Progress in Research on the Role of FGF in the Formation and Treatment of Corneal Neovascularization

Inhibiting PRMT1 protects against CoNV by regulating macrophages through the FGF2/PI3K/Akt pathway

Corneal neovascularization (CoNV) is predominantly initiated by inflammatory processes, resulting in aberrant vascular proliferation and consequent visual impairment. Existing therapeutic interventions for CoNV demonstrate limited efficacy and potential for adverse reactions. Protein arginine methyltransferase 1 (PRMT1) is associated with the regulation of inflammation and M2 macrophage polarization. Nevertheless, the precise mechanism by which PRMT1 operates in CoNV remains uncertain. This study explored the impact of PRMT1 inhibition in a murine model of CoNV induced by alkali burn. Our findings indicated a direct relationship between PRMT1 levels and corneal damage. Moreover, our observations indicated an increase in fibroblast growth factor 2 (FGF2) expression in CoNV, which was reduced after treatment with a PRMT1 inhibitor. The inhibition of PRMT1 alleviated both corneal injury and CoNV, as evidenced by decreased corneal opacity and neovascularization. Immunofluorescence analysis and evaluation of inflammatory factor expression demonstrated that PRMT1 inhibition attenuated M2 macrophage polarization, a phenomenon that was reversed by the administration of recombinant FGF2 protein. These results were confirmed through experimentation on Human Umbilical Vein Endothelial Cells (HUVECs) and Mouse leukemia cells of monocyte macrophage cells (RAW264.7). Furthermore, it was established that FGF2 played a role in PI3K/Akt signal transduction, a critical regulatory pathway for M2 macrophage polarization. Importantly, the activity of this pathway was found to be suppressed by PRMT1 inhibitors. Mechanistically, PRMT1 was shown to promote M2 macrophage polarization, thereby contributing to CoNV, through the FGF2/PI3K/Akt pathway. Therefore, targeting PRMT1 may offer a promising therapeutic approach.

Dynamics of Endothelial Cell Diversity and Plasticity in Health and Disease

Endothelial cells (ECs) are vital structural units of the cardiovascular system possessing two principal distinctive properties: heterogeneity and plasticity. Endothelial heterogeneity is defined by differences in tissue-specific endothelial phenotypes and their high predisposition to modification along the length of the vascular bed. This aspect of heterogeneity is closely associated with plasticity, the ability of ECs to adapt to environmental cues through the mobilization of genetic, molecular, and structural alterations. The specific endothelial cytoarchitectonics facilitate a quick structural cell reorganization and, furthermore, easy adaptation to the extrinsic and intrinsic environmental stimuli, known as the epigenetic landscape. ECs, as universally distributed and ubiquitous cells of the human body, play a role that extends far beyond their structural function in the cardiovascular system. They play a crucial role in terms of barrier function, cell-to-cell communication, and a myriad of physiological and pathologic processes. These include development, ontogenesis, disease initiation, and progression, as well as growth, regeneration, and repair. Despite substantial progress in the understanding of endothelial cell biology, the role of ECs in healthy conditions and pathologies remains a fascinating area of exploration. This review aims to summarize knowledge and concepts in endothelial biology. It focuses on the development and functional characteristics of endothelial cells in health and pathological conditions, with a particular emphasis on endothelial phenotypic and functional heterogeneity.

Acidic fibroblast growth factor inhibits reactive oxygen species-induced epithelial-mesenchymal transdifferentiation in vascular endothelial cells via the miR-155-5p/SIRT1/Nrf2/HO-1 pathway to promote wound healing in diabetic mice

Background

Diabetic chronic wounds are among the most common and serious complications of diabetes and are associated with significant morbidity and mortality. Endothelial-to-mesenchymal transition (EndMT) is a specific pathological state in which endothelial cells are transformed into mesenchymal cells in response to various stimuli, such as high glucose levels and high oxidative stress. Acidic fibroblast growth factor (aFGF), which is a member of the fibroblast growth factor family, possesses strong antioxidant properties and can promote the differentiation of mesenchymal stem cells into angiogenic cells. Therefore, we investigated the role of aFGF in EndMT in diabetic wounds and analysed the underlying mechanisms.

Methods

A diabetic mouse model was used to verify the effect of aFGF on wound healing, and the effect of aFGF on vascular endothelial cells in a high-glucose environment was examined in vitro. We examined the expression of miR-155-5p in a high-glucose environment and the miR-155 downstream target gene SIRT1 by luciferase reporter assays.

Results

aFGF promoted wound closure and neovascularization in a mouse model of type 2 diabetes. In vitro, aFGF inhibited the production of total and mitochondrial reactive oxygen species (ROS) in vascular endothelial cells and alleviated epithelial-mesenchymal transdifferentiation in a high-glucose environment. Mechanistically, aFGF promoted the expression of SIRT1 and the downstream targets Nrf2 and HO-1 by negatively regulating miR-155-5p, thereby reducing ROS generation.

Conclusions

In conclusion, our results suggest that aFGF inhibits ROS-induced epithelial-mesenchymal transdifferentiation in diabetic vascular endothelial cells via the miR-155-5p/SIRT1/Nrf2/HO-1 axis, thereby promoting wound healing.

