Human adipose-derived stem cell transplantation as a potential therapy for collagen VI-related congenital muscular dystrophy

Distinct muscle regenerative capacity of human induced pluripotent stem cell-derived mesenchymal stromal cells in Ullrich congenital muscular dystrophy model mice

BACKGROUND

Ullrich congenital muscular dystrophy (UCMD) is caused by a deficiency in type 6 collagen (COL6) due to mutations in COL6A1, COL6A2, or COL6A3. COL6 deficiency alters the extracellular matrix structure and biomechanical properties, leading to mitochondrial defects and impaired muscle regeneration. Therefore, mesenchymal stromal cells (MSCs) that secrete COL6 have attracted attention as potential therapeutic targets. Various tissue-derived MSCs exert therapeutic effects in various diseases. However, no reports have compared the effects of MSCs of different origins on UCMD pathology.

METHODS

To evaluate which MSC population has the highest therapeutic efficacy for UCMD, in vivo (transplantation of MSCs to Col6a1-KO/NSG mice) and in vitro experiments (muscle stem cell [MuSCs] co-culture with MSCs) were conducted using adipose tissue-derived MSCs, bone marrow-derived MSCs, and xeno-free-induced iPSC-derived MSCs (XF-iMSCs).

RESULTS

In transplantation experiments on Col6a1-KO/NSG mice, the group transplanted with XF-iMSCs showed significantly enhanced muscle fiber regeneration compared to the other groups 1 week after transplantation. At 12 weeks after transplantation, only the XF-iMSCs transplantation group showed a significantly larger muscle fiber diameter than the other groups without inducing fibrosis, which was observed in the other transplantation groups. Similarly, in co-culture experiments, XF-iMSCs were found to more effectively promote the fusion and differentiation of MuSCs derived from Col6a1-KO/NSG mice than the other primary MSCs investigated in this study. Additionally, in vitro knockdown and supplementation experiments suggested that the IGF2 secreted by XF-iMSCs promoted MuSC differentiation.

CONCLUSION

XF-iMSCs are promising candidates for promoting muscle regeneration while avoiding fibrosis, offering a safer and more effective therapeutic approach for UCMD than other potential therapies.

Vitamin K3 promotes CCL5 expression to recruit preadipocytes deposition to skeletal muscle

Intramuscular fat (IMF), also known as ectopic fat deposits in skeletal muscle. Researches of IMF mainly focus on increasing the number and size of intramuscular adipocytes in situ. However, recent studies have shown that chemokines secreted by skeletal muscle recruit adipocytes to increase intramuscular fat content. Chemokine ligand 5 (CCL5), a member of chemokine family, is involved in the regulation of cell migration, inflammatory responses, and energy metabolism. In this study, we determined Vitamin K3 (VK3) enhanced Ccl5 transcription and expression, thus resulting in increased preadipocyte migration. VK3-injected vastus lateralis (VL) was observed an increased CCL5 concentration and IMF deposition, whereas blockade of the CCL5/CCR5 axis decreased IMF deposition.VK3 treatment also increased the body weight and VL ratio in mice. In summary, VK3, which targets CCL5, is expected to be a novel pharmacological regulator for promoting IMF content.

Extracellular matrix: Brick and mortar in the skeletal muscle stem cell niche

The extracellular matrix (ECM) is an interconnected macromolecular scaffold occupying the space between cells. Amongst other functions, the ECM provides structural support to tissues and serves as a microenvironmental niche that conveys regulatory signals to cells. Cell-matrix adhesions, which link the ECM to the cytoskeleton, are dynamic multi-protein complexes containing surface receptors and intracellular effectors that control various downstream pathways. In skeletal muscle, the most abundant tissue of the body, each individual muscle fiber and its associated muscle stem cells (MuSCs) are surrounded by a layer of ECM referred to as the basal lamina. The core scaffold of the basal lamina consists of self-assembling polymeric laminins and a network of collagens that tether proteoglycans, which provide lateral crosslinking, establish collateral associations with cell surface receptors, and serve as a sink and reservoir for growth factors. Skeletal muscle also contains the fibrillar collagenous interstitial ECM that plays an important role in determining tissue elasticity, connects the basal laminae to each other, and contains matrix secreting mesenchymal fibroblast-like cell types and blood vessels. During skeletal muscle regeneration fibroblast-like cell populations expand and contribute to the transitional fibronectin-rich regenerative matrix that instructs angiogenesis and MuSC function. Here, we provide a comprehensive overview of the role of the skeletal muscle ECM in health and disease and outline its role in orchestrating tissue regeneration and MuSC function.

Skeletal Muscle Regeneration in Cardiotoxin-Induced Muscle Injury Models

Skeletal muscle injuries occur frequently in daily life and exercise. Understanding the mechanisms of regeneration is critical for accelerating the repair and regeneration of muscle. Therefore, this article reviews knowledge on the mechanisms of skeletal muscle regeneration after cardiotoxin-induced injury. The process of regeneration is similar in different mouse strains and is inhibited by aging, obesity, and diabetes. Exercise, microcurrent electrical neuromuscular stimulation, and mechanical loading improve regeneration. The mechanisms of regeneration are complex and strain-dependent, and changes in functional proteins involved in the processes of necrotic fiber debris clearance, M1 to M2 macrophage conversion, SC activation, myoblast proliferation, differentiation and fusion, and fibrosis and calcification influence the final outcome of the regenerative activity.

Transcription and proteome changes involved in re-innervation muscle following nerve crush in rats

Severe peripheral nerve injury leads to the irreparable disruption of nerve fibers. This leads to disruption of synapses with the designated muscle, which consequently go through progressive atrophy and damage of muscle function. The molecular mechanism that underlies the re-innervation process has yet to be evaluated using proteomics or transcriptomics. In the present study, multi-dimensional data were therefore integrated with transcriptome and proteome profiles in order to investigate the mechanism of re-innervation in muscles. Two simulated nerve injury muscle models in the rat tibial nerve were compared: the nerve was either cut (denervated, DN group) or crushed but with the nerve sheath intact (re-innervated, RN group). The control group had a preserved and intact tibial nerve. At 4 weeks, the RN group showed better tibial nerve function and recovery of muscle atrophy compared to the DN group. As the high expression of Myh3, Postn, Col6a1 and Cfi, the RN group demonstrated superior re-innervation as well. Both differentially expressed genes (DEGs) and proteins (DEPs) were enriched in the peroxisome proliferator-activated receptors (PPARs) signaling pathway, as well as the energy metabolism. This study provides basic information regarding DEGs and DEPs during re-innervation-induced muscle atrophy. Furthermore, the crucial genes and proteins can be detected as possible treatment targets in the future.

