The potential neuroprotective effect of human adipose stem cells conditioned medium against light-induced retinal damage

Mesenchymal stem cells and mesenchymal stem cell-derived exosomes: a promising strategy for treating retinal degenerative diseases

Mesenchymal stem cells (MSCs) have emerged as a promising therapeutic strategy in regenerative medicine, demonstrating significant potential for clinical applications. Evidence suggests that MSCs not only exhibit multipotent differentiation potential but also exert critical therapeutic effects in retinal degenerative diseases via robust paracrine mechanisms. MSCs protect retinal cells from degenerative damage by modulating inflammation, inhibiting apoptosis, alleviating oxidative stress, and suppressing cell death pathways. Furthermore, MSCs contribute to retinal structural and functional stability by facilitating vascular remodeling and donating mitochondria to retinal cells. Of particular interest, MSC-derived exosomes have gained widespread attention as a compelling cell-free therapy. Owing to their potent anti-inflammatory, anti-apoptotic, and vascular-stabilizing properties, exosomes show significant promise for the treatment of retinal degenerative diseases.

Stem Cell Therapies and Ageing: Unlocking the Potential of Regenerative Medicine

A multifaceted biological process of ageing culminates in the gradual decline of tissue and organ functions, escalating vulnerability to age-related diseases. Stem cell therapies, standing at the frontier of regenerative medicine, hold the potential to mitigate the challenges induced by ageing. By harnessing the unique regenerative capabilities of stem cells, these therapies aim to renew and heal ageing or damaged cells and tissues, thereby bolstering their function. In this chapter, we explore the potential of stem cell-based interventions against age-related degeneration, emphasising their underlying mechanisms, challenges, and future possibilities. As elucidated by the Buck Institute for Research on Aging, ageing is characterised by an accrual of macromolecular damage, genomic instability, and loss of heterochromatin (Campisi et al. Nature 571:183-192, 2019). These aspects culminate in stem cell fatigue and a dwindling tissue regenerative capacity. However, with the advent of stem cell therapy and regenerative medicine, we now hold the tools to reverse these age-induced changes by rejuvenating stem cells, the keystones of tissue regeneration, and fostering their proliferation and differentiation.

Recent Advances of Adipose-Tissue-Derived Mesenchymal Stem Cell-Based Therapy for Retinal Diseases

With the rapid development of stem cell research in modern times, stem cell-based therapy has opened a new era of tissue regeneration, becoming one of the most promising strategies for currently untreatable retinal diseases. Among the various sources of stem cells, adipose tissue-derived mesenchymal stem cells (ADSCs) have emerged as a promising therapeutic modality due to their characteristics and multiple functions, which include immunoregulation, anti-apoptosis of neurons, cytokine and growth factor secretion, and antioxidative activities. Studies have shown that ADSCs can facilitate the replacement of dying cells, promote tissue remodeling and regeneration, and support the survival and growth of retinal cells. Recent studies in this field have provided numerous experiments using different preclinical models. The aim of our review is to provide an overview of the therapeutic strategies, modern-day clinical trials, experimental models, and potential clinical use of this fascinating class of cells in addressing retinal disorders and diseases.

A Review on Mesenchymal Stem Cells for Treatment of Retinal Diseases

Mesenchymal Stem Cells (MSCs) have been studied extensively for the treatment of several retinal diseases. The therapeutic potential of MSCs lies in its ability to differentiate into multiple lineages and secretome enriched with immunomodulatory, anti-angiogenic and neurotrophic factors. Several studies have reported the role of MSCs in repair and regeneration of the damaged retina where the secreted factors from MSCs prevent retinal degeneration, improve retinal morphology and function. MSCs also donate mitochondria to rescue the function of retinal cells and exosomes secreted by MSCs were found to have anti-apoptotic and anti-inflammatory effects. Based on several promising results obtained from the preclinical studies, several clinical trials were initiated to explore the potential advantages of MSCs for the treatment of retinal diseases. This review summarizes the various properties of MSCs that help to repair and restore the damaged retinal cells and its potential for the treatment of retinal degenerative diseases.

