Characteristics and Potentiality of Human Adipose-Derived Stem Cells (hASCs) Obtained from Enzymatic Digestion of Fat Graft. Cells. 2019;8:282. [PMID: 30934588 PMCID: PMC6469026 DOI: 10.3390/cells8030282]

Effects of Nanofat in Plastic and Reconstructive Surgery: A Systematic Review

BACKGROUND

Since nanofat was first introduced by Tonnard in 2013, numerous studies have reported positive findings with its use; however, concerns exist regarding its effects and mechanisms, and the various methods used to generate nanofat also remain unclear. The authors conducted a systematic review to evaluate the efficacy of nanofat grafting alone in plastic and reconstructive surgery.

METHODS

The MEDLINE, Embase, Cochrane Central, Web of Science, and Scopus databases were searched for studies related to the use of nanofat grafting alone in plastic and reconstructive surgery. Outcomes of interest were all clinical results in humans or animals.

RESULTS

Twelve studies were included. No meta-analysis was conducted due to the clinical heterogeneity of the studies. In general, included studies had a low level of evidence. Six studies ( n = 253 patients) showed significant improvements in scar characteristics based on Patient and Observer Scar Assessment Scale, FACE-Q scale, physician assessment, patient satisfaction, and Vancouver Scar Scale scores. Four studies described the benefits of nanofat in skin rejuvenation (wrinkles, fine rhytides, pigmentation, and discoloration) through photographs, questionnaires, and indentation indices. Histologic evaluation illustrated overall increases in skin thickness, collagen, and elastic fibers. Three experimental studies showed the beneficial effects of nanofat on fat grafting, diabetic wound healing, and hair growth, with compelling histological evidence. No severe complication was reported.

CONCLUSIONS

Nanofat grafting shows potential benefits in scar and antiaging treatments, with conclusive histological evidence. Clinical studies of fat grafting, wound healing, and hair growth should be conducted, based on the results of this systematic review. Nanofat grafting could be a practical and safe procedure.

Histological Comparison of Nanofat and Lipoconcentrate: Enhanced Effects of Lipoconcentrate on Adipogenesis and Angiogenesis

BACKGROUND

Nanofat and lipoconcentrate contain adipose-derived stem cells and growth factors, and have wide clinical applications in the regenerative field. This study aimed to investigate the microenvironmental changes associated with nanofat and lipoconcentrate.

METHODS

Conventional fat, nanofat, or lipoconcentrate (0.2 mL each, n = 5 per group) were injected subcutaneously into the dorsal flanks of athymic nude mice. The graft weights were measured at postoperative week 4; the grafts and their overlying skin were used for histological analyses.

RESULTS

Weights of the lipoconcentrate grafts were significantly greater than those of the conventional fat (p < 0.05) and nanofat (p < 0.01) grafts. There was no significant difference in inflammation, oil cysts, and fibrosis between the conventional fat and nanofat groups. Histological examination of the lipoconcentrate grafts showed less macrophage infiltration and the formation of fibrosis and oil cysts. Additionally, adipogenesis and angiogenesis were induced more in the lipoconcentrate grafts than in the nanofat grafts (p < 0.01). Lipoconcentrate and nanofat improved dermal thickness (p < 0.001 and p < 0.01, respectively, versus the baseline).

CONCLUSION

Lipoconcentrate grafts had greater volume and shape retention than conventional fat and nanofat grafts. They had better histological structure and acted as scaffolds for adipogenesis and angiogenesis. Both products showed regenerative effects on dermal thickness; however, only lipoconcentrate grafts had the required volume and regenerative effects, allowing it to serve as a novel adipose-free grafting method for facial rejuvenation and contouring.

NO LEVEL ASSIGNED

This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Lipofilling Enriched with Adipose-Derived Mesenchymal Stem Cells Improves Soft Tissue Deformities and Reduces Scar Pigmentation: Clinical and Instrumental Evaluation in Plastic Surgery

BACKGROUND

Scars and soft tissue deformities (S-STDs), often resulting from hemifacial atrophy, trauma, and outcomes of burns, were usually associated with hyperpigmentation of overlying skin.

OBJECTIVES

This study aimed to evaluate the long-term effects of fat grafting commonly called "Lipofilling" enhanced with adipose-derived mesenchymal stem cells (Lipofilling-AD-MSCs) for treating S-STDs with pigmentary changes.

METHODS

A cohort study has been performed. 50 patients affected by S-STDs with hyperpigmentation treated with Lipofilling-AD-MSCs and 50 patients treated with Lipofilling not enhanced (Lipofilling-NE) were prospectively assessed. The pre-op evaluation included a clinical evaluation, a photographic assessment, magnetic resonance imaging, and ultrasound. Post-op follow-up was performed at 1, 3, 7, 12, 24, 48, weeks, and then annually.

RESULTS

Improvement in volume contours and pigmentation was clinically assessed. All people who underwent the treatments (Lipofilling-AD-MSCs and Lipofilling-NE) were satisfied with the improving pigmentation, texture, and volume contours with some differences. However, the results reported displaying a better trend in patients treated with Lipofilling-AD-MSCs to be more satisfied than patients treated with Lipofilling-NE (p < 0.0001).

CONCLUSIONS

In conclusion, Lipofilling-AD-MSCs was the preferred option for improving the contour deformities related to increased pigmentation of scars.

LEVEL OF EVIDENCE IV

Evidence obtained from cohort studies.

Methods and Limitations of Augmenting Mesenchymal Stem Cells for Therapeutic Applications

Significance: Given their capacity for self-renewal, multilineage differentiation, and immunomodulatory potential, mesenchymal stem cells (MSCs) represent a promising modality of clinical therapy for both regenerative medicine and immune diseases. In this study, we review the key approaches and popular methods utilized to boost potency and modify functions of MSCs for clinical purposes as well as their associated limitations. Recent Advances: Several major domains of cell modification strategies are currently employed by investigators to overcome these deficits and augment the therapeutic potential of MSCs. Priming MSCs with soluble factors or pharmacologic agents as well as manipulating oxygen availability in culture have been demonstrated to be effective biochemical methods to augment MSC potential. Distinct genetic and epigenetic methods have emerged in recent years to modify the genetic expression of target proteins and factors thereby modulating MSCs capacity for differentiation, migration, and proliferation. Physical methods utilizing three-dimensional culture methods and alternative cell delivery systems and scaffolds can be used to recapitulate the native MSC niche and augment their engraftment and viability for in vivo models. Critical Issues: Unmodified MSCs have demonstrated only modest benefits in many preclinical and clinical studies due to issues with cell engraftment, viability, heterogeneity, and immunocompatibility between donor and recipient. Furthermore, unmodified MSCs can have low inherent therapeutic potential for which intensive research over the past few decades has been dedicated to improving cell functionality and potency.

Ultrasound cavitation: a reliable non-enzymatic method for adipose-derived mesenchymal stem cell (ADSC) isolation

BACKGROUND

Adipose tissue is known to serve as an abundant and readily accessible source of adipose-derived stem cells (ADSCs) as an alternative to bone marrow. Collagenase is one of the most widely used methods for the isolation of ADSCs from adipose tissue, but it takes a long time, and there are also debates about safety. We propose an ultrasonic cavitation-treated method that can significantly reduce time and avoid the problem of using xenogeneic enzymes in ADSCs isolation.

METHODS

ADSCs were isolated from adipose tissue using the enzyme treatment method and the ultrasonic cavitation treatment method. Cell proliferation was measured using cell viability assay. The expression levels of the surface markers of ADSCs were estimated by real-time PCR. After, ADSCs were cultured in chondrogenic, osteogenic, or adipogenic differentiation medium; the differentiation potential of ADCSs was analyzed by Alcian blue, Alizarin Red S, Oil Red O, and real-time PCR.

RESULTS

The cells treated with collagenase and ultrasound had similar cell yields and proliferation after isolation. The difference in the expression of surface markers of ADSCs was not statistically significant. ADSCs showed differentiation potential into adipocytes, osteocytes, and chondrocytes, and there was no difference between the enzyme treatment method and the ultrasonic cavitation treatment method. The yield of the ADSC increased in time- and intensity dependently.

CONCLUSIONS

Ultrasound certainly serves as a promising method in advancing ADSC isolation technology.

Human hair follicle-derived mesenchymal stem cells promote tendon repair in a rabbit Achilles tendinopathy model

BACKGROUND

Hair follicles are easily accessible and contain stem cells with different developmental origins, including mesenchymal stem cells (MSCs), that consequently reveal the potential of human hair follicle (hHF)-derived MSCs in repair and regeneration. However, the role of hHF-MSCs in Achilles tendinopathy (AT) remains unclear. The present study investigated the effects of hHF-MSCs on Achilles tendon repair in rabbits.

