Research progress on dedifferentiated fat cells and their application in oral and maxillofacial bone tissue engineering / 口腔疾病防治

@#The identification of suitable seed cells represents a critical scientific problem to be solved in the field of oral and maxillofacial bone tissue regeneration. The application of adipose-derived stem cells (ASCs) in tissue and organ repair and regeneration has been studied extensively. In recent years, dedifferentiated fat (DFAT) cells have also shown broad application prospects in the field of bone tissue engineering. DFAT cells express stem cell-related markers and have the potential to differentiate into adipocytes, osteoblasts, chondrocytes, nerve cells, cardiomyocytes and endothelial cells. In addition, DFAT cells also have the advantages of minimally invasive acquisition, strong proliferation and high homogeneity. Currently, all studies involving the application of DFAT cells in scaffold-based and scaffold-free bone tissue engineering can confirm their effectiveness in promoting bone regeneration. However, cytological research still faces some challenges, including relatively low cell culture purity, unclear phenotypic characteristics and undefined dedifferentiation mechanisms. It is believed that with the continuous development and improvement of isolation, culture, identification and directional induction of osteogenic differentiation methods, DFAT cells are expected to become excellent seed cells in the field of oral and maxillofacial bone tissue engineering in the future.

Experimental study of subcutaneous adipose-derived stem cells inhibiting orthodontic root resorption / 中国修复重建外科杂志

OBJECTIVE@#To investigate the effect of human subcutaneous adipose-derived stem cells (hADSCs) local transplantation on orthodontically induced root resorption (OIRR) and provide theoretical and experimental basis for the clinical application of hADSCs to inhibit OIRR.@*METHODS@#Forty 8-week-old male Sprague Dawley rats were randomly divided into experimental group and control group, with 20 rats in each group, to establish the first molar mesial orthodontic tooth movement (OTM) model of rat right maxillary. The rats in the experimental group were injected with 25 μL of cell suspension containing 2.5×10 5 hADSCs on the 1st, 4th, 8th, and 12th day of modeling, while the rats in the control group were injected with 25 μL of PBS. The rat maxillary models were obtained before and after 7 and 14 days of force application, and 10 rats in each group were killed and sampled after 7 and 14 days of force application. The OTM distance was measured by stereomicroscope, the root morphology of the pressure side was observed by scanning electron microscope and the root resorption area ratio was measured. The root resorption and periodontal tissue remodeling of the pressure side were observed by HE staining and the root resorption index was calculated. The number of cementoclast and osteoclast in the periodontal tissue on the pressure side was counted by tartrate resistant acid phosphatase staining.@*RESULTS@#The TOM distance of both groups increased with the extension of the force application time, and there was no significant difference ( P<0.05). There was no significant difference in OTM distance between the experimental group and the control group after 7 and 14 days of force application ( P>0.05). Scanning electron microscope observation showed that small and shallow scattered resorption lacunae were observed on the root surface of the experimental group and the control group after 7 days of force application, and there was no significant difference in the root resorption area ratio between the two groups ( P>0.05); after 14 days of application, the root resorption lacunae deepened and became larger in both groups, and the root resorption area ratio in the experimental group was significantly lower than that in the control group ( P<0.05). The range and depth of root absorption in the experimental group were smaller and shallower than those in the control group, and the root absorption index in the experimental group was significantly lower than that in the control group after 14 days of force application ( P<0.05). The number of cementoclast in the experimental group was significantly lower than that in the control group after 7 and 14 days of force application ( P<0.05); the number of osteoclasts in the experimental group was significantly lower than that in the control group after 14 days of force application ( P<0.05).@*CONCLUSION@#Local transplantation of hADSCs may reduce the area and depth of root resorption by reducing the number of cementoclasts and osteoclasts during OTM in rats, thereby inhibiting orthodontic-derived root resorption.

Effect of Kartogenin combined with adipose-derived stem cells on tendon-bone healing after anterior cruciate ligament reconstruction / 中国修复重建外科杂志

