Role of pigment epithelium-derived factor in stem/progenitor cell-associated neovascularization

Wiring the ocular surface: A focus on the comparative anatomy and molecular regulation of sensory innervation of the cornea

The cornea is richly innervated with sensory nerves that function to detect and clear harmful debris from the surface of the eye, promote growth and survival of the corneal epithelium and hasten wound healing following ocular disease or trauma. Given their importance to eye health, the neuroanatomy of the cornea has for many years been a source of intense investigation. Resultantly, complete nerve architecture maps exist for adult human and many animal models and these maps reveal few major differences across species. Interestingly, recent work has revealed considerable variation across species in how sensory nerves are acquired during developmental innervation of the cornea. Highlighting such species-distinct key differences, but also similarities, this review provides a full, comparative anatomy analysis of sensory innervation of the cornea for all species studied to date. Further, this article comprehensively describes the molecules that have been shown to guide and direct nerves toward, into and through developing corneal tissue as the final architectural pattern of the cornea's neuroanatomy is established. Such knowledge is useful for researchers and clinicians seeking to better understand the anatomical and molecular basis of corneal nerve pathologies and to hasten neuro-regeneration following infection, trauma or surgery that damage the ocular surface and its corneal nerves.

Comparative Outcomes of Robotic Radical Prostatectomy in Patients with Locally Advanced Prostate Cancer

The effectiveness of radical prostatectomy alone for locally advanced prostate cancer is controversial owing to an increased complication rate and treatment-related morbidity. With technical advances and refinements in surgical techniques, robotic-assisted radical prostatectomy (RARP) has improved the outcomes of patients with locally advanced prostate cancer. RARP therefore plays a role in the treatment of locally advanced prostate cancer. In this study, we enrolled a total of 76 patients with pathologic stage pT3a, pT3b, pT4, or pN1. All patients were followed from surgery to June 2022, and their characteristics, perioperative outcomes, complications, adjuvant therapies and outcomes were analyzed. The median age of the patients was 69 years, and the initial PSA level was 20.5 (IQR 10.8-31.6) ng/mL. The median operative time was 205 (IQR 182-241) minutes. Sixty-six patients (86.8%) regained continence within 1 year, and the continence rate within 3 years of follow-up was 90.8% (69 patients). The overall survival rate was 100%. Twenty-two patients had BCR, of whom 13 received salvage androgen deprivation therapy (ADT), 2 received salvage external beam radiation therapy (EBRT) alone, and 7 received combined ADT and EBRT. No patient had disease progression to castration-resistant prostate cancer during a median 36 months of follow-up after salvage therapy. Our results suggest that RARP can also decrease tumor burden and allow for accurate and precise pathological staging with the need for subsequent treatment. Therefore, we recommend that RARP represents a well-standardized, safe, and oncologically effective option for patients with locally advanced prostate cancer.

Astragalus membranaceus Extract Prevents Calcium Oxalate Crystallization and Extends Lifespan in a Drosophila Urolithiasis Model

Approximately 1 in 20 people develops kidney stones at some point in their life. Although the surgical removal of stones is common, the recurrence rate remains high and it is therefore important to prevent the occurrence of kidney stones. We chose Astragalus membranaceus (AM), which is a traditional Chinese medicine, to study the prevention of urolithiasis using a Drosophila model based on our previous screening of traditional Chinese herbs. Wild-type Drosophila melanogaster Canton-S adult fruit flies were used in this study. Ethylene glycol (EG, 0.5%) was added to food as a lithogenic agent. The positive control agent (2% potassium citrate (K-citrate)) was then compared with AM (2, 8, and 16 mg/mL). After 21 days, the fruit flies were sacrificed under carbon dioxide narcotization, and the Malpighian tubules were dissected, removed, and processed for polarized light microscopy examination to observe calcium oxalate (CaOx) crystallization. Then, the ex vivo dissolution of crystals in the Malpighian tubules was compared between K-citrate and AM. Survival analysis of the EG, K-citrate, and AM groups was also performed. Both 2% K-citrate and AM (16 mg/mL) significantly inhibited EG-induced CaOx crystal formation. Mean lifespan was significantly reduced by the administration of EG, and the results were significantly reversed in the AM (8 and 16 mg/mL) groups. However, AM extract did not directly dissolve CaOx crystals in Drosophila Malpighian tubules ex vivo. In conclusion, AM extract decreased the ratio of CaOx crystallization in the Malpighian tubules and significantly ameliorated EG-induced reduction of lifespan. AM prevented CaOx crystal formation in the Drosophila model.

