A. Cagri Uysal

Bio: A. Cagri Uysal is an academic researcher from Başkent University. The author has contributed to research in topics: Medicine & Regeneration (biology). The author has an hindex of 4, co-authored 4 publications receiving 744 citations.

Concise Review: Adipose‐Derived Stem Cells as a Novel Tool for Future Regenerative Medicine

Abstract: The potential use of stem cell-based therapies for the repair and regeneration of various tissues and organs offers a paradigm shift that may provide alternative therapeutic solutions for a number of diseases. The use of either embryonic stem cells (ESCs) or induced pluripotent stem cells in clinical situations is limited due to cell regulations and to technical and ethical considerations involved in the genetic manipulation of human ESCs, even though these cells are, theoretically, highly beneficial. Mesenchymal stem cells seem to be an ideal population of stem cells for practical regenerative medicine, because they are not subjected to the same restrictions. In particular, large number of adipose-derived stem cells (ASCs) can be easily harvested from adipose tissue. Furthermore, recent basic research and preclinical studies have revealed that the use of ASCs in regenerative medicine is not limited to mesodermal tissue but extends to both ectodermal and endodermal tissues and organs, although ASCs originate from mesodermal lineages. Based on this background knowledge, the primary purpose of this concise review is to summarize and describe the underlying biology of ASCs and their proliferation and differentiation capacities, together with current preclinical and clinical data from a variety of medical fields regarding the use of ASCs in regenerative medicine. In addition, future directions for ASCs in terms of cell-based therapies and regenerative medicine are discussed. STEM CELLS 2012;30:804–810

Tendon regeneration and repair with adipose derived stem cells

Abstract: Tendon, the crucial element of the musculoskeletal system, when damaged, never restores the biological and biomechanical properties completely. Recently, tissue engineering and regenerative medicine have enabled the differentiation of postnatal somatic stem cells or mesenchymal stem cells (MSCs) to different cell lineages and tissues including tendon. In addition, the MSCs, mainly bone marrow derived stem cells (BSCs) were proven to enhance tendon healing. Adipose derived stem cells (ASCs) were shown to be as effective as the other MSCs by their multipotency and proliferative efficiency. However, neither the differentiation of ASCs to tenocytes nor the tendon regeneration using ASCs have been described in literature. Recently, we have studied the effect of ASCs on primary tendon repair in in-vivo model. In this paper, we sought to discuss tendon tissue engineering by focusing on culture of tenocytes, biomaterials, scaffolds, mechanical loading, fibroblasts and mesenchymal stem cells and mainly on adipose derived stem cells. Tendon regeneration using ASCs might be one of the clinical remedies in near future. In addition, the enhancing effect of ASCs on tendon repair and tendon defects might enable better clinical outcomes in musculoskeletal system reconstruction. Advances in biomaterial technology will improve the methodology in tendon regeneration however, up to date, ASCs present an ideal cell source for experimental and clinical research on tendon engineering.

Adipose-Derived Stem Cells as a Novel Tool for Future Regenerative Medicine

Abstract: Stem cell-based therapies for the repair and regeneration of damaged tissues and organs offer a paradigm shift that may provide alternative therapeutic solutions for a number of diseases. The use of either embryonic stem cells or induced pluripotent stem cells in clinical situations may be still limited due to cell behaviors, ethical considerations, and genetic manipulation, even though these cells are theoretically highly beneficial. Adipose-derived stem cells (ASCs) seem to be an ideal population of stem cells for practical regenerative medicine since they are plentiful, of autologous tissue origin and thus non-immunogenic, and are more available due to minimal ethical considerations. Furthermore, recent basic research and preclinical studies have revealed that the use of ASCs in regenerative medicine is not limited to mesodermal components, but extends to both ectodermal and endodermal tissues and organs, even though ASCs are mesodermal in origin. This chapter will describe the biology of ASCs and their proliferation and differentiation capacities, and will summarize the current preclinical and clinical data from a variety of medical fields on the use of ASCs in regenerative medicine.

Differentiation of adipose-derived stem cells for tendon repair.

Abstract: The goal of primary tendon repair is to increase tensile strength at the time of mobilization. Tendon repair and regeneration using mesenchymal stem cells have been described in several studies; however, the use of adipose derived stem cells (ASCs) for tendon repair has only recently been considered. In order to establish a suitable experimental model for the primary tendon repair using ASCs, this chapter describes the detailed methods for: (1) isolating stem cells from adipose tissue, (2) generation of a primary tendon injury and repair model, (3) evaluating functional restoration by measuring tensile strength, and (4) investigating the mechanisms involved in ASC-mediated tendon healing by histological and immunohistochemical analyses. Topical administration of ASCs to the site of injury accelerates tendon repair, as exhibited by a significant increase in tensile strength, direct differentiation of ASCs toward tenocytes and endothelial cells, and increases in angiogenic growth factors. These findings suggest that ASCs may have a positive effect on primary tendon repair and may be useful for future cell-based therapy.

The effect of hydrochlorothiazide on the recurrence of nonmelanoma skin cancer: a 7-year retrospective study comprising 300 patients.