A Synergistic Therapy With Antioxidant and Anti-VEGF: Toward its Safe and Effective Elimination for Corneal Neovascularization

Corneal neovascularization (CNV) is one of the leading causes of blindness in the world. In clinical practice; however, it remains a challenge to achieve a noninvasive and safe treatment. Herein, a biocompatible shell with excellent antioxidant and antivascularity is prepared by co-assembly of epigallocatechin gallate/gallic acid and Cu (II). After loading glucose oxidase (GOx) inside, the shell is modified with dimeric DPA-Zn for codelivering vascular endothelial growth factor (VEGF) small interfering RNA (VEGF-siRNA). Meanwhile, the Arg-Gly-Asp peptide (RGD) peptide-engineered cell membranes coating improves angiogenesis-targeting and is biocompatible for the multifunctional nanomedicine (CEGs/RGD). After eye drops administration, CEGs/RGD targets enrichment in neovascularization and CEGs NPs enter cells. Then, the inner GOx consumes glucose with a decrease in local pH, which in turn leads to the release of EGCE and VEGF-siRNA. As a result, the nanomedicines significantly reduce angiogenesis and inhibit CNV formation through synergistic effect of antioxidant and antivascular via down-regulation of cluster of differentiation 31 and VEGF. The nanomedicine represents a safe and efficient CNV treatment through the combined effect of antioxidant/gene, which provides important theoretical and clinical significance.

An active transport dual adaptive nanocarrier designed to overcome the corneal microenvironment for neovascularization therapy

The eyes have a complicated microenvironment with many clearance mechanisms, making it challenging for effective drug delivery to the targeted areas of the eyes. Substrate transport mediated by active transporters is an important way to change drug metabolism in the ocular microenvironment. We designed multifunctional, dual-adaptive nanomicelles (GSCQ@NTB) which could overcome multiple physiological barriers by acting on both the efflux transporter and influx transporter to achieve deep delivery of the P-gp substrate in the cornea. Specifically, an effective "triple" antiangiogenic agent, nintedanib (NTB), was loaded into the biocompatible micelles. The expression of the efflux transporter was reversed by grafting quercetin. The peptide (glycylsarcosine, GS) was modified to target the influx transporter "Peptide Transporter-1" (PepT-1). Quercetin (QRT) and nintedanib (NTB) were transported to the cornea cooperatively, achieving long retention on the ocular surface and high compatibility. In a New Zealand rabbit model, within 8 hours after local administration, GSCQ@NTB was enriched in corneal stromal neovascularization and effectively inhibited the progress of neovascularization. Its effectiveness is slightly better than that in the first-line clinical application of steroids. In this study, we introduce the preparation of a dual adaptive nano-micelle system, which may provide an effective non-invasive treatment for corneal neovascularization.

Tilapia Fish Skin Treatment of Third-Degree Skin Burns in Murine Model

This study explored the feasibility of using fish skin bandages as a therapeutic option for third-degree skin burns. Following the California wildfires, clinical observations of animals with third-degree skin burns demonstrated increased comfort levels and reduced pain when treated with tilapia fish skin. Despite the promises of this therapy, there are few studies explaining the healing mechanisms behind the application of tilapia fish skin. In this study, mice with third-degree burns were treated with either a hydrocolloid adhesive bandage (control) (n = 16) or fish skin (n = 16) 7 days post-burn. Mice were subjected to histologic, hematologic, molecular, and gross evaluation at days 7, 16, and 28 post-burn. The fish skin offered no benefit to overall wound closure compared to hydrocolloids. Additionally, we detected no difference between fish skin and control treatments in regard to hypermetabolism or hematologic values. However, the fish skin groups exhibited 2 times more vascularization and 2 times higher expression of antimicrobial defensin peptide in comparison to controls. Proteomic analysis of the fish skin revealed the presence of antimicrobial peptides. Collectively, these data suggest that fish skin can serve as an innovative and cost-effective therapeutic alternative for burn victims to facilitate vascularization and reduce bacterial infection.

Effects of the Foam Massage Roller on VEGF-A and FGF-2 Blood Levels in Young Men

BACKGROUND/AIM

Angiogenesis induced in muscles or massaged tissue is thought to support their regeneration and performance. Therefore, different methods that could promote angiogenesis are investigated. The aim of this study was to examine whether the use of the foam roller massager for lower limb muscles affects VEGF-A and FGF-2 levels in young men.

MATERIALS AND METHODS

The study group included 60 healthy young men attending Military University of Land Forces, Wroclaw, Poland. The participants were randomly divided into two groups. The experimental group included 40 individuals who performed self-massage of the lower limbs using a foam roller. The control group comprised 20 individuals who did not perform massage. Massage was applied to lower limb muscles four times a week for seven weeks. Blood was collected before the experiment and after weeks 1, 3, 5, and 7. ELISA was used to determine changes in VEGF-A and FGF-2 levels in blood serum.

RESULTS

The results of the study demonstrated a significant increase in VEGF-A serum levels in the group of individuals who underwent massage each week compared to VEGF-A concentrations before the experiment. The increase in VEGF-A levels in the experimental group was observed throughout the experiment compared to the control group. No significant changes in serum FGF-2 levels were found.

