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Fulltext Long Non-Coding RNA-MALAT1 Mediates Retinal Ganglion Cell Apoptosis Through the PI3K/Akt Signaling Pathway in Rats with Glaucoma

Li HB, You QS, Xu LX, Sun LX, Abdul Majid AS, Xia XB, et al.

Cell Physiol Biochem, 2017;43(5):2117-2132.
PMID: 29065394 DOI: 10.1159/000484231

BACKGROUND/AIMS: The aim of the present study is to investigate the effect of long non-coding RNA-MALAT1 (LncRNA-MALAT1) on retinal ganglion cell (RGC) apoptosis mediated by the PI3K/Akt signaling pathway in rats with glaucoma.
METHODS: RGCs were isolated and cultured, and monoclonal antibodies (anti-rat Thy-1, Brn3a and RBPMS) were examined by immunocytochemistry. An overexpression vector MALAT1-RNA activation (RNAa), gene knockout vector MALAT1-RNA interference (RNAi), and control vector MALAT1-negative control (NC) were constructed. A chronic high intraocular pressure (IOP) rat model of glaucoma was established by episcleral vein cauterization. The RGCs were divided into the RGC control, RGC pressure, RGC pressure + MALAT1-NC, RGC pressure + MALAT1-RNAi and RGC pressure + MALAT1-RNAa groups. Sixty Sprague-Dawley (SD) rats were randomly divided into the normal, high IOP, high IOP + MALAT1-NC, high IOP + MALAT1-RNAa and high IOP + MALAT1-RNAi groups. qRT-PCR and western blotting were used to detect the expression levels of LncRNA-MALAT1 and PI3K/Akt. Terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) and flow cytometry were used to detect RGC apoptosis.
RESULTS: Immunocytochemistry revealed that the cultured RGCs reached 90% purity. Compared with the RGC pressure + MALAT1-NC group, the RGC pressure + MALAT1-RNAa group exhibited elevated expression levels of MALAT1, lower total protein levels of PI3K and Akt and decreased RGC apoptosis, while these expression levels were reversed in the RGC pressure + MALAT1-RNAi group. RGC numbers and PI3K/Akt expression levels in the high IOP model groups were lower than those in the normal group. In the high IOP + MALAT1-RNAa group, the mRNA and protein expression levels of PI3K/Akt were reduced but higher than those in the other three high IOP model groups. Additionally, RGC numbers in the high IOP + MALAT1-RNAa group were lower than those in the normal group but higher than those in the other three high IOP model groups.
CONCLUSION: Our study provides evidence that LncRNA-MALAT1 could inhibit RGC apoptosis in glaucoma through activation of the PI3K/Akt signaling pathway.

Matched MeSH terms: Antigens, Thy-1/genetics; Antigens, Thy-1/metabolism
Fulltext Cancer-associated fibroblasts promote proliferation of endometrial cancer cells

Subramaniam KS, Tham ST, Mohamed Z, Woo YL, Mat Adenan NA, Chung I

PLoS One, 2013;8(7):e68923.
PMID: 23922669 DOI: 10.1371/journal.pone.0068923

Endometrial cancer is the most commonly diagnosed gynecologic malignancy worldwide; yet the tumor microenvironment, especially the fibroblast cells surrounding the cancer cells, is poorly understood. We established four primary cultures of fibroblasts from human endometrial cancer tissues (cancer-associated fibroblasts, CAFs) using antibody-conjugated magnetic bead isolation. These relatively homogenous fibroblast cultures expressed fibroblast markers (CD90, vimentin and alpha-smooth muscle actin) and hormonal (estrogen and progesterone) receptors. Conditioned media collected from CAFs induced a dose-dependent proliferation of both primary cultures and cell lines of endometrial cancer in vitro (175%) when compared to non-treated cells, in contrast to those from normal endometrial fibroblast cell line (51%) (P<0.0001). These effects were not observed in fibroblast culture derived from benign endometrial hyperplasia tissues, indicating the specificity of CAFs in affecting endometrial cancer cell proliferation. To determine the mechanism underlying the differential fibroblast effects, we compared the activation of PI3K/Akt and MAPK/Erk pathways in endometrial cancer cells following treatment with normal fibroblasts- and CAFs-conditioned media. Western blot analysis showed that the expression of both phosphorylated forms of Akt and Erk were significantly down-regulated in normal fibroblasts-treated cells, but were up-regulated/maintained in CAFs-treated cells. Treatment with specific inhibitors LY294002 and U0126 reversed the CAFs-mediated cell proliferation (P<0.0001), suggesting for a role of these pathways in modulating endometrial cancer cell proliferation. Rapamycin, which targets a downstream molecule in PI3K pathway (mTOR), also suppressed CAFs-induced cell proliferation by inducing apoptosis. Cytokine profiling analysis revealed that CAFs secrete higher levels of macrophage chemoattractant protein (MCP)-1, interleukin (IL)-6, IL-8, RANTES and vascular endothelial growth factor (VEGF) than normal fibroblasts. Our data suggests that in contrast to normal fibroblasts, CAFs may exhibit a pro-tumorigenic effect in the progression of endometrial cancer, and PI3K/Akt and MAPK/Erk signaling may represent critical regulators in how endometrial cancer cells respond to their microenvironment.

