Wnt/β‐catenin signalling pathway mediates high glucose induced cell injury through activation of TRPC6 in podocytes

Objectives

Diabetic nephropathy is a major complication of diabetes and a frequent cause of end‐stage renal disease and recent studies suggest that podocyte damage may play a role in the pathogenesis of this. At early onset of diabetic nephropathy there is podocyte drop‐out, which is thought to provoke glomerular albuminuria and subsequent glomerular injury; however, the underlying molecular mechanisms of this remain poorly understood. Here we report that we tested the hypothesis that early diabetic podocyte injury is caused, at least in part, by up‐regulation of transient receptor potential cation channel 6 (TRPC6), which is regulated by the canonical Wnt signalling pathway, in mouse podocytes.

Materials and methods

Mechanism of injury initiation in mouse podocytes, by high concentration of D‐glucose (HG, 30 mM), was investigated by MTT, flow cytometry, real‐time quantitative PCR, and western blot analysis.

Results

HG induced apoptosis and reduced viability of differentiated podocytes. It caused time‐dependent up‐regulation of TRPC6 and activation of the canonical Wnt signalling pathway, in mouse podocytes. In these cells, blockade of the Wnt signalling pathway by dickkopf related protein 1 (Dkk1) resulted in effective reduction of TRPC6 up‐regulation and amelioration of podocyte apoptosis. Furthermore, reduction of cell viability induced by HG was attenuated by treatment with Dkk1.

Conclusion

These findings indicate that the Wnt/β‐catenin signalling pathway may potentially be active in pathogenesis of TRPC6‐mediated diabetic podocyte injury.

     

Low‐intensity pulsed ultrasound induced enhanced adipogenesis of adipose‐derived stem cells

Objective

The aim of this study was to investigate effects of low‐intensity pulsed ultrasound (LIPUS) on differentiation of adipose‐derived stem cells (ASCs), in vitro.

Materials and methods

Murine ASCs were treated with LIPUS for either three or five days, immediately after adipogenic induction, or delayed for 2 days. Expression of adipogenic genes PPAR‐γ1, and APN, was examined by real‐time PCR. Immunofluorescence (IF) staining was performed to test for PPAR‐γ at the protein level.

Results

Our data revealed that specific patterns of LIPUS up‐regulated levels of both PPAR‐γ1 and APN mRNA, and PPAR‐γ protein.

Conclusions

In culture medium containing adipogenic reagents, LIPUS enhanced ASC adipogenesis.

     

Character comparison of abdomen‐derived and eyelid‐derived mesenchymal stem cells

Objectives

While most human adipose tissues, such as those located in the abdomen, hip and thigh, are of mesodermal origin, adipose tissues located in the face are of ectodermal origin. The present study has compared stem cell‐related features of abdomen‐derived adult stem cells (A‐ASCs) with those of eyelid‐derived adult stem cells (E‐ASCs).

Materials and methods

Adipose tissue‐derived cells were maintained in DMEM supplemented with 10% FBS. Before passage 6, cells were analysed using FACS, immunocytochemistry and quantitative real time PCR (qRT‐PCR). To examine multi‐differentiational potential, early passage ASCs were cultivated in each of a commercial Stempro^® Differentiation kit.

Results

Unlike fibroblast‐like morphology of A‐ASCs, E‐ASCs had bipolar morphology. Both types of cell exhibited similar surface antigens, and neuronal cell‐related genes and proteins. However, there were differences in mRNA expression levels of CD90 and CD146; neuron‐specific enolase (NSE) and nuclear receptor‐related protein 1 (Nurr1) were different between the two cell types. There was no difference in multi‐differentiational potential between 3 E‐ASCs lines, however, E‐ASCs had higher expression levels of chondrocyte‐related genes compared to A‐ASCs. These cells underwent senescence and maintained normal karyotypes.

Conclusions

Although isolated from similar adipose tissues, both types of cells displayed many contrasting characteristics. Understanding defining phenotypes of such cells is useful for making suitable choices in differing clinical indications.

     

SOST,an LNGFR target,inhibits the osteogenic differentiation of rat ectomesenchymal stem cells

Objectives

The aim of this study was to investigate whether sclerostin (SOST) regulates the osteogenic differentiation of rat ectomesenchymal stem cells (EMSCs) and whether SOST and low‐affinity nerve growth factor receptor (LNGFR) regulate the osteogenic differentiation of EMSCs.

