Interleukin-15-mediated inflammation promotes non-alcoholic fatty liver disease.

Interleukin-15 (IL-15) is essential for the homeostasis of lymphoid cells particularly memory CD8(+) T cells and NK cells. These cells are abundant in the liver, and are implicated in obesity-associated pathogenic processes. Here we characterized obesity-associated metabolic and cellular changes in the liver of mice lacking IL-15 or IL-15Rα. High fat diet-induced accumulation of lipids was diminished in the livers of mice deficient for IL-15 or IL-15Rα. Expression of enzymes involved in the transport of lipids in the liver showed modest differences. More strikingly, the liver tissues of IL15-KO and IL15Rα-KO mice showed decreased expression of chemokines CCl2, CCL5 and CXCL10 and reduced infiltration of mononuclear cells. In vitro, IL-15 stimulation induced chemokine gene expression in wildtype hepatocytes, but not in IL15Rα-deficient hepatocytes. Our results show that IL-15 is implicated in the high fat diet-induced lipid accumulation and inflammation in the liver, leading to fatty liver disease.

Growth Kinetics, Characterization, and Plasticity of Human Menstrual Blood Stem Cells.

One of the readily available sources of mesenchymal stem cells (MSCs) is menstrual blood-derived stem cells (Men-SCs), which exhibit characteristics similar to other types of MSCs. This study was performed to determine the growth kinetics, plasticity, and characterization of Men-SCs in women. During spring 2014 in the southern Iranian city of Shiraz, menstrual blood (5 mL) was obtained from 10 women on their third day of menstruation in 2 age groups of 30 to 40 and 40 to 50 years old. Ficoll was used to separate the mononuclear cell fraction. After the Men-SCs were cultured, they were subcultured up to passage 4. Growth behavior and population doubling time were evaluated by seeding 5×10(4) cells into 12- and 24-well culture plates, and the colonies were enumerated. The expression of CD44, CD90, and CD34 was evaluated. The osteogenic potential was assessed by alizarin red staining. The Men-SCs were shown to be plastic adherent and spindle-shaped. Regarding the growth curves in the 12- and 24-well culture plates, it was demonstrated that in the women aged between 30 and 40 years, population doubling time was 55.5 and 62 hours, respectively, while these values in the women aged between 40 and 50 years were 70.4 and 72.4 hours, correspondingly. Positive expression of CD44 and CD90 and negative expression of CD34 were noted. In the osteogenic differentiation medium, the cells differentiated toward osteoblasts. As human Men-SCs are easily collectable without any invasive procedure and are a safe and rapid source of MSCs, they can be a good candidate for stem cell banking and cell transplantation in women.

Endometrial mesenchymal stem stromal cells in mature and immature sheep: An in vitro study.

BACKGROUND: Endometrial mesenchymal stem stromal cells (EnMSCs) are critical for uterine function, repair, and regeneration. OBJECTIVE: This study introduced isolation technique of EnMSCs and compared the characteristics of EnMSCs in mature and immature ewes. MATERIALS AND METHODS: Endometrial tissue samples from the uterus of 10 ewes were collected from the slaughterhouse. Endometrial cells were isolated from tissue using cold incubation and then chopping and treating was performed with collagenase type I. Isolated cells were cultured in cell culture medium and then attached cells to flasks were harvested as EnMSCs and subcultured. To enumerate the cells, the population doubling time (PDT) was determined and 2.2×104 cells in passage 4 were seeded into 24-well culture plates to compare the growth curves of isolated cells. Reverse transcription polymerase chain reaction (RT-PCR) was performed for detection of CD34 and CD73 markers. The osteogenic and adipogenic potential of isolated cells were determined using differentiation tests. RESULTS: EnMSCs adhered to the flasks and displayed spindle-shape. Based on findings of the cell count and the growth curves, the EnMSCs growth was significantly more prominent in immature ewes in comparison to mature sheep. The PDT of EnMSCs in immature ewes was about 21 hr whereas this time period was two times higher (45 hr) in mature sheep. RT-PCR analyses of EnMSCs were positive for CD73 and negative for CD34. EnMSCs were differentiated into osteoblasts and adipocytes. CONCLUSION: Based on mesenchymal stem cells characters confirmed in EnMSCs, they can be a candidate for cell therapy and regenerative medicine.

GTPase of the Immune-Associated Nucleotide Protein 5 Regulates the Lysosomal Calcium Compartment in T Lymphocytes.

T lymphocytes from Gimap5lyp/lyp rats carrying a recessive mutation in the GTPase of immune-associated protein 5 (Gimap5) gene undergo spontaneous apoptosis. Molecular mechanisms underlying this survival defect are not yet clear. We have shown that Gimap5lyp/lyp T lymphocytes display reduced calcium influx following T cell antigen receptor (TCR) stimulation that was associated with impaired buffering of calcium by mitochondria. Here, we investigated the subcellular localization of GIMAP5 and its influence on Ca2+ response in HEK293T cells and T lymphocytes. The more abundantly expressed GIMAP5v2 localizes to the lysosome and certain endosomal vesicles. Gimap5lyp/lyp T lymphocytes showed increased accumulation of calcium in the lysosomes as evidenced by Gly-Phe ß-naphthylamide (GPN) triggered Ca2+ release. As a corollary, GPN-induced Ca2+ flux was decreased in HEK293T cells expressing GIMAP5v2. Strikingly, TCR stimulation of rat, mouse, and human T lymphocytes increased lysosomal calcium content. Overall, our findings show that lysosomes modulate cellular Ca2+ response during T cell activation and that GIMAP5 regulates the lysosomal Ca2+ compartment in T lymphocytes.

TCR and IL-7 Signaling Are Altered in the Absence of Functional GTPase of the Immune Associated Nucleotide Binding Protein 5 (GIMAP5).

GTPase of the immune associated nucleotide binding protein (GIMAP) family of proteins are expressed essentially in cells of the hematopoietic system. Mutation in the founding member of this gene family, Gimap5, results in the lymphopenic phenotype in Bio-Breeding diabetes prone rats. In mice, deletion of functional Gimap5 gene affects the survival and renewal of hematopoietic stem cells in addition to the defects observed in T cells. Here we show that T cells from OTII TCR-transgenic Gimap5sph/sph mice do not proliferate in response to its cognate antigen. Furthermore, T cells from Gimap5 mutant rats and mice show decreased phosphorylation of STAT5 following stimulation with IL-7. Our results suggest that functional Gimap5 is required for optimal signaling through TCR and IL-7R in T cells.

Regenerative potential of endometrial stem cells: a mini review.

Recent findings in stem cell biology have opened a new window in regenerative medicine. The endometrium possesses mesenchymal stem cells (MSCs) called endometrial stem cells (EnSCs) having specific regenerative properties linked to adult stem cells. They contribute in tissue remodeling and engineering and were shown to have immuno-modulating effects. Many clinical trials were undertaken to ascertain the therapeutic potential of EnSCS. In this mini review, we showed that EnSCs are readily available sources of adult stem cells in the uterus that can be highlighted for their renewable multipotent and differentiation properties. This cell population may be a practical solution of choice in reproductive biology, regenerative medicine and autologous stem cell therapy.