CONCLUSION

The use of a foam massage roller increased VEGF-A serum levels, which may indicate stimulation of angiogenesis.

Preparation of a Sunitinib loaded microemulsion for ocular delivery and evaluation for the treatment of corneal neovascularization in vitro and in vivo

Background: Corneal neovascularization (CNV) is a pathological condition that can disrupt corneal transparency, thus harming visual acuity. However, there is no effective drug to treat CNV. Sunitinib (STB), a small-molecule multiple receptor tyrosine kinase inhibitor, was shown to have an effect on CNV. The purpose of this study was to develop an STB microemulsion (STB-ME) eye drop to inhibit CNV by topical application. Methods: We successfully prepared an STB-ME by the phase inversion emulsification method, and the physicochemical properties of STB-MEs were investigated. The short-term storage stability, cytotoxicity to human corneal epithelial cells, drug release, ocular irritation, ocular pharmacokinetics and the inhibitory effect on CNV were evaluated in vitro and in vivo. Results: The optimal formulation of STB-ME is composed of oleic acid, CRH 40, Transcutol P, water and sodium hyaluronate (SH). It is a uniform spherical particle with a mean droplet size of 18.74 ± 0.09 nm and a polydispersity index of 0.196 ± 0.004. In the in vitro drug release results, STB-ME showed sustained release and was best fitted by a Korsmeyer-Peppas model (R ² = 0.9960). The results of the ocular pharmacokinetics in rabbits showed that the formulation containing SH increased the bioavailability in the cornea (2.47-fold) and conjunctiva (2.14-fold). STB-ME (0.05% and 0.1%), administered topically, suppressed alkali burn-induced CNV in mice more effectively than saline, and high-dose (0.1%) STB-ME had similar efficacy to dexamethasone (0.025%). Conclusion: This study provides a promising formulation of STB-ME for the inhibition of CNV by topical administration, which has the excellent characteristics of effectiveness, sustained release and high ocular bioavailability.

The Role of TGF-β Signaling in Saphenous Vein Graft Failure after Peripheral Arterial Disease Bypass Surgery

Saphenous vein bypass grafting is an effective technique used to treat peripheral arterial disease (PAD). However, restenosis is the major clinical challenge for the graft vessel among people with PAD postoperation. We hypothesize that there is a common culprit behind arterial occlusion and graft restenosis. To investigate this hypothesis, we found TGF-β, a gene specifically upregulated in PAD arteries, by bioinformatics analysis. TGF-β has a wide range of biological activities and plays an important role in vascular remodeling. We discuss the molecular pathway of TGF-β and elucidate its mechanism in vascular remodeling and intimal hyperplasia, including EMT, extracellular matrix deposition, and fibrosis, which are the important pathways contributing to stenosis. Additionally, we present a case report of a patient with graft restenosis linked to the TGF-β pathway. Finally, we discuss the potential applications of targeting the TGF-β pathway in the clinic to improve the long-term patency of vein grafts.

Angiogenic signaling pathways and anti-angiogenic therapy for cancer

Angiogenesis, the formation of new blood vessels, is a complex and dynamic process regulated by various pro- and anti-angiogenic molecules, which plays a crucial role in tumor growth, invasion, and metastasis. With the advances in molecular and cellular biology, various biomolecules such as growth factors, chemokines, and adhesion factors involved in tumor angiogenesis has gradually been elucidated. Targeted therapeutic research based on these molecules has driven anti-angiogenic treatment to become a promising strategy in anti-tumor therapy. The most widely used anti-angiogenic agents include monoclonal antibodies and tyrosine kinase inhibitors (TKIs) targeting vascular endothelial growth factor (VEGF) pathway. However, the clinical benefit of this modality has still been limited due to several defects such as adverse events, acquired drug resistance, tumor recurrence, and lack of validated biomarkers, which impel further research on mechanisms of tumor angiogenesis, the development of multiple drugs and the combination therapy to figure out how to improve the therapeutic efficacy. Here, we broadly summarize various signaling pathways in tumor angiogenesis and discuss the development and current challenges of anti-angiogenic therapy. We also propose several new promising approaches to improve anti-angiogenic efficacy and provide a perspective for the development and research of anti-angiogenic therapy.

Long-term cultures of human pancreatic islets in self-assembling peptides hydrogels

Human pancreatic islets transplantation is an experimental therapeutic treatment for Type I Diabetes. Limited islets lifespan in culture remains the main drawback, due to the absence of native extracellular matrix as mechanical support after their enzymatic and mechanical isolation procedure. Extending the limited islets lifespan by creating a long-term in vitro culture remains a challenge. In this study, three biomimetic self-assembling peptides were proposed as potential candidates to recreate in vitro a pancreatic extracellular matrix, with the aim to mechanically and biologically support human pancreatic islets, by creating a three-dimensional culture system. The embedded human islets were analyzed for morphology and functionality in long-term cultures (14-and 28-days), by evaluating β-cells content, endocrine component, and extracellular matrix constituents. The three-dimensional support provided by HYDROSAP scaffold, and cultured into MIAMI medium, displayed a preserved islets functionality, a maintained rounded islets morphology and an invariable islets diameter up to 4 weeks, with results analogues to freshly-isolated islets. In vivo efficacy studies of the in vitro 3D cell culture system are ongoing; however, preliminary data suggest that human pancreatic islets pre-cultured for 2 weeks in HYDROSAP hydrogels and transplanted under subrenal capsule may restore normoglycemia in diabetic mice. Therefore, engineered self-assembling peptide scaffolds may provide a useful platform for long-term maintenance and preservation of functional human pancreatic islets in vitro.