METHODS

First, we extracted and characterized hHF-MSCs. Then, a rabbit tendinopathy model was constructed to analyze the ability of hHF-MSCs to promote repair in vivo . Anatomical observation and pathological and biomechanical analyses were performed to determine the effect of hHF-MSCs on AT, and quantitative real-time polymerase chain reaction, enzyme-linked immunosorbent assay, and immunohistochemical staining were performed to explore the molecular mechanisms through which hHF-MSCs affects AT. Furthermore, statistical analyses were performed using independent sample t test, one-way analysis of variance (ANOVA), and one-way repeated measures multivariate ANOVA as appropriate.

RESULTS

Flow cytometry, a trilineage-induced differentiation test, confirmed that hHF-derived stem cells were derived from MSCs. The effect of hHF-MSCs on AT revealed that the Achilles tendon was anatomically healthy, as well as the maximum load carried by the Achilles tendon and hydroxyproline proteomic levels were increased. Moreover, collagen I and III were upregulated in rabbit AT treated with hHF-MSCs (compared with AT group; P  < 0.05). Analysis of the molecular mechanisms revealed that hHF-MSCs promoted collagen fiber regeneration, possibly through Tenascin-C (TNC) upregulation and matrix metalloproteinase (MMP)-9 downregulation.

CONCLUSIONS

hHF-MSCs can be a treatment modality to promote AT repair in rabbits by upregulating collagen I and III. Further analysis revealed that treatment of AT using hHF-MSCs promoted the regeneration of collagen fiber, possibly because of upregulation of TNC and downregulation of MMP-9, thus suggesting that hHF-MSCs are more promising for AT.

Fat grafts enriched with ex-vivo expanded adipose stem cells improve hyperpigmentation of face

Facial contour deformities associated with pigmentary changes are of major concern for plastic surgeons being difficult to treat. No definite ideal treatment option is available to address simultaneously both the contour defects as well as related hyperpigmentation. The aim of the current study is to compare long-term effects of conventional adipose tissue grafting and ex-vivo expanded ASC-enriched adipose tissue grafting for the treatment of contour deformities related pigmentary changes on the face. In this study, 80 patients of contour deformities of face with hyperpigmentation were recruited after informed consent. Two techniques, that is, conventional fat grafting (C-FG) and fat grafts enriched with expanded adipose stem cells (FG-ASCs) were used to address the pigmentation. Both techniques were explained to patients and enrolled patients were divided into two groups, that is, C-FG and FG-ASCs as per patients' choice and satisfaction. Patients of the FG-ASCs group were treated with FG-ASCs while patients of C-FGs group were treated with C-FG (without expanded ASCs). Patients were followed for 12 months and improvement in face pigmentation was assessed clinically as well as measured objectively. Patients' satisfaction was also documented as highly satisfied, satisfied, and unsatisfied. This clinical trial was registered at www.clinicaltrials.gov with ID: NTC03564808. Mean age of patients was 24.42 (±4.49), 66 patients were females. Forehead was involved in 61.20% cases, cheek in 21.20% cases, chin in 11.20% cases, and nose in 6.20% cases. In GF-ASCs group, the integrated color density was decreased (1.08 × 10⁶  ± 4.64 × 10⁵ ) as compared with C-FG group (2.80 × 10⁵  ± 1.69 × 10⁵ ). Patients treated with fat grafts enriched with expanded ASCs were significantly more satisfied as compared with patients treated with C-FG only. In conclusion, ASC-enriched autologous fat grafting is preferred option for improving the contour deformities related increased pigmentation of face skin.

Adipose-derived stem cells applied in skin diseases, wound healing and skin defects: a review

Adipose tissue presents a comparably easy source for obtaining stem cells, and more studies are increasingly investigating the therapeutic potential of adipose-derived stem cells. Wound healing, especially in chronic wounds, and treatment of skin diseases are some of the fields investigated. In this narrative review, the authors give an overview of some of the latest studies concerning wound healing as well as treatment of several skin diseases and concentrate on the different forms of application of adipose-derived stem cells.

The effect of stromal vascular fraction in an experimental frostbite injury model

BACKGROUND

Despite current treatment modalities, frostbite remains an injury with a poor prognosis which may cause functional morbidities. Several experimental and clinical studies have demonstrated that stromal vascular fraction is an autologous mixture, which can improve wound healing and vasculogenesis. The aim of this study was to show the beneficial effects of stromal vascular fraction on experimental frostbite healing.

MATERIAL AND METHODS

Stromal vascular fraction (SVF) was harvested from 5 rats after excision of the inguinal fat pads. Another 20 rats were separated into 2 groups of 10 as the SVF group and the control group. A frostbite injury was created on each rat using a cryoprobe frozen with liquid nitrogen (-196 °C). SVF was applied to the SVF group and phosphate-buffered saline to the control group. All injections were performed subcutaneously within the frostbite injury area. Biopsies were performed on days 5 and 14 for histopathological and immunochemical evaluations. The tissue perfusion rates of both groups were assessed on day 14 using indocyanine green angiography (SPY system).

RESULTS

The increase in mean tissue perfusion was 373.3% ( ± 32.1) in the SVF group and 123.8% ( ± 16.3) in the control group (p < 0.001). The macroscopic wound reduction rates of the SVF and control groups were 25.5% ( ± 19.1) and 18.0% ( ± 5.9), respectively on day 5%, and 78.2% ( ± 9.2) and 57.3% ( ± 16.7) on day 14 (p = 0.007; p = 0.003). Acute inflammation and the fibrosis gradient were significantly decreased in the SVF group compared to the control group (p = 0.004, p = 0.054 respectively on day 14). Granulation tissue amount, re-epithelialization score and neovascularization were significantly increased in the SVF group (p = 0.006, p = 0.010 and p = 0.021, respectively on day 14).

CONCLUSIONS

The study results demonstrated that SVF increases frostbite wound healing by increasing tissue perfusion rate, neovascularization and re-epithelialization, and modulating acute inflammation and fibrosis.

Therapeutic potential of adipose tissue-derivatives in modern dermatology

Stem cell-mediated therapies in combination with biomaterial and growth factor-based approaches in regenerative medicine are rapidly evolving with increasing application beyond the dermatologic field. Adipose-derived stem cells (ADSCs) are the more frequently used adult stem cells due to their abundance and easy access. In the case of volumetric defects, adipose tissue can take the shape of defects, restoring the volume and enhancing the regeneration of receiving tissue. When regenerative purposes prevail on volume restoration, the stromal vascular fraction (SVF) rich in staminal cells, purified mesenchymal stem cells (MSCs) or their cell-free derivatives grafting are favoured. The therapeutic efficacy of acellular approaches is explained by the fact that a significant part of the natural propensity of stem cells to repair damaged tissue is ascribable to their secretory activity that combines mitogenic factors, cytokines, chemokines and extracellular matrix components. Therefore, the secretome's ability to modulate multiple targets simultaneously demonstrated preclinical and clinical efficacy in reversing pathological mechanisms of complex conditions such atopic dermatitis (AD), vitiligo, psoriasis, acne and Lichen sclerosus (LS), non-resolving wounds and alopecia. This review analysing both in vivo and in vitro models gives an overview of the clinical relevance of adipose tissue-derivatives such as autologous fat graft, stromal vascular fraction, purified stem cells and secretome for skin disorders application. Finally, we highlighted the major disease-specific limitations and the future perspective in this field.

Urinary Bladder Patch Made with Decellularized Vein Scaffold Seeded with Adipose-Derived Mesenchymal Stem Cells: Model in Rabbits

BACKGROUND

To evaluate tissue regeneration of the urinary bladder after the implantation of a decellularized vein sown with autologous adipose-derived mesenchymal stem cells (ASC) on luminal surfaces.

METHODS

New Zealand rabbits (n = 10) were distributed in two groups: Group Bioscaffold alone (G1)-decellularized vena cava (1 cm2) was implanted, and Group Bioscaffold plus ACSs (G2)-decellularized vena cava (1 cm2) containing ASCs were implanted. ASCs were expanded, characterized, and maintained for one week in culture with a decellularized vein scaffold. The implants were performed under general anesthesia using a continuous suture pattern. Afterward, 21 d (day) specimens were collected and analyzed by hematoxylin and eosin (HE) histology and scanning electron microscopy (SEM).

RESULTS

The integrity of the urinary bladder was maintained in both groups. A superior regenerative process was observed in the G2 group, compared to the G1 group. We observed a greater urothelial epithelialization and maturity of the mucosa and submucosa fibroblasts. Furthermore, SEM demonstrated a notable amount of urothelial villus in the G2 group.

CONCLUSION

Decellularized vena cava scaffolds were able to maintain the integrity of the urinary bladder in the proposed model. In addition, ASCs accelerated the regenerative process development, observed primarily by the new urothelial epithelization and the maturity of mucosa and submucosa fibroblasts.