Extracellular Vesicles from Human Adipose-Derived Mesenchymal Stem Cells: A Review of Common Cargos

In recent years, the interest in adipose tissue mesenchymal cell–derived extracellular vesicles (AT-MSC-EVs) has increasingly grown. Numerous articles support the potential of human AT-MSC-EVs as a new therapeutic option for treatment of diverse diseases in the musculoskeletal and cardiovascular systems, kidney, skin, and immune system, among others. This approach makes use of the molecules transported inside of EVs, which play an important role in cell communication and in transmission of macromolecules. However, to our knowledge, there is no database where essential information about AT-MSC-EVs cargo molecules is gathered for easy reference. The aim of this study is to describe the different molecules reported so far in AT-MSC- EVs, their main molecular functions, and biological processes in which they are involved. Recently, the presence of 591 proteins and 604 microRNAs (miRNAs) has been described in human AT-MSC-EVs. The main molecular function enabled by both proteins and miRNAs present in human AT-MSC-EVs is the binding function. Signal transduction and gene silencing are the biological processes in which a greater number of proteins and miRNAs from human AT-MSC-EVs are involved, respectively. In this review we highlight the therapeutics effects of AT-MSC-EVs related with their participation in relevant biological processes including inflammation, angiogenesis, cell proliferation, apoptosis and migration, among others.

Paracrine effect of human adipose-derived stem cells on lymphatic endothelial cells

Aim: The proposal of this study was to evaluate, in vitro, the potential paracrine effect of human adipose-derived stem cells (hASCs) to promote lymphangiogenesis in lymphatic endothelial cells isolated from rat diaphragmatic lymphatic vessels. Materials & methods: ELISA on VEGFA, VEGFC and IL6 in hASC-conditioned medium; LYVE1 immunostaining; and gene expression of PROX1, VEGFR3, VEGFC, VEGFA and IL6 were the methods used. Results: In 2D culture, hASC-conditioned medium was able to promote lymphatic endothelial cell survival, maintenance of endothelial cobblestone morphology and induction to form a vessel-like structure. Conclusion: The authors' results represent in vitro evidence of the paracrine effect of hASCs on lymphatic endothelial cells, suggesting the possible role of hASC-conditioned medium in developing new therapeutic approaches for lymphatic system-related dysfunction such as secondary lymphedema.

Recent theranostic paradigms for the management of Age-related macular degeneration

Degenerative diseases of eye like Age-related macular degeneration (AMD), that affects the central portion of the retina (macula), is one of the leading causes of blindness worldwide especially in the elderly population. It is classified mainly as wet and dry form. With expanding knowledge about the underlying pathophysiology of the disease, various treatment strategies are being employed to halt the course of the disease progression. Hitherto, there is no ideal therapy which can cure the disease completely, and targeting the posterior segment of the eye is yet another challenge. The purpose of this review is to summarize the recent advances in the management and treatment stratagems (therapies, delivery systems and diagnostic tools) pertaining to AMD viz. molecular targeting, stem cell therapy, nanotechnology and exosomes with special reference to newer technologies like artificial intelligence and 3D printing. Furthermore, the role of diet and nutritional supplements in the prevention and treatment of the disease has also been highlighted. The alarming increase in the said disorder around the globe demands exhaustive research and investigations in the treatment zone. This review thus additionally directs the attention towards the challenges and future perspectives of different treatment approaches for AMD.

Mesenchymal Stem Cell Secretome Enhancement by Nicotinamide and Vasoactive Intestinal Peptide: A New Therapeutic Approach for Retinal Degenerative Diseases