Combined delivery of small molecule and protein drugs as synergistic therapeutics for treating corneal neovascularization by a one-pot coassembly strategy

Combined drug administration is a potential strategy to increase efficacy through therapeutic synergy. Small molecule drugs and protein drugs are the two most popular kinds of drugs in medicine. However, efficiently encapsulating these two drugs still have key challenges due to their distinct properties (molecular weight, hydrophilicity, chemical groups, etc.), weak ability to penetrate through various biobarriers (cell membrane, endosome escape, tissue barriers dependent on the method of administration, etc.) and the easy deactivation of protein drugs during the construction of carrier and delivery process. Here, we utilize the hexahistidine-metal assembly (HmA), which can encapsulate a wide spectrum of drugs with high loading efficiency, to coencapsulate Dexp (a small molecule drug) and BVZ (protein drug) by a one-pot coassembly strategy. Our data demonstrated that Dexp and BVZ were coloaded into Dexp&BVZ@HmA with high efficiency, while the bioactivity of BVZ was well-maintained. Most importantly, when evaluating the therapeutic outcomes of drugs@HmA in a corneal neovascularization (CNV) model in vitro and in vivo, the combination group presented overwhelming efficacy compared to the monotherapy group. This strategy offers a platform to codeliver protein and small drugs and has the potential for treating anterior segment diseases as well as other diseases that need combination therapy.

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.

Neutrophil Membrane-Coated Therapeutic Liposomes for Targeted Treatment in Acute Lung Injury

Acute lung injury (ALI) is one of the most common comorbidities associated with sepsis and can lead to acute respiratory distress syndrome. Intense inflammatory response due to excessive activation and uncontrolled infiltration of neutrophils are the central processes in the development of sepsis-induced ALI. In this study, a biomimetic nanoplatform that is a neutrophil membrane-coated liposome-loaded acidic fibroblast growth factor (aFGF@NMLs), which can selectively target the inflamed lung and effectively alleviate sepsis-induced ALI via inflammation suppression, was constructed. In vitro findings revealed that aFGF@NMLs has pro-inflammatory cytokine binding capabilities and can promote cellular uptake, substantially attenuate inflammatory responses, and enhance cellular antioxidant capacity. The in vivo results show that aFGF@NMLs can specifically accumulate in injured lungs in ALI mice after intravenous injection, thereby reducing the secretion of pro-inflammatory cytokines, inhibiting pulmonary cell apoptosis, and promoting lung function recovery. In conclusion, aFGF@NMLs demonstrated anti-inflammatory effects, mitigated the progression of ALI, and contributed to the disease prognosis. This research offers an innovative strategy and concept for the clinical treatment of diseases related to pulmonary inflammation.

New Insights on the Regulatory Gene Network Disturbed in Central Areolar Choroidal Dystrophy-Beyond Classical Gene Candidates

Central areolar choroidal dystrophy (CACD) is a rare hereditary disease that mainly affects the macula, resulting in progressive and usually profound visual loss. Being part of congenital retinal dystrophies, it may have an autosomal dominant or recessive inheritance and, until now, has no effective treatment. Given the shortage of genotypic information about the disease, this work systematically reviews the literature for CACD-causing genes. Three independent researchers selected 33 articles after carefully searching and filtering the Scielo, Pubmed, Lilacs, Web of Science, Scopus, and Embase databases. Mutations of six genes (PRPH2, GUCA1A, GUCY2D, CDHR1, ABCA4, and TTLL5) are implicated in the monogenic dominant inheritance of CACD. They are functionally related to photoreceptors (either in the phototransduction process, as in the case of GUCY2D, or the recovery of retinal photodegradation in photoreceptors for GUCA1A, or the formation and maintenance of specific structures within photoreceptors for PRPH2). The identified genetic variants do not explain all observed clinical features, calling for further whole-genome and functional studies for this disease. A network analysis with the CACD-related genes identified in the systematic review resulted in the identification of another 20 genes that may influence CACD onset and symptoms. Furthermore, an enrichment analysis allowed the identification of 13 transcription factors and 4 long noncoding RNAs interacting with the products of the previously mentioned genes. If mutated or dysregulated, they may be directly involved in CACD development and related disorders. More than half of the genes identified by bioinformatic tools do not appear in commercial gene panels, calling for more studies about their role in the maintenance of the retina and phototransduction process, as well as for a timely update of these gene panels.

