Stromal Vascular Fraction Of Adipose Tissue Research Articles

Incretin-responsive human pancreatic adipose tissue organoids: a functional model for fatty pancreas research.

Infiltration of adipocytes into the pancreatic parenchyma has been linked to impaired insulin secretion in individuals with increased genetic risk of T2D and prediabetic conditions. However, the study of this ectopic fat depot has been limited by the lack of suitable in vitro models. Here, we developed a novel 3D model of functionally mature human pancreatic adipose tissue organoids by aggregating human pancreatic adipose tissue-derived stromal vascular fraction (SVF) cells into organoids and differentiating them over 19 days. These organoids carry biological properties of the in situ pancreatic fat, presenting levels of adipogenic markers comparable to native pancreatic adipocytes and improved lipolytic and anti-lipolytic response compared to conventional 2D cultures. The organoids harbour a small population of immune cells, mimicking in vivo adipose environment. Furthermore, they express GIPR, allowing investigation of incretin effects in pancreatic fat. In accordance, GIP and the dual GLP1R/GIPR agonist tirzepatide stimulate lipolysis but had distinct effects on the expression of proinflammatory cytokines. This novel adipose organoid model is a valuable tool to study the metabolic impact of incretin signalling in pancreatic adipose tissue, revealing potential therapeutic targets of incretins beyond islets. The donor-specific metabolic memory of these organoids enables examination of the pancreatic fat-islet crosstalk in a donor-related metabolic context.

Epigenetic modifications in transdifferentiation of adipose tissue-derived stromal cells into spontaneously beating cardiomyocyte-like cells

Abstract Background Adipose tissue-derived stromal vascular fraction (adipose SVF) contains pluripotent mesenchymal stem cells and rarely transdifferentiate into beating cardiomyocytes. We developed a simple culture protocol under which the adult murine inguinal adipose SVF reproductively transdifferentiates into beating cardiomyocyte-like cells (beating CM) without inductions in the primary culture. We also reported that Mef2c is a crucial factor in this conversion. However, the characteristics of beating CM and the factors that regulate the differentiation of adipose SVF toward the cardiac lineage are unknown. Purpose To investigate sequential changes in global gene expression profiles of adipose SVF in primary culture and determine the mechanism of differentiation into beating CM. Methods Adipose SVF cells were isolated from adult mice's inguinal subcutaneous fat pad and cultured using the previously established beating CM induction method (Sci Rep. 2021). At 6 time points (days 0, 3, 7, 14, 21, and 28) in primary culture, total RNA was extracted, and RNA-sequencing was performed (n = 3). The data was analyzed using Subio Platform and MetaCore software. To assess the candidate gene and proteins, adipose SVF cells were transduced with the gene using a lentivirus vector and supplemented with the specific inhibitors. The cardiac differentiation was evaluated by quantitative PCR on day 28. Results The beating CM was confirmed on days 14, 21, and 28 in the primary culture. Among prefiltered 14,574 genes, the expression level of 749 genes were significantly changed (153 genes upregulated vs. 596 genes downregulated) between days 7 and 14 (2-fold, P < 0.05), in which beating CM appeared. The GO molecular functions analysis showed that O-GluNAC transferase and histone deacetylase (HDAC)-associated genes were expressed dominantly before day 7, and KLF4-associated genes were expressed prominently after day 14 in primary culture. The expression of cardiac troponin T (Tnnt2) and myosin light chain ventricular type (Myl2) increased on day 3 and day 14, respectively. The HDAC7, an epigenetic regulator, decreased the expression on day 14 or later. Treatment with the HDAC inhibitor (150 nmol/L) increased the expression of Tnnt2 (5-fold vs. control) on day 28 in adipose SVF. Furthermore, treatment of Mef2c-transduced adipose SVFs with HDAC inhibitors increased expression of cardiac troponin T (29-fold vs. control, P < 0.05). Conclusion The time course analysis demonstrated that a remarkable change occurred in the regulation of transcription on day 14 in adipose SVF primary culture. Alterations in epigenetic modifications increased beating CM in adipose SVFs. Adipose SVF could be applied to new cardiac regeneration therapies by increasing the efficiency of introduction into the beating CM.

Emergence of the stromal vascular fraction and secretome in regenerative medicine.

Recently, we read a mini-review published by Jeyaraman et al. The article explored the optimal methods for isolating mesenchymal stromal cells from adipose tissue-derived stromal vascular fraction (SVF). Key factors include tissue source, processing techniques, cell viability assessment, and the advantages/disadvantages of autologous vs allogeneic use. The authors emphasized the need for standardized protocols for SVF isolation, ethical and regulatory standards for cell-based therapy, and safety to advance mesenchymal stromal cell-based therapies in human patients. This manuscript shares our perspective on SVF isolation in canines. We discussed future directions to potentiate effective regenerative medicine therapeutics in human and veterinary medicine.