Mesenchymal stem cells (MSC) secrete neuroprotective molecules that may be useful as an alternative to cell transplantation itself. Our purpose was to develop different pharmaceutical compositions based on conditioned medium (CM) of adipose MSC (aMSC) stimulated by and/or combined with nicotinamide (NIC), vasoactive intestinal peptide (VIP), or both factors; and to evaluate in vitro their proliferative and neuroprotective potential. Nine pharmaceutical compositions were developed from 3 experimental approaches: (1) unstimulated aMSC-CM collected and combined with NIC, VIP, or both factors (NIC+VIP), referred to as the aMSC-CM combined composition; (2) aMSC-CM collected just after stimulation with the mentioned factors and containing them, referred to as the aMSC-CM stimulated-combined composition; and (3) aMSC-CM previously stimulated with the factors, referred to as the aMSC stimulated composition. The potential of the pharmaceutical compositions to increase cell proliferation under oxidative stress and neuroprotection were evaluated in vitro by using a subacute oxidative stress model of retinal pigment epithelium cells (line ARPE-19) and spontaneous degenerative neuroretina model. Results showed that oxidatively stressed ARPE-19 cells exposed to aMSC-CM stimulated and stimulated-combined with NIC or NIC+VIP tended to have better recovery from the oxidative stress status. Neuroretinal explants cultured with aMSC-CM stimulated-combined with NIC+VIP had better preservation of the neuroretinal morphology, mainly photoreceptors, and a lower degree of glial cell activation. In conclusion, aMSC-CM stimulated-combined with NIC+VIP contributed to improving the proliferative and neuroprotective properties of the aMSC secretome. Further studies are necessary to evaluate higher concentrations of the drugs and to characterize specifically the aMSC-secreted factors related to neuroprotection. However, this study supports the possibility of improving the potential of new effective pharmaceutical compositions based on the secretome of MSC plus exogenous factors or drugs without the need to inject cells into the eye, which can be very useful in retinal pathologies.

The Overexpression of Epidermal Growth Factor (EGF) in HaCaT Cells Promotes the Proliferation, Migration, Invasion and Transdifferentiation to Epidermal Stem Cell Immunophenotyping of Adipose-Derived Stem Cells (ADSCs)

Background and Objectives

The application of adipose derived stem cells (ADSCs) in skin repair has attracted much attention nowadays. Epidermal growth factor (EGF) participates in the progress of skin proliferation, differentiation and so forth. We aimed to explore the role of EGF in the proliferation, invasion, migration and transdifferentiation into epidermal cell phenotypes of ADSCs.

Methods and Results

ADSCs were extracted from adipose tissues from patient. Immunophenotyping was determined by flow cytometry. Overexpressed EGF or siEGF was transfected by lentiviruses. EGF was determined by enzyme linked immunosorbent assay (ELISA) or western blot. ADSCs and HaCaT cells were co-cultured by Transwell chambers. Conditioned medium (CM) was obtained from cultured HaCaT cells and used for the culturing of ADSCs. Cell viability was tested by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Invasion rate was measured by Transwell invasion assay and migration rate by wound healing test. mRNA and protein levels were measured by qPCR and western blot respectively. The extracted cells from adipose tissues were identified as ADSCs by morphology and immunophenotyping. The expression of EGF was up or down regulated constantly in HaCaT cell line after transfection. EGF overexpression upregulated the proliferation, migration and invasion rates of ADSCs, and EGF expression regulated the expression of cytokeratin-19 (CK19) and integrin-β as well.

Conclusions

EGF could be served as a stimulus to promote the proliferation, migration, and invasion as well as the transdifferentiation into epidermal stem cell immunophenotyping of ADSCs. The results showed that EGF had a promising effect on the repair of skin wound.

Cell-based approaches towards treating age-related macular degeneration

Age-related macular degeneration as one of the most common causes of worldwide vision loss needs a proper approach for treatment. Therein, cell therapy and regenerative medicine can hold a great promise to be an effective approach. Accordingly, some preclinical and clinical studies were conducted to search around the therapeutic influence of stem cells in Age-related macular degeneration models and subjects. Hereupon, the purpose of the current review is to discuss the mechanisms of age-related macular degeneration, appropriate animal models along with suitable dosage and route of stem cell administration for its treatment.