Challenges and perspectives of tendon-derived cell therapy for tendinopathy: from bench to bedside

Tendon is composed of dense fibrous connective tissues, connecting muscle at the myotendinous junction (MTJ) to bone at the enthesis and allowing mechanical force to transmit from muscle to bone. Tendon diseases occur at different zones of the tendon, including enthesis, MTJ and midsubstance of the tendon, due to a variety of environmental and genetic factors which consequently result in different frequencies and recovery rates. Self-healing properties of tendons are limited, and cell therapeutic approaches in which injured tendon tissues are renewed by cell replenishment are highly sought after. Homologous use of individual’s tendon-derived cells, predominantly differentiated tenocytes and tendon-derived stem cells, is emerging as a treatment for tendinopathy through achieving minimal cell manipulation for clinical use. This is the first review summarizing the progress of tendon-derived cell therapy in clinical use and its challenges due to the structural complexity of tendons, heterogeneous composition of extracellular cell matrix and cells and unsuitable cell sources. Further to that, novel future perspectives to improve therapeutic effect in tendon-derived cell therapy based on current basic knowledge are discussed.

Adipose-derived stem cells decolonize skin Staphylococcus aureus by enhancing phagocytic activity of peripheral blood mononuclear cells in the atopic rats

Staphylococcus aureus (S. aureus) is known to induce apoptosis of host immune cells and impair phagocytic clearance, thereby being pivotal in the pathogenesis of atopic dermatitis (AD). Adipose-derived stem cells (ASCs) exert therapeutic effects against inflammatory and immune diseases. In the present study, we investigated whether systemic administration of ASCs restores the phagocytic activity of peripheral blood mononuclear cells (PBMCs) and decolonizes cutaneous S. aureus under AD conditions. AD was induced by injecting capsaicin into neonatal rat pups. ASCs were extracted from the subcutaneous adipose tissues of naïve rats and administered to AD rats once a week for a month. Systemic administration of ASCs ameliorated AD-like symptoms, such as dermatitis scores, serum IgE, IFN-γ⁺/IL-4⁺ cell ratio, and skin colonization by S. aureus in AD rats. Increased FasL mRNA and annexin V⁺/7-AAD⁺ cells in the PBMCs obtained from AD rats were drastically reversed when co-cultured with ASCs. In contrast, both PBMCs and CD163⁺ cells bearing fluorescent zymosan particles significantly increased in AD rats treated with ASCs. Additionally, the administration of ASCs led to an increase in the mRNA levels of antimicrobial peptides, such as cathelicidin and β-defensin, in the skin of AD rats. Our results demonstrate that systemic administration of ASCs led to decolonization of S. aureus by attenuating apoptosis of immune cells in addition to restoring phagocytic activity. This contributes to the improvement of skin conditions in AD rats. Therefore, administration of ASCs may be helpful in the treatment of patients with intractable AD.

Role of human adipose-derived stem cells (hADSC) on TGF-β1, type I collagen, and fibrosis degree in bladder obstruction model of Wistar rats

Introduction

Bladder outlet obstruction (BOO) was caused by a series of histological and biochemical changes in the bladder wall, through the inflammation process in the bladder wall, hypertrophy and fibrosis. ADSC has an important role in bladder regeneration.

Methods and materials

This study was an experimental randomized study using male Wistar rats which were monitored at 2 and 4 weeks to determine the effect of ADSC therapy on TGF-β1 type I collagen, and degree of fibrosis.

Result

Rats were divided into 5 groups. In the week 2 BOO group, 1 sample included in the category of moderate fibrosis, 1 sample that was given ADSC with mild fibrosis category, 3 samples included in severe fibrosis category, 3 samples that were given ADSC included in the category of moderate fibrosis. The concentration of TGF-β1 in the hADSC therapy group was significantly lower than the control group at the 2nd and 4th week of monitoring (p2 = 0.048, p4 = 0.048), and also with more type I collagen on 2nd and the 4th week (p2 = 0.048, p4 = 0.048).

Conclusion

ADSC therapy can reduce the concentration of TGF-β1, type I collagen, and degree of fibrosis in the male Wistar BOO model.

Systemic Supplementation of Collagen VI by Neonatal Transplantation of iPSC-Derived MSCs Improves Histological Phenotype and Function of Col6-Deficient Model Mice

Collagen VI is distributed in the interstitium and is secreted mainly by mesenchymal stromal cells (MSCs) in skeletal muscle. Mutations in COL6A1-3 genes cause a spectrum of COL6-related myopathies. In this study, we performed a systemic transplantation study of human-induced pluripotent stem cell (iPSC)-derived MSCs (iMSCs) into neonatal immunodeficient COL6-related myopathy model (Col6a1^KO/NSG) mice to validate the therapeutic potential. Engraftment of the donor cells and the resulting rescued collagen VI were observed at the quadriceps and diaphragm after intraperitoneal iMSC transplantation. Transplanted mice showed improvement in pathophysiological characteristics compared with untreated Col6a1^KO/NSG mice. In detail, higher muscle regeneration in the transplanted mice resulted in increased muscle weight and enlarged myofibers. Eight-week-old mice showed increased muscle force and performed better in the grip and rotarod tests. Overall, these findings support the concept that systemic iMSC transplantation can be a therapeutic option for COL6-related myopathies.

Transcriptome analysis of collagen VI-related muscular dystrophy muscle biopsies

Objective

To define the transcriptomic changes responsible for the histologic alterations in skeletal muscle and their progression in collagen VI‐related muscular dystrophy (COL6‐RD).

Methods

COL6‐RD patient muscle biopsies were stratified into three groups based on the overall level of pathologic severity considering degrees of fibrosis, muscle fiber atrophy, and fatty replacement of muscle tissue. Using microarray and RNA‐Seq, we then performed global gene expression profiling on the same muscle biopsies and compared their transcriptome with age‐ and sex‐matched controls.

Results

COL6‐RD muscle biopsy transcriptomes as a group revealed prominent upregulation of muscle extracellular matrix component genes and the downregulation of skeletal muscle and mitochondrion‐specific genes. Upregulation of the TGFβ pathway was the most conspicuous change across all biopsies and was fully evident even in the mildest/earliest histological group. There was no difference in the overall transcriptional signature between the different histologic groups but polyserial analysis identified relative changes along with COL6‐RD histological severity.

Interpretation

Overall, our study establishes the prominent dysregulation of extracellular matrix genes, TGFβ signaling, and its downstream cellular pathways at the transcriptomic level in COL6‐RD muscle.

Knockdown of miR-423-5p simultaneously upgrades the eNOS and VEGFa pathways in ADSCs and improves erectile function in diabetic rats

This study aimed to explore the possibility of miR‐423‐5p modified adipose‐derived stem cell (ADSCs) therapy on streptozotocin (STZ)‐induced diabetes mellitus erectile dysfunction (DMED) rats. MiR‐423‐5p was knocked down in ADSCs. ADSCs, NC‐miR‐ADSCs and miR‐ADSCs were co‐cultured with human umbilical vein endothelial cells (HUVECs). Normal and high glucose media were supplemented. The supernatant and HUVECs were collected for assessment of eNOS and VEGFa expression, cell proliferation, and apoptosis. HUVECs co‐cultured with ADSCs or miR‐ADSCs exhibited higher eNOS and VEGFa protein expression levels compared to DM groups. MiR‐ADSCs enhanced HUVEC proliferation compared to the ADSCs and NC‐miR‐ADSCs. Lower apoptotic rates were observed when HUVECs were co‐cultured with miR‐ADSCs, compared to ADSCs and NC‐miR‐ADSCs. Fifteen male Sprague‐Dawley (SD) rats aged 12 weeks were induced to develop diabetes mellitus by intraperitoneal injection with STZ, and five healthy SD rats were used as normal controls. Eight weeks after developing diabetes, the rats received ADSCs and miR‐ADSCs via injection into the corpora cavernosa, whereas normal controls and DM controls were injected with saline. Erectile function and histological assessment of penile tissues were performed 8 weeks after injection. The ICP/MAP indicated that erectile function was impaired in the DM rats compared with the normal group. Injection of ADSCs and miR‐ADSCs improved erectile function significantly and was associated with the overexpression of eNOS and VEGFa. MiR‐423‐5p knockdown in ADSCs ameliorated high glucose‐mediated damage to HUVECs and improved erectile function in DM rats by inducing eNOS and VEGFa overexpression, indicating that miR‐423‐5p may be a potential target in the treatment of DMED.