Effect of Stromal Vascular Fraction in the Rat Model of Pharyngocutaneous Fistulas.

A pharyngocutaneous fistula is one of the complications after laryngeal and pharyngeal surgery. It may also contribute to wound healing due to adipose tissue-derived stem cells and the growth factors in the stromal vascular fraction. The aim of this study was to investigate the effects of the adipose tissue-derived stromal vascular fraction on wound healing in the pharyngocutaneous fistula model induced in rats. Approval was received from the Animal Experiments Local Ethics Committee before starting the study (29.01.2016-2016/09). Eleven male Sprague-Dawley rats weighing approximately 300 g were included in the study. The animals were randomly divided into the study and control groups so that each group would include five animals. An animal was assigned as a donor for the removal of omental adipose tissue. Among the animals in which the pharyngocutaneous fistula model was created under general anesthesia, 1 ml of the stromal vascular fraction was injected into the study group on postoperative day 1. In postoperative week 2, all the animals were sacrificed and examined histologically (epithelialization-cell infiltration - mucosal injury). IBM SPSS Statistics for Windows, version 15, was used in the analyses. A p-value <0.05 was considered significant. Epithelialization was higher in the study group compared to the control group. However, no statistically significant difference was found between the two groups (p = 0.08). The cell infiltration was found to be statistically higher in the control group compared to the study group (p = 0.03). The mucosal injury was found to be significantly higher in the control group compared to the study group (p = 0.03). According to the Pearson correlation test, a negative correlation was found between epithelialization and cell infiltration and mucosal injury (p = 0.019 and p = 0.001). A positive correlation was found between cell infiltration and mucosal injury (p = 0.009). It was shown that stromal vascular fraction had a positive effect on wound healing in the pharyngocutaneous fistula model. According to the data we have obtained, we think that it can be effective in the treatment of pharyngocutaneous fistulas after more extensive preclinical and clinical studies are carried out.

The potential of exosomes from adipose-derived stromal-vascular fraction in Increasing Migration Activity of Human Dental Pulp Stromal Cells (in vitro study)

BackgroundMigration of dental pulp stromal cells (DPSCs) significantly responds to wound healing after pulp injury. Deriving from low compliance characteristics, pulp tissue regeneration is challenging and depends on the microenvironmental signals. Exosomes can maintain and carry bioactive proteins that are crucial in cell communication. Adipose tissue-derived stromal vascular fraction (AD-SVF), a heterogeneous group of progenitor cells, is a promising source of exosomes. ObjectiveDiscover the impact of exosomes derived from an adipose-derived stromal-vascular fraction (AD-SVF Exo) on human dental pulp stromal cells (hDPSCs) migration. Methods: In-vitro design involving AD-SVF Exo applied to hDPSCs cultivated until 80% confluence and 3rd-4th passage. AD-SVF Exo isolation through size exclusion chromatography (SEC). The AD-SVF Exo was characterized using Nanoparticle Tracking Analysis (NTA) and flow cytometry assays. hDPSCs were exposed to AD-SVF Exo (0% as the control group, 0.1%, and 1% as the experimental group), subjected to a scratch wound assay, and observed at 6, 24, and 48 h. ResultshDPSCs cultured expressed mesenchymal stem cell mesenchymal stem cell (MSC) markers and formed loose colonies with characteristic spindle-shaped morphology. AD-SVF Exo consisted of marker proteins CD9 and CD63, and NTA measurement demonstrated a diameter of 103 ± 24 nm in diameter with 1,6 x 108 particles/ml. Based on scratch assay, hDPSCs migration activity improved by reduced wound area in experimental groups. Data analyzed utilizing the Friedman (p < 0.001), and Kruskal Wallis (p < 0.05) test indicated differences in wound area after exposure of 0.1 % and 1 % AD-SVF Exo and observed at 6, 24, and 48 h. ConclusionAccording to the findings of this research, AD-SVF Exo successfully enhances the wound healing capabilities of hDPSCs by improved migration activity, with the highest result found in 0.1% AD-SVF Exo.