The Uroprotective Efficacy of Total Ginsenosides in Chinese Ginseng on Chemotherapy with Cyclophosphamide

Hemorrhagic cystitis is a recognizable complication of cyclophosphamide (CYP) attributable to its lively metabolite acrolein, which produces urothelial injury. The study intended to examine the uroprotective efficacy of total ginsenosides in Chinese ginseng (TGCG) in CYP-induced hemorrhagic cystitis. In total, 24 virgin female rats were randomized into four groups as follows: group 1 (control group; injected with normal saline), group 2 (injected with CYP plus a placebo with normal saline), group 3 (given CYP and TGCG (200 mg/kg)), and group 4 (given CYP and 2-mercaptoethane sulfonate sodium (Mesna, 30 mg/kg)). An evaluation by cystometry was conducted. Values of the voiding interval were assessed in anesthetized rats and histological examinations of the bladders were measured. In the cystometry analysis, the voiding interval was significantly reduced in the CYP group. TGCG and Mesna significantly increased in the voiding interval values, individually. Bladder edema and urothelial injury were examined after contact with CYP. Contrasted to the group given CYP, CYP-induced hemorrhagic cystitis, TGCG significantly increased the urothelial thickness, and significantly reduced scores of mucosal break and submucosal edema in the bladder. In conclusion, these findings mean that the treatment with TGCG in CYP rats can avoid hemorrhagic cystitis. TGCG decreases urothelial injury. TGCG may participate as the chief character of uroprotection in CYP-induced hemorrhagic cystitis.

The Detrimental and Beneficial Functions of Macrophages After Cochlear Injury

Macrophages are the main intrinsic immune cells in the cochlea; they can be activated and play a complicated role after cochlear injury. Many studies have shown that the number of macrophages and their morphological characteristics within the major cochlear partitions undergo significant changes under various pathological conditions including acoustic trauma, ototoxic drug treatment, age-related cochlear degeneration, selective hair cell (HC) and spiral ganglion neuron (SGN) elimination, and surgery. However, the exact role of these macrophages after cochlear injury is still unclear. Regulating the migration and activity of macrophages may be a therapeutic approach to reduce the risk or magnitude of trauma-induced hearing loss, and this review highlights the role of macrophages on the peripheral auditory structures of the cochlea and elucidate the mechanisms of macrophage injury and the strategies to reduce the injury by regulating macrophage.

Pigment Epithelium-Derived Factor Enhances the Suppressive Phenotype of Regulatory T Cells in a Murine Model of Dry Eye Disease

Pigment epithelium-derived factor (PEDF) is a widely expressed 50-kDa glycoprotein belonging to the serine protease inhibitor family, with well-established anti-inflammatory functions. Recently, we demonstrated the immunoregulatory role played by PEDF in dry eye disease (DED) by suppressing the maturation of antigen-presenting cells at the ocular surface following exposure to the desiccating stress. In this study, we evaluated the effect of PEDF on the immunosuppressive characteristics of regulatory T cells (Tregs), which are functionally impaired in DED. In the presence of PEDF, the in vitro cultures prevented proinflammatory cytokine (associated with type 17 helper T cells)-induced loss of frequency and suppressive phenotype of Tregs derived from normal mice. Similarly, PEDF maintained the in vitro frequency and enhanced the suppressive phenotype of Tregs derived from DED mice. On systemically treating DED mice with PEDF, moderately higher frequencies and significantly enhanced suppressive function of Tregs were observed in the draining lymphoid tissues, leading to the efficacious amelioration of the disease. Our results demonstrate that PEDF promotes the suppressive capability of Tregs and attenuates their type 17 helper T-cell-mediated dysfunction in DED, thereby playing a role in the suppression of DED.

Pigment Epithelium-derived Factor secreted by corneal epithelial cells regulates dendritic cell maturation in dry eye disease

PURPOSE

In this study, we quantify Pigment Epithelium-derived Factor (PEDF) secreted by corneal epithelial cells and evaluate its immunomodulatory functions in a murine model of dry eye disease (DED).