OBJECTIVE@#To investigate the effect of Kartogenin (KGN) combined with adipose-derived stem cells (ADSCs) on tendon-bone healing after anterior cruciate ligament (ACL) reconstruction in rabbits.@*METHODS@#After the primary ADSCs were cultured by passaging, the 3rd generation cells were cultured with 10 μmol/L KGN solution for 72 hours. The supernatant of KGN-ADSCs was harvested and mixed with fibrin glue at a ratio of 1∶1; the 3rd generation ADSCs were mixed with fibrin glue as a control. Eighty adult New Zealand white rabbits were taken and randomly divided into 4 groups: saline group (group A), ADSCs group (group B), KGN-ADSCs group (group C), and sham-operated group (group D). After the ACL reconstruction model was prepared in groups A-C, the saline, the mixture of ADSCs and fibrin glue, and the mixture of supernatant of KGN-ADSCs and fibrin glue were injected into the tendon-bone interface and tendon gap, respectively. ACL was only exposed without other treatment in group D. The general conditions of the animals were observed after operation. At 6 and 12 weeks, the tendon-bone interface tissues and ACL specimens were taken and the tendon-bone healing was observed by HE staining, c-Jun N-terminal kinase (JNK) immunohistochemical staining, and TUNEL apoptosis assay. The fibroblasts were counted, and the positive expression rate of JNK protein and apoptosis index (AI) were measured. At the same time point, the tensile strength test was performed to measure the maximum load and the maximum tensile distance to observe the biomechanical properties.@*RESULTS@#Twenty-eight rabbits were excluded from the study due to incision infection or death, and finally 12, 12, 12, and 16 rabbits in groups A-D were included in the study, respectively. After operation, the tendon-bone interface of groups A and B healed poorly, while group C healed well. At 6 and 12 weeks, the number of fibroblasts and positive expression rate of JNK protein in group C were significantly higher than those of groups A, B, and D (P<0.05). Compared with 6 weeks, the number of fibroblasts gradually decreased and the positive expression rate of JNK protein and AI decreased in group C at 12 weeks after operation, with significant differences (P<0.05). Biomechanical tests showed that the maximum loads at 6 and 12 weeks after operation in group C were higher than in groups A and B, but lower than those in group D, while the maximum tensile distance results were opposite, but the differences between groups were significant (P<0.05).@*CONCLUSION@#After ACL reconstruction, local injection of a mixture of KGN-ADSCs and fibrin glue can promote the tendon-bone healing and enhance the mechanical strength and tensile resistance of the tendon-bone interface.

Aucubin combined with ADSCs-exos protects TBHP-induced nucleus pulposus cells via TLR4/NF-κB pathway / 中国中药杂志

This paper aims to investigate the effects and mechanisms of adipose-derived stem cells-exosomes(ADSCs-exos) toge-ther with aucubin in protecting human-derived nucleus pulposus cells(NPCs) from inflammatory injury, senescence, and apoptosis. The tert-butyl hydroperoxide(TBHP)-induced NPCs were assigned into normal, model, aucubin, ADSCs-exos, and aucubin+ADSCs-exos groups. The cell viability was examined by cell counting kit-8(CCK-8), cell proliferation by EdU staining, cell senescence by senescence-associated-β-galactosidase(SA-β-Gal), and cell cycle and apoptosis by flow cytometry. Enzyme-linked immunosorbent assay was employed to examine the expression of interleukin-1β(IL-1β), IL-10, and tumor necrosis factor-α(TNF-α). Real-time fluorescence quantitative PCR and Western blot were employed to determine the mRNA and protein levels of aggregated proteoglycan(aggrecan), type Ⅱ collagen alpha 1(COL2A1), Toll-like receptor 4(TLR4), and nuclear factor-kappa B(NF-κB). The results showed that compared with the model group, the aucubin or ADSCs-exos group showed enhanced viability and proliferation of NPCs, decreased proportion of G_0/G_1 phase cells, increased proportion of S phase cells, reduced apoptosis and proportion of cells in senescence, lowered IL-1β and TNF-α levels, elevated IL-10 level, down-regulated mRNA and protein levels of TLR4 and NF-κB, and up-regulated mRNA and protein levels of aggrecan and COL2A1. Compared with the aucubin or ADSCs-exos group, the aucubin+ADSCs-exos combination further increased the viability and proliferation of NPCs, decreased the proportion of G_0/G_1 phase cells, increased the proportion of S phase cells, reduced the apoptosis and proportion of cells in senescence, lowered the IL-1β and TNF-α levels, elevated the IL-10 level, down-regulated the mRNA and protein levels of TLR4 and NF-κB, and up-regulated the mRNA and protein levels of aggrecan and COL2A1. In summary, both aucubin and ADSCs-exos could exert protective effects by inhibiting inflammatory responses, reducing apoptosis and senescence of NPCs, improving cell viability and proliferation as well as extracellular matrix synthesis, which may be associated with the inhibition of TLR4/NF-κB signaling pathway activation. The combination of both plays a synergistic role in the protective effects.

The study of the whole bladder acellular matrix prepared by the perfusion decellularization system combined with the adipose-derived stem cells to construct the tissue engineering bladder / 中华泌尿外科杂志