Materials and methods

EMSCs were isolated from embryonic facial processes from an embryonic 12.5‐day (E12.5d) pregnant Sprague‐Dawley rat. LNGFR⁺ EMSCs and LNGFR^? EMSCs were obtained by fluorescence‐activated cell sorting and were subsequently induced to undergo osteogenic differentiation in vitro. SOST/LNGFR small‐interfering RNAs and SOST/LNGFR overexpression plasmids were used to transfect EMSCs.

Results

LNGFR⁺ EMSCs displayed a higher osteogenic capacity and lower SOST levels compared with LNGFR^? EMSCs. SOST silencing enhanced the osteogenic differentiation of LNGFR^? EMSCs, while SOST overexpression attenuated the osteogenic differentiation of LNGFR⁺ EMSCs. Moreover, LNGFR was present upstream of SOST and strengthened the osteogenic differentiation of EMSCs by decreasing SOST.

Conclusions

SOST alleviated the osteogenic differentiation of EMSCs, and LNGFR enhanced the osteogenic differentiation of EMSCs by decreasing SOST, suggesting that the LNGFR/SOST pathway may be a novel target for promoting dental tissue regeneration and engineering.

     

Overexpression of hCLP46 enhances Notch activation and regulates cell proliferation in a cell type‐dependent manner

Objectives

Human CAP10‐like protein 46 kDa (hCLP46), also known as Poglut1, has been shown to be an essential regulator of Notch signalling. hCLP46 is overexpressed in primary acute myelogenous leukaemia, T‐acute lymphoblastic leukaemia samples and other leukaemia cell lines. However, effects of hCLP46 overexpression, up to now, have remained unknown.

Materials and methods

In this study, we established stable 293TRex cell lines inducibly overexpressing hCLP46, and knocked down hCLP6 with a specific small interfering RNA to explore function of the protein in Notch signalling and cell proliferation.

Results

hCLP46 overexpression enhanced Notch1 activation in 293Trex cells in a ligand‐dependent manner, with increased Notch signalling enhancing Hes1 expression. We further verified that overexpression of hCLP46 inhibited proliferation of 293TRexs and was correlated with increases in cyclin dependent kinase inhibitors p21 and p27, whereas reduced hCLP46 expression moderately increased cell proliferation. In addition, p21 and p27 protein levels were higher when Notch signalling was activated by EDTA treatment.

Conclusions

Taken together, hCLP46 enhanced Notch activation and inhibited 293TRex cell proliferation through CDKI signalling.

     

Fak‐Mapk,Hippo and Wnt signalling pathway expression and regulation in distraction osteogenesis

Objectives

To investigate the mechanism of mechanical stimulation in bone formation and regeneration during distraction osteogenesis.

Materials and methods

In this study, microarray technology was used to investigate the time course of bone‐related molecular changes in distraction osteogenesis in rats. Real‐time PCR and Western‐blot analyses were used to confirm the expression of genes identified in microarrays. Meanwhile, we used a lentivirus vector to inhibit Fak expression, in order to identify the osteogenic effect of Fak and Fak‐Mapk pathway during distraction osteogenesis.

Results

Several components of the Wnt and Hippo pathways were found to be up‐ or down‐regulated during distraction osteogenesis by microarray. Meanwhile, it was found that Fak, Src, Raf‐1, Erk1, Jnk and p38‐Mapk were up‐regulated during gradual distraction, compared with consolidation. To further determine whether Fak‐Mapk pathway played an important role in distraction osteogenesis, Fak was disrupted with a lentivirus vector. The expressions levels of p‐Fak, p‐Erk1/2, p‐JNK and p‐p38Mapk were decreased. Meanwhile, a poor early and late osteogenesis effect was found in the shRNA‐Fak group.

Conclusion

It was inferred that the mechanical stimulus induces increased expression of Fak and activates Fak‐Mapk pathway, by activation of Erk, Jnk and p38‐Mapk pathway, and that Fak at least, in part, plays an important role in maintaining osteogenic effect by activating Fak‐Mapk pathway during distraction osteogenesis.