Porcine Corneas Incubated at Low Humidity Present Characteristic Features Found in Dry Eye Disease

Dry eye is a multifactorial disease that affects the ocular surface and tear fluid. Current treatment options include lubricant eye drop application several times a day. However, these eye drops often cause local side effects like ocular allergies or blurred vision after the application. To test new treatment options, a robust dry eye model is needed. Here, a porcine ex vivo model was established by means of incubation of porcine corneas in low humidity (LH) and characterized by histological damage evaluation, epithelial thickness and by relevant dry eye markers, such as interleukin 1 beta (IL-1β), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), occludin and galectin-3. In the dry eye model proposed, an increased secretion of IL-1β was observed, as well as an upregulation of NF-κB, occludin and galectin-3 mRNA expression. Moreover, the model presented a higher rate of cell death in comparison to the controls. These effects could be reversed with successful treatment of dexamethasone (dexa) and partially reversed with hyaluronic acid (HA) containing eye drops. Furthermore, medium-molecular-weight HA stimulated an increase in IL-1β in the model proposed. In conclusion, this dry eye model mimics the in vivo condition and hence allows for animal-free testing of novel dry eye treatments.

Roles of the fibroblast growth factor signal transduction system in tissue injury repair

Following injury, tissue autonomously initiates a complex repair process, resulting in either partial recovery or regeneration of tissue architecture and function in most organisms. Both the repair and regeneration processes are highly coordinated by a hierarchy of interplay among signal transduction pathways initiated by different growth factors, cytokines and other signaling molecules under normal conditions. However, under chronic traumatic or pathological conditions, the reparative or regenerative process of most tissues in different organs can lose control to different extents, leading to random, incomplete or even flawed cell and tissue reconstitution and thus often partial restoration of the original structure and function, accompanied by the development of fibrosis, scarring or even pathogenesis that could cause organ failure and death of the organism. Ample evidence suggests that the various combinatorial fibroblast growth factor (FGF) and receptor signal transduction systems play prominent roles in injury repair and the remodeling of adult tissues in addition to embryonic development and regulation of metabolic homeostasis. In this review, we attempt to provide a brief update on our current understanding of the roles, the underlying mechanisms and clinical application of FGFs in tissue injury repair.

Methacrylated gelatin shape-memorable cryogel subcutaneously delivers EPCs and aFGF for improved pressure ulcer repair in diabetic rat model

Pressure ulcer (PU) in patients with diabetes mellitus (DM) is still a clinical intractable issue due to the complicated physiological characteristics by the prolonged high glucose level and impaired angiogenesis. The PU treatment includes surgical debridement, stem cell therapy and growth factors, leading to high cost and repeated professional involvement. Developing effective wound dressing combining the therapeutic cells and growth factors has become highly demanded. Herein, we reported the direct subcutaneous administration of endothelial progenitor cells (EPCs) and acid fibroblast growth factor (aFGF) with a shape-memorable methacrylated gelatin cryogel (EPCs/aFGF@GelMA) for the therapy of PU in rats with DM. This EPCs/aFGF@GelMA cryogel system presented microporous structure, elastic mechanical strength and enhanced cell migration property with controlled release of aFGF. Moreover, compared with EPCs/aFGF and GelMA alone, in vivo results showed that this EPCs/aFGF@GelMA system exhibited accelerated wound closure rate, enhanced granulation formation, collagen deposition as well as re-epithelization. Importantly, we found that the excellent positive performance of EPCs/aFGF@GelMA is due to its up-regulation of HIF-ɑ upon the wound site, modulating the microenvironment of wound site to initiate the impaired local angiogenesis. Collectively, this hybrid gelatin cryogels show great promise for biomedical applications, especially in tissue engineering and regenerative medicine.

The Role of Immune Cells in Post-Stroke Angiogenesis and Neuronal Remodeling: The Known and the Unknown

Following a cerebral ischemic event, substantial alterations in both cellular and molecular activities occur due to ischemia-induced cerebral pathology. Mounting evidence indicates that the robust recruitment of immune cells plays a central role in the acute stage of stroke. Infiltrating peripheral immune cells and resident microglia mediate neuronal cell death and blood-brain barrier disruption by releasing inflammation-associated molecules. Nevertheless, profound immunological effects in the context of the subacute and chronic recovery phase of stroke have received little attention. Early attempts to curtail the infiltration of immune cells were effective in mitigating brain injury in experimental stroke studies but failed to exert beneficial effects in clinical trials. Neural tissue damage repair processes include angiogenesis, neurogenesis, and synaptic remodeling, etc. Post-stroke inflammatory cells can adopt divergent phenotypes that influence the aforementioned biological processes in both endothelial and neural stem cells by either alleviating acute inflammatory responses or secreting a variety of growth factors, which are substantially involved in the process of angiogenesis and neurogenesis. To better understand the multiple roles of immune cells in neural tissue repair processes post stroke, we review what is known and unknown regarding the role of immune cells in angiogenesis, neurogenesis, and neuronal remodeling. A comprehensive understanding of these inflammatory mechanisms may help identify potential targets for the development of novel immunoregulatory therapeutic strategies that ameliorate complications and improve functional rehabilitation after stroke.

The Role of Fibroblast Growth Factor (FGF) Signaling in Tissue Repair and Regeneration

Fibroblast growth factors (FGFs) are a large family of secretory molecules that act through tyrosine kinase receptors known as FGF receptors. They play crucial roles in a wide variety of cellular functions, including cell proliferation, survival, metabolism, morphogenesis, and differentiation, as well as in tissue repair and regeneration. The signaling pathways regulated by FGFs include RAS/mitogen-activated protein kinase (MAPK), phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)–protein kinase B (AKT), phospholipase C gamma (PLCγ), and signal transducer and activator of transcription (STAT). To date, 22 FGFs have been discovered, involved in different functions in the body. Several FGFs directly or indirectly interfere with repair during tissue regeneration, in addition to their critical functions in the maintenance of pluripotency and dedifferentiation of stem cells. In this review, we summarize the roles of FGFs in diverse cellular processes and shed light on the importance of FGF signaling in mechanisms of tissue repair and regeneration.