METHODS

We induced DED in female C57BL/6 mice using a controlled environment chamber for 14 days. We quantified mRNA expression of Serpinf1 gene and PEDF protein synthesis by corneal epithelial cells (CEpCs) using RT-PCR and ELISA. CEpCs from normal or DED mice were cultured with IFNγ-stimulated-dendritic cells (DCs) for 24 h, and expression of MHC-II and CD86 by DCs was determined using flow cytometry. Next, we either added recombinant PEDF (rPEDF) or anti-PEDF antibody to co-culture, and DC expression of the above maturation markers was quantified. Lastly, we treated DED mice with either topical rPEDF, anti-PEDF Ab or murine serum albumin (MSA), and DC maturation, expression of pro-inflammatory cytokines, and DED severity were investigated.

RESULTS

Serpinf1 mRNA expression and PEDF protein production levels by CEpCs were upregulated in DED. CEpCs from DED mice exhibited an enhanced suppressive effect on the expression of MHC-II and CD86 by DCs, compared to normal mice. This effect was abolished by blocking endogenous PEDF with anti-PEDF Ab or enhanced by supplementing with rPEDF. Treatment with anti-PEDF antibody blocked the effect of endogenous-PEDF and increased DC maturation, expression of pro-inflammatory cytokines in conjunctivae, and exacerbated disease severity in DED mice. Conversely, topical rPEDF enhanced the suppressive effect of endogenous PEDF on DC maturation, decreased expression of pro-inflammatory cytokines in conjunctivae, and reduced disease severity.

CONCLUSIONS

The results from our study elucidate the role of PEDF in impeding DC maturation, and suppression of ocular surface inflammation, explicating a promising therapeutic potential of PEDF in limiting the corneal epitheliopathy as a consequence of DED.

Macrophages in Noise-Exposed Cochlea: Changes, Regulation and the Potential Role

Acoustic trauma is an important physical factor leading to cochlear damage and hearing impairments. Inflammation responds to this kind of cochlear damage stress. Macrophages, the major innate immune cells in the cochlea, are important drivers of inflammatory and tissue repair responses after cochlear injury. Recently, studies have shown that after noise exposure, the distribution, phenotype, and the number of cochlear macrophages have significantly changed, and the local environmental factors that shape macrophage differentiation and behavior are also drastically altered. However, the exact role of these immune cells in the cochlea after acoustic injury remains unknown. Here we review the properties of cochlear macrophages both under steady-state conditions and non-homeostatic conditions after cochlear acoustic injury and discuss their potential role in noise-exposed cochlea.

Upregulation of VEGF and PEDF in Placentas of Women with Lower Extremity Venous Insufficiency during Pregnancy and Its Implication in Villous Calcification

Pregnancy is a period in a woman's life in which changes can occur that affect different physiological processes. Common conditions during this period include vascular changes, such as lower extremity venous insufficiency (VI). This is an observational, analytical, and prospective cohort study in which 114 pregnant women were analyzed, of which 62 were clinically diagnosed with VI. In parallel, 52 control patients without VI (HC) were studied. The aim of this study was to observe changes in angiogenesis and inflammation markers as well as the presence of calcium deposits. The expression of vascular endothelial growth factor (VEGF), transforming growth factor-β (TGF-β), and pigment epithelium-derived factor (PEDF) was analyzed by immunohistochemistry and RT-qPCR. The presence of calcium deposits was revealed using the von Kossa method. In the placentas of mothers with VI, gene expression of VEGF (34.575 [32.380–36.720] VI vs 32.965 [30.580–36.320] HC) and PEDF (25.417 [24.459–27.675] VI vs 24.400 [23.102–30.223] HC) significantly increased, as was protein expression in the placental villi. An increase in calcium deposits was observed in the placentas of women with VI (72.58% VI/53.84% HC). This study revealed the existence of cellular damage in the placental villi of mothers with VI with tissue implications such as increased calcification.

Future perspectives of genome-scale sequencing

INTRODUCTION

In recent decades, we witnessed a revolution in genetic technology. Some 20 years ago, analysing a single gene was quite laborious and time-consuming. In addition, diagnostic testing was only available for selected genes. Nowadays, whole exome analysis - a technique enabling sequencing of all protein coding sequences in the entire genome - is gradually introduced in a clinical setting. Whole genome sequencing forms the ultimate exponent of this evolution and offers an even broader application.

METHODS

A review of the application of these technologies in a diagnostic setting is presented.