The Role of Mesenchymal Stromal Cells in Tissue Repair and Fibrosis

Significance: The present review covers an overview of the current understanding of biology of mesenchymal stromal cells (MSCs) and suggests an important role of their differential potential for clinical approaches associated with tissue repair and fibrosis. Recent Advances: Genetic lineage tracing technology has enabled the delineation of cellular hierarchies and examination of MSC cellular origins and myofibroblast sources. This technique has led to the characterization of perivascular MSC populations and suggests that pericytes might provide a local source of tissue-specific MSCs, which can differentiate into tissue-specific cells for tissue repair and fibrosis. Autologous adipose tissue MSCs led to the advance in tissue engineering for regeneration of damaged tissues. Critical Issues: Recent investigation has revealed that perivascular MSCs might be the origin of myofibroblasts during fibrosis development, and perivascular MSCs might be the major source of myofibroblasts in fibrogenic disease. Adipose tissue MSCs combined with cytokines and biomaterials are available in the treatment of soft tissue defect and skin wound healing. Future Directions: Further investigation of the roles of perivascular MSCs may enable new approaches in the treatment of fibrogenic disease; moreover, perivascular MSCs might have potential as an antifibrotic target for fibrogenic disease. Autologous adipose tissue MSCs combined with cytokines and biomaterials will be an alternative method for the treatment of soft tissue defect and skin wound healing.

Safety and efficacy of mesenchymal stem cells in severe/critical patients with COVID-19: A systematic review and meta-analysis

BACKGROUND

The present study aims to better understand the efficacy and safety of mesenchymal stromal cells (MSCs) in treating severe/critical patients with COVID-19.

METHODS

PubMed, the Cochrane Library, and the Chinese electronic database CNKI were searched from inception up to Dec 19, 2021. Original comparative studies for MSC treatment + standard treatment for severe/critical patients with COVID-19, with placebo or standard treatment as the control group, were included. The primary outcomes were in-hospital mortality and adverse events (AEs). A meta-analysis was performed to compare the mortality rates between the two groups. Then, a subgroup analysis was performed according to the category of the disease (severe or critical) and MSC dose. Afterwards, a descriptive analysis was performed for AEs and secondary outcomes. The funnel plot and Egger's test were used for the publication bias assessment.

FINDINGS

Compared to placebo or standard care, MSCs provide significant benefit in the treatment of patients with severe/critical COVID-19, in terms of in-hospital mortality rate (odds ratio: 0.52, 95% CI 0.32-0.84), with very low heterogeneity (P=0.998 [Q test], I ²=0.0%) and less AEs. No significant difference was found in mortality rate due to the different disease categories or MSC doses. Furthermore, no publication bias was found.

INTERPRETATION

The present study demonstrates that MSCs are highly likely to reduce mortality and are safe to use for patients with severe or critical COVID-19, regardless of whether 1-3 doses are applied. However, due to the small sample size of the included studies, further high-quality, large-scale trials are needed to confirm this statement in the future.

FUNDING

The National Key Research and Development Program of China (No. 2020YFC0860900), the Science and Technology Project of Wuhan (No. 2020020602012112), the Tianjin Science and Technology Research Program (18PTSYJC00070 and 16PTWYHZ00030), Haihe Laboratory of Cell Ecosystem Innovation Fund (HH22KYZX0046), and the Tianjin Free Trade Zone Innovation Development Project (ZMCY-03-2021002-01) funded the study. We are also grateful for the support from the 3551 Talent Plan of China Optics Valley.

Polycystin-2 mediates mechanical tension-induced osteogenic differentiation of human adipose-derived stem cells by activating transcriptional co-activator with PDZ-binding motif

Human adipose-derived stem cells (hASCs) have multi-directional differentiation potential including osteogenic differentiation. Mechanical stimulation is thought to be a key regulator of bone remodeling and has been proved to promote osteogenic differentiation of mesenchymal stem cells. However, the mechanism how mechanical tension-induced osteogenesis of hASCs still remains poor understood. Polycystin-2 (PC2), a member of the transient receptor potential polycystic (TRPP) family, is involved in cilia-mediated mechanical transduction. To understand the role of PC2 in osteogenic differentiation under mechanical stimuli in hASCs, PKD2 gene was stably silenced by using lentivirus-mediated shRNA technology. The results showed that mechanical tension sufficiently enhanced osteogenic differentiation but hardly affected proliferation of hASCs. Silencing PKD2 gene caused hASCs to lose the ability of sensing mechanical stimuli and subsequently promoting osteogenesis. PC2 knock-out also reduced the cilia population frequency and cilia length in hASCs. TAZ (transcriptional coactivator with PDZ-binding motif, also known as Wwtr1) could mediate the genes regulation and biological functions of mechanotransduction signal pathway. Here, mechanical tension also enhanced TAZ nuclear translocation of hASCs. PC2 knock-out blocked tension-induced upregulation of nuclear TAZ and suppress tension-induced osteogenesis. TAZ could directly interact with Runx2, and inhibiting TAZ could suppress tension-induced upregulation of Runx2 expression. In summary, our findings demonstrated that PC2 mediate mechanical tension-induced osteogenic differentiation of hASCs by activating TAZ.

Knockout of integrin β1 in induced pluripotent stem cells accelerates skin-wound healing by promoting cell migration in extracellular matrix

Background

Induced pluripotent stem cells (iPSCs) have the potential to promote wound healing; however, their adhesion to the extracellular matrix (ECM) might decrease iPSC migration, thereby limiting their therapeutic potential. Integrin β1 (Itgb1) is the major integrin subunit that mediates iPSC-ECM adhesion, suggesting that knocking out Itgb1 might be an effective method for enhancing the therapeutic efficacy of iPSCs.

Methods

We knocked out Itgb1 in mouse iPSCs and evaluated its effects on the therapeutic potential of topically applied iPSCs, as well as their underlying in vivo and in vitro mechanisms.

Results

The Itgb1-knockout (Itgb1-KO) did not change iPSC pluripotency, function, or survival in the absence of embedding in an ECM gel but did accelerate wound healing, angiogenesis, blood perfusion, and survival in skin-wound lesions. However, embedding in an ECM gel inhibited the in vivo effects of wild-type iPSCs but not those of Itgb1-knockout iPSCs. Additionally, in vitro results showed that Itgb1-knockout decreased iPSC-ECM adhesion while increasing ECM-crossing migration. Moreover, ECM coating on the culture surface did not change cell survival, regardless of Itgb1 status; however, the in vivo and in vitro functions of both Itgb1-knockout and wild-type iPSCs were not affected by the presence of agarose gel, which does not contain integrin-binding sites. Knockout of Integrin α4 (Itga4) did not change the above-mentioned cellular and therapeutic functions of iPSCs.

Conclusions

Itgb1-knockout increased iPSCs migration and the wound-healing-promoting effect of topically applied iPSCs. These findings suggest the inhibition of Itgb1 expression is a possible strategy for increasing the efficacy of iPSC therapies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-03085-7.

Transforming growth factor‑β family and stem cell‑derived exosome therapeutic treatment in osteoarthritis (Review)

Osteoarthritis (OA), although extensively researched, still lacks an effective and safe treatment. The only current treatment option available for advanced OA is joint replacement surgery. This surgery may pose the risks of persistent pain, surgical complications and limited implant lifespan. Transforming growth factor (TGF)‑β has a crucial role in multiple cellular processes such as cell proliferation. Any deterioration in TGF‑β signaling pathways can have an immense impact on OA. Owing to the crucial role of TGF‑β in cartilage homeostasis, targeting it could be an alternative therapeutic approach. Additionally, stem cell‑based therapy has recently emerged as an effective treatment strategy that could replace surgery. A number of recent findings suggest that the tissue regeneration effect of stem cells is attributed to the paracrine secretion of anti‑inflammatory and chondroprotective mediators or trophic factors, particularly nanosized extracellular vesicles (i.e., exosomes). Literature searches were performed in the MEDLINE, EMBASE, Cochrane Library and PubMed electronic database for relevant articles published before September 2021. Multiple investigators have confirmed TGF‑β3 as a promising candidate which has the chondrogenic potential to repair articular cartilage degeneration. Combining TGF‑β3 with bone morphogenetic proteins‑6, which has synergistic effect on chondrogenesis, with an efficient platform such as exosomes, which themselves possess a chondroprotective function, offers an innovative and more efficient approach to treat injured cartilage. In addition, multiple findings stating the role of exosomes in chondroprotection has also verified a similar fact showing exosomes may be a more favorable choice than the source itself. In the present review, the importance of TGF‑β family in OA and the possibility of therapeutic treatment using stem cell‑derived exosomes are described.