Objective:To prepare the whole bladder acellular matrix (BAM) using the self-designed perfusion decellularization system, and evaluate the feasibility of constructing the tissue engineering bladder with the adipose-derived stem cells (ADSCs).Methods:This study was conducted from October 2020 to April 2021. The self-designed perfusion decellularization system was used, and four different decellularization protocols (group A, group B, group C and group D) were formulated, according to the flow direction of the perfusate and the action time of different decellularization solutions. Among them, the urethral orifice of the bladder tissue was used as the outflow tract of the perfusion fluid in groups A and B. The top of the bladder was cut off and used as the outflow tract of the perfusion fluid in groups C and D. In groups A and C, 1% Triton X-100 was treated for 6 h, and 1% sodium dodecyl sulfate (SDS) was treated for 2 h. In groups B and D, 1% Triton X-100 was treated for 7 h, and 1% sodium dodecyl sulfate (SDS) was treated for 1 h. In addition, the tissue in the normal bladder group was directly obtained from the natural bladder tissue, which did not require perfusion, cryopreservation and thawing. The fast and efficient decellularization protocol was screened out through HE, DAPI, Masson trichrome and Alcian Blue staining and quantitative analyses to prepare the whole bladder scaffold. The prepared BAM was used as the scaffold material, and the ADSCs were used as the seeding cells to construct the tissue engineering bladder. HE and DAPI staining were used to observe the distribution of ADSCs on the BAM.Results:HE and DAPI staining showed that there was no obvious nuclear residue in the group C. Masson trichrome and Alcian Blue staining showed that the collagen structure and glycosaminoglycan were well preserved in the group C. There was no significant difference in bladder wall thickness between the group C and the normal bladder group [(975.44±158.62)μm vs.(1 064.49±168.52)μm, P > 0.05]. The DNA content in the group C [(43.59 ±4.59) ng/mg] was lower than that in the normal bladder group, group A, group B and group D [(532.50±26.69), (135.17±6.99), (182.49±13.69) and(84.00±4.38)ng/mg], and the difference was statistically significant ( P<0.05). The collagen content [(10.98 ± 0.29)μg/mg] and glycosaminoglycan content [(2.30±0.18)μg/mg] in group C were not significantly different with those in the normal bladder group [(11.69±0.49) and (2.36±0.09)μg/mg, P>0.05]. Scanning electron microscopy showed that a large number of pore structures could be observed on the surface of the prepared BAM in groups A-D and were facilitated to cell adhesion. The isolated and cultured ADSCs were identified by flow cytometry to confirm the positive expression of CD90 and CD29, and the negative expression of CD45 and CD106. Live/dead staining and CCK-8 detection confirmed that the prepared BAM in the group C had no cytotoxicity. HE and DAPI staining showed that a large number of ADSCs were distributed on the surface and inside of the tissue engineering bladder. Conclusions:The whole bladder shape BAM prepared by the self-designed perfusion decellularization system could be used as the scaffold material for bladder tissue engineering, and the constructed tissue engineering bladder could be used for bladder repair and reconstruction.

The study on the tissue engineered bladder patch constructed with the double-layer silk scaffold and adipose-derived stem cells for bladder repair and reconstruction / 中华泌尿外科杂志

Objective:To investigate the effect of tissue engineered bladder patch constructed by double-layer silk scaffold and adipose-derived stem cells (ADSCs) in the repair and reconstruction of bladder.Methods:This study was conducted from May 2020 to March 2021. The silk fibroin (SF) aqueous solution was obtained from silkworm cocoons, and a double-layer silk scaffold composed of silk fibroin film and silk fibroin sponge was further prepared. The rat ADSCs were isolated, cultured, and the ADSCs surface markers (CD29, CD90, CD45, CD106) were identified by flow cytometry. The ADSCs were planted on a double-layer silk scaffold to construct a tissue-engineered bladder patch. Thirty-six male SD rats were randomly divided into three groups: tissue engineered bladder patch group (SF-ADSCs group, n=15), double-layer silk scaffold group (SF group, n=15), control group ( n=6). The tissue engineered bladder patch (SF-ADSCs group) and double-layer silk scaffold (SF group) were wrapped on the omentum to promote vascularization. The vascularization was evaluated by HE and immunofluorescence staining. The wrapped tissue engineered bladder patch and double-layer silk scaffold were used to repair the defective bladder. In the control group (six rats), the incision was closed immediately after the bladder tissue fully exposed. At 4 weeks and 12 weeks after operation, the general morphology of bladder tissue and cystography were performed to evaluate the recovery of bladder morphology. After the graft was harvested, HE and Masson's trichrome staining and immunofluorescence staining were used to observe the regeneration of bladder wall tissue. Urodynamics was used to assess the recovery of bladder function at 12 weeks after operation. Results:The flow cytometry results confirmed that the isolated cells positively expressed CD29 and CD90, and there was no significant expression of CD45 and CD106. Gross observation and scanning electron microscope confirmed that the preparation of double-layer silk scaffold not only had a pore structure that was conducive to cell planting, but also had good toughness and was facilitated to surgical suture. The number (43.50±2.66) and area (0.73±0.03)% of vascular-like structures in the SF-ADSCs group after the omentum encapsulation was significantly higher than that in the SF group [(24.50±3.51), (0.55±0.05)%], and the difference was statistically significant ( P<0.05). At 4 weeks after bladder repair, the histological staining of the grafts in the SF-ADSCs and SF groups showed a large number of degraded fragments of double-layer silk scaffold. At 12 weeks, the morphology of the graft in the SF-ADSCs group showed uniform bladder morphology, which was similar to that of normal bladder tissue. Immunofluorescence staining showed that the continuous urothelial layer, abundant smooth muscle tissue, vascular structure and regenerated neurons could be observed in the SF-ADSCs group. Urodynamic test showed that the bladder maximum volume (0.74±0.03)ml and compliance (16.68±0.44)μl/cm H 2O in the SF-ADSCs group, which were better than that in the SF group [(0.47±0.05)ml, (14.89±0.37)μl/cm H 2O], but lower than that in the control group [(1.12±0.08)ml, (19.34±0.45)μl/cm H 2O], and the difference was statistically significant ( P<0.05). Conclusions:The tissue engineered bladder patch constructed with double-layer silk scaffolds and ADSCs could promote the morphological repair of bladder tissue, the regeneration of bladder wall structure and the recovery of bladder physiological function.