Effectiveness of Autodermoplasty in Combination with Injection of Autological Stromal-Vascular Cell Fraction in Treatment of Deep Burns

Introduction. The use of autologous stromal-vascular cell fraction of adipose tissue seems to be one of the promising technologies to increase the effectiveness of skin grafting and other skin restoration options in burnt patients. The main regenerative component of the stromal-vascular fraction are mesenchymal stem cells, which have a high reparative potential and low immunogenicity.The aim of the study was to increase the effectiveness of surgical treatment of patients with skin burns through the injection of autological stromal-vascular cell fraction of the adipose tissue.Materials and methods. The study was conducted as part of a prospective, open, randomized study involving 61 patients with extensive skin burns treated in burn centers Dzhanelidze Saint-Petersburg Research Institute of Emergency Medicine and Vishnevsky National Medical Research Center of Surgery, Ministry of Health of Russia, in 2021-2023. Cells of the stromal-vascular fraction of the adipose tissue were obtained mechanically and enzymatically. The prepared cell suspension was introduced into the granulation tissue during skin grafting with split autodermal grafts having a high perforation coefficient. During the study, planimetric parameters, as well as the results of histological and immunohistochemical tests, were assessed. The obtained findings were processed using generally accepted algorithms of variation and descriptive statistics. The alternative hypothesis was accepted at p0.05.Results. The proposed technique of autologous stromal-vascular cell fraction of the adipose tissue with simultaneous autodermoplasty with a split perforated graft allowed reducing the time of perforating cell epithelization by 28% (p0.05), the time of final engraftment by 11% (p0.05), the frequency of infectious complications in the postoperative period by 20% (p0.05), as well as the frequency of lysis and rejection reactions by 15% (p0.05). As stated, the introduction of an autologous stromal-vascular fraction during skin grafting resulted in early relief of the inflammatory reaction in the area of a deep burn wound, the fact being supported by clinical, cytological, histological and immunohistochemical tests.Conclusion. The use of cells from the stromal-vascular fraction of the adipose tissue can significantly increase the effectiveness of surgical treatment of patients with extensive skin burns. The proposed technique to obtain and apply the stromal-vascular fraction of the adipose tissue at the stage of autodermoplasty can be introduced into clinical practice in both burn centers and surgical/trauma departments, since it does not require special equipment.

Cytokine production by bovine adipose tissue stromal vascular fraction cells upon Neospora caninum stimulation

In bovines few studies addressed the contribution of adipose tissue to the host immune response to infection. Here we evaluated the in vitro response of bovine adipose tissue stromal vascular fraction (SVF) cells to the protozoan parasite Neospora caninum, using live and freeze-killed tachyzoites. Live N. caninum induced the production of IL-6, IL-1β and IL-10 by SVF cells isolated from subcutaneous adipose tissue (SAT), while in mesenteric adipose tissue (MAT) SVF cell cultures only IL-1β and IL-10 production was increased, showing slight distinct responses between adipose tissue depots. Whereas a clear IL-8 increase was detected in peripheral blood leucocytes (PBL) culture supernatants in response to live N. caninum, no such increase was observed in SAT or MAT SVF cell cultures. Nevertheless, in response to LPS, increased IL-8 levels were detected in all cell cultures. IL-10 levels were always increased in response to stimulation (live, freeze-killed N. caninum and LPS). Overall, our results show that bovine adipose tissue SVF cells produce cytokines in response to N. caninum and can therefore be putative contributors to the host immune response against this parasite.

Effect of sternocleidomastoid flap repair and endoscopic injection of emulsified adipose tissue stromal vascular fraction in the treatment of refractory cervical anastomotic leak contaminating mediastinum.

Mediastinal infection caused by anastomotic leak is hard to cure, mainly because the poor drainage at the site of mediastinal infection leads to persistent cavity infection, which in turn becomes a refractory mediastinal abscess cavity after minimally invasive esophagectomy (MIE)-McKeown. Herein, we explored sternocleidomastoid (SCM) muscle flaps and emulsified adipose tissue stromal vascular fraction containing adipose-derived stem-cells to address this issue. We studied 10 patients with esophageal cancer who underwent MIE-McKeown + 2-field lymphadenectomy and developed anastomotic and mediastinal leak and received new technology treatment in the Affiliated Cancer Hospital of Zhengzhou University from June 2018 to March 2022. The clinical data and prognosis of the patients were collected and analyzed. A total of 5 patients received this surgery, and no other complications occurred during the perioperative period. Among the 5 patients, 1 patient was partially cured, and 4 patients were completely cured. During the follow-up 3 months postoperatively, all these 5 patients could eat regular food smoothly, and no relapse of leak and mediastinal infection occurred. The new surgical method has achieved good results in the treatment of anastomotic leak. Compared with the traditional thoracotomy, it is a less invasive and feasible surgical approach, which can be used as a supplement to the effective surgical treatment of cervical anastomotic leak contaminating the mediastinum.