Multilineage-differentiating stress-enduring cells alleviate atopic dermatitis-associated behaviors in mice

BACKGROUND

Pruritus is a recurring, long-lasting skin disease with few effective treatments. Many patients have unsatisfactory responses to currently available antipruritic treatments, and effective therapeutics are urgently needed to relieve symptoms. A previous study reported that mesenchymal stem cell (MSC)-mediated immune regulation could be used to treat skin inflammatory diseases. Multilineage-differentiating stress-enduring (Muse) cells are a new type of pluripotent stem cell that may also have the potential to treat inflammatory skin diseases.

METHODS

Muse cells were isolated from human bone marrow-derived MSCs (BMSCs) via the 8-h longterm trypsin incubation (LTT) method. Repeated use of 2,4-dinitrofluorobenzene (DNFB) induced atopic dermatitis (AD) in a mouse model. Immunofluorescence, behavior recording, and image analysis were used to evaluate the therapeutic effect of subcutaneous Muse cell injection. Real-time quantitative polymerase chain reaction (qPCR) was used to measure the expression of inflammatory factors. In vitro, wound healing and cell proliferation experiments were used to examine the effect of Muse cell supernatant on keratinocytes.

RESULTS

Our results showed that subcutaneous injection of Muse cells after AD model induction significantly alleviated scratching behavior in mice. The evaluation of dermatitis and photos of damaged skin on the back of the neck revealed that Muse cells reduced dermatitis, playing an active role in healing the damaged skin. The activation of spinal glial cells and scratching behavior were also reduced by Muse cell injection. In addition, we also showed that the expression levels of the inflammatory factors interleukin (IL)-6, IL-17α, and IL-33 in both the spinal cord and skin were suppressed by Muse cells. Furthermore, Muse cells not only exerted anti-inflammatory effects on lipopolysaccharide (LPS)-induced human HaCat cells but also promoted wound healing and keratinocyte proliferation.

CONCLUSIONS

In vivo, Muse cells could alleviate scratching symptoms, reduce epidermal inflammation, and promote wound healing. In vitro, Muse cells could also promote the migration and proliferation of keratinocytes. In summary, Muse cells may become a new therapeutic agent for the treatment of AD.

Osteocalcin biomarker level evaluation on fracture healing with bone defect after stromal vascular fraction application in murine model

Introduction

Bone defect (3 mm in murine model) is a condition when the bone tissue cannot undergo a natural healing process caused by severe trauma, tumor, or irradiation. A bone defect is a challenge even for experienced Orthopaedic surgeons. Stromal vascular fraction (SVF) is a heterogeneous cell population derived from adipose tissue that results from minimal manipulation of the adipose tissue itself. Several studies have elucidated the effect of either SVF on bone defect healing. However, to the author's knowledge, there is no study evaluating the effect of SVF application on fracture healing, which was measured with osteocalcin biomarker. This study aims to evaluate the effect of SVF application on bone defect healing measured with osteocalcin as a biomarker of bone healing.

Materials and methods

This was an animal study involving twelve Wistar strain Rattus norvegivus. They were divided into three groups: negative group (normal rats), positive group (rats with bone defect and treated without SVF application), and SVF group (rats with bone defect and treated with SVF application). After 30 days, the rats were sacrificed, the osteocalcin biomarkers were evaluated. This biomarker was quantified using ELISA.

Results

Osteocalcin biomarker expressions were higher in the group treated with SVF application than those without using SVF. All comparisons of the SVF group and positive control group showed significant differences (p < 0.05).

Conclusion

SVF application could aid the healing process in a murine model with bone defect, marked by increased osteocalcin levels.

•

A study evaluating the effect of SVF application on fracture healing, measured with osteocalcin biomarker.

•

Osteocalcin is useful in the evaluation of bone turnover and the clinical setting of bone loss.

•

SVF could aid the healing process in a murine model with bone defect.

•

A bone defect is a challenge even for experienced Orthopaedic surgeons.

Effect of Stromal Vascular Fraction on Fracture Healing with Bone Defects by Examination of Bone Morphogenetic Protein-2 Biomarkers in Murine Model

BACKGROUND: Fractures and segmental bone defects are a significant cause of morbidity and a source of a high economic burden in healthcare. A severe bone defect (3 mm in murine model) is a devastating condition, which the bone cannot heal naturally despite surgical stabilization and usually requires further surgical intervention. The stromal vascular fraction (SVF) contains a heterogeneous collection of cells and several components, primarily: MSCs, HSCs, Treg cells, pericytic cells, AST cells, extracellular matrix, and complex microvascular beds (fibroblasts, white blood cells, dendritic cells, and intra-adventitial smooth muscular-like cells). Bone morphogenetic protein (BMP) is widely known for their important role in bone formation during mammalian development and confers a multifunctional role in the body, which has potential for therapeutic use. Studies have shown that BMPs play a role in the healing of large size bone defects. AIM: In this study, researchers aim to determine the effect of administering SVF from adipose tissue on the healing process of bone defects assessed based on the level biomarker of BMP-2. MATERIALS AND METHODS: This was an animal study involving 12 Wistar strain Rattus norvegivus. They were divided into three groups: Negative group (normal rats), positive group (rats with bone defect without SVF application), and SVF group (rats with bone defect with SVF application). After 30 days, the rats were sacrificed; the biomarkers that were evaluated are BMP-2. This biomarker was quantified using ELISA. RESULTS: BMP-2 biomarker expressions were higher in the SVF application group than in the group without SVF. All comparisons of the SVF group and positive control group showed significant differences (p = 0.026). CONCLUSION: SVF application could aid the healing process in a murine model with bone defect marked by the increased level of BMP-2 as a bone formation marker.

Mesenchymal stem/stromal cell therapy in atopic dermatitis and chronic urticaria: immunological and clinical viewpoints

Allergic diseases are immune-mediated diseases. Allergies share a common immunopathogenesis, with specific differences according to the specific disease. Mesenchymal stem/stromal cells (MSCs) have been applied to people suffering from allergic and many other diseases. In this review, the immunologic roles of MSCs are systemically reviewed according to disease immunopathogenesis from a clinical viewpoint. MSCs seem to be a promising therapeutic modality not only as symptomatic treatments but also as causative and even preventive treatments for allergic diseases, including atopic dermatitis and chronic urticaria.

Insight into the role of dermal white adipose tissue loss in dermal fibrosis

The loss of dermal white adipose tissue (dWAT) is vital to the formation of dermal fibrosis (DF), but the specific mechanism is not well understood. A few studies are reviewed to explore the role of dWAT in the formation of DF. Recent findings indicated that the adipocytes-to-myofibroblasts transition in dWAT reflects the direct contribution to the DF formation. While adipose-derived stem cells (ADSCs) contained in dWAT express antifibrotic cytokines, the loss of ADSCs leads to skin protection decreased, which indirectly exacerbates DF and tissue damage. Therefore, blocking or reversing the adipocytes-to-myofibroblasts transition or improving the survival of ADSCs in dWAT and the expression of antifibrotic cytokines may be an effective strategy for the treatment of DF.

Efficacy of adipose-derived stromal vascular fraction cells in the management of chronic ulcers: a randomized clinical trial

Background: Cell therapy is a promising method for improving healing in chronic ulcers through delivery of isolated adipose-derived stromal vascular fraction. Objectives: This study investigates the autologous stem cell yield of adipose tissue and its efficacy in chronic ulcers compared with conventional methods. Methods: This study was a randomized controlled trial. After the study design and protocol were established and ethical committee approval was obtained, we enrolled 100 patients divided into study and control groups. In the study group, we performed debridement and autologous stem cell injection every 3 weeks. The control group was treated with debridement and conventional dressing. Assessments included clinical and histological parameters. Results: The study group showed improved healing. Conclusion: Using autologous adipose-derived stromal vascular fraction cells is an effective treatment method for chronic ulcers. This study was registered on the Pan-African Clinical Trial Registry and the number of the registry was PACTR201709002519185.

Therapeutic Potential of Adipose-Derived Stem Cells in the Treatment of Pulmonary Diseases

Stem cells derived from adipose tissues (ADSCs) have emerged as an ideal candidate for various models of respiratory diseases, including asthma, chronic obstructive pulmonary disease (COPD), and acute respiratory distress syndrome. ADSCs have qualities that may make them better suited for treating inflammatory lung diseases than other MSCs. ADSCs show a lower senescence ratio, higher proliferative capacity and stability in terms of their genetic and morphology during long-term culture over bone marrow-derived mesenchymal stem cells (BMMSCs). With advanced research techniques, the advantageous effects of ADSCs seem limited to their ability to engraft, differentiate, and be related to their secretion of trophic factors. These trophic factors regulate the therapeutic and regenerative outcomes in various lung inflammatory diseases. Taken together, these particular qualities of ADSCs make them significantly relevant for clinical applications. This article discusses a recent advance of ADSCs biology and their translational application emphasizing their anti-inflammatory, immunomodulatory and regenerative properties particularly on lung inflammatory diseases. Besides, the relevant advancements made in the field, the regulatory aspects, and other challenges and obstacles will be highlighted.

