Sieun S. Kim and Seung-Jae V. LeeMol. Cells 2019; 42(5): 379-385 https://doi.org/10.14348/molcells.2019.0077
Abstract : Non-coding RNAs (ncRNAs) comprise various RNA species, including small ncRNAs and long ncRNAs (lncRNAs). ncRNAs regulate various cellular processes, including transcription and translation of target messenger RNAs. Recent studies also indicate that ncRNAs affect organismal aging and conversely aging influences ncRNA levels. In this review, we discuss our current understanding of the roles of ncRNAs in aging and longevity, focusing on recent advances using the roundworm
Kyung Jin Lee, Deokhee Kang, and Hee-Sung ParkMol. Cells 2019; 42(5): 386-396 https://doi.org/10.14348/molcells.2019.0078
Abstract : Labeling of a protein with a specific dye or tag at defined positions is a critical step in tracing the subtle behavior of the protein and assessing its cellular function. Over the last decade, many strategies have been developed to achieve selective labeling of proteins in living cells. In particular, the site-specific unnatural amino acid (UAA) incorporation technique has gained increasing attention since it enables attachment of various organic probes to a specific position of a protein in a more precise way. In this review, we describe how the UAA incorporation technique has expanded our ability to achieve site-specific labeling and visualization of target proteins for functional analyses in live cells.
Seok Ho Yoon, and Taijoon ChungMol. Cells 2019; 42(4): 285-291 https://doi.org/10.14348/molcells.2019.0011
Abstract : Eukaryotic cells use conserved quality control mechanisms to repair or degrade defective proteins, which are synthesized at a high rate during proteotoxic stress. Quality control mechanisms include molecular chaperones, the ubiquitin-proteasome system, and autophagic machinery. Recent research reveals that during autophagy, membrane-bound organelles are selectively sequestered and degraded. Selective autophagy is also critical for the clearance of excess or damaged protein complexes (e.g., proteasomes and ribosomes) and membrane-less compartments (e.g., protein aggregates and ribonucleoprotein granules). As sessile organisms, plants rely on quality control mechanisms for their adaptation to fluctuating environments. In this mini-review, we highlight recent work elucidating the roles of selective autophagy in the quality control of proteins and RNA in plant cells. Emphasis will be placed on selective degradation of membrane-less compartments and protein complexes in the cytoplasm. We also propose possible mechanisms by which defective proteins are selectively recognized by autophagic machinery.
Jeongmin Park, Yeonsoo Joe, Stefan W. Ryter, Young-Joon Surh, and Hun Taeg ChungMol. Cells 2019; 42(4): 292-300 https://doi.org/10.14348/molcells.2019.0016
Abstract : Immunometabolism, defined as the interaction of metabolic pathways with the immune system, influences the pathogenesis of metabolic diseases. Metformin and carbon monoxide (CO) are two pharmacological agents known to ameliorate metabolic disorders. There are notable similarities and differences in the reported effects of metformin and CO on immunometabolism. Metformin, an anti-diabetes drug, has positive effects on metabolism and can exert anti-inflammatory and anti-cancer effects
Yoon Ha Choi, and Jong Kyoung KimMol. Cells 2019; 42(3): 189-199 https://doi.org/10.14348/molcells.2019.2446
Abstract : Cell-to-cell variability in gene expression exists even in a homogeneous population of cells. Dissecting such cellular heterogeneity within a biological system is a prerequisite for understanding how a biological system is developed, homeo-statically regulated, and responds to external perturbations. Single-cell RNA sequencing (scRNA-seq) allows the quantitative and unbiased characterization of cellular heterogeneity by providing genome-wide molecular profiles from tens of thousands of individual cells. A major question in analyzing scRNA-seq data is how to account for the observed cell-to-cell variability. In this review, we provide an overview of scRNA-seq protocols, computational approaches for dissecting cellular heterogeneity, and future directions of single-cell transcriptomic analysis.
Yujeong Oh, and Jiwon JangMol. Cells 2019; 42(3): 200-209 https://doi.org/10.14348/molcells.2019.2439
Abstract : Embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) have been used as promising tools for regenerative medicine, disease modeling, and drug screening. Traditional and common strategies for pluripotent stem cell (PSC) differentiation toward disease-relevant cell types depend on sequential treatment of signaling molecules identified based on knowledge of developmental biology. However, these strategies suffer from low purity, inefficiency, and time-consuming culture conditions. A growing body of recent research has shown efficient cell fate reprogramming by forced expression of single or multiple transcription factors. Here, we review transcription factor-directed differentiation methods of PSCs toward neural, muscle, liver, and pancreatic endocrine cells. Potential applications and limitations are also discussed in order to establish future directions of this technique for therapeutic purposes.
Szu-Hsien (Sam) Wu, Ji-Hyun Lee, and Bon-Kyoung KooMol. Cells 2019; 42(2): 104-112 https://doi.org/10.14348/molcells.2019.0006
Abstract : Tracking the fate of individual cells and their progeny through lineage tracing has been widely used to investigate various biological processes including embryonic development, homeostatic tissue turnover, and stem cell function in regeneration and disease. Conventional lineage tracing involves the marking of cells either with dyes or nucleoside analogues or genetic marking with fluorescent and/or colorimetric protein reporters. Both are imaging-based approaches that have played a crucial role in the field of developmental biology as well as adult stem cell biology. However, imaging-based lineage tracing approaches are limited by their scalability and the lack of molecular information underlying fate transitions. Recently, computational biology approaches have been combined with diverse tracing methods to overcome these limitations and so provide high-order scalability and a wealth of molecular information. In this review, we will introduce such novel computational methods, starting from single-cell RNA sequencing-based lineage analysis to DNA barcoding or genetic scar analysis. These novel approaches are complementary to conventional imaging-based approaches and enable us to study the lineage relationships of numerous cell types during vertebrate, and in particular human, development and disease.