Comparison of two different levels of adipose derived stem cells in fat transplantation in nude mice / 中华医学美学美容杂志

Objective:To explore the mechanism of fat formation induced by PLA-adipose derived stem cells (ADSC) and LAF-ADSC cells, and to provide a new direction and idea for cell-assisted granular fat transplantation.Methods:The liposuction operation of normal human body was performed in the plastic surgery operating room of Chengdu Badachu Medical Cosmetic Hospital. The liposuction obtained through the operation was placed still, and the upper granular adipose tissue was digested, isolated, cultured and identified by PLA-ADSC; the obtained lower liquid tissue was centrifuged, and the precipitate was digested, isolated, cultured and identified by LAF-ADSC; the differentiation characteristics and growth ability of PLA-ADSC and LAF-ADSC were compared. Then animal experiments were carried out: PLA-ADSC and LAF-ADSC were mixed with matrix glue Matrigel and transplanted into nude mice as experimental group 1 and experimental group 2. Matrix glue Matrigel was transplanted into nude mice as control group. The lipogenic ability of the three groups in nude mice was compared.Results:The cell experiment showed that the cells extracted from the static granular fat and the lower filtrate sediment could adhere to the wall and grew and subcultured smoothly. The cells from the above two different sources expressed CD44, CD73 and CD105, with positive rates of 99.5%, 99.99% and 99.7% respectively, while CD19, CD31 and CD45 were negative. The results of lipogenic induction and differentiation showed that there were lipid droplets in the cytoplasm, and the lipid droplets were orange red after cell oil red O staining. The results of animal experiment showed that three months after transplantation, the average graft volume of experimental group 1 was (0.070±0.009) cm 3, that of experimental group 2 was (0.067±0.007) cm 3, and that of the control group was (0.009±0.005) cm 3. The difference between the graft volume of experimental group 1 and experimental group 2 and the control group was statistically significant ( t=26.522 and t=37.183, all P<0.01), There was no significant difference in graft volume ( t=1.250, P>0.05). The wet weight of grafts in experimental group 1 was (0.200±0.021) g, that in experimental group 2 was (0.175±0.019) g, and that in the control group was (0.129±0.012) g, there was significant difference between experimental groups 1 and 2 and the control group ( t=11.601 and t=9.978, P<0.05), but there was no significant difference between experimental group 1 and experimental group 2 ( t=3.650, P>0.05). After oil red O staining, the grafts in experimental groups 1 and 2 were generally orange yellow, and the control group was scattered light yellow. The expression of CD31 in the experimental groups 1 and 2 was positive, and the expression of CD31 in control group was negative. Conclusions:Active ADSCs can be extracted from the granular fat layer and the lower filtrate of the static fat aspirate, and the ADSCs from both sources have good lipogenic ability in nude mice.

Role of active ADM microparticle in skin wound healing of diabetic mice / 中华医学美学美容杂志

Objective:To evaluate the effects of adipose-derived stem cells (ADSCs) and ADM microparticle on diabetic wound healing.Methods:ADSCs was co-cultured with ADM microparticle in vitro. The models of diabetic nude mice were established by intraperitoneal injection of STZ and the full-thickness skin defects were designed on the back. All 24 diabetic mice were randomly divided into 4 group: experimental groups were transplanted with ADSCs and ADM microparticle and the other groups were transplanted with ADSCs, ADM microparticle and blank control group was set up. On the 7th and 14 th days, the wound healing rate of 3 mice randomly selected from each group was calculated, and the thickness between dermis and epidermis was measured by hematoxylin and eosin staining. The density of neovascularization was measured by immunohistochemical staining. The differences were compared between the groups.Results:Compared to the ADSCs groups, the mice of the experimental groups showed higher cell survival rate. The wound healing rate in the experimental groups was (86.0±2.7)% (7 days) and (98.5±1.1)% (14 days), thicker dermis-epidermis distance was (99.1±1.8) μm (7 days) and (124.3±4.3) μm (14 days) ( P<0.05), and higher density of neovascularization was noted. Conclusions:The transplantation with active ADM microparticle can significantly promote neovascularization and wound healing of diabetic wound.

Stem cell therapy for alopecia areata / 中华皮肤科杂志

It is currently considered that alopecia areata is caused by the impairment of immune privilege in hair follicles. Stem cells have immunoregulatory functions, and can secrete a variety of cytokines to promote immune privilege in hair follicles. Stem cell therapy, especially umbilical cord- and adipose-derived stem cell therapy, has been applied to a variety of preclinical and clinical studies on alopecia, providing a new approach to refractory alopecia areata.