Differentiation Behaviour of Adipose-Derived Stromal Cells (ASCs) Seeded on Polyurethane-Fibrin Scaffolds In Vitro and In Vivo

Adipose-derived stromal cells (ASCs) are a promising cell source for tissue engineering and regenerative medicine approaches for cartilage replacement. For chondrogenic differentiation, human (h)ASCs were seeded on three-dimensional polyurethane (PU) fibrin composites and induced with a chondrogenic differentiation medium containing TGF-ß3, BMP-6, and IGF-1 in various combinations. In addition, in vitro predifferentiated cell-seeded constructs were implanted into auricular cartilage defects of New Zealand White Rabbits for 4 and 12 weeks. Histological, immunohistochemical, and RT-PCR analyses were performed on the constructs maintained in vitro to determine extracellular matrix (ECM) deposition and expression of specific cartilage markers. Chondrogenic differentiated constructs showed a uniform distribution of cells and ECM proteins. RT-PCR showed increased gene expression of collagen II, collagen X, and aggrecan and nearly stable expression of SOX-9 and collagen I. Rabbit (r)ASC-seeded PU-fibrin composites implanted in ear cartilage defects of New Zealand White Rabbits showed deposition of ECM with structures resembling cartilage lacunae by Alcian blue staining. However, extracellular calcium deposition became detectable over the course of 12 weeks. RT-PCR showed evidence of endochondral ossification during the time course with the expression of specific marker genes (collagen X and RUNX-2). In conclusion, hASCs show chondrogenic differentiation capacity in vitro with the expression of specific marker genes and deposition of cartilage-specific ECM proteins. After implantation of predifferentiated rASC-seeded PU-fibrin scaffolds into a cartilage defect, the constructs undergo the route of endochondral ossification.

Exosomes as Part of the Human Adipose-Derived Stem Cells Secretome- Opening New Perspectives for Cell-Free Regenerative Applications

Human adipose-derived stem cells (hASCs) represent a great resource for regenerative medicine based on their accessibility, self-renewal potential, low immunogenicity, high proliferative rate and potential to differentiate on multiple lineages. Their secretome is rich in chemokines, cytokines and protein growth factors that are actively involved in regeneration processes. In addition, part of this secretome are also the exosomes (hASC-exos), which display high content in proteins, messenger RNAs (mRNAs) and non-coding RNAs (ncRNAs). Due to their content, exosomes promote tissue regeneration by different mechanisms, either by activating or inhibiting several signaling pathways involved in wound healing, extracellular matrix remodeling, immunomodulation, angiogenesis, anti-apoptotic activity and cell migration, proliferation and differentiation. The use of hASC-exos may provide an improved alternative to standard therapies used in regenerative medicine, as a cell-free new approach with multiple possibilities to be modulated according to the patient needs. This review offers an updated overview on the functions and applications of hASC-exos in all areas of tissue regeneration, aiming to highlight to the reader the benefits of using hASCs in modern tissue engineering and regenerative medicine applications.

Adipose mesenchymal stem cells combined with platelet-rich plasma accelerate diabetic wound healing by modulating the Notch pathway

Background

Diabetic foot ulceration is a serious chronic complication of diabetes mellitus characterized by high disability, mortality, and morbidity. Platelet-rich plasma (PRP) has been widely used for diabetic wound healing due to its high content of growth factors. However, its application is limited due to the rapid degradation of growth factors. The present study aimed to evaluate the efficacy of combined adipose-derived mesenchymal stem cells (ADSCs) and PRP therapy in promoting diabetic wound healing in relation to the Notch signaling pathway.

Methods

Albino rats were allocated into 6 groups [control (unwounded), sham (wounded but non-diabetic), diabetic, PRP-treated, ADSC-treated, and PRP+ADSCs-treated groups]. The effect of individual and combined therapy was evaluated by assessing wound closure rate, epidermal thickness, dermal collagen, and angiogenesis. Moreover, gene and protein expression of key elements of the Notch signaling pathway (Notch1, Delta-like canonical Notch ligand 4 (DLL4), Hairy Enhancer of Split-1 (Hes1), Hey1, Jagged-1), gene expression of angiogenic marker (vascular endothelial growth factor and stromal cell-derived factor 1) and epidermal stem cells (EPSCs) related gene (ß1 Integrin) were assessed.

Results

Our data showed better wound healing of PRP+ADSCs compared to their individual use after 7 and 14 days as the combined therapy caused reepithelialization and granulation tissue formation with a marked increase in area percentage of collagen, epidermal thickness, and angiogenesis. Moreover, Notch signaling was significantly downregulated, and EPSC proliferation and recruitment were enhanced compared to other treated groups and diabetic groups.

Conclusions

These data demonstrated that PRP and ADSCs combined therapy significantly accelerated healing of diabetic wounds induced experimentally in rats via modulating the Notch pathway, promoting angiogenesis and EPSC proliferation.

Adipose-Derived Stem Cells Secretome and Its Potential Application in "Stem Cell-Free Therapy"

Adipose-derived stem cells (ASCs) secrete many cytokines, proteins, growth factors, and extracellular vesicles with beneficial outcomes that can be used in regenerative medicine. It has great potential, and the development of new treatment strategies using the ASCs secretome is of global interest. Besides cytokines, proteins, and growth factors, the therapeutic effect of secretome is hidden in non-coding RNAs such as miR-21, miR-24, and miR-26 carried via exosomes secreted by adequate cells. The whole secretome, including ASC-derived exosomes (ASC-exos) has been proven in many studies to have immunomodulatory, proangiogenic, neurotrophic, and epithelization activity and can potentially be used for neurodegenerative, cardiovascular, respiratory, inflammatory, and autoimmune diseases as well as wound healing treatment. Due to limitations in the use of stem cells in cell-based therapy, its secretome with emphasis on exosomes seems to be a reasonable and safer alternative with increased effectiveness and fewer side effects. Moreover, the great advantage of cell-free therapy is the possibility of biobanking the ASCs secretome. In this review, we focus on the current state of knowledge on the use of the ASCs secretome in stem cell-free therapy.

A randomized, controlled clinical trial of autologous stromal vascular fraction cells transplantation to promote mechanical stretch-induced skin regeneration

BACKGROUND

The regeneration response of the skin to mechanical stretching in vivo has been explored in reconstructive surgery to repair large-scale deformities. The ability of the skin to regenerate limits the reconstructive outcome. Here, we propose an approach in which autologous stromal vascular fraction (SVF) cells and mechanical stretching are combined to overcome this limitation and promote skin regeneration.

METHODS

This randomized, blinded, placebo-controlled clinical trial screened 22 participants undergoing tissue expansion with exhausted regeneration. Twenty eligible participants received intradermal injections of the SVF or placebo treatments. Follow-ups were conducted at 4, 8, and 12 weeks to assess efficacy and at 2 years to assess safety. The primary endpoint was the expanded skin thickness at 12 weeks. The secondary endpoints included skin thickness at 4 and 8 weeks, the expansion index (EI), and the skin texture score at 12 weeks.

RESULTS

The skin thickness of the SVF group was significantly higher than that of the control group at both 8 weeks (mean difference 0.78 [95% CI - 1.43 to - 0.11]; p = 0.018) and 12 weeks (0.65 [95% CI - 1.30 to - 0.01]; p = 0.046). In the SVF group, the increase in skin thickness was significant at 4 weeks (0.49 [95% CI - 0.80 to - 0.06]; p = 0.010) to 8 weeks (0.45 [95% CI - 0.92 to 0.02]; p = 0.026) and maintained after 12 weeks, whereas that in the control group was reduced after 8 weeks (0.42 [95% CI - 0.07 to 0.91]; p = 0.037). The SVF group showed greater EI increases than the control group (0.50 [95% CI - 0.00 to 0.99]; p = 0.047). The skin texture scores in the SVF group were greater than those in the control group at 12 weeks. Histologically, SVF-treated expanded skin showed more proliferating cells and blood vessels, and the extracellular matrix volume increased. No severe adverse events occurred.

CONCLUSIONS

Transplantation of SVF cells can expedite the potency of mechanical stretch-induced skin regeneration and provide clinical reconstruction with plentiful tissue.

TRIAL REGISTRATION

This trial was registered with the Chinese Clinical Trial Registry, ChiCTR2000039317 (registered 23 October 2020-retrospectively registered).

Comparison of the Efficacy and Safety of Cell-Assisted Lipotransfer and Platelet-Rich Plasma Assisted Lipotransfer: What Should We Expect from a Systematic Review with Meta-Analysis?

