Effects of atelocollagen on neural stem cell function and its migrating capacity into brain in psychiatric disease model

The Efficacy of Atelocollagen to Inhibit Fibrotic Proliferation in Tenon Tissue: In vitro Study

INTRODUCTION

The aim of the study was to evaluate the safety and efficacy of atelocollagen in preventing the fibrotic change of human tenon tissue induced by transforming growth factor β1 (TGFβ1).

METHODS

Primary cultured human Tenon's fibroblasts (HTFs) were incubated with TGFβ1 alone and with various concentrations of atelocollagen, respectively. Cell viability was measured by Cell Counting Kit-8 (CCK-8). The mRNA levels of α-smooth muscle actin (α-SMA), vimentin, fibronectin, zonular occludens scaffolding protein (ZO-1), cellular communication network factor 2 (CCN2), and interleukin 6 (IL-6) were measured by quantitative reverse transcription polymerase chain reaction, Western blot, and immunofluorescence analysis. Wound healing assay and collagen contraction assay were additionally evaluated for identifying the inhibitory effect of atelocollagen in HTFs. To elucidate the mechanism by which atelocollagen affects HTF proliferation, the phospho-extracellular-signal-regulated kinases (pERK)/total-extracellular-signal-regulated kinases (tERK), phospho-focal adhesion kinase (pFAK)/total-focal adhesion kinase (tFAK), and pSmad3/tSmad3 protein expression ratios were measured by Western blot.

RESULTS

The safety of atelocollagen in HTF was identified by CCK-8 analysis. The expression of α-SMA and vimentin in HTFs treated with 0.023% and 0.046% atelocollagen significantly decreased at both mRNA and protein levels, while that of ZO-1 in 0.046% atelocollagen increased compared with TGFβ1-treated cells. The protein expression of fibronectin, CCN2, and IL-6 in HTFs treated with 0.023% and 0.046% atelocollagen significantly decreased. The immunofluorescence microscopy of α-SMA and ZO-1 showed results similar to those of the Western blot. In the wound-scratch assays, cell migration was significantly attenuated in HTFs treated with 0.005% atelocollagen. Atelocollagen at 0.005, 0.011, and 0.023% significantly inhibited the gel contraction induced by TGFβ1 at both 24 h and 48 h. The increase in pERK/tERK and pSmad3/tSmad3 protein expression ratios in TGFβ1-treated HTFs significantly decreased after treatment with 0.023 and 0.046% atelocollagen.

CONCLUSION

Since atelocollagen gel effectively suppresses the proliferation of HTFs in TGFβ1-induced transdifferentiation, it may be a potential therapeutic agent in glaucoma surgery.

Intra-cerebral implantation of a variety of collagenous scaffolds with nervous embryonic cells

Collagenous scaffolds provide good conditions for embryonic nerve cell growth. The aim of the current study was to assess the brains reaction to the implantation of 3D sponge-shaped scaffolds. These scaffolds consisted of collagen (Col) and Col with chondroitin sulphate, which is modified by carbodiimide, or Col crosslinked with dialdehyde cellulose. The current study also evaluated the expression of integrins α2 and β1 in embryonic nerve cells. Embryonic nerve cells were isolated from the brains of rat embryos. Acellular scaffolds, or scaffolds populated with embryonic nerve cells, were implanted into the rats brain. The fibers of all the implanted scaffolds remained intact and served as a template for cell infiltration. The implants induced minimal to moderate inflammatory responses and minimal glial scar formations. Immunohistochemical studies did not indicate any microtubule-associated protein 2 or glial fibrillary acidic protein-positive cells inside the scaffolds. Acellular and cell-populated scaffolds yielded similar responses in the brain. The expression of integrin α2 and β1 was observed in embryonic nervous cells. TC-I15, the integrin α2β1 inhibitor, was not demonstrated to modify cell entrapment within the collagenous scaffolds. All applied scaffolds were well tolerated by the tissue and were indicated to support blood vessel formation. Therefore, all tested biomaterials are recommended for further studies. Additional chemical modifications of the material are suggested to protect the seeded cells from apoptosis after implantation into the brain.

Stem cell therapy: a new approach to the treatment of refractory depression

To better understand the relationship of repeated exposure to adversity during early development as a risk factor for refractory depression, we exposed pregnant female rats to ethanol and the resulting pups to corticosterone during adolescence. A stressful forced swim test was then used to induce depression-like behavior. The adolescent rat brains were examined for the possible therapeutic benefit of a combination of sertraline, an antidepressant, and neural stem cells (NSCs) complexed with atelocollagen in relation to the level of GABAergic interneuron and synaptic protein density in different brain regions. The combined exposures of prenatal and adolescent stress resulted in a reduction in parvalbumin (PV)-positive phenotype of GABAergic interneurons and reduced postsynaptic density protein 95 (PSD-95) levels in the anterior cingulate cortex, amygdala, and hippocampus. Treatments with sertraline and NSCs reversed the reductions in PV-positive cells and PSD-95 levels. Furthermore, the combined treatment of sertraline and NSCs resulted in reduced depressive-like behaviors. These experiments underscore a potentially important role for synaptic remodeling and GABAergic interneuron genesis in the treatment of refractory depression and highlight the therapeutic potential of stem cell and pharmacological combination treatments for refractory depression.