Comparison of the Effectiveness of Methods for Obtaining and Application the Stromal-Vascular Fraction of Adipose Tissue in an Experimental Model of a Donor Wound in Burns

Introduction. The optimal method of obtaining and application a stromal-vascular fraction (SVF) of adipose tissue in the treatment of donor wounds in burned patients has not been determined.Objective — to compare the effectiveness of the stromal-vascular fraction of adipose tissue in the treatment of donor wounds, depending on the method of obtaining (mechanical and enzymatic) and the injection (subdermal, intradermal) into the tissue.Material and methods. Wistar rats (n = 30) were divided into 2 investigated groups: in the first group (eSVF) enzymatic processing of adipose tissue (n = 10) was used, in the second group (mSVF) mechanical processing was used (n = 10). Another 10 rats were used as adipose tissue donors’ group. A deep burn was created in all animals, and after 4 days two more donor wounds were created by taking a split thickness skin autograft: the stromal-vascular fraction was injected intradermally into one of the wounds, subdermally into the other. After 14 days, the area of epithelialization, the microcirculation index and the histological microstructure of the skin were evaluated.Results. The proportion of completely epithelized donor wounds in the eSVF-group was 85 %, in the mSVF-group — 55 % (p &lt; 0.05). The index of microcirculation significantly decreased after intradermal injections in the eSVF-group (p &lt; 0.01), and after subdermal injections — in the mSVF-group (p &lt; 0.05). According to histomorphometry, with intradermal injections of eSVF, the thickness of the epidermis and the layer of granulation tissue is less than in the mSVF group (p &lt; 0.01). At the same time, the relative density of collagen fibers in the granulation tissue was significantly higher after the injections of eSVF than after mSVF (p &lt; 0.01). Comparison of injections of the stromal-vascular fraction showed: no significant differences were found when using eSVF; when using mSVF, the subdermal injections are preferable, since it was accompanied by a significantly lower thickness of granulation tissue (p &lt; 0.01).Conclusions. The enzymatically obtained stromal-vascular fraction of adipose tissue has advantages over the mechanically obtained one: the efficiency of eSVF is equally high when used with intradermally and subdermally injections, which are confirmed by the structure and blood circulation in the newly formed skin. When using mSVF, intradermal injections are the least effective, and subdermal injections are accompanied by a moderately pronounced positive dynamic in the microstructure of the skin of donor wounds.

Efficacy of the immediate adipose-derived stromal vascular fraction autograft on functional sensorimotor recovery after spinal cord contusion in rats.

Spinal cord injuries (SCI) lead to functional alteration with important consequences such as motor and sensory disorders. The repair strategies developed to date remain ineffective. The adipose tissue-derived stromal vascular fraction (SVF) is composed of a cocktail of cells with trophic, pro-angiogenic and immunomodulatory effects. Numerous therapeutic benefits were shown for tissue reconstitution, peripheral neuropathy and for the improvement of neurodegenerative diseases. Here, the therapeutic efficacy of SVF on sensorimotor recovery after an acute thoracic spinal cord contusion in adult rats was determined. Male Sprague Dawley rats (n = 45) were divided into 3 groups: SHAM (without SCI and treatment), NaCl (animals with a spinal lesion and receiving a saline injection through the dura mater) and SVF (animals with a spinal lesion and receiving a fraction of fat removed from adipocytes through the dura mater). Some animals were sacrificed 14days after the start of the experiment to determine the inflammatory reaction by measuring the interleukin-1β, interleukin-6 and Tumor Necrosis Factor-α in the lesion area. Other animals were followed once a week for 12weeks to assess functional recovery (postural and locomotor activities, sensorimotor coordination). At the end of this period, spinal reflexivity (rate-dependent depression of the H-reflex) and physiological adjustments (ventilatory response to metabosensitive muscle activation following muscle fatigue) were measured with electrophysiological tools. Compared to non-treated animals, results indicated that the SVF reduced the endogenous inflammation and increased the behavioral recovery in treated animals. Moreover, H-reflex depression and ventilatory adjustments to muscle fatigue were found to be comparable between SHAM and SVF groups. Our results highlight the effectiveness of SVF and its high therapeutic potential to improve sensorimotor functions and to restore the segmental sensorimotor loop and the communication between supra- and sub-lesional spinal cord regions after traumatic contusion.

Effect of adipose tissue-derived stromal vascular fraction on the viability of random-pattern skin flaps: an experimental study