RESULTS

Whole exome sequencing has a prominent place in modern clinical diagnostics. It offers a cost- and time-efficient way to interrogate all protein coding portions of the genome leading to a quick and adequate diagnosis, also in cases of phenotypic heterogeneity. As sequencing costs continue to drop, whole genome sequencing will take over in the near future guaranteeing a further improvement of the quality of genetic testing.

CONCLUSION

Due to technological advances in the past decades, the field of clinical diagnostics has changed dramatically. With techniques such as whole exome and whole genome sequencing, the diagnostic yield increases serving both the patient and the health care system.

Antiangiogenic effects of catalpol on rat corneal neovascularization

To investigate the effects of catalpol on corneal neovascularization (CNV) and associated inflammation, eye drops (5 mM catalpol or PBS) were administered four times daily to alkali-burn rat models of CNV and inflammation. Clinical evaluations of CNV and the degree of inflammation were performed on days 0, 4, 7, 10 and 14 under slit lamp microscopy. Eyes were collected on day 14 and prepared for hematoxylin and eosin, and immunofluorescence staining; corneal cell apoptosis was investigated via terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) staining. Protein expression levels of angiogenic and proinflammatory factors, including vascular endothelial growth factor (VEGF), pigment epithelium-derived factor (PEDF), tumor necrosis factor-α (TNF-α) and necrosis factor-κB (NF-κB) were determined by western blotting. The effects of catalpol on cell proliferation were investigated in vitro using human umbilical vein endothelial cells (HUVECs) and a Cell Counting kit-8 (CCK-8); alterations in migration and tube formation were investigated via HUVEC wound closure and tube formation assays. HUVEC viability and proliferative ability were inhibited in a dose-dependent manner; catalpol also decreased HUVEC cell migration and tube forming ability. Within alkali-burn rat models, decreased inflammation and CNV was associated with catalpol administration; as demonstrated with TUNEL, corneal cell apoptosis was decreased in response to catalpol. Western blot analysis revealed reduced protein expression levels of VEGF and TNF-α; however, PEDF and phosphorylated-NF-κB p65 were increased due to catalpol administration. The present study demonstrated the inhibitory effects exerted by catalpol on CNV and inflammation within alkali-burned rat models. Topical application of catalpol in vivo was associated with reduced CNV and inflammation; therefore, catalpol may be considered an anti-inflammatory agent for the clinical treatment of CNV.

Pigment epithelium-derived factor protects retinal ganglion cells from hypoxia-induced apoptosis by preventing mitochondrial dysfunction

AIM

To investigate the potential of pigment epithelium-derived factor (PEDF) to protect the immortalized rat retinal ganglion cells-5 (RGC-5) exposed to CoCl₂-induced chemical hypoxia.

METHODS

After being differentiated with staurosporine (SS), RGC-5 cells were cultured in four conditions: control group cells cultured in Dulbecco's modified eagle medium (DMEM) supplemented with 10% fetal bovine serum, 100 µmol/mL streptomycin and penicillin (named as normal conditions); hypoxia group cells cultured in DMEM containing 300 µmol/mL CoCl₂; cells in the group protected by PEDF were first pretreated with 100 ng/mL PEDF for 2h and then cultured in the same condition as hypoxia group cells; and PEDF group cells that were cultured in the presence of 100 ng/mL PEDF under normal conditions. The cell viability was assessed by MTT assay, the percentage of apoptotic cells was quantified using Annexin V-FITC apoptosis kit, and intra-cellar reactive oxygen species (ROS) was measured by dichloro-dihydro-fluorescein diacetate (DCFH-DA) probe. The mitochondria-mediated apoptosis was also examined to further study the underlying mechanism of the protective effect of PEDF. The opening of mitochondrial permeability transition pores (mPTPs) and membrane potential (Δψm) were tested as cellular adenosine triphosphate (ATP) level and glutathione (GSH). Also, the expression and distribution of Cyt C and apoptosis inducing factor (AIF) were observed.

RESULTS

SS induced differentiation of RGC-5 cells resulting in elongation of their neurites and establishing contacts between outgrowths. Exposure to 300 µmol/mL CoCl₂ triggered death of 30% of the total cells in cultures within 24h. At the same time, pretreatment with 100 ng/mL PEDF significantly suppressed the cell death induced by hypoxia (P<0.05). The apoptosis induced by treatment of CoCl₂ was that induced cell death accompanied with increasing intra-cellar ROS and decreasing GSH and ATP level. PEDF pre-treatment suppressed these effects (P<0.05). Additionally, PEDF treatment inhibited the opening of mPTPs and suppressed decreasing of Δψm in RGC-5 cells, resulting in blocking of the mitochondrial apoptotic pathway.