Deciphering the focal role of endostatin in Alzheimer's disease

Alzheimer's disease (AD) is a paramount chronic neurodegenerative condition that has been affecting elderly people since the 1900s. It causes memory loss, disorientation, and poor mental function. AD is considered to be one of the most serious problems that dementia sufferers face. Despite extensive investigation, the pathological origin of Alzheimer's disease remains a mystery. The amyloid cascade theory and the vascular hypothesis, which stresses the buildup of Aβ plaques, have dominated research into dementia and aging throughout history. However, research into this task failed to yield the long-awaited therapeutic miracle lead for Alzheimer's disease. Perhaps a hypothetical fragility in the context of Alzheimer's disease was regarded as a state distinct from aging in general, as suggested by the angiogenesis hypothesis, which suggests that old age is one state associated with upregulation of angiogenic growth factors, resulting in decreased microcirculation throughout the body. There has also been evidence that by controlling or inhibiting the components involved in the sequence of events that cause angiogenesis, there is a visible progression in AD patients. In Alzheimer's disease, one such antiangiogenic drug is being used.

Tissue Engineering Meets Nanotechnology: Molecular Mechanism Modulations in Cornea Regeneration

Nowadays, tissue engineering is one of the most promising approaches for the regeneration of various tissues and organs, including the cornea. However, the inability of biomaterial scaffolds to successfully integrate into the environment of surrounding tissues is one of the main challenges that sufficiently limits the restoration of damaged corneal tissues. Thus, the modulation of molecular and cellular mechanisms is important and necessary for successful graft integration and long-term survival. The dynamics of molecular interactions affecting the site of injury will determine the corneal transplantation efficacy and the post-surgery clinical outcome. The interactions between biomaterial surfaces, cells and their microenvironment can regulate cell behavior and alter their physiology and signaling pathways. Nanotechnology is an advantageous tool for the current understanding, coordination, and directed regulation of molecular cell-transplant interactions on behalf of the healing of corneal wounds. Therefore, the use of various nanotechnological strategies will provide new solutions to the problem of corneal allograft rejection, by modulating and regulating host-graft interaction dynamics towards proper integration and long-term functionality of the transplant.

miR-340-5p mediates the therapeutic effect of mesenchymal stem cells on corneal neovascularization

BACKGROUND

Our previous study revealed that mesenchymal stem cells (MSCs) inhibited angiogenesis via miRNA-mediated repression of prospero homeobox 1 (PROX1). This study aimed to verify whether miR-340-5p participates in the therapeutic effect of MSCs on corneal neovascularization (CNV) via repressing PROX1 and epithelial membrane protein 2 (EMP2).

MATERIALS AND METHODS

The rat CNV model was established by corneal alkali burn. The binding relationship between miR-340-5p and 3'-untranslational regions (3'UTRs) of EMP2 and PROX1 was confirmed using dual-luciferase reporter assay. After culturing corneal epithelial cells (CECs) using MSC supernatants, the vascular endothelial growth factor (VEGF) level in CEC supernatants and the CEC viability were detected. The role of miR-340-5p in the therapeutic effect of MSC on CNV was determined via lentivirus-mediated miR-340-5p intervention in vivo.

RESULTS

The expression of miR-340-5p was reduced and EMP2 and PROX1 were increased in CNV corneal tissues. The lentivirus-mediated overexpression of miR-340-5p inhibited the expressions of EMP2 and PROX1. The dual-luciferase reporter assay confirmed that miR-340-5p could bind with the 3'UTRs of EMP2 and PROX1. miR-340-5p was enriched in MSC supernatants and the culture of CECs using MSC supernatants increased the miR-340-5p expression in CECs. After being cultured in miR-340-5p-knocking down MSC supernatants, the expressions of EMP2 and PROX1 were increased, and the VEGF level and CEC viability were restored. The in vivo experiments also indicated that the therapeutic effect of MSCs was mediated by miR-340-5p.

CONCLUSIONS

miR-340-5p mediates the therapeutic effect of MSCs on CNV via binding and repressing the expressions of EMP2 and PROX1.

Lymphatic Trafficking in the Eye: Modulation of Lymphatic Trafficking to Promote Corneal Transplant Survival

(Lymph)angiogenesis into the cornea prior to and after corneal transplantation is a critical risk factor for allograft rejection. Lymphatic vessels even more than blood vessels seem important in mediating immune responses, as they facilitate allograft sensitization in the draining lymph nodes. Thus, the concept of modulating lymphatic trafficking to promote corneal graft survival seems promising. A variety of approaches has been developed to inhibit progressive lymphangiogenesis in experimental settings. Recently, additionally to pharmacological approaches, clinically available techniques such as UVA-based corneal collagen crosslinking and fine needle diathermy were reported to be effective in regressing lymphatic vessels and to experimentally promote graft survival. Clinical pilot studies also suggest the efficacy of blocking antigen presenting cell trafficking to regional lymph nodes by regressing corneal lymphatic vessels to enhance allograft survival in high-risk eyes. In this article, we will give an overview of current strategies to modulate lymphatic trafficking with a special focus on recently reported strategies, which may be easy to translate into clinical practice. This novel concept of temporary, pretransplant regression of lymphatic vessels at the site of transplantation to promote subsequent corneal transplant survival ("lymphangioregressive preconditioning") may also be applicable to other transplantation sites later.

