Woong-Kyung SuhMol. Cells 2015; 38(3): 195-201 https://doi.org/10.14348/molcells.2015.2331
Abstract : Antibodies are powerful defense tools against pathogens but may cause autoimmune diseases when erroneously directed toward self-antigens. Thus, antibody producing cells are carefully selected, refined, and expanded in a highly regulated microenvironment (germinal center) in the peripheral lymphoid organs. A subset of T cells termed T follicular helper cells (Tfh) play a central role in instructing B cells to form a repertoire of antibody producing cells that provide life-long supply of high affinity, pathogen-specific antibodies. Therefore, understanding how Tfh cells arise and how they facilitate B cell selection and differentiation during germinal center reaction is critical to improve vaccines and better treat autoimmune diseases. In this review, I will summarise recent findings on molecular and cellular mechanisms underlying Tfh generation and function with an emphasis on T cell costimulation.
Lok-Hei Chan, Steve T. Luk, and Stephanie MaMol. Cells 2015; 38(3): 202-209 https://doi.org/10.14348/molcells.2015.2356
Abstract : Hepatocellular carcinoma (HCC), a highly malignant disease and the third leading cause of all cancer mortalities worldwide, often responses poorly to current treatments and results in dismal outcomes due to frequent chemoresistance and tumor relapse. The heterogeneity of HCC is an important attribute of the disease. It is the outcome of many factors, including the cross-talk between tumor cells within the tumor microenvironment and the acquisition and accumulation of genetic and epigenetic alterations in tumor cells. In addition, there is accumulating evidence in recent years to show that the malignancy of HCC can be attributed partly to the presence of cancer stem cell (CSC). CSCs are capable to self-renew, differentiate and initiate tumor formation. The regulation of the stem cell-like properties by several important signaling pathways have been found to endow the tumor cells with an increased level of tumorigenicity, chemoresistance, and metastatic ability. In this review, we will discuss the recent findings on hepatic CSCs, with special emphasis on their putative origins, relationship with hepatitis viruses, regulatory signaling networks, tumor microenvironment, and how these factors control the stemness of hepatic CSCs. We will also discuss some novel therapeutic strategies targeted at hepatic CSCs for combating HCC and perspectives of future investigation.
Jeong-An Gim, Chang Pyo Hong, Dae-Soo Kim, Jae-Woo Moon, Yuri Choi, Jungwoo Eo, Yun-Jeong Kwon, Ja-Rang Lee, Yi-Deun Jung, Jin-Han Bae, Bong-Hwan Choi, Junsu Ko, Sanghoon Song, Kung Ahn, Hong-Seok Ha, Young Mok Yang, Hak-Kyo Lee, Kyung-Do Park, Kyoung-Tag Do, Kyudong Han, Joo Mi Yi, Hee-Jae Cha, Selvam Ayarpadikannan, Byung-Wook Cho, Jong Bhak, and Heui-Soo KimMol. Cells 2015; 38(3): 210-220 https://doi.org/10.14348/molcells.2015.2138
Abstract : Athletic performance is an important criteria used for the selection of superior horses. However, little is known about exercise-related epigenetic processes in the horse. DNA methylation is a key mechanism for regulating gene expression in response to environmental changes. We carried out comparative genomic analysis of genome-wide DNA methylation profiles in the blood samples of two different thoroughbred horses before and after exercise by methylated-DNA immunoprecipitation sequencing (MeDIP-Seq). Differentially methylated regions (DMRs) in the pre-and post-exercise blood samples of superior and inferior horses were identified. Exercise altered the methylation patterns. After 30 min of exercise, 596 genes were hypomethylated and 715 genes were hypermethylated in the superior horse, whereas in the inferior horse, 868 genes were hypomethylated and 794 genes were hypermethylated. These genes were analyzed based on gene ontology (GO) annotations and the exercise-related pathway patterns in the two horses were compared. After exercise, gene regions related to cell division and adhesion were hypermethylated in the superior horse, whereas regions related to cell signaling and transport were hypermethylated in the inferior horse. Analysis of the distribution of methylated CpG islands confirmed the hypomethylation in the gene-body methylation regions after exercise. The methylation patterns of transposable elements also changed after exercise. Long interspersed nuclear elements (LINEs) showed abundance of DMRs. Collectively, our results serve as a basis to study exercise-based reprogramming of epigenetic traits.