Aims: Random pattern skin flaps are still widely used in plastic surgery. However, necrosis in distal flap sections resulting from ischemia is a serious problem, increasing the cost of treatment and hospitalization. The aim of this study was to test the effects of adipose tissue derived stromal vascular fraction (SVF) on random pattern skin flaps in rats. Methods: In this experimental study conducted on Wistar rats, three groups were formed using the simple random sampling technique. Group 1 consisted of rats with a raised flap and a subcutaneous SVF injection. Group 2 comprised rats that underwent a flap operation with no additional treatment. Group 3 included rats with a raised flap and a subcutaneous saline injection. Tissue necrosis and level of survival area was detected with planimetric method and histopathologic examination was performed for detect of level of vascular density. On the 7th day post-operation, the viability assessment was calculated based on the ratio of the living flap area to the total flap area. Results: The mean viability rate in Group 1 was higher compared to other groups, while there was no significant difference between Group 2 and Group 3 (Group 1 = 79.2 ± 4.9 % vs. Group 2 = 41.0 ± 5.9 % vs. Group 3= 39.2 ± 2.7 %, p &lt; 0.001). The mean vascular densities of the flaps were higher in Group 1 compared to the other groups, while it were similar between Group 2 and Group 3 (Group 1 = 29.8 ± 1.2 vs. Group 2 = 8.4 ± 4.6 vs. Group 3= 9.3 ± 1.8, p &lt; 0.001). Conclusion: The use of fat tissue-derived SVF injections has been found to be advantageous in improving the survival of random pattern flaps, frequently utilized in plastic and reconstructive surgery.

Treatment of medication-related osteonecrosis of the jaw with cell therapy.

Introduction: Medication-related osteonecrosis of the jaw (MRONJ) poses a significant challenge considering the absence of a "gold standard" treatment. Cell-based therapy and tissue engineering offer promising therapeutic alternatives. This study aimed to harness the regenerative properties of adipose-tissue stromal vascular fraction (AT-SVF) and leukocyte-platelet-rich fibrin (L-PRF) for MRONJ treatment. AT-SVF contains mesenchymal stromal cells (MSC) and endothelial progenitor cells (EPC), which promote bone formation, while the L-PRF scaffold can serve as a three-dimensional scaffold for the AT-SVF and support tissue healing through growth factor release. Materials and methods: The protocol involved applying autologous AT-SVF within an L-PRF matrix following surgical debridement. Age, gender, body mass index, comorbidities, underlying oncological condition, prescribed antiresorptive treatment: BP or DMB, antiresorptive treatment duration, antiresorptive treatment potential discontinuation, number of MRONJ lesion, MRONJ location, MRONJ stage, MRONJ trigger factor were assessed for each patient. Patients underwent the procedure and were monitored for a minimum of 6months based on clinical, biological and medical imaging criteria. Results: Nine patients, with a total of ten MRONJ lesions, participated in the study. Six patients were female, and three were male, with a mean age of 68 ± 8years. Four patients had multiple myeloma (MM), three had metastatic breast cancer, and two had metastatic prostate cancer. Seven MRONJ cases were classified as stage II, and three were classified as stage III. Soft tissue completely healed within a month after treatment in nine cases, with no clinical improvement observed in the remaining case. During follow-up, no sign of MRONJ recurrence was observed. Tridimensional medical imaging revealed bone healing 6months after the surgical procedure. Immunophenotyping confirmed the presence of MSC and EPC in the AT-SVF: 12,6 ± 4,5% CD31+, 20.5 ± 7,8% CD34+, 34,4 ± 7,3% CD146+ and 54,6 ± 7,4% CD45+. Conclusion: This prospective study introduces a potential new treatment approach for MRONJ using autologous AT-SVF within an L-PRF scaffold. Our results are encouraging and suggest the need for further investigation with a larger patient cohort to better understand the underlying mechanisms.

LncRNA U90926 is dispensable for the development of obesity-associated phenotypes invivo.

Obesity is a global health problem characterized by excessive fat accumulation, driven by adipogenesis and lipid accumulation. Long non-coding RNAs (lncRNAs) have recently been implicated in regulating adipogenesis and adipose tissue function. Mouse lncRNA U90926 was previously identified as a repressor of invitro adipogenesis in 3T3-L1 preadipocytes. Consequently, we hypothesized that, invivo, U90926 may repress adipogenesis, and hence its deletion would increase weight gain and adiposity. We tested the hypothesis by applying U90926-deficient (U9-KO) mice to a high-throughput phenotyping pipeline. Compared with WT, U9-KO mice showed no major differences across a wide range of behavioral, neurological, and other physiological parameters. In mice fed a standard diet, we have found no differences in obesity-related phenotypes, including weight gain, fat mass, and plasma concentrations of glucose, insulin, triglycerides, and free fatty acids, in U9-KO mice compared to WT. U90926 deficiency lacked a major effect on white adipose tissue morphology and gene expression profile. Furthermore, in mice fed a high-fat diet, we found increased expression of U90926 in adipose tissue stromal vascular cell fraction, yet observed no effect of U90926 deficiency on weight gain, fat mass, adipogenesis marker expression, and immune cell infiltration into the adipose tissue. These data suggest that the U90926 lacks an essential role in obesity-related phenotypes and adipose tissue biology invivo.