NmFGF1-Regulated Glucolipid Metabolism and Angiogenesis Improves Functional Recovery in a Mouse Model of Diabetic Stroke and Acts via the AMPK Signaling Pathway

Diabetes increases the risk of stroke, exacerbates neurological deficits, and increases mortality. Non-mitogenic fibroblast growth factor 1 (nmFGF1) is a powerful neuroprotective factor that is also regarded as a metabolic regulator. The present study aimed to investigate the effect of nmFGF1 on the improvement of functional recovery in a mouse model of type 2 diabetic (T2D) stroke. We established a mouse model of T2D stroke by photothrombosis in mice that were fed a high-fat diet and injected with streptozotocin (STZ). We found that nmFGF1 reduced the size of the infarct and attenuated neurobehavioral deficits in our mouse model of T2D stroke. Angiogenesis plays an important role in neuronal survival and functional recovery post-stroke. NmFGF1 promoted angiogenesis in the mouse model of T2D stroke. Furthermore, nmFGF1 reversed the reduction of tube formation and migration in human brain microvascular endothelial cells (HBMECs) cultured in high glucose conditions and treated with oxygen glucose deprivation/re-oxygenation (OGD). Amp-activated protein kinase (AMPK) plays a critical role in the regulation of angiogenesis. Interestingly, we found that nmFGF1 increased the protein expression of phosphorylated AMPK (p-AMPK) both in vivo and in vitro. We found that nmFGF1 promoted tube formation and migration and that this effect was further enhanced by an AMPK agonist (A-769662). In contrast, these processes were inhibited by the application of an AMPK inhibitor (compound C) or siRNA targeting AMPK. Furthermore, nmFGF1 ameliorated neuronal loss in diabetic stroke mice via AMPK-mediated angiogenesis. In addition, nmFGF1 ameliorated glucose and lipid metabolic disorders in our mouse model of T2D stroke without causing significant changes in body weight. These results revealed that nmFGF1-regulated glucolipid metabolism and angiogenesis play a key role in the improvement of functional recovery in a mouse model of T2D stroke and that these effects are mediated by the AMPK signaling pathway.

aFGF Targeted Mediated by Novel Nanoparticles-Microbubble Complex Combined With Ultrasound-Targeted Microbubble Destruction attenuates Doxorubicin-Induced Heart Failure via Anti-Apoptosis and Promoting Cardiac Angiogenesis

The purpose of this study was to evaluate the protective effect of acidic fibroblast growth factor targeted mediated by novel nanoparticles–cationic lipid microbubbles complex (aFGF–NP + CPMBs) combined with ultrasound targeted microbubble destruction (UTMD)on doxorubicin–induced heart failure (HF)and its mechanism. Heart failure rats induced by intraperitoneal injection with doxorubicin (DOX) to achieve cummulative dose of 15mg/kg for continuous 6 weeks showed left ventricular dysfunction, seriously oxidative stress, cardiomyocyte apoptosis, and decrease of myocardial vascular density. In contrast, aFGF–NP + CPMBs combined with UTMD therapy (3ug/kg, caudal vein injection, twice a week, 6weeks)prominently ameliorated left ventricular dysfunction by increased ejection fraction (EF) and fractional shortening (FS), decreased brain natriuretic peptide (BNP); strengthened the ability of antioxidant stress confirmed by increasing the activity of SOD and reducing the production of MDA; exerted the effect of anti–cardiomyocyte apoptosis and promotion angiogenesis by inhibited Bax expression and increased Bcl–2 expression and platelet endothelial cell adhesion molecule (CD31) expression. Taken together, the research suggested that aFGF targeted mediated by novel nanoparticles–cationic lipid microbubbles complex combined with UTMD should be a promising targeted treatment for heart failure.

Inflammation-Mediated Angiogenesis in Ischemic Stroke

Stroke is the leading cause of disability and mortality in the world, but the pathogenesis of ischemic stroke (IS) is not completely clear and treatments are limited. Mounting evidence indicate that neovascularization is a critical defensive reaction to hypoxia that modulates the process of long-term neurologic recovery after IS. Angiogenesis is a complex process in which the original endothelial cells in blood vessels are differentiated, proliferated, migrated, and finally remolded into new blood vessels. Many immune cells and cytokines, as well as growth factors, are directly or indirectly involved in the regulation of angiogenesis. Inflammatory cells can affect endothelial cell proliferation, migration, and activation by secreting a variety of cytokines via various inflammation-relative signaling pathways and thus participate in the process of angiogenesis. However, the mechanism of inflammation-mediated angiogenesis has not been fully elucidated. Hence, this review aimed to discuss the mechanism of inflammation-mediated angiogenesis in IS and to provide new ideas for clinical treatment of IS.