Due to the high absorption rate of traditional autologous fat grafting, cell-assisted lipotransfer (CAL) and platelet-rich plasma (PRP)-assisted lipotransfer were developed. The purpose of this article was to evaluate the efficacy and safety of CAL and PRP in promoting the survival of autologous fat grafting through systematic review and meta-analysis. We searched Pubmed, Cochrane Library, Web of Science, and EMBASE for clinical studies on CAL and PRP-assisted lipotransfer published from January 2010 to January 2020. Then a meta-analysis was performed to assess the efficacy of CAL and PRP-assisted lipotransfer through data analysis of fat survival rate. We also assessed the incidence of complications and multiple operations to analyze their safety. A total of 36 studies (1697 patients) were included in this review. Regardless of the recipient area, CAL and PRP-assisted lipotransfer significantly improved the fat survival rate (CAL vs non-CAL: 71% vs 48%, P < 0.0001; PRP vs non-PRP: 70% vs 40%, P < 0.0001; CAL vs PRP: 71% vs 70%, P = 0.7175). However, in large-volume fat grafting, such as breast reconstruction, both increased the incidence of complications and did not decrease the frequency of multiple operations after lipotransfer. Further prospective studies are needed to evaluate the clinical benefits of CAL and PRP-assisted lipotransfer.

SARS-CoV-2: the "Uncensored" Truth about Its Origin and Adipose-Derived Mesenchymal Stem Cells as New Potential Immune-Modulatory Weapon

In this second return of the pandemic, January 2021, it appears to be clear that a Nano-sized organism, the SARS-CoV-2, has rendered the human race helpless, made the global health status decline, and drowned the world economy. However, it does not appear clear the real origin of the SARS-CoV-2 and the aim of this work is to report and discuss, maybe for the first time since the pandemic began, the scientific data published in this specific field, analyzing the potentially available weapons against the SARS-CoV-2. About this last point, a ray of hope comes from the potential of Mesenchymal Stem Cells (MSCs) that has already been established in Coronavirus Disease 2019 (COVID-19), and in particular from the Adipose-Derived Mesenchymal Stem Cells (AD-MSCs). However, cell-based therapy has its own limits, especially represented by the know-how in this field and by the rules of applications. It was suggested a biological therapy using AD-MSCs as a weapon against COVID-19, as they can be a game-changer owing to their immuno-modulatory nature, which combats the cytokine storm characterizing this disease, and their practical efficiency, which will realistically aid large access to therapy worldwide.

Taming of Covid-19: potential and emerging application of mesenchymal stem cells

Coronavirus Disease 2019 (COVID-19) caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has turned out to cause a pandemic, with a sky scraping mortality. The virus is thought to cause tissue injury by affecting the renin-angiotensin system. Also, the role of the over-activated immune system is noteworthy, leading to severe tissue injury via the cytokine storms. Thus it would be feasible to modulate the immune system response in order to attenuate the disease severity, as well as treating the patients. Today different medicines are being administered to the patients, but regardless of the efficacy of these treatments, adverse effects are pretty probable. Meanwhile, mesenchymal stem cells (MSCs) prove to be an effective candidate for treating the patients suffering from COVID-19 pneumonia, owing to their immunomodulatory and tissue-regenerative potentials. So far, several experiments have been conducted; transplanting MSCs and results are satisfying with no adverse effects being reported. This paper aims to review the recent findings regarding the novel coronavirus and the conducted experiments to treat patients suffering from COVID-19 pneumonia utilizing MSCs.

Will mesenchymal stem cells be future directions for treating radiation-induced skin injury?

Radiation-induced skin injury (RISI) is one of the common serious side effects of radiotherapy (RT) for patients with malignant tumors. Mesenchymal stem cells (MSCs) are applied to RISI repair in some clinical cases series except some traditional options. Though direct replacement of damaged cells may be achieved through differentiation capacity of MSCs, more recent data indicate that various cytokines and chemokines secreted by MSCs are involved in synergetic therapy of RISI by anti-inflammatory, immunomodulation, antioxidant, revascularization, and anti-apoptotic activity. In this paper, we not only discussed different sources of MSCs on the treatment of RISI both in preclinical studies and clinical trials, but also summarized the applications and mechanisms of MSCs in other related regenerative fields.

Systematic Review: Adipose-Derived Mesenchymal Stem Cells, Platelet-Rich Plasma and Biomaterials as New Regenerative Strategies in Chronic Skin Wounds and Soft Tissue Defects

The number of clinical trials evaluating adipose-derived mesenchymal stem cells (AD-MSCs), platelet-rich plasma (PRP), and biomaterials efficacy in regenerative plastic surgery has exponentially increased during the last ten years. AD-MSCs are easily accessible from various fat depots and show intrinsic plasticity in giving rise to cell types involved in wound healing and angiogenesis. AD-MSCs have been used in the treatment of soft tissue defects and chronic wounds, employed in conjunction with a fat grafting technique or with dermal substitute scaffolds and platelet-rich plasma. In this systematic review, an overview of the current knowledge on this topic has been provided, based on existing studies and the authors’ experience. A multistep search of the PubMed, MEDLINE, Embase, PreMEDLINE, Ebase, CINAHL, PsycINFO, Clinicaltrials.gov, Scopus database, and Cochrane databases has been performed to identify papers on AD-MSCs, PRP, and biomaterials used in soft tissue defects and chronic wounds. Of the 2136 articles initially identified, 422 articles focusing on regenerative strategies in wound healing were selected and, consequently, only 278 articles apparently related to AD-MSC, PRP, and biomaterials were initially assessed for eligibility. Of these, 85 articles were excluded as pre-clinical, experimental, and in vitro studies. For the above-mentioned reasons, 193 articles were selected; of this amount, 121 letters, expert opinions, commentary, and editorials were removed. The remaining 72 articles, strictly regarding the use of AD-MSCs, PRP, and biomaterials in chronic skin wounds and soft tissue defects, were analyzed. The studies included had to match predetermined criteria according to the patients, intervention, comparator, outcomes, and study design (PICOS) approach. The information analyzed highlights the safety and efficacy of AD-MSCs, PRP, and biomaterials on soft tissue defects and chronic wounds, without major side effects.

SPATA4 improves aging-induced metabolic dysfunction through promotion of preadipocyte differentiation and adipose tissue expansion

Spermatogenesis‐associated protein 4 (SPATA4) is conserved across multiple species. However, the function of this gene remains largely unknown. In this study, we generated Spata4 transgenic mice to explore tissue‐specific function of SPATA4. Spata4 overexpression mice displayed increased subcutaneous fat tissue compared with wild‐type littermates at an old age, while this difference was not observed in younger mice. Aging‐induced ectopic fat distribution, inflammation, and insulin resistance were also significantly attenuated by SPATA4. In vitro, SPATA4 promoted preadipocyte differentiation through activation of the ERK1/2 and C/EBPβ pathway and increased the expression of adipokines. These data suggest SPATA4 can regulate lipid accumulation in a tissue‐specific manner and improve aging‐induced dysmetabolic syndromes. Clarifying the mechanism of SPATA4 functioning in lipid metabolism might provide novel therapeutic targets for disease interventions.

Microenvironmental changes induced by placenta-derived mesenchymal stem cells restore ovarian function in ovariectomized rats via activation of the PI3K-FOXO3 pathway

Background

Translational studies have explored the therapeutic potential and feasibility of mesenchymal stem cells (MSCs) in several degenerative diseases; however, mechanistic studies of the function of these cells have been insufficient. As ovarian failure causes anovulation as well as ovarian steroid hormonal imbalances, the specific aims of this study were to analyze the therapeutic role of placenta-derived MSCs (PD-MSCs) in an ovarian failure ovariectomy (OVX) rat model and evaluate whether PD-MSC transplantation (Tx) improved folliculogenesis and oocyte maturation in the injured ovary through PI3K/Akt and FOXO signaling.

Methods

Blood and ovary tissue were collected and analyzed after various PD-MSC Tx treatments in an ovariectomized rat model. Changes in the expression of folliculogenesis- and ovary regeneration-related genes induced by PD-MSC treatments were analyzed by qRT-PCR, Western blotting, and histological analysis.

Results

The levels of hormones related to ovary function were significantly increased in the PD-MSC Tx groups compared with those in the nontransplantation group (NTx). The follicle numbers in the ovarian tissues were increased along with the increased expression of genes related to folliculogenesis in the PD-MSC Tx groups compared with the NTx groups. Furthermore, Tx PD-MSCs induced follicle maturation by increasing the phosphorylation of GSK3 beta and FOXO3 (p < 0.05) and shifting the balance of growth and apoptosis in oocytes.

Conclusions

Taken together, these results show that PD-MSC Tx can restore ovarian function and induce ovarian folliculogenesis via the PI3K/Akt and FOXO signaling pathway.

