natural ligands. In this paper, we comprehensively analyzed the intracellular signals induced by DNA aptamer agonist TD0 targeting FGFR1, and compared them with those by natural protein ligand FGF2. It was found that the intracellular signals were highly similar for short-term stimulation. On the other hand, the receptor and the downstream cellular signals showed different activation behaviors for long-time stimulation. Evaluating the stability and sustained activity of DNA aptamer agonist TD0 and FGF2 in the medium suggested that ligand stability may be important in properly regulating cellular responses.

STK33 as the functional substrate of miR-454-3p for suppression and apoptosis in neuroblastoma

miR-454-3p has been reported to be a tumor-suppressive microRNA (miRNA) in multiple cancer types. We identified the kinase STK33 mRNA, which is a high-risk factor for survival in neuroblastoma (NB) patients, as being a substrate of miR-454-3p in NB. Even though STK33 is an attractive target for several cancers, the development of inhibitors of STK33 has been challenging. For the various cell lines tested, we demonstrated reduced growth and viability with the miR-454-3p mimic. From among the candidate NB-associated miRNAs, miR-454-3p mimic and its antagonist had the most profound effect on STK33 mRNA and protein-level changes. Under various conditions of growth and external stress for the cells, the RNA levels for miR-454-3p and STK33 also negatively correlated. Luciferase reporter assays demonstrated STK33 as a substrate for miR-454-3p, and recombinant versions of STK33 resistant to miR-454-3p significantly blunted the suppressive effect of the miR-454-3p and established STK33 as the major functional substrate of miR-454-3p. Overexpression of miR-454-3p or knockdown of STK33 mRNA promoted autophagy and at the same time, increased the apoptotic markers in the tested NB cells, indicating a mechanism for the suppressive effect of the agents. Given the difficult-to-drug targets such as STK33 and the recent successes in RNA delivery methods for cancer treatment, it is thought that targeting cancer cells with a suppressive miRNA such as miR-454-3p for STK33-dependent cancer types may be an alternative means of NB therapy.

Clinical advances and challenges in targeting FGF/FGFR signaling in lung cancer

Fibroblast growth factors (FGFs) and their receptors regulate numerous cellular processes, such as metabolism and signal transduction, but can also drive tumorigenesis. Specifically, in lung cancer, the overexpression of FGFs, as well as the amplification, mutation and fusion of FGFR genes, are closely linked to the initiation, progression and resistance of the disease, suggesting that targeting FGF/FGFR is an attractive therapeutic strategy for lung cancer treatment. Nintedanib, a multitarget tyrosine kinase inhibitor (TKI) used in combination with docetaxel, has shown some success as a second-line therapy for lung cancer. However, clinical trials evaluating other FGFR inhibitors have yielded mixed results, indicating substantial complexity in targeting aberrant FGF/FGFR signaling. In this review, we describe the aberrations in FGF/FGFR signaling in lung cancer and summarize the clinical efficacy of FGFR inhibitors, such as multitarget TKIs, selective FGFR-TKIs and biological agents. We also discuss various challenges associated with FGFR targeting in lung cancer, including precision patient selection, toxicity and resistance. Finally, we provide perspectives on future directions, namely, developing novel FGFR-targeting drugs, such as FGFR degraders and more specific FGFR-TKIs, adopting combination therapy and targeting FGFs.

Cancer-Associated Fibroblast-Derived FGF7 Promotes Clear Cell Renal Cell Carcinoma Progression and Macrophage Infiltration