Extracellular vesicle activities regulating macrophage- and tissue-mediated injury and repair responses

Macrophages are typically identified as classically activated (M1) macrophages and alternatively activated (M2) macrophages, which respectively exhibit pro- and anti-inflammatory phenotypes, and the balance between these two subtypes plays a critical role in the regulation of tissue inflammation, injury, and repair processes. Recent studies indicate that tissue cells and macrophages interact

Research progress of hydrogel combined with mesenchymal stem cells in the treatment of spinal cord injury / 生物医学工程学杂志

Spinal cord injury (SCI) is a complex pathological process. Based on the encouraging results of preclinical experiments, some stem cell therapies have been translated into clinical practice. Mesenchymal stem cells (MSCs) have become one of the most important seed cells in the treatment of SCI due to their abundant sources, strong proliferation ability and low immunogenicity. However, the survival rate of MSCs transplanted to spinal cord injury is rather low, which hinders its further clinical application. In recent years, hydrogel materials have been widely used in tissue engineering because of their good biocompatibility and biodegradability. The treatment strategy of hydrogel combined with MSCs has made some progress in SCI repair. This review discusses the significance and the existing problems of MSCs in the repair of SCI. It also describes the research progress of hydrogel combined with MSCs in repairing SCI, and prospects its application in clinical research, aiming at providing reference and new ideas for future SCI treatment.

Effect of donor age on biological characteristics of adipose-derived stem cells / 中华医学美学美容杂志

Objective:To identify the influence of age factors on biological characteristics of human adipose-derived stem cells (ADSCs), and to compare the differences in morphology, aging characteristics, differentiation potential, surface marker expression, and proliferation ability of human ADSCs with different ages and the effect of human ADSCs of different ages on proliferation and migration of fibroblasts.Methods:Adipose tissues from 27 individuals of healthy beauty treatments, aged 0-59 years, were collected from Department of Burns and Plastic Surgery, the 940th Hospital of Joint Logistics Support Force from January 2020 to December 2020. According to the age of the donor, they were divided into 6 groups. 0-9 years old group (4 cases), 10-19 years old group (4 cases), 20-29 years old group (5 cases), 30- 39 years old group (5 cases), 40-49 years old group (5 cases), and 50-59 years old group (4 cases). We obtained and cultured the ADSCs of each group, subcultured to obtain the ADSCs, and observed the morphological characteristics of each group; the proliferation ability of each group of ADSCs was detected by CCK-8 method; the differentiation potential of each group of ADSCs was detected by in vitro adipogenesis and osteogenic induction. Flow cytometry was used to detect the surface marker expression levels of each group of ADSCs, and qPCR was used to detect the expression levels of HGF, PPAR-γ, type Ⅲ collagen and DbX2 in each group. We also collected the skin tissues of a healthy person from Department of Burns and Plastic Surgery of the 940th Hospital of Joint Logistics Support Force in 2020, obtained and cultured fibroblasts, subcultured to obtain the second generation of fibroblasts, and prepared each group of ADSCs conditioned medium (ADSCs-CM); the proliferation ability of fibroblasts cultured in each group of ADSCs-CM was detected by CCK-8 method, and the migration ability of fibroblasts cultured in each group of ADSCs-CM was detected by cell scratch method. SPSS 21.0 software was used for data analysis and P<0.05 was considered statistically significant. Results:The cells of all age groups were in a typical spindle shape. The cells of the younger age group showed small nuclei and the cell morphology were uniform and similar; the cells of the older age group had larger nuclei and uneven morphology. With aging, the proliferation ability of ADSCs gradually decreased. In vitro adipogenic differentiation induction results showed that with the increase in age, the ability of ADSCs to differentiate into adipocytes gradually decreased. In vitro osteogenic differentiation induction results also demonstrated that with the increase in age, the ability of ADSCs to differentiate into osteoblasts gradually decreased. The expression rates of positive surface markers of ADSCs in each group of ADSCs were all above 93%. With aging, the expression levels of PPAR-γ, HGF, and type Ⅲ collagen decreased, and the expression levels of DbX2 showed an upward trend with age. The number of β-galactosidase staining positive cells increased with age, while the difference between groups A, B and C was not statistically significant, and the difference between groups A and D, E, and F was statistically significant ( P<0.05). The ADSCs conditioned medium of each group was able to promote the proliferation of fibroblasts, but the difference between the groups was not statistically significant. With aging, the ability of ADSCs conditioned medium to promote the migration of fibroblasts gradually decreased. Conclusions:The proliferation ability and multidirectional differentiation ability of human ADSCs and the ability to secrete a variety of cytokines that promote the proliferation and migration of fibroblasts show a downward trend, but the adipogenic differentiation ability of ADSCs declines significantly after the age of 40 years. ADSCs in all age groups could promote the proliferation and migration of fibroblasts.

The role of LncRNA00602 in Ad36-induced differentiation of adipocytes / 中华内分泌代谢杂志