     

Effects of serum reduction and VEGF supplementation on angiogenic potential of human adipose stromal cells in vitro

Objectives

This study investigated effects of reduced serum condition and vascular endothelial growth factor (VEGF) on angiogenic potential of adipose stromal cells (ASCs) in vitro.

Materials and methods

Adipose stromal cells were cultured in three different types of medium: (i) F12/DMEM (FD) supplemented with 10% FBS from passage 0 (P0) to P6; (ii) FD supplemented with 2% FBS at P6; and (iii) FD supplemented with 2% FBS plus 50 ng/ml of VEGF at P6. Morphological changes and growth rate of ASCs were recorded. Changes in stemness, angiogenic and endogenic genes’ expressions were analysed using Real‐Time PCR.

Results

Adipose stromal cells changed from fibroblast‐like shape when cultured in 10% FBS medium to polygonal when cultured in 2% FBS plus VEGF‐supplemented medium. Their growth rate was lower in 2% FBS medium, but increased with addition of VEGF. Real‐Time PCR showed that ASCs maintained most of their stemness and angiogenic genes’ expression in 10% FBS at P1, P5 and P6, but this increased significantly in 2% FBS at P6. Endogenic genes expression such as PECAM‐1, VE chaderin and VEGFR‐2 decreased after serial passage in 10% FBS, but increased significantly at P6 in 2% FBS. Addition of VEGF did not cause any significant change in gene expression level.

Conclusion

Adipose stromal cells had greater angiogenic potential when cultured in reduced serum conditions. VEGF did not enhance their angiogenic potential in 2% FBS‐supplemented medium.

     

Downregulation of heat shock protein B8 decreases osteogenic differentiation potential of dental pulp stem cells during in vitro proliferation

Objectives

Tissue‐derived stem cells, such as dental pulp stem cells (DPSCs), reduce differentiation capability during in vitro culture. We found that cultured DPSCs reduce expression of heat shock protein B8 (HspB8) and GIPC PDZ domain containing family member 2 (Gipc2). Our objectives were to evaluate the changes in DPSC composition during in vitro proliferation and to determine whether HspB8 and Gipc2 have function in differentiation potential of DPSCs.

Materials and Methods

Different passages of rat DPSCs were evaluated for changes in CD90+ and/or CD271+ stem cells and changes in osteogenic potential. Real‐time RT‐PCR and immunostaining were conducted to determine expression of HspB8 and Gipc2. Expression of the genes in DPSCs was knocked down by siRNA, followed by osteogenic induction to evaluate the function of the genes.

Results

About 90% of cells in the DPSC cultures were CD90+ and/or CD271+ cells without dramatic change during in vitro proliferation. The DPSCs at passages 3 to 5 (P3 to P5) possess strong osteogenic potential, but such potential was greatly reduced at later passages. Expression of HspB8 and Gipc2 was significantly reduced at P11 versus P3. Knock‐down of HspB8 expression abolished osteogenic potential of the DPSCs, but knock‐down of Gipc2 had no effect.

Conclusions

CD90+ and CD271+ cells are the major components of DPSCs in in vitro culture. High‐level expression of HspB8 was critical for maintaining differentiation potential of DPSCs.

     

Effect of substrate stiffness on proliferation and differentiation of periodontal ligament stem cells

Objectives

The aim of this study was to understand the effect of substrate stiffness (a mechanical factor of the extracellular matrix) on periodontal ligament stem cells (PDLSCs) and its underlying mechanism.

Materials and methods

Elastic substrates were fabricated by mixing 2 components, a base and curing agent in proportions of 10:1, 20:1, 30:1 or 40:1. PDLSC morphology was observed using scanning electron microscopy (SEM). Cell proliferation and differentiation were assessed after PDLSCs was cultured on various elastic substrates. Data were analysed using one‐way ANOVA.

Results

SEM revealed variations in the morphology of PDLSCs cultured on elastic substrates. PDLSC proliferation increased with substrate stiffness (P < .05). Osteogenic differentiation of PDLSCs was higher on stiff substrates. Notch pathway markers were up‐regulated in PDLSCs cultured on stiff substrates.

Conclusions

Results suggested that the osteogenic differentiation of PDLSCs might be promoted by culturing them in a stiffness‐dependent manner, which regulates the Notch pathway. This might provide a new method of enhancing osteogenesis in PDLSCs.