Adipose Stem Cell-Based Clinical Strategy for Neural Regeneration: A Review of Current Opinion

Nerve injury is a critical problem in the clinic. Nerve injury causes serious clinic issues including pain and dysfunctions for patients. The disconnection between damaged neural fibers and muscles will result in muscle atrophy in a few weeks if no treatment is applied. Moreover, scientists have discovered that nerve injury can affect the osteogenic differentiation of skeletal stem cells (SSCs) and the fracture repairing. In plastic surgery, muscle atrophy and bone fracture after nerve injury have plagued clinicians for many years. How to promote neural regeneration is the core issue of research in the recent years. Without obvious effects of traditional neurosurgical treatments, research on stem cells in the past 10 years has provided a new therapeutic strategy for us to address this problem. Adipose stem cells (ASCs) are a kind of mesenchymal stem cells that have differentiation potential in adipose tissue. In the recent years, ASCs have become the focus of regenerative medicine. They play a pivotal role in tissue regeneration engineering. As a type of stem cell, ASCs are becoming popular for neuroregenerative medicine due to their advantages and characteristics. In the various diseases of the nervous system, ASCs are gradually applied to treat the related diseases. This review article focuses on the mechanism and clinical application of ASCs in nerve regeneration as well as the related research on ASCs over the past decades.

Secretome of Mesenchymal Stem Cells and Its Potential Protective Effects on Brain Pathologies

Previous studies have indicated that mesenchymal stem cells (MSCs) have a fundamental role in the repair and regeneration of damaged tissues. There is strong evidence showing that much of the beneficial effects of these cells are due to the secretion of bioactive molecules-besides microRNAs, hormones, and neurotrophins-with anti-inflammatory, immunoregulatory, angiogenic, and trophic effects. These factors have been reported by many studies to possess protective effects on the nervous tissue. Although the beneficial effects of the secretory factors of MSCs have been suggested for various neurological diseases, their actions on astrocytic cells are not well understood. Hence, it is important to recognize the specific effects of MSCs derived from adipose tissue, in addition to the differences presented by the secretome, depending on the source and methods of analysis. In this paper, the different sources of MSCs and their main characteristics are described, as well as the most significant advances in regeneration and protection provided by the secretome of MSCs. Also, we discuss the possible neuroprotective mechanisms of action of the MSC-derived biomolecules, with special emphasis on the effect of MSCs derived from adipose tissue and their impact on glial cells and brain pathologies.

Concentrated Conditioned Media from Adipose Tissue Derived Mesenchymal Stem Cells Mitigates Visual Deficits and Retinal Inflammation Following Mild Traumatic Brain Injury

Blast concussions are a common injury sustained in military combat today. Inflammation due to microglial polarization can drive the development of visual defects following blast injuries. In this study, we assessed whether anti-inflammatory factors released by the mesenchymal stem cells derived from adipose tissue (adipose stem cells, ASC) can limit retinal tissue damage and improve visual function in a mouse model of visual deficits following mild traumatic brain injury. We show that intravitreal injection of 1 μL of ASC concentrated conditioned medium from cells pre-stimulated with inflammatory cytokines (ASC-CCM) mitigates loss of visual acuity and contrast sensitivity four weeks post blast injury. Moreover, blast mice showed increased retinal expression of genes associated with microglial activation and inflammation by molecular analyses, retinal glial fibrillary acidic protein (GFAP) immunoreactivity, and increased loss of ganglion cells. Interestingly, blast mice that received ASC-CCM improved in all parameters above. In vitro, ASC-CCM not only suppressed microglial activation but also protected against Tumor necrosis alpha (TNFα) induced endothelial permeability as measured by transendothelial electrical resistance. Biochemical and molecular analyses demonstrate TSG-6 is highly expressed in ASC-CCM from cells pre-stimulated with TNFα and IFNγ but not from unstimulated cells. Our findings suggest that ASC-CCM mitigates visual deficits of the blast injury through their anti-inflammatory properties on activated pro-inflammatory microglia and endothelial cells. A regenerative therapy for immediate delivery at the time of injury may provide a practical and cost-effective solution against the traumatic effects of blast injuries to the retina.