Abstract: BACKGROUND Hydrochlorothiazide (HCTZ) possesses well-described photosensitizing properties, and a causal association with nonmelanoma skin cancer (NMSC) was recently shown. However, previous studies have not shown whether HCTZ use is associated with the risk of recurrence of basal cell carcinoma (BCC) or squamous cell carcinoma (SCC). This study aims to investigate the association between HCTZ use and recurrence in patients with NMSC. METHODS We identified cases with NMSC from our hospital archives during the period between 2013 and 2019. Patients were divided into groups according to the pathological diagnosis, HCTZ use, and recurrence. Multivariable analysis was performed to determine factors associated with recurrence in BCC and SCC. RESULTS Recurrences of BCC were significantly higher in HCTZ users with ORs of 4.839221 (95% confidence interval [CI], 1.22-19.12).In HCTZ users, NMSC cases were associated with increased age (p < 0.001 for both BCC and SCC). BCC recurrences were statistically significant with age, longer follow-up, and positive margins after excision in HCTZ users (p = 0.048, 0.020, and, 0.003, respectively). SCC recurrences were not significantly associated with HCTZ use. DISCUSSION HCTZ use is significantly associated with BCC recurrences. Especially in the elderly population, cases with a positive margin should be followed closely.

Same or Not the Same? Comparison of Adipose Tissue-Derived Versus Bone Marrow-Derived Mesenchymal Stem and Stromal Cells

Abstract: Mesenchymal stem/stromal cells (MSCs) comprise a heterogeneous population of cells with multilineage differentiation potential, the ability to modulate oxidative stress, and secrete various cytokines and growth factors that can have immunomodulatory, angiogenic, anti-inflammatory and anti-apoptotic effects. Recent data indicate that these paracrine factors may play a key role in MSC-mediated effects in modulating various acute and chronic pathological conditions. MSCs are found in virtually all organs of the body. Bone marrow-derived MSCs (BM-MSCs) were discovered first, and the bone marrow was considered the main source of MSCs for clinical application. Subsequently, MSCs have been isolated from various other sources with the adipose tissue, serving as one of the alternatives to bone marrow. Adipose tissue-derived MSCs (ASCs) can be more easily isolated; this approach is safer, and also, considerably larger amounts of ASCs can be obtained compared with the bone marrow. ASCs and BM-MSCs share many biological characteristics; however, there are some differences in their immunophenotype, differentiation potential, transcriptome, proteome, and immunomodulatory activity. Some of these differences may represent specific features of BM-MSCs and ASCs, while others are suggestive of the inherent heterogeneity of both BM-MSC and ASC populations. Still other differences may simply be related to different isolation and culture protocols. Most importantly, despite the minor differences between these MSC populations, ASCs seem to be as effective as BM-MSCs in clinical application, and, in some cases, may be better suited than BM-MSCs. In this review, we will examine in detail the ontology, biology, preclinical, and clinical application of BM-MSCs versus ASCs.

Concise Review: Adipose‐Derived Stem Cells as a Novel Tool for Future Regenerative Medicine

Abstract: The potential use of stem cell-based therapies for the repair and regeneration of various tissues and organs offers a paradigm shift that may provide alternative therapeutic solutions for a number of diseases. The use of either embryonic stem cells (ESCs) or induced pluripotent stem cells in clinical situations is limited due to cell regulations and to technical and ethical considerations involved in the genetic manipulation of human ESCs, even though these cells are, theoretically, highly beneficial. Mesenchymal stem cells seem to be an ideal population of stem cells for practical regenerative medicine, because they are not subjected to the same restrictions. In particular, large number of adipose-derived stem cells (ASCs) can be easily harvested from adipose tissue. Furthermore, recent basic research and preclinical studies have revealed that the use of ASCs in regenerative medicine is not limited to mesodermal tissue but extends to both ectodermal and endodermal tissues and organs, although ASCs originate from mesodermal lineages. Based on this background knowledge, the primary purpose of this concise review is to summarize and describe the underlying biology of ASCs and their proliferation and differentiation capacities, together with current preclinical and clinical data from a variety of medical fields regarding the use of ASCs in regenerative medicine. In addition, future directions for ASCs in terms of cell-based therapies and regenerative medicine are discussed. STEM CELLS 2012;30:804–810

Advances in skin grafting and treatment of cutaneous wounds.

Abstract: The ability of the skin to repair itself after injury is vital to human survival and is disrupted in a spectrum of disorders. The process of cutaneous wound healing is complex, requiring a coordinated response by immune cells, hematopoietic cells, and resident cells of the skin. We review the classic paradigms of wound healing and evaluate how recent discoveries have enriched our understanding of this process. We evaluate current and experimental approaches to treating cutaneous wounds, with an emphasis on cell-based therapies and skin transplantation.

Spinal Fusion in the Next Generation: Gene and Cell Therapy Approaches

Abstract: Bone fusion represents a challenge in the orthopedics practice, being especially indicated for spine disorders. Spinal fusion can be defined as the bony union between two vertebral bodies obtained through the surgical introduction of an osteoconductive, osteoinductive, and osteogenic compound. Autogenous bone graft provides all these three qualities and is considered the gold standard. However, a high morbidity is associated with the harvest procedure. Intensive research efforts have been spent during the last decades to develop new approaches and technologies for successful spine fusion. In recent years, cell and gene therapies have attracted great interest from the scientific community. The improved knowledge of both mesenchymal stem cell biology and osteogenic molecules allowed their use in regenerative medicine, representing attractive approaches to achieve bone regeneration also in spinal surgery applications. In this review we aim to describe the developing gene- and cell-based bone regenerative approaches as promising future trends in spine fusion.