Matched MeSH terms: Antigens, Thy-1/metabolism
Comparison of different methods for the isolation of mesenchymal stem cells from human umbilical cord Wharton's jelly

Salehinejad P, Alitheen NB, Ali AM, Omar AR, Mohit M, Janzamin E, et al.

In Vitro Cell Dev Biol Anim, 2012 Feb;48(2):75-83.
PMID: 22274909 DOI: 10.1007/s11626-011-9480-x

Several techniques have been devised for the dissociation of tissues for primary culture. These techniques can affect the quantity and quality of the isolated cells. The aim of our study was to develop the most appropriate method for the isolation of human umbilical cord-derived mesenchymal (hUCM) cells. In the present study, we compared four methods for the isolation of hUCM cells: three enzymatic methods; collagenase/hyaluronidase/trypsin (CHT), collagenase/trypsin (CT) and trypsin (Trp), and an explant culture (Exp) method. The trypan blue dye exclusion test, the water-soluble tetrazolium salt-1 (WST-1) assay, flow cytometry, alkaline phosphatase activity and histochemical staining were used to evaluate the results of the different methods. The hUCM cells were successfully isolated by all methods but the isolation method used profoundly altered the cell number and proliferation capacity of the isolated cells. The cells were successfully differentiated into adipogenic and osteogenic lineages and alkaline phosphatase activity was detected in the hUCM cell colonies of all groups. Flow cytometry analysis revealed that CD44, CD73, CD90 and CD105 were expressed in all groups, while CD34 and CD45 were not expressed. The expression of C-kit in the enzymatic groups was higher than in the explant group, while the expression of Oct-4 was higher in the CT group compared to the other groups. We concluded that the collagenase/trypsin method of cell isolation yields a higher cell density than the others. These cells expressed a higher rate of pluripotent cell markers such as C-kit and Oct-4, while the explant method of cell isolation resulted in a higher cell proliferation rate and activity compared to the other methods.

Matched MeSH terms: Antigens, Thy-1/biosynthesis
Generation of mesenchymal stem cell from human umbilical cord tissue using a combination enzymatic and mechanical disassociation method

Tong CK, Vellasamy S, Tan BC, Abdullah M, Vidyadaran S, Seow HF, et al.

Cell Biol Int, 2011 Mar;35(3):221-6.
PMID: 20946106 DOI: 10.1042/CBI20100326

MSCs (mesenchymal stem cells) promise a great potential for regenerative medicine due to their unique properties of self-renewal, high plasticity, modulation of immune response and the flexibility for genetic modification. Therefore, the increasing demand for cellular therapy necessitates a larger-scale production of MSC; however, the technical and ethical issues had put a halt on it. To date, studies have shown that MSC could be derived from human UC (umbilical cord), which is once considered as clinical waste. We have compared the two conventional methods which are classic enzymatic digestion and explant method with our newly tailored enzymatic-mechanical disassociation method to generate UC-MSC. The generated UC-MSCs from the methods above were characterized based on their immunophenotyping, early embryonic transcription factors expression and mesodermal differentiation ability. Our results show that enzymatic-mechanical disassociation method increase the initial nucleated cell yield greatly (approximately 160-fold) and maximized the successful rate of UC-MSC generation. Enzymatic-mechanical disassociation-derived UC-MSC exhibited fibroblastic morphology and surface markers expression of CD105, CD73, CD29, CD90 and MHC class I. Furthermore, these cells constitutively express early embryonic transcription factors (Nanog, Oct-4, Sox-2 and Rex-1), as confirmed by RT-PCR, indicating their multipotency and high self-renewal capacity. They are also capable of differentiating into osteoblasts and adipocytes when given an appropriate induction. The present study demonstrates a new and efficient approach in generating MSC from UC, hence serving as ideal alternative source of mesenchymal stem cell for clinical and research use.

Matched MeSH terms: Antigens, Thy-1/metabolism