Collagen-VI supplementation by cell transplantation improves muscle regeneration in Ullrich congenital muscular dystrophy model mice

Background

Mesenchymal stromal cells (MSCs) function as supportive cells on skeletal muscle homeostasis through several secretory factors including type 6 collagen (COL6). Several mutations of COL6A1, 2, and 3 genes cause Ullrich congenital muscular dystrophy (UCMD). Skeletal muscle regeneration deficiency has been reported as a characteristic phenotype in muscle biopsy samples of human UCMD patients and UCMD model mice. However, little is known about the COL6-dependent mechanism for the occurrence and progression of the deficiency. The purpose of this study was to clarify the pathological mechanism of UCMD by supplementing COL6 through cell transplantation.

Methods

To test whether COL6 supplementation has a therapeutic effect for UCMD, in vivo and in vitro experiments were conducted using four types of MSCs: (1) healthy donors derived-primary MSCs (pMSCs), (2) MSCs derived from healthy donor induced pluripotent stem cell (iMSCs), (3) COL6-knockout iMSCs (COL6KO-iMSCs), and (4) UCMD patient-derived iMSCs (UCMD-iMSCs).

Results

All four MSC types could engraft for at least 12 weeks when transplanted into the tibialis anterior muscles of immunodeficient UCMD model (Col6a1KO) mice. COL6 protein was restored by the MSC transplantation if the MSCs were not COL6-deficient (types 1 and 2). Moreover, muscle regeneration and maturation in Col6a1KO mice were promoted with the transplantation of the COL6-producing MSCs only in the region supplemented with COL6. Skeletal muscle satellite cells derived from UCMD model mice (Col6a1KO-MuSCs) co-cultured with type 1 or 2 MSCs showed improved proliferation, differentiation, and maturation, whereas those co-cultured with type 3 or 4 MSCs did not.

Conclusions

These findings indicate that COL6 supplementation improves muscle regeneration and maturation in UCMD model mice.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02514-3.

Collagen VI as a driver and disease biomarker in human fibrosis

Fibrosis of visceral organs such as the lungs, heart, kidneys and liver remains a major cause of morbidity and mortality and is also associated with many other disorders, including cancer and metabolic disease. In this review, we focus upon the microfibrillar collagen VI, which is present in the extracellular matrix (ECM) of most tissues. However, expression is elevated in numerous fibrotic conditions, such as idiopathic pulmonary disease (IPF), and chronic liver and kidney diseases. Collagen VI is composed of three subunits α1, α2 and α3, which can be replaced with alternate chains of α4, α5 or α6. The C-terminal globular domain (C5) of collagen VI α3 can be proteolytically cleaved to form a biologically active fragment termed endotrophin, which has been shown to actively drive fibrosis, inflammation and insulin resistance. Tissue biopsies have long been considered the gold standard for diagnosis and monitoring of progression of fibrotic disease. The identification of neoantigens from enzymatically processed collagen chains have revolutionised the biomarker field, allowing rapid diagnosis and evaluation of prognosis of numerous fibrotic conditions, as well as providing valuable clinical trial endpoint determinants. Collagen VI chain fragments such as endotrophin (PRO-C6), C6M and C6Mα3 are emerging as important biomarkers for fibrotic conditions.

Extracellular Vesicles Derived From Human Adipose-Derived Stem Cell Prevent the Formation of Hypertrophic Scar in a Rabbit Model

Preventing scar formation during wound healing has important clinical implications. Numerous studies have indicated that adipose-derived stem cell culture mediums, which are rich in cytokines and extracellular vesicles (EVs), regulate matrix remodeling and prevent scar formation after wound healing. Therefore, using a rabbit scar model, we tried to demonstrate which factor in adipose-derived stem cell culture mediums plays a major role in preventing scar formation (EVs or cytokines), as well as revealing the underlying mechanism.

Adipose-mesenchymal stromal cells suppress experimental Sjögren syndrome by IL-33-driven expansion of ST2+ regulatory T cells

Adipose-derived mesenchymal stromal cells (ADSCs) play important roles in the alleviation of inflammation and autoimmune diseases. Interleukin-33 (IL-33), a member of the IL-1 family, has been shown to regulate innate and adaptive immunity. However, it is still unknown whether ADSCs regulate immune responses via IL-33. We show here that ADSCs produced IL-33 in response to IL-1β stimulation, which depended on TAK1, ERK, and p38 pathways. ADSCs-derived IL-33 drove the proliferation of CD4⁺Foxp3⁺ST2⁺ regulatory T cells (Tregs) and alleviated experimental autoimmune Sjögren syndrome in mice. Importantly, human ADSCs also produced IL-33 in response to IL-1β. Thus, we have revealed a previously unrecognized immunoregulatory function of ADSCs by IL-33 production in experimental autoimmunity, which may have clinical applications for human immunopathology.

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Human and mouse ADSCs express IL-33 in response to IL-β stimulation

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mADSC-derived IL-33 inhibits inflammation in salivary glands in SS model

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mADSC-derived IL-33 expand ST2⁺ Tregs in vitro and in SS model

Congenital muscular dystrophy-associated inflammatory chemokines provide axes for effective recruitment of therapeutic adult stem cell into muscles

Background

Congenital muscular dystrophies (CMD) are a clinically and genetically heterogeneous group of neuromuscular disorders characterized by muscle weakness. The two most prevalent forms of CMD, collagen VI-related myopathies (COL6RM) and laminin α2 deficient CMD type 1A (MDC1A), are both caused by deficiency or dysfunction of extracellular matrix proteins. Previously, we showed that an intramuscular transplantation of human adipose-derived stem cells (ADSC) into the muscle of the Col6a1^−/− mice results in efficient stem cell engraftment, migration, long-term survival, and continuous production of the collagen VI protein, suggesting the feasibility of the systemic cellular therapy for COL6RM. In order for this therapeutic approach to work however, stem cells must be efficiently targeted to the entire body musculature. Thus, the main goal of this study is to test whether muscle homing of systemically transplanted ADSC can be enhanced by employing muscle-specific chemotactic signals originating from CMD-affected muscle tissue.