Bone defect management with tissue-engineered constructs based on deproteinized cancellous bone: an experimental study

Background Management of bone defects with autologous bone grafting has always been the "gold standard" but it is not always possible to use it for a number of reasons. Preprocessed materials of biological and non-biological origin were developed as an alternative. A new branch of these materials is tissue-engineered constructs that fully imitate autologous bone in required volume.Aim is to study in vivo the possibility of using deproteinized human cancellous bone tissue as a matrix for creating tissue-engineered constructs.Methods The study was carried out on 24 NZW line rabbits, since this line has a fully characterized stromal-vascular fraction formula (SVF). The study design included 3 groups. First group (control) had surgical modeling of bone defects in the diaphysis of the contralateral femur without reconstruction; Group 2 had bone defect reconstruction using fragments of a deproteinized cancellous bone graft; group 3 underwent bone defect reconstruction using fragments of deproteinized cancellous bone matrix along with the autologous adipose tissue SVF (obtained according to ACP SVF technology). Animals were sacrificed with ether anesthesia at 2, 4 and 6 weeks after the operation and subsequent histological study followed.Result During all periods of the study, the newly formed bone tissue volume density in the 3rd group (reconstruction with deproteinized human cancellous bone + stromal-vascular fraction) was 1.78 times higher (p &lt; 0.001) than in the first group (bone defect without reconstruction), 1.21 times higher (p &lt; 0.001) than in the 2nd group (reconstruction with deproteinized cancellous bone alone). The dynamics of changes in the mature bone tissue volume density was similar to those of the newly formed bone tissue.Discussion The comparative analysis of reparative processes using a tissue engeneered construst based on deproteinized cancellous human bone with adipose tissue stromal vascular fraction revealed that the use of these bone substitute materials contributes not only to the early activation of reparative regeneration of the main structural elements of bone tissue at the site of bone defect, but also their timely differentiation.Conclusion The use of deproteinized cancellous bone matrix combined with stromal-vascular fraction to create a tissue-engineered construct could unleash several regeneration mechanisms and accelerate the process of bone defect site repair, compared with 1st and 2nd group of study.

Adipose Derived Stromal Vascular Fraction and Mesenchymal Stem Cells Improve Angiogenesis in a Rat Hindlimb Ischaemia Model

This study aimed to investigate the effect of human adipose tissue derived stromal vascular fraction (AD-SVF) and mesenchymal stem cells (AD-MSCs) on blood flow recovery and neovascularisation in a rat hindlimb ischaemia model. SVF was isolated using an automated centrifugal system, and AD-MSCs were obtained from adherent cultures of SVF cells. Rats were divided into four groups of six rats each: non-ischaemia (Group 1); saline treated ischaemia (Group 2); SVF treated ischaemia (Group 3); and AD-MSC treated ischaemia (Group 4). Unilateral hindlimb ischaemia was induced in Sprague-Dawley rats via femoral artery ligation. Saline, SVF, or AD-MSCs were injected intramuscularly into the adductor muscle intra-operatively. Cell viability was calculated as the percentage of live cells relative to total cell number. Blood flow improvement, muscle fibre injury, and angiogenic properties were validated using thermal imaging and histological assessment. The viabilities of SVF and AD-MSCs were 83.3% and 96.7%, respectively. Group 1 exhibited no significant temperature difference between hindlimbs, indicating a lack of blood flow changes. The temperature gradient gradually decreased in SVF and AD-MSC treated rats compared with saline treated rats. In addition, only normal muscle fibres with peripherally located nuclei were observed in Group 1. Groups 3 and 4 exhibited significantly fewer centrally located nuclei, indicating less muscle damage compared with Group 2. Regarding angiogenic properties, CD31 staining of endothelial cells showed similar patterns among all groups, whereas expression of vascular endothelial growth factor, as a crucial angiogenesis factor, was enhanced in the SVF and AD-MSC treated groups. SVF and AD-MSCs improved blood flow and neovascularisation in a rat hindlimb ischaemia model, suggesting their potential ability to promote angiogenesis. Further extensive research is warranted to explore their potential applications in the treatment of severe lower extremity arterial disease.