Ji-Yun Seo, Ji-Hoon Kim, and Young-Yun KongMol. Cells 2019; 42(2): 97-103 https://doi.org/10.14348/molcells.2019.0004
Abstract : Androgens act in almost all tissues throughout the lifetime and have important roles in skeletal muscles. The levels of androgens increase during puberty and remain sustained at high levels in adulthood. Because androgens have an anabolic effect on skeletal muscles and muscle stem cells, these increased levels of androgens after puberty should lead to spontaneous muscle hypertrophy and hyperplasia in adulthood. However, the maintenance of muscle volume, myonuclei number per myofiber, and quiescent state of satellite cells in adulthood despite the high levels of androgens produces paradoxical outcomes. Our recent study revealed that the physiological increase of androgens at puberty initiates the transition of muscle stem cells from proliferation to quiescence by the androgen-Mindbomb1-Notch signaling axis. This newly discovered androgen action on skeletal muscles underscores the physiological importance of androgens on muscle homeostasis throughout life. This review will provide an overview of the new androgen action on skeletal muscles and discuss the paradoxical effects of androgens suggested in previous studies.
Sewoon Kim, and Sunjoo JeongMol. Cells 2019; 42(1): 8-16 https://doi.org/10.14348/molcells.2018.0436
Abstract : Mutations in the β-catenin gene (
Chang-Hee Lee, and Taehoon ChunMol. Cells 2019; 42(1): 1-7 https://doi.org/10.14348/molcells.2018.0419
Abstract : Macrophage is an important innate immune cell that not only initiates inflammatory responses, but also functions in tissue repair and anti-inflammatory responses. Regulating macrophage activity is thus critical to maintain immune homeostasis. Tyro3, Axl, and Mer are integral membrane proteins that constitute TAM family of receptor tyrosine kinases (RTKs). Growing evidence indicates that TAM family receptors play an important role in anti-inflammatory responses through modulating the function of macrophages. First, macrophages can recognize apoptotic bodies through interaction between TAM family receptors expressed on macrophages and their ligands attached to apoptotic bodies. Without TAM signaling, macrophages cannot clear up apoptotic cells, leading to broad inflammation due to over-activation of immune cells. Second, TAM signaling can prevent chronic activation of macrophages by attenuating inflammatory pathways through particular pattern recognition receptors and cytokine receptors. Third, TAM signaling can induce autophagy which is an important mechanism to inhibit NLRP3 inflammasome activation in macrophages. Fourth, TAM signaling can inhibit polarization of M1 macrophages. In this review, we will focus on mechanisms involved in how TAM family of RTKs can modulate function of macrophage associated with anti-inflammatory responses described above. We will also discuss several human diseases related to TAM signaling and potential therapeutic strategies of targeting TAM signaling.
Soyeon Lee, and Kyung-Tai MinMol. Cells 2018; 41(12): 1000-1007 https://doi.org/10.14348/molcells.2018.0438
Abstract : Mitochondria and endoplasmic reticulum (ER) are essential organelles in eukaryotic cells, which play key roles in various biological pathways. Mitochondria are responsible for ATP production, maintenance of Ca2+ homeostasis and regulation of apoptosis, while ER is involved in protein folding, lipid metabolism as well as Ca2+ homeostasis. These organelles have their own functions, but they also communicate via mitochondrial-associated ER membrane (MAM) to provide another level of regulations in energy production, lipid process, Ca2+ buffering, and apoptosis. Hence, defects in MAM alter cell survival and death. Here, we review components forming the molecular junctions of MAM and how MAM regulates cellular functions. Furthermore, we discuss the effects of impaired ER-mitochondrial communication in various neurodegenerative diseases.
Heegwon Shin, Youngmi Kim, Meehyein Kim, and Younghoon LeeMol. Cells 2018; 41(12): 993-999 https://doi.org/10.14348/molcells.2018.0425
Abstract : One of the most interesting findings from genome-wide expression analysis is that a considerable amount of noncoding RNA (ncRNA) is present in the cell. Recent studies have identified diverse biological functions of ncRNAs, which are expressed in a much wider array of forms than proteins. Certain ncRNAs associated with diseases, in particular, have attracted research attention as novel therapeutic targets and diagnostic markers. BC200 RNA, a 200-nucleotide ncRNA originally identified as a neuron-specific transcript, is abnormally over-expressed in several types of cancer tissue. A number of recent studies have suggested mechanisms by which abnormal expression of BC200 RNA contributes to the development of cancer. In this article, we first provide a brief review of a recent progress in identifying functions of BC200 RNA in cancer cells, and then offer examples of other ncRNAs as new therapeutic targets and diagnostic markers for human cancer. Finally, we discuss future directions of studies on BC200 RNA for new cancer treatments.
Yuan-Shen Chen, Wei-Chu Chuang, Hsiu-Ni Kung, Ching-Yuan Cheng, Duen-Yi Huang, Ponarulselvam Sekar, and Wan-Wan LinMol. Cells 2022;45: 257-272 https://doi.org/10.14348/molcells.2021.0193
Feng Guo, Chengchun Tang, Bo Huang, Lifei Gu, Jun Zhou, Zongyang Mo, Chang Liu, and Yuqing LiuMol. Cells 2022;45: 122-133 https://doi.org/10.14348/molcells.2021.0066
Bor Luen TangMol. Cells 2016;39: 87-95 https://doi.org/10.14348/molcells.2021.0066
Jin Young Huh, Yoon Jeong Park, Mira Ham, and Jae Bum KimMol. Cells 2014;37: 365-371 https://doi.org/10.14348/molcells.2021.0066