CONCLUSION

Pretreatment of RGC-5 cells with 100 ng/mL PEDF significantly decreases the extent of apoptosis. PEDF inhibits the opening of mPTPs and suppresses decreasing of Δψm. Moreover, PEDF also reduces ROS production and inhibits cellular ATP level's reduction. Cyt C and AIF activation in PEDF-pretreated cultures are also reduced. These results demonstrate the potential for PEDF to protect RGCs against hypoxic damage in vitro by preventing mitochondrial dysfunction.

Ocular progenitor cells and current applications in regenerative medicines - Review

The recent emerging field of regenerative medicine is to present solutions for chronic diseases which cannot be sufficiently repaired by the body's own mechanisms. Stem cells are undifferentiated biological cells and have the potential to develop into many different cell types in the body during early life and growth. Self renewal and totipotency are the characteristic features of stem cells and it holds a promising result for treating various diseases like diabetic foot ulcer, heart diseases, lung diseases, Autism, Skin diseases, arthritis including eye disease. Failure of complete recovery of eye diseases and complications that follow conventional treatments have shifted search to a new form of regenerative medicine using Stem cells. The ocular progenitor cells are remarkable in stem cell biology and replenishing degenerated cells despite being present in low quantity and quiescence in our body has a high therapeutic value. In this paper we have review the applications on ocular progenitor stem cells in treatment of human eye diseases and address the strategies that have been exploited in an effort to regain visual function in the advance treatment of stem cells without any side effects and also present the significance in advance stem cell research.

Pigment Epithelium-Derived Factor (PEDF) mediates cartilage matrix loss in an age-dependent manner under inflammatory conditions

Background

Inflammation is a major cause of cartilage destruction and leads to the imbalance of metabolic activities in the arthritic joint. Pigment epithelium-derived factor (PEDF) has been reported to have both pro- and anti-inflammatory activities in various cell types and to be upregulated in the arthritic joint, but its role in joint destruction is unclear. Our aim was to investigate the role of PEDF in cartilage degeneration under inflammatory conditions.

Methods

PEDF was ectopically expressed in primary human articular chondrocytes, and catabolic gene expression and protein secretion in response to the pro-inflammatory cytokine interleukin 1 beta (IL-1β) were evaluated. Metatarsal bones from PEDF-deficient and wild type mice were cultured in the presence or absence of IL-1β. Cartilage matrix integrity and matrix metalloproteinases MMP-1, MMP-3, and MMP-13 were evaluated. PEDF-deficient and wild type mice were evaluated in the monosodium iodoacetate (MIA) inflammatory joint destruction animal model to determine the role of PEDF in inflammatory arthritis in vivo. Student’s t-tests and Mann–Whitney tests were employed where appropriate, for parametric and non-parametric data, respectively.

Results

We showed that PEDF protein levels were higher in human osteoarthritis samples compared to normal samples. We demonstrated that ectopic PEDF expression in primary human articular chondrocytes exacerbated catabolic gene expression in the presence of IL-1β. In whole bone organ cultures, IL-1β induced MMP-1, MMP-3 and MMP-13 protein production, and caused significant cartilage matrix loss. Interestingly, Toluidine Blue staining showed that PEDF-deficient bones from 29 week old animals, but not 10 week old animals, had reduced matrix loss in response to IL-1β compared to their wild type counterparts. In addition, PEDF-deficiency in 29 week old animals preserved matrix integrity and protected against cell loss in the MIA joint destruction model in vivo.

Conclusion

We conclude that PEDF exacerbates cartilage degeneration in an age-dependent manner under an inflammatory setting. This is the first study identifying a specific role for PEDF in joint inflammation and highlights the multi-faceted activities of PEDF.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-017-1410-y) contains supplementary material, which is available to authorized users.