Intraperitoneal administration of adipose tissue-derived stem cells for the rescue of retinal degeneration in a mouse model via indigenous CNTF up-regulation by IL-6

As the world's population begins to age, retinal degeneration is an increasing problem, and various treatment modalities are being developed. However, there have been no therapies for degenerative retinal conditions that are not characterized by neovascularization. We investigated whether transplantation of mouse adipose tissue-derived stem cells (mADSC) into the intraperitoneal space has a rescue effect on NaIO3 -induced retinal degeneration in mice. In this study, mADSC transplantation recovered visual function and preserved the retinal outer layer structure compared to the control group without any integration of mADSC into the retina. Moreover, endogenous ciliary neurotrophic factor (CNTF) was elevated in the retinas of mADSC-treated mice. We found that lipopolysaccharide (LPS) or LPS-stimulated monocyte supernatant induced the secretion of granulocyte colony stimulating factor (GCSF), CD54, CXCL10, interleukin-6 (IL-6), and CCL5 from the mADSC by cytokine array. Network inference was conducted to investigate signaling networks related to CNTF regulation. Based on bioinformatics data, the expression of IL-6 was related to the expression of CNTF. Additionally, intravitreal injection of IL-6 in rats produced up-regulation of endogenous CNTF in the retina. mADSC had a rescue effect on retinal degeneration through the up-regulation of endogenous CNTF by IL-6. Thus, transplantation of mADSC could be a potential treatment option for retinal degeneration.

Stem Cell Treatment in Retinal Diseases: Recent Developments

Stem cells are undifferentiated cells which have the ability to self-renew and differentiate into mature cells. They are highly proliferative, implying that an unlimited number of mature cells can be generated from a given stem cell source. On this basis, stem cell replacement therapy has been evaluated in recent years as an alternative for various pathologies. Degenerative retinal diseases cause progressive visual decline which originates from continuing loss of photoreceptor cells and outer nuclear layers. Theoretically, this therapy will enable the generation of new retinal cells from stem cells to replace the damaged cells in the diseased retina. In addition, stem cells are able to perform multiple functions, such as immunoregulation, anti-apoptosis of neurons, and neurotrophin secretion. With recent progress in experimental stem cell applications, phase I/II clinical trials have been approved. These latest stem cell transplantation studies showed that this therapy is a promising approach to restore visual function in eyes with degenerative retinal diseases such as retinitis pigmentosa, Stargardts’ macular dystrophy, and age-related macular degeneration. This review focuses on new developments in stem cell therapy for degenerative retinal diseases.

Decellularized matrix of adipose-derived mesenchymal stromal cells enhanced retinal progenitor cell proliferation via the Akt/Erk pathway and neuronal differentiation

BACKGROUND AIMS

Retinal progenitor cells (RPCs) are a promising cell therapy treatment for retinal degenerative diseases. However, problems with limited proliferation ability and differentiation preference toward glia rather than neurons restrict the clinical application of these RPCs. The extracellular matrix (ECM) has been recognized to provide an appropriate microenvironment to support stem cell adhesion and direct cell behaviors, such as self-renewal and differentiation.

METHODS

In this study, decellularized matrix of adipose-derived mesenchymal stromal cells (DMA) was manufactured using a chemical agent method (0.5% ammonium hydroxide Triton + 20 mmol/L NH4OH) in combination with a biological agent method (DNase solution), and the resulting DMA were evaluated by scanning electron microscopy (SEM) and immunocytochemistry. The effect of DMA on RPC proliferation and differentiation was evaluated by quantitative polymerase chain reaction, Western blot and immunocytochemistry analysis.

RESULTS

DMA was successfully fabricated, as demonstrated by SEM and immunocytochemistry. Compared with tissue culture plates, DMA may effectively enhance the proliferation of RPCs by activating Akt and Erk phosphorylation; when the two pathways were blocked, the promoting effect was reversed. Moreover, DMA promoted the differentiation of RPCs toward retinal neurons, especially rhodopsin- and recoverin-positive photoreceptors, which is the most interesting class of cells for retinal degeneration treatment.