Combined treatment with ultrasound-targeted microbubble destruction technique and NM-aFGF-loaded PEG-nanoliposomes protects against diabetic cardiomyopathy-induced oxidative stress by activating the AKT/GSK-3β1/Nrf-2 pathway

The present study sought to investigate the effect of non-mitogenic acidic fibroblast growth factor (NM-aFGF) loaded PEGylated nanoliposomes (NM-aFGF-PEG-lips) combined with the ultrasound-targeted microbubble destruction (UTMD) technique on modulating diabetic cardiomyopathy (DCM)and the mechanism involved. Animal studies showed that the diabetes mellitus (DM) group exhibited typical myocardial structural and functional changes of DCM. The indexes from the transthoracic echocardiography showed that the left ventricular function in the NM-aFGF-PEG-lips + UTMD group was significantly improved compared with the DM group. Histopathological observation further confirmed that the cardiomyocyte structural abnormalities and mitochondria ultrastructural changes were also significantly improved in the NM-aFGF-PEG-lips + UTMD group compared with DM group. The cardiac volume fraction (CVF) and apoptosis index in the NM-aFGF-PEG-lips + UTMD group decreased to 10.31 ± 0.76% and 2.16 ± 0.34, respectively, compared with those in the DM group (CVF = 21.4 ± 2.32, apoptosis index = 11.51 ± 1.24%). Moreover, we also found significantly increased superoxide dismutase (SOD) activity and glutathione peroxidase (GSH-Px) activity as well as clearly decreased lipid hydroperoxide levels and malondialdehyde (MDA) activity in the NM-aFGF-PEG-lips + UTMD group compared with those in the DM group (p < .05). Western blot analysis further revealed the highest level of NM-aFGF, p-AKT, p-GSK-3β1, Nrf-2, SOD2 and NQO1 in the NM-aFGF-PEG-lips + UTMD group. This study confirmed using PEGylated nanoliposomes combined with the UTMD technique can effectively deliver NM-aFGF to the cardiac tissue of diabetic rats. The NM-aFGF can then inhibit myocardial oxidative stress damage due to DM by activating the AKT/GSK/Nrf-2 signaling pathway, which ultimately improved the myocardial structural and functional lesions in diabetic rats.

Loss of Osteopontin Expression Reduces HSV-1-Induced Corneal Opacity

Purpose

Corneal opacity and neovascularization (NV) are often described as outcomes of severe herpes simplex virus type 1 (HSV-1) infection. The current study investigated the role of colony-stimulating factor 1 receptor (CSF1R)+ cells and soluble factors in the progression of HSV-1-induced corneal NV and opacity.

Methods

MaFIA mice were infected with 500 plaque-forming units of HSV-1 in the cornea following scarification. From day 10 to day 13 post-infection (pi), mice were treated with 40 µg/day of AP20187 (macrophage ablation) or vehicle intraperitoneally. For osteopontin (OPN) neutralization experiments, C57BL/6 mice were infected as above and treated with 2 µg of goat anti-mouse OPN or isotypic control IgG subconjunctivally every 2 days from day 4 to day 12 pi. Mice were euthanized on day 14 pi, and tissue was processed for immunohistochemistry to quantify NV and opacity by confocal microscopy and absorbance or detection of pro- and anti-angiogenic and inflammatory factors and cells by suspension array analysis and flow cytometry, respectively.

Results

In the absence of CSF1R+ cells, HSV-1-induced blood and lymphatic vessel growth was muted. These results correlated with a loss in fibroblast growth factor type 2 (FGF-2) and an increase in OPN expression in the infected cornea. However, a reduction in OPN expression in mice did not alter corneal NV but significantly reduced opacity.

Conclusions

Our data suggest that CSF1R+ cell depletion results in a significant reduction in HSV-1-induced corneal NV that correlates with the loss of FGF-2 expression. A reduction in OPN expression was aligned with a significant drop in opacity associated with reduced corneal collagen disruption.

VEGF-A in Cardiomyocytes and Heart Diseases

The vascular endothelial growth factor (VEGF), a homodimeric vasoactive glycoprotein, is the key mediator of angiogenesis. Angiogenesis, the formation of new blood vessels, is responsible for a wide variety of physio/pathological processes, including cardiovascular diseases (CVD). Cardiomyocytes (CM), the main cell type present in the heart, are the source and target of VEGF-A and express its receptors, VEGFR1 and VEGFR2, on their cell surface. The relationship between VEGF-A and the heart is double-sided. On the one hand, VEGF-A activates CM, inducing morphogenesis, contractility and wound healing. On the other hand, VEGF-A is produced by CM during inflammation, mechanical stress and cytokine stimulation. Moreover, high concentrations of VEGF-A have been found in patients affected by different CVD, and are often correlated with an unfavorable prognosis and disease severity. In this review, we summarized the current knowledge about the expression and effects of VEGF-A on CM and the role of VEGF-A in CVD, which are the most important cause of disability and premature death worldwide. Based on clinical studies on angiogenesis therapy conducted to date, it is possible to think that the control of angiogenesis and VEGF-A can lead to better quality and span of life of patients with heart disease.