Objective:To investigate the possible role of long non-coding RNA (LncRNA) 00602 in promoting browning in adipocytes induced by adenovirus type 36 (Ad36).Methods:According to Ad36 infection, adipose tissue samples of obese patients were divided into Ad36-negative group and Ad36-infected group. Realtime fluorescent quantitative PCR (qRT-PCR) was used to detect the changes in the expression of LncRNA00602 mRNA in omental adipose tissue of the two groups, and analyze the differences between the two groups. The correlation between waist-to-hip ratio, systolic blood pressure, diastolic blood pressure, fasting blood glucose, triacylglyceride and other indicators of the patients in the group with LncRNA00602 mRNA expression were analyzed. HE staining was used to detect the size of adipocytes in the omental adipose tissue of the Ad36 negative group and the Ad36 infection group. qRT-PCR and Western blotting were used to detect the mRNA and protein expression levels of uncoupling protein 1 (UCP1) and PR domain containing 16 (PRDM16) in omental adipose tissue of two groups of patients. Human adipose-derived stem cells (hADSC) were isolated and cultured, using Ad36 to induce differentiation, and divided into control group and LncRNA00602 knockdown group. On 0, 2, and 4 days after LncRNA00602 knockdown, fluoroboron dipyrrole (BODIPY) and mitochondrial red fluorescence (Mito-Tracker Red) were used to stain intracellular lipid droplets and mitochondria. At the same time, qRT-PCR and Western blotting were used to detect changes in the expression of UCP1 and PRDM16.Results:The expression of LncRNA00602 gene in the Ad36 infection group was higher than that in the Ad36 negative group (all P<0.05). The expression of LncRNA00602 in the Ad36 negative group was not significantly different from the above clinical indicators, while the expression of LncRNA00602 was negatively correlated with serum fasting blood glucose and triacylglyceride ( r=-0.522, -0.486, P<0.05) in the Ad36 infection group; HE staining showed that the average adipocyte area of the Ad36 infection group was smaller than that of the Ad36 negative group. At the same time, UCP1 and PRDM16 gene expression were higher than the negative group (all P<0.05). At the cellular level, on the 2nd and 4th days after knockdown of LncRNA00602, the lipid droplet area of adipocytes in the LncRNA00602 knockdown group was larger than that of the control group, the number of mitochondria decreased compared with the control group, and difference was statistically significant ( P<0.05 or P<0.01); Compared with the control group, there was significantly lower expression of the browning marker genes UCP1, PRDM16, and protein in the adipocytes in the LncRNA00602 knockdown group (all P<0.05). Conclusion:In Ad36-induced adipocyte differentiation, LncRNA00602 may positively regulate the expression of UCP1, PRDM16 and lipid droplet metabolism, and promote the browning of adipocytes.

Roles of adipocytes and adipose-derived stem cells in the lipophilic metastasis of ovarian cancer / 中国肿瘤临床

Ovarian cancer is the most common cause of cancer-associated deaths among the gynecological malignancies. The 5-year survival rate of the patients is less than 30%. This high mortality rate is mainly due to the metastasis. Adipose-rich omentum is the main site of metastasis, suggesting that ovarian cancer may have the characteristic of "lipophilic" metastasis. Adipocytes and adipose-derived stem cells are the most important components of the omentum. These cell ssecrete cytokines and adipokines and modify glucose and lipid metabolism to induce migration of ovarian cancer cells to the omentum. Simultaneously, they create a suitable microenvironment for the metastasis and colonization of these cancer cells by interacting with vascular endothelial cells, tumor-associated macrophages, and cancer-associated fibroblasts. This article reviews the recent advances in the role of adipocytes and adipose-derived stem cells in the "lipophilic" metastasis of ovarian cancer, aiming at providing new ideas for preventing ovarian cancer metastases and improving the survival rate of patients with ovarian cancer.

Effects of adipose-derived stem cell released exosomes on wound healing in diabetic mice / 中国修复重建外科杂志

Objective: To investigate the effects of adipose-derived stem cell released exosomes (ADSC-Exos) on wound healing in diabetic mice. Methods: The ADSCs were isolated from the adipose tissue donated by the patients and cultured by enzymatic digestion. The supernatant of the 3rd generation ADSCs was used to extract Exos (ADSC-Exos). The morphology of ADSC-Exos was observed by transmission electron microscopy. The membrane-labeled proteins (Alix and CD63) were detected by Western blot, and the particle size distribution was detected by nanoparticle tracking analyzer. The fibroblasts were isolated from the skin tissue donated by the patients and cultured by enzymatic digestion. The 5th generation fibroblasts were cultured with PKH26-labeled ADSC-Exos, and observed by confocal fluorescence microscopy. The effects of ADSC-Exos on proliferation and migration of fibroblasts were observed with cell counting kit 8 (CCK-8) and scratch method. Twenty-four 8-week-old Balb/c male mice were used to prepare a diabetic model. A full-thickness skin defect of 8 mm in diameter was prepared on the back. And 0.2 mL of ADSC-Exos and PBS were injected into the dermis of the experimental group ( n=12) and the control group ( n=12), respectively. On the 1st, 4th, 7th, 11th, 16th, and 21st days, the wound healing was observed and the wound healing rate was calculated. On the 7th, 14th, and 21st days, the histology (HE and Masson) and CD31 immunohistochemical staining were performed to observe the wound structure, collagen fibers, and neovascularization. Results: ADSC-Exos were the membranous vesicles with clear edges and uniform size; the particle size was 40-200 nm with an average of 102.1 nm; the membrane-labeled proteins (Alix and CD63) were positive. The composite culture observation showed that ADSC-Exos could enter the fibroblasts and promote the proliferation and migration of fibroblasts. Animal experiments showed that the wound healing of the experimental group was significantly faster than that of the control group, and the wound healing rate was significantly different at each time point ( P<0.05). Compared with the control group, the wound healing of the experimental group was better. There were more microvessels in the early healing stage, and more deposited collagen fibers in the late healing stage. There were significant differences in the length of wound on the 7th, 14th, and 21st days, the number of microvessels on the 7th and 14th days, and the rate of deposited collagen fibers on the 14th and 21st days between the two groups ( P<0.05). Conclusion: ADSC-Exos can promote the wound healing in diabetic mice by promoting angiogenesis and proliferation and migration of fibroblasts and collagen synthesis.