ИММУНОФЕНОТИП МЕЗЕНХИМАЛЬНЫХ СТВОЛОВЫХ КЛЕТОК ЖИРОВОЙ ТКАНИ ПАЦИЕНТОВ С СЕРДЕЧНО СОСУДИСТЫМИ ЗАБОЛЕВАНИЯМИ

Introduction. Due to a set of unique properties, for example, the ability to differentiate into different types of connective tissue cells, mesenchymal stem cells (MSCs) are attracting more and more attention from researchers. In 2001, stem cells were found in the stromal-vascular fraction of adipose tissue, which, unlike bone marrow MSCs, show a higher tissue density, grow faster, and are available in large numbers when collected from a small amount of adipose tissue. Currently, a large number of studies are devoted to the study of the morphology and immunophenotype of subcutaneous and visceral adipose tissue stem cells (ASSCs) due to the possibility of easy cell production. Experimental work aimed at studying MSCs of cardiac localization is currently insufficient. Objective: to evaluate the immunophenotype of adipose tissue stromal cells isolated from epicardial and perivascular fat depots in patients with coronary heart disease and acquired heart defects. Materials and methods. The study included 5 patients with ischemic heart disease and 5 with acquired heart disease. The average age is 64.5±2.5 years. All patients had indications for open heart intervention - direct myocardial revascularization by coronary bypass grafting (CABG) or heart valve surgery. SCZhT from subcutaneous, epicardial and perivascular VT biopsies (3-5 years) obtained from patients during surgery (CABG or correction of heart defects) and isolated according to the method of Zeng G. [Zeng G. et al., 2013] . When cells grew to 80–90% confluence, they were digested with 0.25% trypsin and subjected to continuous cell growth and proliferation for subsequent experimental analyses. Flow cytometry analysis was performed on passage 2 cells. Results: The obtained results showed that the MSC culture of the 2nd passage was characterized by increased expression of CD73, CD90, CD105 antigens. Approximately 90% of passage 2 cells derived from epicardial adipose tissue (EAT) and perivascular adipose tissue (PVAT) from a patient with coronary heart disease (CHD) expressed classical MSC markers (CD73, CD90, CD105). In EAT cell culture in a patient with acquired heart disease (ACD), we observed a lower level of co-expression of the main markers of stem cells, in contrast to a patient with CHD (CD90 and CD105 about 61% of cells, and CD90 and CD73 - 58.72%) . The percentage of the studied stem markers on cells isolated from PVAT in a patient with heart disease did not differ significantly from the level of expression of these markers in a patient with coronary artery disease. The level of CD34 expression varied depending on the localization of VT and the disease: thus, in patients with coronary artery disease, the level of CD34 did not exceed 3.5% in both epicardial and perivascular VT. At the same time, a higher percentage of CD34 (32.32%) was found in the epicardial adipose tissue of a patient with PPS. It should be noted that in addition to the main population, both in the EAT culture and in the PVAT, there were 2 minor ones: 1 - CD 90- CD 105+ CD 34-/+ CD 73+ - presumably endothelial population, 2 - CD 90+ CD 105- CD 34- CD 73- - the smallest population. Conclusion: In the early stages of cultivation, cells of the stromal-vascular fraction isolated from epicardial and perivascular adipose tissue express surface markers characteristic of adipose tissue stem cells.

Clinical Outcome of Minimally Manipulated, Mechanically Isolated Autologous Adipose Tissue-Derived Stromal Vascular Fraction (Sahaj Therapy®) in Knee Osteoarthritis-Randomized Controlled Trial.

Regenerative therapy has shown promising results in the treatment of osteoarthritis (OA) knee with Kellgren-Lawrence (KL) Grades I-III. We compared the safety, efficacy, functional, and clinical outcomes of intra-articular implantation of autologous adipose tissue-derived stromal vascular fraction (SVF) isolated using direct ultrasonic cavitation (Sahaj therapy-Cell Innovation Patented Technology) and saline injection in knee osteoarthritis. The present prospective observational study was conducted over 3years. We enrolled 120 patients in our study, where four patients got excluded as they did not meet the inclusion criteria. The remaining 116 patients were randomized into two groups, one with autologous adipose tissue-derived SVF and the other group with saline injection. A comparison of mean KOOS and VAS scores at different follow-ups was done using Paired 't' test. A p value of < 0.05 was considered significant. The results show that the SVF group had significantly higher KOOS scores (78.49 ± 6.54 in the SVF group vs 59.19 ± 5.14 in the saline group), respectively (p < 0.001). Similarly, the SVF group had significantly lesser VAS scores (3.17 ± 0.94 in the SVF group vs 3.89 ± 1.04 in the saline group), respectively (p < 0.001). Autologous adipose tissue-derived SVF is a better choice for treating knee osteoarthritis. For individuals with degenerative osteoarthritis, autologous SVF grafting in the same surgical procedure is an innovative and promising treatment modality. Even after 3years of follow-up, the study participants with OA knee have shown a good clinical and functional outcome.

Effect of Donor Site Selection for Fat Grafting on the Yield and Viability of the Stromal Vascular Fraction.