     

Combined Erlotinib and PF‐03084014 treatment contributes to synthetic lethality in head and neck squamous cell carcinoma

Objectives

Head and neck squamous cell carcinoma (HNSCC) is characterized by high mortality and low survival rates. As an epidermal growth factor receptor (EGFR) inhibitor, Erlotinib has been approved for treatment of various tumours. PF‐03084014 is a selective inhibitor of Notch1 signalling. This study aimed to explore new approaches for simultaneously targeting EGFR and Notch1 signalling to attenuate tumour growth and improve survival.

Materials and methods

Cell proliferation was determined by CCK‐8 assay and Flow cytometry. Cell invasive ability was determined by Transwell assay. Western blot was used to test the expression of Notch1 and EGFR pathway. Cleaved Caspase‐3 staining and TUNEL assay were used to verify the apoptosis through combined treatment.

Results

We first confirmed proliferative inhibition and cell death in HNSCC with combined Erlotinib and PF‐03084014 treatment. Moreover, we found PF‐03084014 reversed the increased invasion induced by Erlotinib. In a preclinical therapeutic drug trial in vivo, combined treatment effectively abrogated tumour growth. Most importantly, one mechanism was found that PF‐03084014 alone could activate the PI3K/AKT signalling, the downstream of EGFR signalling, and Erlotinib alone could activate the intracellular domain of Notch1 (NICD), while combined treatment of PF‐03084014 and Erlotinib suppressed the HNSCC growth.

Conclusions

These results suggested that concomitant inhibition of the Notch1 and EGFR pathways represented a rational strategy for promoting apoptosis in HNSCC and overcoming treatment resistance.

     

Finasteride accelerates prostate wound healing after thulium laser resection through DHT and AR signalling

Objectives

Urinary tract infection, urinary frequency, urgency, urodynia and haemorrhage are common post‐operative complications of thulium laser resection of the prostate (TmLRP). Our study mainly focuses on the role of finasteride in prostate wound healing through AR signalling.

Materials and methods

TmLRP beagles were randomly distributed into different treatment groups. Serum and intra‐prostatic testosterone and DHT level were determined. Histological analysis was conducted to study the re‐epithelialization and inflammatory response of the prostatic urethra in each group. We investigated the role of androgen in proliferation and inflammatory response in prostate. In addition, the effects of TNF‐α on prostate epithelium and stromal cells were also investigated.

Results

Testosterone and DHT level increased in testosterone group and DHT decreased in finasteride group. Accelerated wound healing of prostatic urethra was observed in the finasteride group. DHT suppressed proliferation of prostate epithelium and enhanced inflammatory response in prostate. We confirmed that DHT enhanced macrophages TNF‐α secretion through AR signalling. TNF‐α suppressed proliferation of prostate epithelial cells and retarded cell migration. TNF‐α also played a pivotal role in suppressing fibroblasts activation and contraction.

Conclusion

Testosterone treatment repressed re‐epithelialization and wound healing of prostatic urethra. Finasteride treatment may be an effective way to promote prostate re‐epithelialization.

     

Critical role of inflammatory mast cell in fibrosis: Potential therapeutic effect of IL‐37

Background

Fibrosis involves the activation of inflammatory cells, leading to a decrease in physiological function of the affected organ or tissue.

Aims

To update and synthesize relevant information concerning fibrosis into a new hypothesis to explain the pathogenesis of fibrosis and propose potential novel therapeutic approaches.

Materials and Methods

Literature was reviewed and relevant information is discussed in the context of the pathogenesis of fibrosis.

Results

A number of cytokines and their mRNA are involved in the circulatory system and in organs of patients with fibrotic tissues. The profibrotic cytokines are generated by several activated immune cells, including fibroblasts and mast cells (MCs), which are important for tissue inflammatory responses to different types of injury. MC‐derived TNF, IL‐1, and IL‐33 contribute crucially to the initiation of a cascade of the host defence mechanism(s), leading to the fibrosis process. Inhibition of TNF and inflammatory cytokines may slow the progression of fibrosis and improve the pathological status of the affected subject. IL‐37 is generated by various types of immune cells and is an IL‐1 family member protein. IL‐37 is not a receptor antagonist; it binds IL‐18 receptor alpha (IL‐18Rα) and delivers the inhibitory signal by using TIR8. It has been shown that IL‐37 can be protective in inflammation and injury, and inhibits both innate and adaptive immunity.