Methods

Proteomic screens of chemotactic molecules were conducted in the skeletal muscles of COL6RM- and MDC1A-affected patients and CMD mouse models to define the inflammatory and immune activities, thus, providing potential markers of disease activity or treatment effect. Also using a pre-clinical animal model, recapitulating mild Ullrich congenital muscular dystrophy (UCMD), the therapeutic relevance of identified chemotactic pathways was investigated in vivo, providing a basis for future clinical investigations.

Results

Comprehensive proteomic screens evaluating relevant human and mouse skeletal muscle biopsies offered chemotactic axes to enhance directional migration of systemically transplanted cells into CMD-affected muscles, including CCL5-CCR1/3/5, CCL2-CCR2, CXCL1/2-CXCR1,2, and CXCL7-CXCR2. Also, the specific populations of ADSC selected with an affinity for the chemokines being released by damaged muscle showed efficient migration to injured site and presented their therapeutic effect.

Conclusions

Collectively, identified molecules provided insight into the mechanisms governing directional migration and intramuscular trafficking of systemically infused stem cells, thus, permitting broad and effective application of the therapeutic adult stem cells for CMD treatment.

Native extracellular matrix, synthesized ex vivo by bone marrow or adipose stromal cells, faithfully directs mesenchymal stem cell differentiation

Mesenchymal stem cells (MSCs) are highly responsive to cues in the microenvironment (niche) that must be recapitulated ex vivo to study their authentic behavior. In this study, we hypothesized that native bone marrow (BM)- and adipose (AD)-derived extracellular matrices (ECM) were unique in their ability to control MSC behavior. To test this, we compared proliferation and differentiation of bone marrow (BM)-derived MSCs when maintained on native decellularized ECM produced by BM versus AD stromal cells (i.e. BM- versus AD-ECM). We found that both ECMs contained similar types of collagens but differed in the relative abundance of each. Type VI collagen was the most abundant (≈60% of the total collagen present), while type I was the next most abundant at ≈30%. These two types of collagen were found in nearly equal proportions in both ECMs. In contrast, type XII collagen was almost exclusively found in AD-ECM, while types IV and V were only found in BM-ECM. Physically and mechanically, BM-ECM was rougher and stiffer, but less adhesive, than AD-ECM. During 14 days in culture, both ECMs supported BM-MSC proliferation better than tissue culture plastic (TCP), although MSC-related surface marker expression remained relatively high on all three culture surfaces. BM-MSCs cultured in osteogenic (OS) differentiation media on BM-ECM displayed a significant increase in calcium deposition in the matrix, indicative of osteogenesis, while BM-MSCs cultured on AD-ECM in the presence of adipogenic (AP) differentiation media showed a significant increase in Oil Red O staining, indicative of adipogenesis. Further, culture on BM-ECM significantly increased BM-MSC-responsiveness to rhBMP-2 (an osteogenic inducer), while culture on AD-ECM enhanced responsiveness to rosiglitazone (an adipogenic inducer). These findings support our hypothesis and indicate that BM- and AD-ECMs retain unique elements, characteristic of their tissue-specific microenvironment (niche), which promote retention of MSC differentiation state (i.e. "stemness") during expansion and direct cell response to lineage-specific inducers. This study provides a new paradigm for precisely controlling MSC fate to a desired cell lineage for tissue-specific cell-based therapies.

The effect of intravenous human adipose-derived stem cells (hADSC) on transforming growth factor β1 (TGF-β1), collagen type 1, and kidney histopathological features in the unilateral ureteropelvic junction obstruction model of wistar rats

OBJECTIVE

The fibrotic process of kidney resulting in glomerulosclerosis was found in patients with ureteropelvic junction obstruction (UPJO) who underwent renal biopsy during pyeloplasty. Transforming growth factor β1 (TGF-β1) plays a role in collagen accumulation, resulting in fibrosis. Adipose tissue-derived stem cells (ADSCs) have an anti-apoptotic effect on target cells and enhance the kidney function recovery. We will further investigate the use of ADSC in the prevention of kidney fibrosis in the unilateral UPJO model of Wistar rats.

MATERIAL AND METHODS

A total of twenty-two 12-week-old Wistar rats were divided into three groups. We made the UPJO models using nylon 6-0 inside the left ureter and tied the ureter with nylon 6-0, creating partial ureteral obstruction. The treatment group was then injected with 1.0 × 10⁶ cells of human ADSC via the tail vein of rats. All rats were euthanized after 2 and 4 weeks of treatment. The left kidney used hematoxylin-eosin for histopathological examination. Statistical analysis using one-way analysis of variance (ANOVA) was done with SPSS version 21.0.

RESULTS

TGF-β1 concentration in the treatment group was significantly lower in the 4^th week of observation (p4=0.0001), as well as collagen type 1, which was also significantly lower in the 4^th week (p4=0.0001). There was a significant difference in the glomerulus count between the control group and the human ADSC (hADSC) group therapy in week 2 and week 4 (p2=0.0001 and p4=0.026).

CONCLUSION

Administration of hADSC therapy reduces TGF-β1 and collagen type 1 levels and then improves the histopathological features in the process of renal fibrosis in the UPJO model.

Effect of Intracorporeal Human Adipose-Derived Stem Cells (hADSCs) on Corpora Cavernosa Transforming Growth Factor β1 (TGFβ1) and Collagen Type I Concentration in Wistar Rat Priapism Model

Introduction

The ischemic process in priapism can lead to displacement of normal tissue with fibrotic tissue, due to collagen deposition, and eventually leads to erectile dysfunction. Many studies have identified that the supernatant of adipose tissue–derived stem cells (ADSCs) significantly ameliorates fibrosis of different tissue, but limited attention has been paid to its efficacy on fibrosis of the corpora cavernosa.

Methods

A total of 22 Wistar rats divided into five groups, with two groups each consisting of five male wistar rats with priapism without human ADSC (hADSC) therapy (group I) and two other groups consisting of five rats with priapism, were given 10⁶ cells' intracorporeal hADSC injection after 12 hours of penile clamping (group II) were euthanized after 2 and 4 weeks of observation. The last group consisted of two rats without any treatment or model (group III). Following euthanasia, penises were harvested for TGFβ₁ and collagen type I measurement using ELISA. Statistical analysis using independent-sample t-tests was done with SPSS 21.0.

Results

Penile TGFβ₁ concentration in the treatment group was significantly lower in the second and fourth weeks of observation (p₂=0.004, p₄=0.003), and collagen type I was significantly lower in the second and fourth weeks (p₂=0.003, p₄=0.011).

Conclusion

Intracorporeal hADSC injection limited the fibrosis process in a priapism model. Although the mechanism was unclear, it may be related to the potential of hADSCs to produce various growth factors that could limit TGFβ₁ and collagen production.

Mechanical Micronization of Lipoaspirates for the Treatment of Horizontal Neck Lines

BACKGROUND

Horizontal neck wrinkles develop as a result of the aging process. Stromal vascular fraction (SVF) gel, which is rich in extracellular matrix and functional cells, can be produced by a series of simple mechanical processes, including intersyringe shifting and centrifugation. This study aimed to assess stromal vascular fraction gel in the treatment of horizontal neck wrinkles.