CONCLUSIONS

These results indicate that DMA has important roles in governing RPC proliferation and differentiation and may contribute to the application of RPCs in treating retinal degenerative diseases.

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.

Overview of retinal differentiation potential of mesenchymal stem cells: A promising approach for retinal cell therapy

Retinal disease caused by retinal cell apoptosis leads to irreversible vision loss. Stem cell investigation efforts have been made to solve and cure retinal disorders. There are several sources of stem cells which have been used in these experiments. Numerous studies demonstrated that transplanted stem cells can migrate into and integrate in different layers of retina. Among these, mesenchymal stem cells (MSCs) were considered a promising source for cell therapy. Here, we review the literature assessing the potential of MSCs to differentiate into retinal cells in vivo and in vitro as well as their clinical application. However, more investigation is required to define the protocols that optimize stem cell differentiation and their functional integration in the retina.

Subretinal adipose tissue-derived mesenchymal stem cell implantation in advanced stage retinitis pigmentosa: a phase I clinical safety study

BACKGROUND

This prospective clinical case series aimed to investigate the safety of subretinal adipose tissue-derived mesenchymal stem cell (ADMSC) implantation in advanced stage retinitis pigmentosa (RP).

METHODS

This study included 11 patients with end-stage RP who received subretinal implantation of ADMSCs. All patients had a total visual field defect and five of them only had light perception. The best corrected visual acuity (BCVA) in the study was 20/2000. All patients had undetectable electroretinography (ERG). The worst eye of the patient was operated on and, after total vitrectomy with a 23 gauge, ADMSCs were injected subretinally. Patients were evaluated at day 1, at weeks 1-4, and then once a month for 6 months, postoperatively. BCVA, anterior segment and fundus examination, color photography, and optical coherence tomography (OCT) were carried out at each visit. Fundus fluorescein angiography (FFA), perimetry, and ERG recordings were performed before treatment and at the end of month 6, and anytime if necessary during the follow-up.

RESULTS

All 11 patients completed the 6-month follow-up. None of them had systemic complications. Five patients had no ocular complications. One of the patients experienced choroidal neovascular membrane (CNM) at the implantation site and received an intravitreal anti-vascular endothelial growth factor drug once. Five patients had epiretinal membrane around the transplantation area and at the periphery, and received a second vitrectomy and silicon oil injection. There was no statistically significant difference in BCVA and ERG recordings from baseline. Only one patient experienced an improvement in visual acuity (from 20/2000 to 20/200), visual field, and ERG. Three patients mentioned that the light and some colors were brighter than before and there was a slight improvement in BCVA. The remaining seven patients had no BCVA improvement (five of them only had light perception before surgery).

CONCLUSIONS

Stem cell treatment with subretinal implantation of ADMSCs seems to have some ocular complications and should be applied with caution. The results of this study provide the first evidence of the short-term safety of ADMSCs in humans, and clarifies the complications of the therapy which would be beneficial for future studies. To optimize the cell delivery technique and to evaluate the effects of this therapy on visual acuity and the quality of life of these patients, future studies with a larger number of cases will be necessary.

Research progress of stem cells on glaucomatous optic nerve injury

Glaucoma, the second leading cause of blindness, is an irreversible optic neuropathy. The mechanism of optic nerve injury caused by glaucoma is undefined at present. There is no effective treatment method for the injury. Stem cells have the capacity of self-renewal and differentiation. These two features have made them become the research focus on improving the injury at present. This paper reviews the application progress on different types of stem cells therapy for optic nerve injury caused by glaucoma.

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.

Storage effect on viability and biofunctionality of human adipose tissue-derived stromal cells

BACKGROUND AIMS

In our recent studies, the transplantation of human adipose tissue-derived stromal cells (ASCs) has shown promise for treatment of diseases related to bone and joint disorders.