Discussion

IL‐37 may be useful for suppression of inflammatory diseases induced by inhibiting MyD88‐dependent TLR signalling. In addition, IL‐37 downregulates NF‐κB induced by TLR2 or TLR4 through a mechanism dependent on IL‐18Rα.

Conclusion

This review summarizes current knowledge on the role of MC in inflammation and tissue/organ fibrosis, with a focus on the therapeutic potential of IL‐37‐targeting cytokines.

     

Topographical cues of direct metal laser sintering titanium surfaces facilitate osteogenic differentiation of bone marrow mesenchymal stem cells through epigenetic regulation

Objectives

To investigate the role of hierarchical micro/nanoscale topography of direct metal laser sintering (DMLS) titanium surfaces in osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs), as well as the possible underlying epigenetic mechanism.

Materials and methods

Three groups of titanium specimens were prepared, including DMLS group, sandblasted, large‐grit, acid‐etched (SLA) group and smooth titanium (Ti) group. BMSCs were cultured on discs followed by surface characterization. Cell adhesion and proliferation were examined by SEM and CCK‐8 assay, while osteogenic‐related gene expression was detected by real‐time RT‐PCR. Immunofluorescence, western blotting and in vivo study were also performed to evaluate the potential for osteogenic induction of materials. In addition, to investigate the underlying epigenetic mechanisms, immunofluorescence and western blotting were performed to evaluate the global level of H3K4me3 during osteogenesis. The H3K4me3 and H3K27me3 levels at the promoter area of the osteogenic gene Runx2 were detected by ChIP assay.

Results

The DMLS surface exhibits greater protein adsorption ability and shows better cell adhesion performance than SLA and Ti surfaces. Moreover, both in vitro and in vivo studies demonstrated that the DMLS surface is more favourable for the osteogenic differentiation of BMSCs than SLA and Ti surfaces. Accordingly, osteogenesis‐associated gene expression in BMSCs is efficiently induced by a rapid H3K27 demethylation and increase in H3K4me3 levels at gene promoters upon osteogenic differentiation on DMLS titanium surface.

Conclusions

Topographical cues of DMLS surfaces have greater potential for the induction of osteogenic differentiation of BMSCs than SLA and Ti surfaces both in vitro and in vivo. A potential epigenetic mechanism is that the appropriate topography allows rapid H3K27 demethylation and an increased H3K4me3 level at the promoter region of osteogenesis‐associated genes during the osteogenic differentiation of BMSCs.

     

The role of Sprouty1 in the proliferation,differentiation and apoptosis of epidermal keratinocytes

Objectives

Sprouty (SPRY) 1 is one of the SPRY proteins that inhibits signalling from various growth factors pathways and has also been known as a tumour suppressor in various malignancies. However, no study elucidates the role of SPRY1 in the skin. Our study was conducted to determine the function of SPRY1 in human keratinocytes and the epidermis.

Materials and methods

In vitro primary cultured epidermal keratinocytes were used to investigate the proliferation, differentiation and apoptosis of these cells. We also established overexpression of SPRY1 in vitro and K14‐SPRY1 transgenic mice.

Results

SPRY1 was mainly located in the cytoplasm of the epidermal keratinocytes from the granular epidermal layer of the skin and cultured cells. Overexpressed SPRY1 in keratinocytes resulted in up‐regulation of P21, P27 and down‐regulation of cyclin B1; decrease in MMP3 and integrin α6. SPRY1‐overexpressed primary keratinocytes exhibited a lower proliferation and migration capability and higher rates of apoptosis. Epidermis of SPRY1‐TG mice represented delayed wound healing. Proteomics analysis and GO enrichment showed DEPs of SPRY1 TG mice epidermis is significantly enriched in immune‐ and inflammatory‐associated biological process.

Conclusions

In summary, SPRY1 expression was inversely correlated with cell proliferation, migration and promote cell apoptosis of keratinocytes. SPRY1 maybe a negative feedback regulator in normal human epidermal keratinocytes and cutaneous inflammatory responses. Our study raised the possibility that enhancing expression of SPRY1 may have the potential to promote anti‐inflammatory effects.