METHODS

This single-center study included female patients with horizontal neck wrinkles (Fitzpatrick types II to IV) treated with either SVF gel or botulinum toxin type A (BTX A) injection. SVF gel was first diffusely distributed subcutaneously along the neck line and then injected in a diluted way intracutaneously at points 0.5 cm apart along the horizontal lines. BTX A was injected at points 1.5 cm apart (2 U in each injection site). Satisfaction and improvement scores were compared between the two groups, and the collagen content of the neck wrinkle was compared by histologic evaluation before and after treatment.

RESULTS

Twenty-eight patients received SVF gel and 22 received BTX A. In patients with type II neck wrinkles, BTX A and SVF gel treatment resulted in similar improvement scores and patient satisfaction in the first 3 months. In patients with type III and IV neck wrinkles, SVF gel resulted in significantly higher improvement scores and better patient satisfaction. A longer duration of adverse events was seen in the SVF gel treatment group. Histologic assessment suggested that SVF gel increased the collagen density of neck wrinkles.

CONCLUSION

SVF gel is an effective treatment for horizontal neck wrinkles, particularly in patients with type III and IV wrinkles.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, II.

Basement membrane collagens and disease mechanisms

Basement membranes (BMs) are specialised extracellular matrix (ECM) structures and collagens are a key component required for BM function. While collagen IV is the major BM collagen, collagens VI, VII, XV, XVII and XVIII are also present. Mutations in these collagens cause rare multi-systemic diseases but these collagens have also been associated with major common diseases including stroke. Developing treatments for these conditions will require a collective effort to increase our fundamental understanding of the biology of these collagens and the mechanisms by which mutations therein cause disease. Novel insights into pathomolecular disease mechanisms and cellular responses to these mutations has been exploited to develop proof-of-concept treatment strategies in animal models. Combined, these studies have also highlighted the complexity of the disease mechanisms and the need to obtain a more complete understanding of these mechanisms. The identification of pathomolecular mechanisms of collagen mutations shared between different disorders represent an attractive prospect for treatments that may be effective across phenotypically distinct disorders.

Regenerative Capacity of Adipose Derived Stem Cells (ADSCs), Comparison with Mesenchymal Stem Cells (MSCs)

Adipose tissue is now on the top one of stem cell sources regarding its accessibility, abundance, and less painful collection procedure when compared to other sources. The adipose derived stem cells (ADSCs) that it contains can be maintained and expanded in culture for long periods of time without losing their differentiation capacity, leading to large cell quantities being increasingly used in cell therapy purposes. Many reports showed that ADSCs-based cell therapy products demonstrated optimal efficacy and efficiency in some clinical indications for both autologous and allogeneic purposes, hence becoming considered as potential tools for replacing, repairing, and regenerating dead or damaged cells. In this review, we analyzed the therapeutic advancement of ADSCs in comparison to bone marrow (BM) and umbilical cord (UC)-mesenchymal stem cells (MSCs) and designed the specific requirements to their best clinical practices and safety. Our analysis was focused on the ADSCs, rather than the whole stromal vascular fraction (SVF) cell populations, to facilitate characterization that is related to their source of origins. Clinical outcomes improvement suggested that these cells hold great promise in stem cell-based therapies in neurodegenerative, cardiovascular, and auto-immunes diseases.

Regenerative Capacity of Adipose Derived Stem Cells (ADSCs), Comparison with Mesenchymal Stem Cells (MSCs)

Adipose tissue is now on the top one of stem cell sources regarding its accessibility, abundance, and less painful collection procedure when compared to other sources. The adipose derived stem cells (ADSCs) that it contains can be maintained and expanded in culture for long periods of time without losing their differentiation capacity, leading to large cell quantities being increasingly used in cell therapy purposes. Many reports showed that ADSCs-based cell therapy products demonstrated optimal efficacy and efficiency in some clinical indications for both autologous and allogeneic purposes, hence becoming considered as potential tools for replacing, repairing, and regenerating dead or damaged cells. In this review, we analyzed the therapeutic advancement of ADSCs in comparison to bone marrow (BM) and umbilical cord (UC)-mesenchymal stem cells (MSCs) and designed the specific requirements to their best clinical practices and safety. Our analysis was focused on the ADSCs, rather than the whole stromal vascular fraction (SVF) cell populations, to facilitate characterization that is related to their source of origins. Clinical outcomes improvement suggested that these cells hold great promise in stem cell-based therapies in neurodegenerative, cardiovascular, and auto-immunes diseases.

Skeletal Muscle Regenerative Engineering

Skeletal muscles have the intrinsic ability to regenerate after minor injury, but under certain circumstances such as severe trauma from accidents, chronic diseases or battlefield injuries the regeneration process is limited. Skeletal muscle regenerative engineering has emerged as a promising approach to address this clinical issue. The regenerative engineering approach involves the convergence of advanced materials science, stem cell science, physical forces, insights from developmental biology, and clinical translation. This article reviews recent studies showing the potential of the convergences of technologies involving biomaterials, stem cells and bioactive factors in concert with clinical translation, in promoting skeletal muscle regeneration. Several types of biomaterials such as electrospun nanofibers, hydrogels, patterned scaffolds, decellularized tissues, and conductive matrices are being investigated. Detailed discussions are given on how these biomaterials can interact with cells and modulate their behavior through physical, chemical and mechanical cues. In addition, the application of physical forces such as mechanical and electrical stimulation are reviewed as strategies that can further enhance muscle contractility and functionality. The review also discusses established animal models to evaluate regeneration in two clinically relevant muscle injuries; volumetric muscle loss (VML) and muscle atrophy upon rotator cuff injury. Regenerative engineering approaches using advanced biomaterials, cells, and physical forces, developmental cues along with insights from immunology, genetics and other aspects of clinical translation hold significant potential to develop promising strategies to support skeletal muscle regeneration.

Adipose-Derived Stem Cells of Blind Mole Rat Spalax Exhibit Reduced Homing Ability: Molecular Mechanisms and Potential Role in Cancer Suppression

Adipose-derived stem cells (ADSCs) are recruited by cancer cells from the adjacent tissue, and they become an integral part of the tumor microenvironment. Here, we report that ADSCs from the long-living, tumor-resistant blind mole rat, Spalax, have a low ability to migrate toward cancer cells compared with cells from its Rattus counterpart. Tracking 5-ethynyl-2'-deoxyuridine (EdU)-labeled ADSCs, introduced to tumor-bearing nude mice, toward the xenografts, we found that rat ADSCs intensively migrated and penetrated the tumors, whereas only a few Spalax ADSCs reached the tumors. Moreover, rat ADSCs, but not Spalax ADSCs, acquired endothelial-like phenotype and incorporated in the intratumoral reticular structure resembling a vasculature. Likewise, endothelial-like cells differentiated from Spalax and rat ADSCs could form capillary-like structures; however, the tube densities were higher in rat-derived cells. Using time-lapse microscopy, in vitro wound-healing, and transwell migration assays, we demonstrated the impaired motility and low polarization ability of Spalax ADSCs. To assess whether the phosphorylated status of myosin light chain (MLC) is involved in the decreased motility of Spalax ADSCs, we inhibited MLC phosphorylation by blocking of Rho-kinase (ROCK). Inhibition of ROCK resulted in the suppression of MLC phosphorylation, acquisition of actin polarization, and activation of motility and migration of Spalax ADSCs. We propose that reduced ADSCs migration to cancer and poor intratumoral angiogenesis play a role in Spalax's cancer resistance. Learning more about the molecular strategy of noncancerous cells in Spalax to resist oncogenic stimuli and maintain a nonpermissive tumor milieu may lead us to developing new cancer-preventive strategy in humans. Stem Cells 2018;36:1630-1642.