The efficacy of stromal vascular fraction (SVF) treatment, or stem cell treatment, directly depends on the SVF cell count and the cells' viability. The SVF cell count and viability are in direct correlation with the adipose tissue harvesting site that yields SVF cells, making this research a contribution to developing tissue guidance. The aim of this study was to investigate the importance of harvesting subcutaneous adipose tissue-derived SVF cells on the concentration and viability of SVF. Adipose tissue was collected by vibration-assisted liposuction from the regions of the upper and lower abdomen, lumbar region, and inner thigh region. With the semiautomatic UNISTATION 2nd Version system, the obtained fat was chemically processed (with collagenase enzyme) and a concentrate of SVF cells was obtained by centrifugation. These samples were then analyzed with the Luna-Stem Counter device to measure the number and viability of SVF cells. When comparing the regions of the upper abdomen, lower abdomen, lumbar region, and inner thigh, the highest concentration of SVF was found in the lumbar region, specifically at an average of 97,498.00 per 1.0 mL of concentrate. The lowest concentration was found in the upper abdominal region. When ranking the viability values, the highest cell viability of SVF was observed in the lumbar region, measuring 36.6200%. The lowest viability was found in the upper abdominal region, measuring 24.4967%. By comparing the upper and lower abdominal, lumbar, and inner thigh regions, the authors have come to the conclusion that, on average, the largest number of cells with the highest viability was obtained from the lumbar region.

Inhibition of nucleotide biosynthesis disrupts lipid accumulation and adipogenesis

Energy balance and nutrient availability are key determinants of cellular decisions to remain quiescent, proliferate, or differentiate into a mature cell. After assessing its environmental state, the cell must rewire its metabolism to support distinct cellular outcomes. Mechanistically, how metabolites regulate cell fate decisions is poorly understood. We used adipogenesis as our model system to ascertain the role of metabolism in differentiation. We isolated adipose tissue stromal vascular fraction cells and profiled metabolites before and after adipogenic differentiation to identify metabolic signatures associated with these distinct cellular states. We found that differentiation alters nucleotide accumulation. Furthermore, inhibition of nucleotide biosynthesis prevented lipid storage within adipocytes and downregulated the expression of lipogenic factors. In contrast to proliferating cells, in which mechanistic target of rapamycin complex 1 is activated by purine accumulation, mechanistic target of rapamycin complex 1 signaling was unaffected by purine levels in differentiating adipocytes. Rather, our data indicated that purines regulate transcriptional activators of adipogenesis, peroxisome proliferator-activated receptor γ and CCAAT/enhancer-binding protein α, to promote differentiation. Although de novo nucleotide biosynthesis has mainly been studied in proliferation, our study points to its requirement in adipocyte differentiation.

Deproteinized Bone Tissue as a Matrix for Tissue-Engineered Construction: Experimental Study

Background. At present, for a number of reasons the complete bone defect replacement with autogenous bone is not always possible. Bone substitute materials are used as an alternative to autogenous bone tissue and can be of either biological or non-biological origin. One of the ways of development of reconstructive technologies is the use of tissue-engineered constructs that fully imitate autogenous bone tissue in the required volume.&#x0D; Aim of study to define in vivo the possibility of using deproteinized human cancellous bone tissue as a matrix for creating tissue-engineered constructs.&#x0D; Methods. An in vivo study was carried out on NZW rabbits. To create a construct, we used the fragments of deproteinized cancellous bone tissue of the human femoral head and stromal vascular fraction of rabbit adipose tissue as a matrix. Bone defect modeling with its subsequent replacement was performed to evaluate the efficacy of reparative osteogenesis during bone defects reconstruction. Study groups were defined: group 1 (control) surgical modeling of a bone defect of the femur without its reconstruction; group 2 surgical modeling of a bone defect of the femur with its reconstruction using fragments of deproteinized cancellous bone matrix; group 3 surgical modeling of a bone defect of the femur with its reconstruction using fragments of deproteinized cancellous bone matrix in combination with stromal vascular fraction of adipose tissue (according to ACP SVF technology).&#x0D; Results. Comparative analysis of reparative processes in case of applying tissue-engineered constructs based on deproteinized human cancellous bone matrix in combination with adipose tissue-derived stromal vascular fraction on in vivo experimental model revealed that the use of these bone substitute materials contributes not only to an early activation of reparative regeneration of main structural elements of the bone tissue in the area of the bone defect replacement, but also to its well-timed differentiation. This determines the restoration of structural and functional viability of the bone tissue at the damage site without developing discernible reactive inflammation. Moreover, the effect of the selected tissue-engineered construct with the combined influence of several factors (ACP SVF) in its composition turned out to be more effective in stimulating bone tissue repair and differentiation.&#x0D; Conclusion. Combination of SVF and deproteinized bone matrix for creating tissue-engineered constructs enables to engage several regeneration mechanisms and accelerate the process of bone defect replacement in comparison with isolated deproteinized bone matrix without bone defect reconstruction.