Qian Chen, Zhijian Zhang, Jinbo Liu, Qinghua He, Yuepeng Zhou, Genbao Shao, Xianglan Sun, Xudong Cao, Aihua Gong, and Ping JiangMol. Cells 2015; 38(3): 221-228 https://doi.org/10.14348/molcells.2015.2170
Abstract : Because Schwann cells perform the triple tasks of myelination, axon guidance and neurotrophin synthesis, they are candidates for cell transplantation that might cure some types of nervous-system degenerative diseases or injuries. However, Schwann cells are difficult to obtain. As another option, ectomesenchymal stem cells (EMSCs) can be easily harvested from the nasal respiratory mucosa. Whether fibrin, an important transplantation vehicle, can improve the differentiation of EMSCs into Schwann-like cells (SLCs) deserves further research. EMSCs were isolated from rat nasal respiratory mucosa and were purified using anti-CD133 magnetic cell sorting. The purified cells strongly expressed HNK-1, nestin, p75NTR, S-100, and vimentin. Using nuclear staining, the MTT assay and Western blotting analysis of the expression of cell-cycle markers, the proliferation rate of EMSCs on a fibrin matrix was found to be significantly higher than that of cells grown on a plastic surface but insignificantly lower than that of cells grown on fibronectin. Additionally, the EMSCs grown on the fibrin matrix expressed myelination-related molecules, including myelin basic protein (MBP), 2′,3′-cyclic nucleotide 3′-phosphodiesterase (CNPase) and galactocerebrosides (GalCer), more strongly than did those grown on fibronectin or a plastic surface. Furthermore, the EMSCs grown on the fibrin matrix synthesized more neurotrophins compared with those grown on fibronectin or a plastic surface. The expression level of integrin in EMSCs grown on fibrin was similar to that of cells grown on fibronectin but was higher than that of cells grown on a plastic surface. These results demonstrated that fibrin not only promoted EMSC proliferation but also the differentiation of EMSCs into the SLCs. Our findings suggested that fibrin has great promise as a cell transplantation vehicle for the treatment of some types of nervous system diseases or injuries.
Ju Yeon Kwak, Hyun Joo Ham, Cheol Min Kim, and Eun Seong HwangMol. Cells 2015; 38(3): 229-235 https://doi.org/10.14348/molcells.2015.2253
Abstract : Nicotinamide (NAM) has been shown to suppress reactive oxygen species (ROS) production in primary human fibroblasts, thereby extending their replicative lifespan when added to the medium during long-term cultivation. Based on this finding, NAM is hypothesized to affect cellular senescence progression by keeping ROS accumulation low. In the current study, we asked whether NAM is indeed able to reduce ROS levels and senescence phenotypes in cells undergoing senescence progression and those already in senescence. We employed two different cellular models: MCF-7 cells undergoing senescence progression and human fibroblasts in a state of replicative senescence. In both models, NAM treatment substantially decreased ROS levels. In addition, NAM attenuated the expression of the assessed senescence phenotypes, excluding irreversible growth arrest.
Hyemin Min, Ichiro Kawasaki, Joomi Gong, and Yhong-Hee ShimMol. Cells 2015; 38(3): 236-242 https://doi.org/10.14348/molcells.2015.2282
Abstract : Intake of caffeine during pregnancy can cause retardation of fetal development. Although the significant influence of caffeine on animal development is widely recognized, much remains unknown about its mode of action because of its pleiotropic effects on living organisms. In the present study, by using
Sang Eun Jun, Kiu-Hyung Cho, Ji-Young Hwang, Wael Abdel-Fattah, Alexander Hammermeister, Raffael Schaffrath, John L. Bowman, and Gyung-Tae KimMol. Cells 2015; 38(3): 243-250 https://doi.org/10.14348/molcells.2015.2297
Abstract : Patterning of the polar axis during the early leaf developmental stage is established by cell-to-cell communication between the shoot apical meristem (SAM) and the leaf primordia. In a previous study, we showed that the
Jun-hyeon Jeong, Areum Jo, Pilgu Park, Hyunsook Lee, and Hae-Ock LeeMol. Cells 2015; 38(3): 251-258 https://doi.org/10.14348/molcells.2015.2302
Abstract : Germline mutations in the breast cancer type 2 susceptibility gene (
Phanu Serivichyaswat, Hak-Seung Ryu, Wanhui Kim, Soonkap Kim, Kyung Sook Chung, Jae Joon Kim, and Ji Hoon AhnMol. Cells 2015; 38(3): 259-266 https://doi.org/10.14348/molcells.2015.2311
Abstract : The regulation of flowering time has crucial implications for plant fitness. MicroRNA156 (miR156) represses the floral transition in
David W. Green, Hyuk-Jae Kwon, and Han-Sung JungMol. Cells 2015; 38(3): 267-272 https://doi.org/10.14348/molcells.2015.2315
Abstract : Nacre seashell is a natural osteoinductive biomaterial with strong effects on osteoprogenitors, osteoblasts, and osteoclasts during bone tissue formation and morphogenesis. Although nacre has shown, in one study, to induce bridging of new bone across large non-union bone defects in 8 individual human patients, there have been no succeeding human surgical studies to confirm this outstanding potency. But the molecular mechanisms associated with nacre osteoinduction and the influence on bone marrow-derived mesenchymal stem cells (BMSC’s), skeletal stem cells or bone marrow stromal cells remain elusive. In this study we highlight the phenotypic and biochemical effects of