Exendin-4 promotes proliferation of adipose-derived stem cells through PI3K/Akt-Wnt signaling pathways

Adipose-derived stem cell (ADSC) transplantation has emerged as a potential tool for the treatment of cardiovascular disease and skin wounds. However, with a limited renewal capacity and the need for mass cells during the engraftment, strategies are needed to enhance ADSC proliferative capacity. In this study, we explored the effects of Exendin-4, a glucagon-like peptide-1 analog, on the growth of ADSCs, focusing in particular on phosphatidylinositol 3-kinase (PI3K)-protein kinase B (Akt) and Wnt signaling pathways. Firstly, ADSCs were isolated and cultured in vitro. Then, flow cytometry demonstrated that ADSCs were positive for CD44, CD90 and CD29 but negative for CD31, CD34, and CD45. Exendin-4 (0-200 nM) treatment increased ADSC proliferation. In order to examine specific signaling pathways, a western blotting assay was performed. Our results demonstrate that after treated with 50 nM Exendin-4 for 48 h, the phosphorylation of PI3K, Akt, and GSK3β were increased and phosphorylation of β-catenin was decreased. From these results, we concluded that PI3K-Akt and Wnt-β-catenin signaling pathways mediate Exendin-4 induced ADSC proliferation, the function of which might contribute to the regulation of ADSC proliferation. Our findings provided new insights into the function of the mechanisms underlying Exendin-4 of ADSCs.

Extracellular matrix protein production in human adipose-derived mesenchymal stem cells on three-dimensional polycaprolactone (PCL) scaffolds responds to GDF5 or FGF2

Purpose

The poor healing potential of intra-articular ligament injuries drives a need for the development of novel, viable 'neo-ligament' alternatives. Ex vivo approaches combining stem cell engineering, 3-dimensional biocompatible scaffold design and enhancement of biological and biomechanical functionality via the introduction of key growth factors and morphogens, represent a promising solution to ligament regeneration.

Methods

We investigated growth, differentiation and extracellular matrix (ECM) protein production of human adipose-derived mesenchymal stem/stromal cells (MSCs), cultured in 5% human platelet lysate (PL) and seeded on three-dimensional polycaprolactone (PCL) scaffolds, in response to the connective-tissue related ligands fibroblast growth factor 2 (basic) (FGF2) and growth and differentiation factor-5 (GDF5). Phenotypic alterations of MSCs under different biological conditions were examined using cell viability assays, real time qPCR analysis of total RNA, as well as immunofluorescence microscopy.

Results

Phenotypic conversion of MSCs into ECM producing fibroblastic cells proceeds spontaneously in the presence of human platelet lysate. Administration of FGF2 and/or GDF5 enhances production of mRNAs for several ECM proteins including Collagen types I and III, as well as Tenomodulin (e.g., COL1A1, TNMD), but not Tenascin-C (TNC). Differences in the in situ deposition of ECM proteins Collagen type III and Tenascin-C were validated by immunofluorescence microscopy.

Summary

Treatment of MSCs with FGF2 and GDF5 was not synergistic and occasionally antagonistic for ECM production. Our results suggest that GDF5 alone enhances the conversion of MSCs to fibroblastic cells possessing a phenotype consistent with that of connective-tissue fibroblasts.

Human adipose derived stem cells regress fibrosis in a chronic renal fibrotic model induced by adenine

BACKGROUND AND AIMS

ADSCs transplantation had been shown in some experimental models of kidney damage that it improves kidney function and reduces fibrosis. In this study we evaluated the effect of human adipose tissue-derived stem cell (hADSC) therapy in a chronic kidney damage experimental model.

METHODS

A chronic kidney injury was induced by daily orogastric administration of adenine (100mg/kg) to male Wistar rats for 28 days. hADSCs were isolated, expanded and characterized before transplantation. hADSC administration was performed in a tail vein at a dose of 2 x106 cells/animal. Animals were sacrificed at 7 days post-treatment. The percentage of fibrotic tissue, serum and urine levels of urea, creatinine, total protein and renal mRNA of COL1A1, TGFB1, CTGF, ACTA2, IL6, IL10, TNF were analyzed.

RESULTS

hADSCs treatment significantly reduces kidney fibrosis, improves urea and creatinine serum and urine levels, and diminishes COL1A1, TGFB1, CTGF, ACTA2 mRNA kidney levels.

CONCLUSIONS

These results showed that cell therapy using hADSCs improves renal function and reduces fibrosis.

Pro-Inflammatory Chemokines and Cytokines Dominate the Blister Fluid Molecular Signature in Patients with Epidermolysis Bullosa and Affect Leukocyte and Stem Cell Migration

Hereditary epidermolysis bullosa (EB) is associated with skin blistering and the development of chronic nonhealing wounds. Although clinical studies have shown that cell-based therapies improve wound healing, the recruitment of therapeutic cells to blistering skin and to more advanced skin lesions remains a challenge. Here, we analyzed cytokines and chemokines in blister fluids of patients affected by dystrophic, junctional, and simplex EB. Our analysis revealed high levels of CXCR1, CXCR2, CCR2, and CCR4 ligands, particularly dominant in dystrophic and junctional EB. In vitro migration assays demonstrated the preferential recruitment of CCR4⁺ lymphocytes and CXCR1⁺, CXCR2⁺, and CCR2⁺ myeloid cells toward EB-derived blister fluids. Immunophenotyping of skin-infiltrating leukocytes confirmed substantial infiltration of EB-affected skin with resting (CD45RA⁺) and activated (CD45RO⁺) T cells and CXCR2⁺ CD11b⁺ cells, many of which were identified as CD16b⁺ neutrophils. Our studies also showed that abundance of CXCR2 ligand in blister fluids also creates a favorable milieu for the recruitment of the CXCR2⁺ stem cells, as validated by in vitro and in-matrix migration assays. Collectively, this study identified several chemotactic pathways that control the recruitment of leukocytes to the EB-associated skin lesions. These chemotactic axes could be explored for the refinement of the cutaneous homing of the therapeutic stem cells.