Stem Cell Therapy for Treatment of Ocular Disorders

Sustenance of visual function is the ultimate focus of ophthalmologists. Failure of complete recovery of visual function and complications that follow conventional treatments have shifted search to a new form of therapy using stem cells. Stem cell progenitors play a major role in replenishing degenerated cells despite being present in low quantity and quiescence in our body. Unlike other tissues and cells, regeneration of new optic cells responsible for visual function is rarely observed. Understanding the transcription factors and genes responsible for optic cells development will assist scientists in formulating a strategy to activate and direct stem cells renewal and differentiation. We review the processes of human eye development and address the strategies that have been exploited in an effort to regain visual function in the preclinical and clinical state. The update of clinical findings of patients receiving stem cell treatment is also presented.

Bee Venom Accelerates Wound Healing in Diabetic Mice by Suppressing Activating Transcription Factor-3 (ATF-3) and Inducible Nitric Oxide Synthase (iNOS)-Mediated Oxidative Stress and Recruiting Bone Marrow-Derived Endothelial Progenitor Cells

Multiple mechanisms contribute to impaired diabetic wound healing including impaired neovascularization and deficient endothelial progenitor cell (EPC) recruitment. Bee venom (BV) has been used as an anti-inflammatory agent for the treatment of several diseases. Nevertheless, the effect of BV on the healing of diabetic wounds has not been studied. Therefore, in this study, we investigated the impact of BV on diabetic wound closure in a type I diabetic mouse model. Three experimental groups were used: group 1, non-diabetic control mice; group 2, diabetic mice; and group 3, diabetic mice treated with BV. We found that the diabetic mice exhibited delayed wound closure characterized by a significant decrease in collagen production and prolonged elevation of inflammatory cytokines levels in wounded tissue compared to control non-diabetic mice. Additionally, wounded tissue in diabetic mice revealed aberrantly up-regulated expression of ATF-3 and iNOS followed by a marked elevation in free radical levels. Impaired diabetic wound healing was also characterized by a significant elevation in caspase-3, -8, and -9 activity and a marked reduction in the expression of TGF-β and VEGF, which led to decreased neovascularization and angiogenesis of the injured tissue by impairing EPC mobilization. Interestingly, BV treatment significantly enhanced wound closure in diabetic mice by increasing collagen production and restoring the levels of inflammatory cytokines, free radical, TGF-β, and VEGF. Most importantly, BV-treated diabetic mice exhibited mobilized long-lived EPCs by inhibiting caspase activity in the wounded tissue. Our findings reveal the molecular mechanisms underlying improved diabetic wound healing and closure following BV treatment. J. Cell. Physiol. 231: 2159-2171, 2016. © 2016 Wiley Periodicals, Inc.

PEDF and its roles in physiological and pathological conditions: implication in diabetic and hypoxia-induced angiogenic diseases

Pigment epithelium-derived factor (PEDF) is a broadly expressed multifunctional member of the serine proteinase inhibitor (serpin) family. This widely studied protein plays critical roles in many physiological and pathophysiological processes, including neuroprotection, angiogenesis, fibrogenesis and inflammation. The present review summarizes the temporal and spatial distribution patterns of PEDF in a variety of developing and adult organs, and discusses its functions in maintaining physiological homoeostasis. The major focus of the present review is to discuss the implication of PEDF in diabetic and hypoxia-induced angiogenesis, and the pathways mediating PEDF's effects under these conditions. Furthermore, the regulatory mechanisms of PEDF expression, function and degradation are also reviewed. Finally, the therapeutic potential of PEDF as an anti-angiogenic drug is briefly summarized.

The mammalian blastema: regeneration at our fingertips

In the mouse, digit tip regeneration progresses through a series of discrete stages that include inflammation, histolysis, epidermal closure, blastema formation, and redifferentiation. Recent studies reveal how each regenerative stage influences subsequent stages to establish a blastema that directs the successful regeneration of a complex mammalian structure. The focus of this review is on early events of healing and how an amputation wound transitions into a functional blastema. The stepwise formation of a mammalian blastema is proposed to provide a model for how specific targeted treatments can enhance regenerative performance in humans.

Heterogeneity of hepatocellular carcinoma contributes to cancer progression

Hepatocellular carcinoma (HCC) is a highly heterogeneous disease displaying differences in angiogenesis, extracellular matrix proteins, the immune microenvironment and tumor cell populations. Additionally, genetic variations and epigenetic changes of HCC cells could lead to aberrant signaling pathways, induce cancer stem cells and enhance tumor progression. Thus, the heterogeneity in HCC contributes to disease progression and a better understanding of its heterogeneity will greatly aid in the development of strategies for the HCC treatment.