Xeno-free approach for the expansion of human adipose derived mesenchymal stem cells for ocular therapies

To restore corneal transparency and vision loss after an injury on the ocular surface, the use of human stem cells from different origins has been recently proposed. Mesenchymal stem cells (MSCs) seem to be an appropriate adult source of autologous stem cells due to their accessibility, high proliferation rate, and multipotent capacity. In this work, we developed a simple culture system to prepare a graft based on a fibrin membrane seeded with human MSCs. A commercial kit, PRGF Endoret®, was used to prepare both, the growth factors used as culture media supplement and the fibrin membrane grafts. Adipose-derived MSCs (Ad-MSCs) were expanded, characterised by flow cytometry and their multilineage differentiation potential confirmed by inducing adipogenesis, osteogenesis and chondrogenesis. Ad-MSCs seeded on the fibrin membranes were grafted onto athymic mice showing good biocompatibility with no adverse reactions observed during the follow up period. These findings support the assumption that a system in which all the biological components (cells, grow factors and carrier) are autologous, could potentially be used for future ex vivo expansion of Ad-MSCs to treat ocular conditions such as an inflammatory milieu, traumatic scars and loss of the regenerative capacity of the corneal epithelium that compromise the quality of vision.

Functionally enhanced placenta-derived mesenchymal stem cells inhibit adipogenesis in orbital fibroblasts with Graves' ophthalmopathy

BACKGROUND

Placenta-derived mesenchymal stem cells (PD-MSCs) have unique immunomodulatory properties. Phosphatase of regenerating liver-1 (PRL-1) regulates the self-renewal ability of stem cells and promotes proliferation. Graves' ophthalmopathy (GO) is an autoimmune inflammatory disease of the orbit and is characterized by increased orbital levels of adipose tissue. Here, we evaluated the therapeutic mechanism for regulation of adipogenesis by PRL-1-overexpressing PD-MSCs (PD-MSCs^PRL-1, PRL-1+) in orbital fibroblast (OF) with GO patients.

METHODS

PD-MSCs isolated from human placenta were transfected with the PRL-1 gene using nonviral transfection method. Primary OFs were isolated from orbital adipose tissue specimens from GO patients. After maturation as adipogenic differentiation, normal and GO-derived OFs were cocultured with naïve and PD-MSCs^PRL-1. We analyzed the protein levels of adipogenesis markers and their signaling pathways in OFs from GO patients.

RESULTS

The characteristics of PD-MSCs^PRL-1 were similar to those of naïve cells. OFs from GO patients induced adipocyte differentiation and had significantly decreased a lipid accumulation after coculture with PD-MSCs^PRL-1 compared to naïve cells. The mRNA and protein expression of adipogenic markers was decreased in PD-MSCs^PRL-1. Insulin-like growth factor-binding proteins (IGFBPs) secreting PD-MSCs^PRL-1 downregulated the phosphorylated PI3K/AKT/mTOR expression in OFs from GO patients. Interestingly, IGFBP2, - 4, - 6, and - 7 expression in PD-MSCs^PRL-1, which was mediated by integrin alpha 4 (ITGA4) and beta 7 (ITGB7), was higher than that in naïve cells and upregulated phosphorylated FAK downstream factor.

CONCLUSION

In summary, IGFBPs secreting PD-MSC^PRL-1 inhibit adipogenesis in OFs from GO patients by upregulating phosphorylated FAK and downregulating PI3K/AKT/mTOR signaling pathway. The functional enhancement of PD-MSCs by nonviral gene modification provides a novel therapeutic strategy for the treatment of degenerative diseases.

New normal: two aspects of adipose tissue in COVID-19-treat and threat?

INTRODUCTION

Adipose-derived stromal cells (ADSCs) can be an important alternative in COVID-19 prevention, treatment, and subsequent sequelae repair. However, ACE-2 plays a common role in the pathogenesis of adipocyte hypertrophy and COVID 19.

AREAS COVERED

In this 'Perspective,' the author would like to emphasize the use of adipose tissue-derived stromal cells in COVID 19 and the issues that clinicians should pay attention to in fat graft applications in terms of adipose tissue-RAS relationship. The new normal for adipose tissue in COVID 19 will be highlighted.

EXPERT OPINION

ADSCs may potentially be used in COVID-19. However, it has been speculated that ACE2 receptors are responsible for the pathogenesis of adipose tissue overgrowth and may be a potential danger in terms of the relationship between ACE2 receptors and COVID19. We speculate that reducing the size of overgrown fat tissue by ultra-sharp blades and using near-normal adipocytes will create a 'new normal.'

Exosomes From Adipose-Derived Stem Cells: The Emerging Roles and Applications in Tissue Regeneration of Plastic and Cosmetic Surgery

Adipose-derived stem cells (ASCs) are an important stem cell type separated from adipose tissue, with the properties of multilineage differentiation, easy availability, high proliferation potential, and self-renewal. Exosomes are novel frontiers of intercellular communication regulating the biological behaviors of cells, such as angiogenesis, immune modulation, proliferation, and migration. ASC-derived exosomes (ASC-exos) are important components released by ASCs paracrine, possessing multiple biological activities. Tissue regeneration requires coordinated “vital networks” of multiple growth factors, proteases, progenitors, and immune cells producing inflammatory cytokines. Recently, as cell-to-cell messengers, ASC-exos have received much attention for the fact that they are important paracrine mediators contributing to their suitability for tissue regeneration. ASC-exos, with distinct properties by encapsulating various types of bioactive cargoes, are endowed with great application potential in tissue regeneration, mechanically via the migration and proliferation of repair cells, facilitation of the neovascularization, and other specific functions in different tissues. Here, this article elucidated the research progress of ASC-exos about tissue regeneration in plastic and cosmetic surgery, including skin anti-aging therapy, dermatitis improvement, wound healing, scar removal, flap transplantation, bone tissue repair and regeneration, obesity prevention, fat grafting, breast cancer, and breast reconstruction. Deciphering the biological properties of ASC-exos will provide further insights for exploring novel therapeutic strategies of tissue regeneration in plastic and cosmetic surgery.

Regenerative application of stromal vascular fraction cells enhanced fat graft maintenance: clinical assessment in face rejuvenation

OBJECTIVES

The aim of this study was to evaluate the safety and efficacy of the use of FG-SVFs in face rejuvenation for esthetic improvement.

METHODS

33 female patients affected by face's soft-tissue defects with loss of volume, study group (SG), were treated with FG-SVFs, comparing results with a control group (CG) (n = 30) treated with fat graft not enhanced (FG). Clinical evaluation, a photographic assessment, magnetic resonance imaging (MRI), and ultrasound (US) were performed. Post-operative follow-up was performed at 1, 3, 7, 12, 24, 48, weeks, and then annually.

RESULTS

SG patients showed 61% maintenance of the contour restoring and of volume after 3 years compared with the CG treated with FG, who showed 31% maintenance. 60.7% (n = 20) of SG patients, presented an increase of 6.6 mm in the soft tissue volume after 36 months, which was reported in only 33,3% (n = 10) of the CG. Volumetric persistence in the SG was higher than that in the CG (p <. 0001 vs. CG). MRI and US moreover confirmed the absence of important side effects, as fat necrosis, and cytosteatonecrotic areas.

CONCLUSIONS

The use of FG-SVFs was safe and effective in this series of a case treated.

SIRT1-modified human umbilical cord mesenchymal stem cells ameliorate experimental peritoneal fibrosis by inhibiting the TGF-β/Smad3 pathway

Introduction

Peritoneal fibrosis is a serious complication of long-term peritoneal dialysis (PD). Combination therapies are emerging as a promising treatment for tissue damage. Here, we investigated the therapeutic potential of SIRT1-modified human umbilical cord mesenchymal stem cells (hUCMSCs) for peritoneal fibrosis.

Methods

SIRT1 was overexpressed in hUCMSCs to establish SIRT1-modified hUCMSCs. Co-culture and transplantation experiments were performed in TGF-β-stimulated Met-5A cells and peritoneal damage rodent model to assess the therapeutic potential of SIRT1-modified hUCMSCs for peritoneal fibrosis through qPCR, Western blot, and peritoneal function analyses.

Results

SIRT1-modified hUCMSC administration had more potent anti-fibrosis ability than hUCMSCs, which significantly inhibited the expression of fibrotic genes and suppressed EMT process, increased ultrafiltration volume, and restored homeostasis of bioincompatible factors in dialysis solution. Mechanistically, SIRT1-modified hUCMSCs attenuated peritoneal fibrosis through reducing peritoneal inflammation and inhibiting the TGF-β/Smad3 pathway in peritoneal omentum tissues.

Conclusion

SIRT1-modified hUCMSCs might work as a promising therapeutic strategy for the treatment of peritoneal dialysis-induced peritoneal damage and fibrosis.

3D co-culture model of endothelial colony-forming cells (ECFCs) reverses late passage adipose-derived stem cell senescence for wound healing

Background

Extensive passage of adipose-derived stem cells (ASCs) in vitro leads to loss of function. Endothelial colony-forming cells (ECFCs) can be isolated from adult peripheral blood. A 3D co-culture system may rescue in vitro ASC senescence.