Effects of adipose stem cell sheets on colon anastomotic leakage in an experimental model: Proof of principle

The most dreaded complication of colorectal surgery is anastomotic leakage. Adipose tissue-derived stem cell sheets (ASC sheets) prepared from temperature-responsive culture surfaces can be easily transplanted onto tissues. These sheets are proposed to improve cell transplant efficiency and enhance wound healing. The aim of this study was to investigate whether application of ASC sheets could prevent leakage of sutured colorectal anastomoses. Insufficient suturing of colorectal anastomoses was performed in Wistar rats to create a colorectal anastomotic leakage model. Rats were randomized to ASC sheet application or control group. Leakage, abscess formation, adhesion formation, anastomotic bursting pressure (ABP), and histology were evaluated on postoperative day 3 or 7. ASC sheet application significantly reduced anastomotic leakage compared to controls, without increased adhesion formation. ASC sheet transplantation resulted in more CD3+ T-cells and CD163+ anti-inflammatory macrophages at the anastomotic site than the control group. ABP, vessel density and collagen deposition were not different between groups. Using cell sheet technology, we generated ASC sheets that prevented disruption of sutured colorectal anastomoses as shown by reduced leakage. Increased numbers of anti-inflammatory macrophages and T-cells might have contributed to this positive effect.

Therapeutic effects of adipose-derived stem cells-based microtissues on erectile dysfunction in streptozotocin-induced diabetic rats

This study aimed to explore the therapeutic effects of adipose-derived stem cells (ADSCs)-based microtissues (MTs) on erectile dysfunction (ED) in streptozotocin (STZ)-induced diabetic rats. Fifty-six 8-week-old Sprague-Dawley rats received intraperitoneal injection of STZ (60 mg kg⁻¹), and 8 weeks later, the determined diabetic rats randomly received intracavernous (IC) injection of phosphate buffer solution (PBS), ADSCs, or MTs. Another eight normal rats equally got IC injection of PBS. MTs were generated with a hanging drop method, and the injected cells were tracked in ADSC- and MT-injected rats. Four weeks after the treatments, intracavernous pressure (ICP), histopathological changes in corpus cavernosum (CC), and functional proteins were measured. Rat cytokine antibody array was used to detect ADSCs or MTs lysate. The results showed that MTs expressed vascular endothelial growth factor (VEGF), nerve growth factor (NGF), and tumor necrosis factor-stimulated gene-6 (TSG-6). MTs injection had a higher retention than ADSCs injection and MTs treatment improved ICP, neuronal nitric oxide synthase (nNOS) expression, smooth muscle, and endothelial contents in diabetic rats, ameliorated local inflammation in CC better. Thus, our findings demonstrate that IC injection of MTs improves erectile function and histopathological changes in STZ-induced diabetic rats and appears to be more promising than traditional ADSCs. The underlying mechanisms involve increased cell retention accompanied with neuroprotection and anti-inflammatory behaviors of the paracrine factors.

Cell therapy for basement membrane-linked diseases

For most disorders caused by mutations in genes encoding basement membrane (BM) proteins, there are at present only limited treatment options available. Genetic BM-linked disorders can be viewed as especially suited for treatment with cell-based therapy approaches because the proteins that need to be restored are located in the extracellular space. In consequence, complete and permanent engraftment of cells does not necessarily have to occur to achieve substantial causal therapeutic effects. For these disorders cells can be used as transient vehicles for protein replacement. In addition, it is becoming evident that BM-linked genetic disorders are modified by secondary diseases mechanisms. Cell-based therapies have also the ability to target such disease modifying mechanisms. Thus, cell therapies can simultaneously provide causal treatment and symptomatic relief, and accordingly hold great potential for treatment of BM-linked disorders. However, this potential has for most applications and diseases so far not been realized. Here, we will present the state of cell therapies for BM-linked diseases. We will discuss use of both pluripotent and differentiated cells, the limitation of the approaches, their challenges, and the way forward to potential wider implementation of cell therapies in the clinics.

Chemotaxis-driven disease-site targeting of therapeutic adult stem cells in dystrophic epidermolysis bullosa

Background

Dystrophic epidermolysis bullosa (DEB), a rare genodermatosis, is characterized by the formation of intra-epidermal blistering and the development of chronic nonhealing skin wounds. Recently, attempts have been made to develop cell-based therapies for this currently intractable disorder. The molecular mechanisms that govern directional migration of the adult stem cells, allowing their efficient and controlled homing to the skin affected with DEB, are poorly understood. The key mechanism that regulates recruitment of leukocytes and progenitor stem cells to distal anatomical tissues affected with disease is chemotaxis, which depends on the signaling molecules, chemokines, and acts primarily as part of the host defense and repair mechanism.

Methods

Comprehensive proteomic screening of chemokines in the blister fluids of DEB-affected mice was conducted to define the inflammatory and immune activities, thus providing potential to examine local biological mechanisms and define the protein signature within lesional skin as a potential marker of disease activity. Also, the therapeutic relevance of identified chemotactic pathways was investigated in vivo, providing a basis for future clinical investigations.

Results

Assessment of blister fluid-derived chemokines showed a persistent presence of several chemotactic molecules, including CXCL1 + 2 and CXCL5. The majority of blister-originated chemotactic signals were associated with preferential recruitment of CD45⁺CXCR2⁺ and CD11b⁺CXCR2⁺ leukocytes. Systemic transplantation of an enriched CXCR2 population of mouse adipose-derived stem cells (mADSC) into DEB-affected mice demonstrated effective recruitment of cells to the blistering skin under the influence of blister-derived ligands and deposition of therapeutic type VII collagen.

Conclusions

Collectively, these studies demonstrate that recruitment of mADSC into DEB skin is tightly controlled by disease-site chemotactic activities and suggest a potential mechanism for effective application of therapeutic stem cells for DEB.

Cell-Imprinted Substrates Modulate Differentiation, Redifferentiation, and Transdifferentiation

Differentiation of stem cells into mature cells through the use of physical approaches is of great interest. Here, we prepared smart nanoenvironments by cell-imprinted substrates based on chondrocytes, tenocytes, and semifibroblasts as templates and demonstrated their potential for differentiation, redifferentiation, and transdifferentiation. Analysis of shape and upregulation/downregulation of specific genes of stem cells, which were seeded on these cell-imprinted substrates, confirmed that imprinted substrates have the capability to induce specific shapes and molecular characteristics of the cell types that were used as templates for cell-imprinting. Interestingly, immunofluorescent staining of a specific protein in chondrocytes (i.e., collagen type II) confirmed that adipose-derived stem cells, semifibroblasts, and tenocytes can acquire the chondrocyte phenotype after a 14 day culture on chondrocyte-imprinted substrates. In summary, we propose that common polystyrene tissue culture plates can be replaced by this imprinting technique as an effective and promising way to regulate any cell phenotype in vitro with significant potential applications in regenerative medicine and cell-based therapies.

Adipose-Derived Stromal Cells from Lipomas: Isolation, Characterisation and Review of the Literature

OBJECTIVE

The aim of this study was to characterize adipose-derived stromal cells (ADSCs) from patients diagnosed with multiple symmetric lipomatosis (MSL) in order to obtain potentially new insights into the pathophysiology, pathogenesis and treatment of this disease.