Angiogenesis is inhibitory for mammalian digit regeneration

The regenerating mouse digit tip is a unique model for investigating blastema formation and epimorphic regeneration in mammals. The blastema is characteristically avascular and we previously reported that blastema expression of a known anti‐angiogenic factor gene, Pedf, correlated with a successful regenerative response (Yu, L., Han, M., Yan, M., Lee, E. C., Lee, J. & Muneoka, K. (2010). BMP signaling induces digit regeneration in neonatal mice. Development, 137, 551–559). Here we show that during regeneration Vegfa transcripts are not detected in the blastema but are expressed at the onset of differentiation. Treating the amputation wound with vascular endothelial growth factor enhances angiogenesis but inhibits regeneration. We next tested bone morphogenetic protein 9 (BMP9), another known mediator of angiogenesis, and found that BMP9 is also a potent inhibitor of digit tip regeneration. BMP9 induces Vegfa expression in the digit stump suggesting that regenerative failure is mediated by enhanced angiogenesis. Finally, we show that BMP9 inhibition of regeneration is completely rescued by treatment with pigment epithelium‐derived factor. These studies show that precocious angiogenesis is inhibitory for regeneration, and provide compelling evidence that the regulation of angiogenesis is a critical factor in designing therapies aimed at stimulating mammalian regeneration.

Whole bone marrow cell culture: A convenient protocol for the in vitro expansion of endothelial progenitor cells

The number and function of endothelial progenitor cells (EPCs) may be a predictive factor for the severity and outcome of cardiovascular disease. However, the manipulation of bone marrow mononuclear cell (BMMC) cultures for EPCs is an elaborate and difficult procedure in small experimental animals. The present study aimed to assess the feasibility of whole bone marrow cell (WBMC) culture for expanding EPCs in small experimental animals. C57BL/6 mice (age, 3–4 weeks; weight, 9.47±0.76 g) were used as the experimental animals, and WBMCs were isolated from the femora and tibiae and cultured in endothelial cell growth medium-2. A BMMC culture for EPCs was used as a control. EPC growth, phenotype and functions were assessed in vitro and in vivo. The results demonstrated that EPCs were easily obtained from a WBMC culture in vitro. The cells exhibited similar growth and biological characteristics when compared with the EPCs derived from the traditional BMMC culture system. Thus, the cells were able to simultaneously bind to lectin and cause phagocytosis of acetylated-low density lipoproteins. In addition, the cells exhibited high expression levels of cluster of differentiation 34 and fetal liver kinase 1, and possessed similar functional properties to BMMC-derived EPCs, including vascular network formation, proliferation, adhesion and migration abilities in vitro. Thus, WBMC-derived EPCs can improve the outcome of pulmonary vascular disease when transplanted into a monocrotaline-induced pulmonary hypertension mouse model. The results of the present study indicated that the WBMC culture system is a more convenient and effective method of obtaining and expanding EPCs compared with BMMC culture, with the advantage of a simplified procedure.

Pigment epithelium-derived factor promotes Fas-induced cardiomyocyte apoptosis via its receptor phospholipase A2

AIMS

Cardiovascular diseases cause significant morbidity and mortality worldwide. Recently, our research team demonstrated that a multifunctional cytokine, pigment epithelium-derived factor (PEDF), plays a critical role in regulating myocardial infarction. However, few researchers have studied the molecular mechanisms by which PEDF and its receptors influence the pathophysiology of cardiovascular disease. We tested the hypothesis that PEDF affects cardiomyocyte apoptosis under hypoxic conditions and determined the role that its receptors phospholipase A2 (PLA2) and laminin receptor play in this process.

MAIN METHODS

Cardiomyocytes were isolated from neonatal mice and treated with PEDF under normoxic and hypoxic conditions; then, apoptosis was assessed using Annexin V/PI staining and flow cytometry. Western blotting and immunofluorescence staining were used to detect PEDF receptor expression, and siRNA knockdown of PEDF receptors was performed to determine which receptor was involved in mediating cardiomyocyte apoptosis.

KEY FINDINGS

Our results demonstrated that PEDF increased cardiomyocyte apoptosis during hypoxia via Fas and that PEDF receptors were expressed on cardiomyocyte cell membranes. Furthermore, siRNA experiments indicated that the PEDF receptor PLA2 was responsible for inducing cardiomyocyte apoptosis via the Fas pathway.