     

Mesenchymal‐like stem cells in canine ovary show high differentiation potential

Objectives

Recent studies have reported the existence of stem cells in ovarian tissue that show enhanced proliferative and differentiation potential compared to other adult tissues. Based on this evidence, we hypothesized that ovarian tissue contained mesenchymal‐like stem cells (MSC) that could be isolated using a novel rapid plastic adhesion technique.

Materials and methods

We established MSC lines derived from ovarian and adipose tissue based on their ability to rapidly adhere to plastic culture dishes in the first 3 hours after plating and studied their potentiality in terms of molecular markers and differentiation capacity.

Results

Morphological and kinetic properties of in vitro cultured ovarian MSC were similar to adipose‐derived MSC, and both reached senescence after similar passage numbers. Ovarian‐derived MSC expressed mesenchymal (CD90 and CD44) but not haematopoietic markers (CD34 and CD45), indicating similarity to adipose‐derived MSC. Moreover, ovarian‐derived MSC expressed NANOG, TERT, SOX2, OCT4 and showed extensive capacity to differentiate not only into adipogenic, osteogenic and chondrogenic tissue but also towards neurogenic and endodermal lineages and even precursors of primordial germ cells.

Conclusion

These results show for the first time the derivation of ovarian cells with the molecular properties of MSC as well as wide differentiation potential. Canine ovarian tissue is accessible, expandable, multipotent and has high plasticity, holding promise for applications in regenerative medicine.

     

Knockdown of ubiquitin D inhibits adipogenesis during the differentiation of porcine intramuscular and subcutaneous preadipocytes

Objectives

Intramuscular fat (IMF) has a significant influence on porcine meat quality. Ubiquitin D (UBD) is involved in the management of diverse intracellular processes. However, its physiological functions in adipose cell differentiation and proliferation are still poorly defined.

Materials and methods

Intramuscular and subcutaneous preadipocytes were isolated from the longissimus dorsi and neck subcutaneous deposits of Chinese native Guanzhong Black piglets (3‐5 days old), respectively. Lentivirus with short hairpin RNA (shRNA) for UBD was applied to knockdown UBD expression. We used real‐time PCR and Western blot analysis to detect gene expression. Lipid droplets were dyed with Oil Red O, and cell proliferation was assessed using flow cytometry, 5‐ethynyl‐2′‐deoxyuridine incorporation and cell counting assays.

Results

Lipogenesis through the Akt/mTOR pathway was inhibited when preadipocytes were transfected with UBD shRNA. The expression of adipogenic genes and the number of lipid droplets were obviously diminished. Moreover, repression of UBD attenuated cell proliferation. UBD downregulation resulted in cell cycle arrest because of a decreased proportion of S‐phase cells, and the expression of positive cell proliferation markers was significantly decreased.

Conclusion

These observations illustrated that knockdown of UBD partially suppressed porcine intramuscular and subcutaneous preadipocyte adipogenesis through the Akt/mTOR signalling and inhibited cell proliferation, suggesting the essential role of UBD in the differentiation of preadipocytes.

     

Mesenchymal stem cell transfusion for desensitization of positive lymphocyte cross‐match before kidney transplantation: outcome of 3 cases

Objectives

Donor specific antibodies (DSA) and a positive cross‐match are contraindications for kidney transplantation. Trials of allograft transplantation across the HLA barrier have employed desensitization strategies, including the use of plasmapheresis, intravenous immunoglobulins, anti‐B‐cell monoclonal antibodies and splenectomy, associated with high‐intensity immunosuppressive regimens. Our case 1 report suffered from repeatedly positive lymphocyte cross match after 1st renal transplantation. Graft nephrectomy could not correct the state of sensitization. Splenectomy was done in a trial to get rid of the antibody producing clone. Furthermore plasmapheresis with low dose IVIG could not as well revert the state of sensitization for the patient.

Material and methods

About 50 millions donor specific MSCs were injected to the patient.

Results

MSCs transfusion proved to be the only procedure which could achieve successful desensitization before performing the second transplantation owing to their immunosuppressive properties.

Conclusion

This case indicates that DS‐MSCs is a potential option for anti‐HLA desensitization. In cases 2 and 3 IV DS‐MSCs transfusion was selected from the start as a successful line of treatment for pre renal transplantation desensitization to save other unnecessary lines of treatment that were tried in case 1.