METHODS

Cells from the stromal vascular fraction were analysed by the colony-forming efficiency assay and flow cytometry using standard markers. Moreover, the power of adipogenic plasticity was evaluated. Finally, a literature review was performed from 1982 to 2015 using the US National Institutes of Health's PubMed database.

RESULTS

Three European-descent patients diagnosed with either MSL type I or II could be identified for analysis. The resulting mean colony-forming efficiency assay was 14.3 ± 5%. Flow-cytometric analysis of the ADSCs revealed high levels of CD34 (70 ± 9%), CD45 (37 ± 13%) and CD73 (55.8 ± 14%), whereas low levels of CD31 (16.8 ± 14%) and CD105 (5.8 ± 0.7%) were detected. Furthermore, ADSCs showed a strong adipogenic potential, which is in line with the literature review. The stem cell pool in lipoma shows several alterations in biological activities, such as proliferation, apoptosis and stemness.

CONCLUSIONS

ADSCs from lipoma may be interesting in the application of regenerative medicine. We discuss possible molecular treatment options to regulate their activities at the source of the MSL.

Adhesion of adipose-derived mesenchymal stem cells to glycosaminoglycan surfaces with different protein patterns

Proteins and glycosaminoglycans (GAGs) are the main constituents of the extracellular matrix (ECM). They act in synergism and are equally critical for the development, growth, function, or survival of an organism. In this work, we developed surfaces that display these two classes of biomacromolecules, namely, GAGs and proteins, in a spatially controlled fashion. The generated surfaces can be used as a minimalistic but straightforward model aiding the elucidation of cell-ECM interactions. GAGs (hyaluronic acid and heparin) were covalently bound to amino functionalized surfaces, and albumin or fibronectin was patterned by microcontact printing on top of them. We demonstrate that adipose-derived stem cells (ASCs) can adhere either on the protein or on the GAG pattern as a function of the patterned molecules. ASCs found on the GAG pattern had different morphology and expressed different surface markers than the cells adhered on the protein pattern. ASCs morphology and spreading were also dependent on the size of the pattern. These results show that the developed supports can also be used for ASCs differentiation into different lineages.

Vital roles of stem cells and biomaterials in skin tissue engineering

Tissue engineering essentially refers to technology for growing new human tissue and is distinct from regenerative medicine. Currently, pieces of skin are already being fabricated for clinical use and many other tissue types may be fabricated in the future. Tissue engineering was first defined in 1987 by the United States National Science Foundation which critically discussed the future targets of bioengineering research and its consequences. The principles of tissue engineering are to initiate cell cultures in vitro, grow them on scaffolds in situ and transplant the composite into a recipient in vivo. From the beginning, scaffolds have been necessary in tissue engineering applications. Regardless, the latest technology has redirected established approaches by omitting scaffolds. Currently, scientists from diverse research institutes are engineering skin without scaffolds. Due to their advantageous properties, stem cells have robustly transformed the tissue engineering field as part of an engineered bilayered skin substitute that will later be discussed in detail. Additionally, utilizing biomaterials or skin replacement products in skin tissue engineering as strategy to successfully direct cell proliferation and differentiation as well as to optimize the safety of handling during grafting is beneficial. This approach has also led to the cells’ application in developing the novel skin substitute that will be briefly explained in this review.

Ullrich congenital muscular dystrophy: clinicopathological features, natural history and pathomechanism(s)

Collagen VI is widely distributed throughout extracellular matrices (ECMs) in various tissues. In skeletal muscle, collagen VI is particularly concentrated in and adjacent to basement membranes of myofibers. Ullrich congenital muscular dystrophy (UCMD) is caused by mutations in either COL6A1, COL6A2 or COL6A3 gene, thereby leading to collagen VI deficiency in the ECM. It is known to occur through either recessive or dominant genetic mechanism, the latter most typically by de novo mutations. UCMD is well defined by the clinicopathological hallmarks including distal hyperlaxity, proximal joint contractures, protruding calcanei, scoliosis and respiratory insufficiency. Recent reports have depicted the robust natural history of UCMD; that is, loss of ambulation by early teenage years, rapid decline in respiratory function by 10 years of age and early-onset, rapidly progressive scoliosis. Muscle pathology is characterised by prominent interstitial fibrosis disproportionate to the relative paucity of necrotic and regenerating fibres. To date, treatment for patients is supportive for symptoms such as joint contractures, respiratory failure and scoliosis. There have been clinical trials based on the theory of mitochondrion-mediated myofiber apoptosis or impaired autophagy. Furthermore, the fact that collagen VI producing cells in skeletal muscle are interstitial mesenchymal cells can support proof of concept for stem cell-based therapy.

Collagen VI at a glance

Collagen VI represents a remarkable extracellular matrix molecule, and in the past few years, studies of this molecule have revealed its involvement in a wide range of tissues and pathological conditions. In addition to its complex multi-step pathway of biosynthesis and assembly that leads to the formation of a characteristic and distinctive network of beaded microfilaments in the extracellular matrix, collagen VI exerts several key roles in different tissues. These range from unique biomechanical roles to cytoprotective functions in different cells, including myofibers, chondrocytes, neurons, fibroblasts and cardiomyocytes. Indeed, collagen VI has been shown to exert a surprisingly broad range of cytoprotective effects, which include counteracting apoptosis and oxidative damage, favoring tumor growth and progression, regulating autophagy and cell differentiation, and even contributing to the maintenance of stemness. In this Cell Science at a Glance article and the accompanying poster, we present the current knowledge of collagen VI, and in particular, discuss its relevance in stemness and in preserving the mechanical properties of tissues, as well as its links with human disorders.

Successful nucleofection of rat adipose-derived stroma cells with Ambystoma mexicanum epidermal lipoxygenase (AmbLOXe)

INTRODUCTION

Adipose-derived stroma cells (ASCs) are attractive cells for cell-based gene therapy but are generally difficult to transfect. Nucleofection has proven to be an efficient method for transfection of primary cells. Therefore, we used this technique to transfect ASCs with a vector encoding for Ambystoma mexicanum epidermal lipoxygenase (AmbLOXe) which is a promising bioactive enzyme in regenerative processes. Thereby, we thought to even further increase the large regenerative potential of the ASCs.

METHODS

ASCs were isolated from the inguinal fat pad of Lewis rats and were subsequently transfected in passage 1 using Nucleofector® 2b and the hMSC Nucleofector kit. Transfection efficiency was determined measuring co-transfected green fluorescent protein (GFP) in a flow cytometer and gene expression in transfected cells was detected by reverse transcription polymerase chain reaction (RT-PCR). Moreover, cell migration was assessed using a scratch assay and results were tested for statistical significance with ANOVA followed by Bonferroni's post hoc test.

RESULTS

High initial transfection rates were achieved with an average of 79.8 ± 2.82% of GFP positive cells although longer cultivation periods reduced the number of positive cells to below 5% after four passages. Although successful production of AmbLOXe transcript could be proven the gene product had no measureable effect on cell migration.

CONCLUSIONS

Our study demonstrates the feasibility of ASCs to serve as a vehicle of AmbLOXe transport for gene therapeutic purposes in regenerative medicine. One potential field of applications could be peripheral nerve injuries.