Construction of tissue engineered adipose by human adipose tissue derived extracellular vesicle combined with decellularized adipose tissues scaffold / 中国修复重建外科杂志

Objective: To explore the possibility of constructing tissue engineered adipose by adipose tissue derived extracellular vesicles (hAT-EV) combined with decellularized adipose tissue (DAT) scaffolds, and to provide a new therapy for soft tissue defects. Methods: The adipose tissue voluntarily donated by the liposuction patient was divided into two parts, one of them was decellularized and observed by HE and Masson staining and scanning electron microscope (SEM). Immunohistochemical staining and Western blot detection for collagen type Ⅰ and Ⅳ and laminin were also employed. Another one was incubated with exosome-removed complete medium for 48 hours, then centrifuged to collect the medium and to obtain hAT-EV via ultracentrifugation. The morphology of hAT-EV was observed by transmission electron microscopy; the nanoparticle tracking analyzer (NanoSight) was used to analyze the size distribution; Western blot was used to analyse membrane surface protein of hAT-EV. Adipose derived stem cells (ADSCs) were co-cultured with PKH26 fluorescently labeled hAT-EV, confocal fluorescence microscopy was used to observe the uptake of hAT-EV by ADSCs. Oil red O staining was used to evaluate adipogenic differentiation after hAT-EV and ADSCs co-cultured for 15 days. The DAT was scissored and then injected into the bilateral backs of 8 C57 mice (6-week-old). In experimental group, 0.2 mL hAT-EV was injected weekly, and 0.2 mL PBS was injected weekly in control group. After 12 weeks, the mice were sacrificed, and the new fat organisms on both sides were weighed. The amount of new fat was evaluated by HE and peri-lipoprotein immunofluorescence staining to evaluate the ability of hAT-EV to induce adipogenesis in vivo. Results: After acellularization of adipose tissue, HE and Masson staining showed that DAT was mainly composed of loosely arranged collagen with no nucleus; SEM showed that no cells and cell fragments were found in DAT, and thick fibrous collagen bundles could be seen; immunohistochemical staining and Western blot detection showed that collagen type Ⅰ and Ⅳ and laminin were retained in DAT. It was found that hAT-EV exhibited a spherical shape of double-layer envelope, with high expressions of CD63, apoptosis-inducible factor 6 interacting protein antibody, tumor susceptibility gene 101, and the particle size of 97.9% hAT-EV ranged from 32.67 nmto 220.20 nm with a peak at 91.28 nm. Confocal fluorescence microscopy and oil red O staining showed that hAT-EV was absorbed by ADSCs and induced adipogenic differentiation. In vivo experiments showed that the wet weight of fat new organisms in the experimental group was significantly higher than that in the control group ( t=2.278, P=0.048). HE staining showed that the structure of lipid droplets in the experimental group was more than that in the control group, and the collagen content in the control group was higher than that in the experimental group. The proportion of new fat in the experimental group was significantly higher than that in the control group ( t=4.648, P=0.017). Conclusion: DAT carrying hAT-EV can be used as a new method to induce adipose tissue regeneration and has a potential application prospect in the repair of soft tissue defects.

Research progress of adipose-derived stem cells in promoting the repair of peripheral nerve injury / 中国修复重建外科杂志

Objective: To summarize the research progress of adipose-derived stem cells (ADSCs) in promoting the repair of peripheral nerve injury. Methods: The related literature at home and abroad in recent years was widely reviewed, the mechanism of ADSCs promoting the repair of peripheral nerve injury was introduced, and its basic research progress was analyzed and summarized. Finally, the clinical transformation application of ADSCs in the treatment of peripheral nerve injury was introduced, the existing problems were pointed out, and the new treatment regimen was prospected. Results: ADSCs have the function of differentiation and paracrine, and their secreted neurotrophic factors, antiapoptosis, and antioxidant factors can promote the repair of peripheral nerve injury. Conclusion: ADSCs are rich in content and easy to obtain, which has a definite effectiveness on the repair of peripheral nerve injury with potential clinical prospect.

In vitro study on promoting migration ability of rat adipose derived stem cells modified by stromal cell-derived factor 1α / 中国修复重建外科杂志