METHODS

For the current clinical applications, ASCs were formulated and suspended in PlasmaLyte A supplemented with heparin, glucose and human serum albumin, balanced to pH 7.4 with sodium bicarbonate. This cell solution constitutes 20% of the overall transplanted mixture and is supplemented with hyaluronic acid (60%) and OraGraft particles (20%). We intended to investigate the effect of this transplantation mixture on the viability and biofunctionality of ASCs in bone formation. Freshly harvested cells were resuspended and incubated in the indicated mixture for up to 48 h at 4°C. Cell viability was assessed using trypan blue and AlamarBlue, and cell functionality was determined by quantifying their adhesion rate in vitro and bone formation in an ectopic mouse model.

RESULTS

More than 80% of the ASCs stored in the transplantation mixture were viable for up to 24 h. Cell viability beyond 24 h in storage decreased to approximately 50%. In addition, an equal degree of bone formation was observed between the cells transplanted following incubation in transplantation mixture for up to 24 h and zero-time non-incubated cells (control).

CONCLUSIONS

The viability and functionality of ASCs stored in the presented formulation will make such cell therapy accessible to larger and more remote populations.

Are They Really Stem Cells? Scrutinizing the Identity of Cells and the Quality of Reporting in the Use of Adipose Tissue-Derived Stem Cells

There is an increasing concern that the term adipose tissue-derived stem cell (ASC) is inappropriately used to refer to the adipose stromal vascular fraction (SVF). To evaluate the accuracy and quality of reporting, 116 manuscripts on the application of ASC in humans and animals were examined based on the 2013 published International Federation for Adipose Therapeutics and Science (IFATS)/ International Society for Cellular Therapy (ISCT) joint statement and in reference to current guidelines for clinical trials and preclinical studies. It is disconcerting that 4 among the 47 papers or 8.51% (CI 2.37-20.38) surveyed after publication of IFATS/ISCT statement reported using ASCs but in fact they used unexpanded cells. 28/47 or 59.57% (CI 44.27-73.63) explicitly reported that adherent cells were used, 35/47 or 74.47% (CI 59.65-86.06) identified expression of surface markers, and 25/47 or 53.19% (CI 14.72-30.65) verified the multilineage potential of the cells. While there are a number of papers examined in this survey that were not able to provide adequate information on the characteristics of ASCs used with some erroneously referring to the SVF as stem cells, there are more room for improvement in the quality of reporting in the application of ASCs in humans and animals.

Epiretinal transplantation of human bone marrow mesenchymal stem cells rescues retinal and vision function in a rat model of retinal degeneration

Vision incapacitation and blindness associated with incurable retinal degeneration affect millions of people worldwide. In this study, 0.25×10(6) human bone marrow stem cells (hBM-MSCs) were transplanted epiretinally in the right eye of Royal College Surgeons (RCS) rats at the age of 28 days. Epiretinally transplanted cells were identified as a thin layer of cells along vitreous cavity, in close proximity to the retina or attached to the lens capsule, up to 6 weeks following transplantation. Epiretinal transplantation delayed photoreceptor degeneration and rescued retinal function up to 20 weeks following cell transplantation. Visual functions remained close to normal levels in epiretinal transplantation rats. No inflammation or any other adverse effects were observed in transplanted eyes. Our findings suggest that transplantation of hBM-MSCs as a thin epiretinal layer is effective for treatment of retinal degeneration in RCS rats, and that transplanting the cells in close proximity to the retina enhances hBM-MSC therapeutic effect compared with intravitreal injection.

Clinical features of infectious endophthalmitis in South Korea: a five-year multicenter study

BACKGROUND

To investigate clinical features of infectious endophthalmitis over five years in a South Korean population.

METHODS

Medical records of consecutive patients diagnosed with infectious endophthalmitis at eight institutions located in Gyeongsangnam-do and Pusan city between January 1, 2004 and July 31, 2010 were reviewed.