Methods

A 3D co-culture model was successfully established using hyaluronic acid (HA) gel and a 10:1 ratio of late-passage ASCs and ECFCs. Cell density and culture conditions were optimized. Stem cell phenotype was characterized by flow cytometry. ELISA was used to measure the trophic effect of angiogenic growth factors and compare the effects of these factors between the 3-D co-culture and single-cell culture. Therapeutic potential of ASC/ECFC 3-D co-cultures was evaluated in a mouse chronic injury model.

Results

Following incubation in a HA substrate 3D co-culture system, ASC morphology, phenotype, secretory profile, and differentiation capacity were restored. The ASC/ECFC co-culture increased the secretion of cytokines, such as hepatocyte growth factor, compared with single-cell 3D culture or monolayer culture. Mice radiation-ulcer wounds treated with ASC/ECFC 3-D co-cultures (spheroids) showed epithelialization and improved healing compared with wounds treated with ASCs or ECFCs alone. Further, transplanted ASC/ECFC spheroids exhibited superior angiogenic potential due to the ability of the ASCs to transdifferentiate into pericytes.

Conclusion

3D co-culture of ECFCs and ASCs in vitro restored native ASC properties by reversing cellular senescence and loss of trophic function. Transplant of ASC/ECFC 3D spheroids in vivo demonstrated pro-angiogenic capacity with improved therapeutic potential.

Fat Graft Enhanced With Adipose-Derived Stem Cells in Aesthetic Breast Augmentation: Clinical, Histological, and Instrumental Evaluation

BACKGROUND

Fat graft enhanced with adipose-derived stem cells (FG-e-ASCs) has been utilized in outcomes of radiotherapy after mastectomy, breast soft tissue defects, ulcers, and loss of substance. The authors present their experience utilizing FG-e-ASCs in breast augmentation.

OBJECTIVES

The aim of this study was to evaluate the safety and efficacy of a study group (SG) regarding utilization of FG-e-ASCs in breast augmentation for aesthetic improvement, comparing the results with a control group (CG).

METHODS

A total of 46 patients affected by breast hypoplasia were treated with FG-e-ASCs, comparing results with those of a CG (n = 30) treated with fat graft not enhanced with adipose-derived stem cells (FG-ne-ASCs). The preoperative evaluation included a complete clinical evaluation, a photographic assessment, magnetic resonance imaging of the soft tissue, ultrasound, and mammography. Postoperative follow-up took place at 1, 3, 7, 12, 24, and 48 weeks and then annually.

RESULTS

The patients treated with FG-e-ASCs showed 58% maintenance of the contour restoring and of 3-dimensional (3D) volume after 3 years compared with the patients of the CG treated with FG-ne-ASCs, who showed 29% maintenance. In 67.4% (n = 31) of breast augmentations treated with FG-e-ASCs, we observed a restoration of the breast contour and an increase of 10.3 mm in the 3D volume after 36 months, which was observed in only 20.0% (n = 6) of patients in the CG treated with FG-ne-ASCs. Volumetric persistence in the SG was higher than that in the CG (P < 0.0001 SG vs CG).

CONCLUSIONS

Utilization of FG-e-ASCs was safe and effective in this series of cases performed.

LEVEL OF EVIDENCE: 4

Efficacy of stem cell therapy for burn wounds: a systematic review and meta-analysis of preclinical studies

BACKGROUND

Burns remain a serious public health problem with high morbidity and mortality rates worldwide. Although there are various treatment options available, there is no consensus on the best treatment for severe burns as of yet. Stem cell therapy has a bright prospect in many preclinical studies of burn wounds. The systematic review was performed for these preclinical studies to assess the efficacy and possible mechanisms of stem cells in treating burn wounds.

METHODS

Twenty-two studies with 595 animals were identified by searching PubMed, EMBASE, Web of Science, and Cochrane Library databases from inception to 13 May 2020. In addition, a manual search of references of studies was performed to obtain potential studies. No language or time restrictions were enforced. RevMan 5.3 was used for all data analysis.

RESULTS

The overall meta-analysis showed that stem cell therapy significantly improved burn healing rate (SMD 3.06, 95% CI 1.98 to 4.14), irrespective of transplant type, burn area, and treatment method in the control group. Subgroup analyses indicated that hair follicle stem cells seemed to exert more beneficial effects on animals with burn wounds (SMD 7.53, 95% CI 3.11 to 11.95) compared with other stem cells. Furthermore, stem cell therapy seemed to exert more beneficial effects on burn wounds with second-degree (SMD 7.53, 95% CI 3.11 to 11.95) compared with third-degree (SMD 2.65, 95% CI 1.31 to 4.00).

CONCLUSIONS

Meta-analysis showed that stem cell therapy exerts a healing function for burn wounds, mainly through angiogenesis and anti-inflammatory actions. These findings also demonstrate the need for considering variations in future clinical studies using stem cells to treat a burn wound in order to maximize the effectiveness. In general, stem cells can potentially become a novel therapy candidate for burn wounds.

A randomized blinded retrospective study: the combined use of micro-needling technique, low-level laser therapy and autologous non-activated platelet-rich plasma improves hair re-growth in patients with androgenic alopecia

INTRODUCTION

Mini-invasive therapies based on autologous non-activated Platelet-Rich Plasma (ANA-PRP), Low-Level Laser Therapy (LLL-T), and Micro-Needling Technique (MN-T) used in combining for hair re-growth need to be standardized.

OBJECTIVES

The work aims to show in vivo outcomes resulted from retrospective case-series study in which ANA-PRP + MN-T + LLL-T were used in combined in patients affected by Androgenic alopecia.

METHODS

23 patients were treated, of which 13 males were classified in stage I-V by the Norwood-Hamilton scale, and 10 females were classified in stage I-III by the Ludwig scale. Assessment of hair re-growth was evaluated with photography, physician's and patient's global assessment scale, and standardized phototrichograms during a follow-up: T0 - baseline, T1 - 12 weeks, T2 - 23 weeks, T3 - 44 weeks, T4 - 58 weeks.

RESULTS

Interesting outcomes represented by a hair density increase of 81 ± 5 hairs/cm² and 57 ± 7 hairs/cm² respectively at T1 and T2 compared with baseline (173 ± 5 hairs/cm² at T1 and 149 ± 9 hairs/cm² at T2 versus 92 ± 2 hairs/cm² at baseline) were observed using computerized trichograms.

EXPERT OPINION

The main limitation in the autologous regenerative therapies and biotechnologies in hair-regrowth is the extreme variability of PRP products used, in the absence of standardized protocols and widely shared. Appropriate PRP preparations have to be pick after carefully thinking about their bio-molecular specifications and intended indications for use in patients. This approach will aid in matching the optimal PRP product to specific patient factors, leading to improved outcomes and the elucidation of the cost-effectiveness of this treatment. The combined use of biotechnologies as the association of PRP with micro-needling and low-level laser therapy may improve the results in terms of hair count and hair density compared with those obtained by alone PRP. All the procedures must be performed in the full respect of international and local rules.

CONCLUSIONS

The effect of the combined use of MN-T, LLL-T, and ANA-PRP has been demonstrated.

Application and prospect of adipose stem cell transplantation in treating lymphedema

BACKGROUND

Lymphedema is a chronic, debilitating and incurable disease that affects 0.13%-2% of the global population. Emerging evidence indicates that adipose-derived stem cells (ADSCs) might serve as suitable seed cells for lymphatic tissue engineering and lymphedema therapy.

AIM

To summarize applications of ADSCs for treating lymphedema in both animal studies and clinical trials.

METHODS

A systematic search was performed on four databases – PubMed, Clinicaltrials.gov, the evidence-based Cochrane Library, and OVID – using the following search string: (“lymphedema” or “lymphoedema” or “lymphangiogenesis”) and (“adipose-derived stem cells” or “adipose-derived stromal cells” or “adipose-derived regenerative cells”). A manual search was performed by skimming the references of relevant studies. Animal studies and clinical trials using adipose-derived cells for the treatment of any kind of lymphedema were included.

RESULTS

A total of eight research articles published before November 2019 were included for this analysis. Five articles focused on animal studies and another three focused on clinical trials. ADSC transplantation therapy was demonstrated to be effective against lymphedema in all studies. The animal studies found that coadministration of ADSCs and controlled-release vascular endothelial growth factor-C or platelet-rich plasma could improve the effectiveness of ADSC therapy. Three sequential clinical trials were conducted on breast cancer-related lymphedema patients, and all showed favorable results.

CONCLUSION

ADSC-based therapy is a promising option for treating lymphedema. Large-scale, multicenter randomized controlled trials are needed to develop more effective and durable therapeutic strategies.