Objective: To explored the effect of stromal cell-derived factor 1α (SDF-1α) on promoting the migration ability of rat adipose derived stem cells (rADSCs) by constructed the rADSCs overexpression SDF-1α via adenovirus transfection. Methods: rADSCs were isolated from adipose tissue of 6-week-old SPF Sprague Dawley rats. Morphological observation, multi-directional differentiations (osteogenic, adipogenic, and chondrogenic inductions), and flow cytometry identification were performed. Transwell cell migration experiment was used to observe and screen the optimal concentration of exogenous SDF-1α to optimize the migration ability of rADSCs; the optimal multiplicity of infection (MOI) of rADSCs was screened by observing the cell status and fluorescence expression after transfection. Then the third generation of rADSCs were divided into 4 groups: group A was pure rADSCs; group B was rADSCs co-cultured with SDF-1α at the best concentration; group C was rADSCs infected with recombinant adenovirus-mediated green fluorescent protein (Adv-GFP) with the best MOI; group D was rADSCs infected with Adv-GFP-SDF-1α overexpression adenovirus with the best MOI. Cell counting kit 8 (CCK-8) and Transwell cell migration experiment were preformed to detect and compare the effect of exogenous SDF-1α and SDF-1α overexpression on the proliferation and migration ability of rADSCs. Results: The cell morphology, multi-directional differentiations, and flow cytometry identification showed that the cultured cells were rADSCs. After screening, the optimal stimulating concentration of exogenous SDF-1α was 12.5 nmol/L; the optimal MOI of Adv-GFP adenovirus was 200; the optimal MOI of Adv-GFP-SDF-1α overexpression adenovirus was 400. CCK-8 method and Transwell cell migration experiment showed that compared with groups A and C, groups B and D could significantly improve the proliferation and migration of rADSCs ( P<0.05); the effect of group D on enhancing the migration of rADSCs was weaker than that of group B, but the effect of promoting the proliferation of rADSCs was stronger than that of group D ( P<0.05). Conclusion: SDF-1α overexpression modification on rADSCs can significantly promote the proliferation and migration ability, which may be a potential method to optimize the application of ADSCs in tissue regeneration and wound repair.

Ammonium chloride lysis method versusnon-lysis method for isolation of human adipose-derived stem cells / 中国组织工程研究

BACKGROUND: A general standard has not been established for the extraction and purification of adipose-derived stem cells (ADSCs). An erythrocyte lysis step for stromal vascular fraction is the commonly used method in the procedure for ADSCs isolation. However, there is a lack of evidence on whether this step will have adverse effects on human ADSCs (hADSCs). OBJECTIVE: To test the efficiency of two hADSCs isolation methods, which are erythrocyte-lysis method based on ammonium chloride and non-lysis method. Moreover, the biological characteristics of the hADSCs isolated by the two methods were also compared. METHODS: After collagenase digestion of lipoaspirate, erythrocyte lysis buffer was used to purify stromal vascular fraction in erythrocyte-lysis method, while in non-lysis method the buffer was not used. A Muse™ cell analyzer was used to assess living cell counting and proportion of stromal vascular fraction in both methods. Then hADSCs were cultured to the second passage for next testing. Cell morphology was observed under light microscope. Cell phenotype was detected by flow cytometry. Cell counting kit-8 was used to evaluate cell proliferation. Oil red O staining and alizarin staining were used to evaluate adipogenic and osteogenic ability of hADSCs after adipogenic and osteogenic induction. This study was approved by the Ethics Committee of the Plastic Surgery Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, and informed consents were signed by all participants. RESULTS AND CONCLUSION: (1) Compared with the erythrocyte lysis group, hADSCs obtained in the non-lysis group contained a larger number and a larger percentage of non-erythrocyte living cells. (2) The two groups of hADSCs were spindle-shaped and arranged as a fish shape. (3) The cell phenotypes of both groups met the phenotypic requirements for human mesenchymal stem cells. (4) The cell proliferation in the non-lysis group was faster than that in the erythrocyte lysis group, while there was no difference in the adipogenic and osteogenic abilities between the two groups. In conclusion, the use of erythrocyte lysis buffer reduces the isolation efficiency of hADSCs and inhibits cell proliferation. The non-lysis isolation method does not affect phenotypes, adipogenic and osteogenic ability of hADSCs. Therefore, it is not recommended to implement erythrocyte lysis during the isolation of hADSCs.

Research progress in osteogenic differentiation of adipose-derived stem cells induced by bioscaffold materials / 中国组织工程研究

BACKGROUND: Adipose-derived stem cells are easy to access and have strong proliferative capacity, which are considered as ideal seed cells for bone defect repair. The bone tissue engineering research progress reveals that bioscaffold material modification can directly regulate the osteogenic differentiation of stem cells. OBJECTIVE: To review various biological scaffold materials that can regulate the osteogenic differentiation of adipose-derived stem cells. METHODS: The first author searched the articles in CNKI, WanFang, VIP, PubMed, Embase and Web of Science databases published from January 2016 to May 2019. The search terms were “adipose derived stem cells, scaffold, osteogenic, metal, Ti” in Chinese and English, respectively. Finally 62 eligible articles were selected. RESULTS AND CONCLUSION: Scaffold materials for bone tissue engineering are classified into inorganic materials (hydroxyapatite, tricalcium phosphate, bioglass, titanium, and magnesium), natural polymer materials (collagen, silk fibroin, and chitosan) and synthetic polymer materials (polycaprolactone, polylactic acid, polyglycolic acid and poly(lactic-co-glycolic acid)). The studies on materials that interact with cells to guide their biological response and bone differentiation are increasing. But how to create a safe, rational, and close to the micro-environment of cell growth in vivo is a challenge. Modification of bioscaffold materials can directly regulate osteogenic differentiation of stem cells. Moreover, vascularization and post-implantation infections are issues of concern.