RESULTS

A total of 197 patients were diagnosed and treated. An average of 30.0 infectious endophthalmitis per year was developed. The annual incidence rate of postoperative endophthalmitis during 2006~2009 was 0.037%. The ratios of male to female and right to left were 50.2%: 49.8 % and 54.8%: 43.2%, respectively. Eighth decade and spring were the peak age (36.6%) and season (32.0%) to develop the infectious endophthalmitis. The most common past history in systemic disease was hypertension (40.4%), followed by diabetes (23.4%). Cataract operation (60.4%) was the most common cause, among which most of them was uneventful phacoemulsification (95.9%). Corneal laceration (51.6%) and liver abscess (42.9%) were the most common causes of traumatic and endogenous endophthalmitis, respectively. The percentages of patients with initial and final visual acuity less than counting fingers were 62.6% and 35.2%, respectively. Treatment with vitrectomy with or without intravitreal antibiotics injection was administered to 72.6% of patients, while 17.3% received intravitreal antibiotics only.

CONCLUSIONS

Our study revealed that the development of infectious endophthalmitis was related with seasonal variation and increased during our study period. Pars plana vitrectomy was preferred for the treatment of infectious endophthalmitis in South Korea.

Stem cell treatment of degenerative eye disease

Stem cell therapies are being explored extensively as treatments for degenerative eye disease, either for replacing lost neurons, restoring neural circuits or, based on more recent evidence, as paracrine-mediated therapies in which stem cell-derived trophic factors protect compromised endogenous retinal neurons from death and induce the growth of new connections. Retinal progenitor phenotypes induced from embryonic stem cells/induced pluripotent stem cells (ESCs/iPSCs) and endogenous retinal stem cells may replace lost photoreceptors and retinal pigment epithelial (RPE) cells and restore vision in the diseased eye, whereas treatment of injured retinal ganglion cells (RGCs) has so far been reliant on mesenchymal stem cells (MSC). Here, we review the properties of non-retinal-derived adult stem cells, in particular neural stem cells (NSCs), MSC derived from bone marrow (BMSC), adipose tissues (ADSC) and dental pulp (DPSC), together with ESC/iPSC and discuss and compare their potential advantages as therapies designed to provide trophic support, repair and replacement of retinal neurons, RPE and glia in degenerative retinal diseases. We conclude that ESCs/iPSCs have the potential to replace lost retinal cells, whereas MSC may be a useful source of paracrine factors that protect RGC and stimulate regeneration of their axons in the optic nerve in degenerate eye disease. NSC may have potential as both a source of replacement cells and also as mediators of paracrine treatment.

Paracrine-mediated neuroprotection and neuritogenesis of axotomised retinal ganglion cells by human dental pulp stem cells: comparison with human bone marrow and adipose-derived mesenchymal stem cells

We have investigated and compared the neurotrophic activity of human dental pulp stem cells (hDPSC), human bone marrow-derived mesenchymal stem cells (hBMSC) and human adipose-derived stem cells (hAMSC) on axotomised adult rat retinal ganglion cells (RGC) in vitro in order to evaluate their therapeutic potential for neurodegenerative conditions of RGC. Using the transwell system, RGC survival and length/number of neurites were quantified in coculture with stem cells in the presence or absence of specific Fc-receptor inhibitors to determine the role of NGF, BDNF, NT-3, VEGF, GDNF, PDGF-AA and PDGF-AB/BB in stem cell-mediated RGC neuroprotection and neuritogenesis. Conditioned media, collected from cultured hDPSC/hBMSC/hAMSC, were assayed for the secreted growth factors detailed above using ELISA. PCR array determined the hDPSC, hBMSC and hAMSC expression of genes encoding 84 growth factors and receptors. The results demonstrated that hDPSC promoted significantly more neuroprotection and neuritogenesis of axotomised RGC than either hBMSC or hAMSC, an effect that was neutralized after the addition of specific Fc-receptor inhibitors. hDPSC secreted greater levels of various growth factors including NGF, BDNF and VEGF compared with hBMSC/hAMSC. The PCR array confirmed these findings and identified VGF as a novel potentially therapeutic hDPSC-derived neurotrophic factor (NTF) with significant RGC neuroprotective properties after coculture with axotomised RGC. In conclusion, hDPSC promoted significant multi-factorial paracrine-mediated RGC survival and neurite outgrowth and may be considered a potent and advantageous cell therapy for retinal nerve repair.