SIGNIFICANCE

PEDF promoted Fas-induced cardiomyocyte apoptosis via its receptor PLA2.

Characterization and inflammatory response of perivascular-resident macrophage-like melanocytes in the vestibular system

A large number of perivascular cells expressing both macrophage and melanocyte characteristics (named perivascular-resident macrophage-like melanocytes, PVM/Ms), previously found in the intra-strial fluid–blood barrier, are also found in the blood–labyrinth barrier area of the vestibular system in normal adult cochlea, including in the three ampullae of the semicircular canals (posterior, superior, and horizontal), utricle, and saccule. The cells were identified as PVM/Ms, positive for the macrophage and melanocyte marker proteins F4/80 and GSTα4. Similar to PVM/Ms present in the stria vascularis, the PVM/Ms in the vestibular system are closely associated with microvessels and structurally intertwined with endothelial cells and pericytes, with a density in normal (unstimulated) utricle of 225 ± 43/mm²; saccule 191 ± 25/mm²; horizontal ampullae 212 ± 36/mm²; anterior ampullae 238 ± 36/mm²; and posterior ampullae 223 ± 64/mm². Injection of bacterial lipopolysaccharide into the middle ear through the tympanic membrane causes the PVM/Ms to activate and arrange in an irregular pattern along capillary walls in all regions within a 48-h period. The inflammatory response significantly increases vascular permeability and leakage. The results underscore the morphological complexity of the blood barrier in the vestibular system, with its surrounding basal lamina, pericytes, as well as second line of defense in PVM/Ms. PVM/Ms may be important to maintain blood barrier integrity and initiating local inflammatory response in the vestibular system.

Perivascular macrophage-like melanocyte responsiveness to acoustic trauma--a salient feature of strial barrier associated hearing loss

Tissue perivascular resident macrophages (PVM/Ms), a hybrid cell type with characteristics of both macrophages and melanocytes, are critical for establishing and maintaining the endocochlear potential (EP) required for hearing. The PVM/Ms modulate expression of tight- and adherens-junction proteins in the endothelial barrier of the stria vascularis (intrastrial fluid-blood barrier) through secretion of a signaling molecule, pigment epithelium growth factor (PEDF). Here, we identify a significant link between abnormalities in PVM/Ms and endothelial barrier breakdown from acoustic trauma to the mouse ear. We find that acoustic trauma causes activation of PVM/Ms and physical detachment from capillary walls. Concurrent with the detachment, we find loosened tight junctions between endothelial cells and decreased production of tight- and adherens-junction protein, resulting in leakage of serum proteins from the damaged barrier. A key factor in the intrastrial fluid-blood barrier hyperpermeability exhibited in the mice is down-regulation of PVM/M modulated PEDF production. We demonstrate that delivery of PEDF to the damaged ear ameliorates hearing loss by restoring intrastrial fluid-blood barrier integrity. PEDF up-regulates expression of tight junction-associated proteins (ZO-1 and VE-cadherin) and PVM/M stabilizing neural cell adhesion molecule (NCAM-120). These studies point to the critical role PVM/Ms play in regulating intrastrial fluid-blood barrier integrity in healthy and noise-damaged ears.

Endothelial progenitor cell dysfunction in cardiovascular diseases: role of reactive oxygen species and inflammation

Endothelial progenitor cells (EPCs) move towards injured endothelium or inflamed tissues and incorporate into foci of neovascularisation, thereby improving blood flow and tissue repair. Patients with cardiovascular diseases have been shown to exhibit reduced EPC number and function. It has become increasingly apparent that these changes may be effected in response to enhanced oxidative stress, possibly as a result of systemic and localised inflammatory responses. The interplay between inflammation and oxidative stress affects the initiation, progression, and complications of cardiovascular diseases. Recent studies suggest that inflammation and oxidative stress modulate EPC bioactivity. Clinical medications with anti-inflammatory and antioxidant properties, such as statins, thiazolidinediones, angiotensin II receptor 1 blockers, and angiotensin-converting enzyme inhibitors, are currently administered to patients with cardiovascular diseases. These medications appear to exert beneficial effects on EPC biology. This review focuses on EPC biology and explores the links between oxidative stress, inflammation, and development of cardiovascular diseases.