As the predominant stromal cells in the ccRCC surrounding environment, cancer-associated fibroblasts (CAFs) have been established as supportive of tumor growth. However, the detailed molecular mechanisms underlying the supporting role of CAFs in ccRCC have not been well characterized. Evidence from the clustering consensus analysis, single-cell analysis, and the experimental results illustrate that CAF-derived FGF7 plays a crucial role as a signaling mediator between CAFs and ccRCC tumor cells. Mechanistically, CAF-derived FGF7 triggers AKT activation to promote cell growth and cell invasion of ccRCC tumor cells. As a response, ccRCC tumor cells stimulate STAT3-mediated transcriptional regulation, directly increasing FGF7 expression at the chromatin level in CAFs. Moreover, there exists a positive clinical correlation between the abundance of CAFs, FGF7 expression, and the infiltration of M2 type macrophages. The RENCA in vivo mouse model also confirmed that FGF7 depletion could impede RCC development by reducing the recruitment of M2 type macrophages. Overall, this study delineates a key signaling axis governing the crosstalk between CAFs and ccRCC tumor cells, highlighting FGF7 as a promising therapeutic target of ccRCC.

The FGF/FGFR/c-Myc axis as a promising therapeutic target in multiple myeloma

Among blood cancers, multiple myeloma (MM) represents the second most common neoplasm and is characterized by the accumulation and proliferation of monoclonal plasma cells within the bone marrow. Despite the last few decades being characterized by the development of different therapeutic strategies against MM, at present such disease is still considered incurable. Although MM is highly heterogeneous in terms of genetic and molecular subtypes, about 67% of MM cases are associated with abnormal activity of the transcription factor c-Myc, which has so far revealed a protein extremely difficult to target. We have recently demonstrated that activation of fibroblast growth factor (FGF) signaling protects MM cells from oxidative stress-induced apoptosis by stabilizing the oncoprotein c-Myc. Accordingly, secretion of FGF ligands and autocrine activation of FGF receptors (FGFR) is observed in MM cells and FGFR3 genomic alterations represent some 15-20% MM cases and are associated with poor outcome. Thus, FGF/FGFR blockade may represent a promising strategy to indirectly target c-Myc in MM. On this basis, the present review aims at providing an overview of recently explored connections between the FGF/FGFR system and c-Myc oncoprotein, sustaining the therapeutic potential of targeting the FGF/FGFR/c-Myc axis in MM by using inhibitors targeting FGF ligands or FGF receptors. Importantly, the provided findings may represent the rationale for using FDA approved FGFR TK inhibitors (i.e. Pemigatinib, Futibatinib, Erdafitinib) for the treatment of MM patients presenting with an aberrant activation of this axis.

Fibroblast Growth Factors in Cardiovascular Disease

Despite advancements in managing traditional cardiovascular risk factors, many cardiovascular diseases (CVDs) persist. Fibroblast growth factors (FGFs) have emerged as potential diagnostic markers and therapeutic targets for CVDs. FGF1, FGF2, and FGF4 are primarily used for therapeutic angiogenesis. Clinical applications are being explored based on animal studies using approaches such as recombinant protein administration and adenovirus-mediated gene delivery, targeting patients with coronary artery disease and lower extremity arterial disease. Although promising results have been observed in animal models and early-stage clinical trials, further studies are required to assess their therapeutic potential. The FGF19 subfamily, consisting of FGF19, FGF21, and FGF23, act via endocrine signaling in various organs. FGF19, primarily expressed in the small intestine, plays important roles in glucose, lipid, and bile acid metabolism and has therapeutic potential for metabolic disorders. FGF21, found in various tissues, improves glucose metabolism and insulin sensitivity, suggesting potential for treating obesity and diabetes. FGF23, primarily secreted by osteocytes, regulates vitamin D and phosphate metabolism and serves as an important biomarker for chronic kidney disease and CVDs. Thus, FGFs holds promise for both therapeutic and diagnostic applications in metabolic and cardiovascular diseases. Understanding the mechanisms of FGF may pave the way for novel strategies to prevent and manage CVDs, potentially addressing the limitations of current treatments. This review explores the roles of FGF1, FGF2, FGF4, and the FGF19 subfamily in maintaining cardiovascular health. Further research and clinical trials are crucial to fully understand the therapeutic potential of FGFs in managing cardiovascular health.