Kim Etal Research Articles

CHD2: One Gene, Many Roles

Mutations in the chromodomain helicase DNA-binding 2 (CHD2) gene have been found in patients with a range of neurodevelopmental disorders. In this issue of Neuron, Kim etal. (2018) showed that Chd2 haploinsufficiency compromises cortical development, synaptic function, and memory in mice.

The Next Generation in Detection of Leukemia-Associated Translocations

This commentary highlights the article by Kim etal that suggests use of two different next-generation sequencing-based assays for detection of fusion RNAs in patients with acute leukemia.

A Mitochondrial-Derived Peptide Exercises the Nuclear Option

The vast majority of mitochondrial proteins are encoded by nuclear genes, giving the nucleus ultimate control of mitochondrial biogenesis, dynamics, and function. However, in this issue Kim etal. (2018) demonstrate a reversal of fortune, whereby an mtDNA-encoded peptide, MOTS-c, is targeted to the nucleus to signal changes in gene expression.

Penile fasciocutaneous flap urethroplasty for the reconstruction of pediatric long anterior urethral stricture

Though pediatric urethral stricture is an uncommon urological problem, it is a challenging urological one. The causative factors are iatrogenic, traumatic, and inflammatory. In the current study, the authors report their experience of the treatment of pediatric long anterior urethral stricture using penile circular fasciocutaneous flap. The study included 23 pediatric patients who had long anterior urethral strictures, which were repaired using circular penile fasciocutaneous flap. The flap was elevated through a subcoronal circumferential incisionand then it was split ventrally. The strictured portion of the urethra was sharply incised ventrally, extending to 1cm into normal urethra. The flap was sutured to the urethral plate over silicone catheter of suitable size, which was removed after 3 weeks. The follow-up was scheduled every 3 months for the first year and then yearly thereafter. The urethroplasty was successful in 20 cases (86.96%). There were two cases complicated by stricture recurrence, which was managed by visual internal urethrotomy. Fistula formation was reported in one case and was repaired by simple excision and closure. Penile skin necrosis was reported in only one patient and was managed by frequent dressing. During the last five decades, there was a substantial advancement in the reconstruction of long or complex anterior strictures due to the use of grafts and flaps. During pediatric urethral stricture repair, particular attention must be paid to the differences between adults and children anatomy, e.g. the small urethral lumen and tissue delicateness. McAninch introduced the reconstruction of complex anterior urethral strictures utilizing circular penile fasciocutaneous flap. The technique of penile fasciocutaneous flap urethroplasty takes long time and requires meticulous dissection. Therefore, it should be restricted for long or complex anterior urethra strictures. Success rate in this study was 86.96%, which is in the same league as that reported in literature as regard adults penile fasciocutaneous flap urethroplasty. Whitson etal. reported success rates of 84% and 79% in the 5th and 10th years, respectively. In another study, Kim etal. revealed a success rate of 68.9%. In this study, complications incidence was 21.6%, which is consistent with reported incidence of complications of adults penile fasciocutaneous flap urethroplasty (8%-20%). According to the outcomes of this study, penile fasciocutaneous flap urethroplasty is a reasonable modality for the reconstruction of long anterior urethral stricture in pediatric patients especially after circumcision.

Intestinal Tolerance, with a Little Help from Our Microbial Friends

The intestinal immune system performs a tightrope walk between anti-pathogen immunity and tolerance to innocuous luminal antigens. In this issue of Immunity, Kim etal. (2018) demonstrate that the microbiota is driving tolerance to food antigens and dampening inflammatory responses through CX3CR1+ mononuclear phagocytes.

Dynamics under the Telomeric Bridge

In this issue of Molecular Cell, Kim etal. (2017) have studied the structure and organization of the shelterin protein complex protecting telomeres in Schizosaccharomyces pombe and humans and discovered an allosteric structural transition that drives the formation of the shelterin complex and participates in telomere length regulation.

Brain, Immunity, Gut: “BIG” Links between Pregnancy and Autism

Although dysregulation of brain, immune, and gut physiology during pregnancy have each been implicated in neuropsychiatric disorders, whether and how these presumably distinct systems are linked to cause disease is unclear. Kim etal. (2017) and Shin Yim etal. (2017) identify a pathway to explain how these aspects of our physiology are deeply and inextricably connected.

Functions at the junction - membrane proteins and myoblast fusion.

The fusion of myoblasts is an essential step in the formation of multinucleated muscle fibres and the molecular underpinnings of this process are being actively investigated. In this issue, Kim etal. report that the membrane protein Xkr8 plays a role in myotube fusion, adding another class of membrane proteins to the list of potential contributors to myoblast differentiation and fusion.

Protectors of the Neonatal Gut: Clostridia Send Pathogens Packing

Commensal bacteria are known to provide colonization resistance in the gut. But exactly which ones provide this function? In a recent paper in Science, Kim etal. (2017) revealed that Clostridia added to mouse infant gutmicrobiota are sufficient to limit colonization of pathogenic Enterobacteriaceae.

In the Red: Deficits in Immune Regulation Underlie Psoriasis Severity

IL-17-driven pathways are active in the skin of patients with psoriasis. Kim etal. examined lesions from mild and moderate to severe psoriasis and found that differences in cutaneous disease severity may be the outcome of lapses in immunoregulatory mechanisms; because as much, if not more, T helper type 17-induced inflammation was seen in mild psoriasis, these patients may also benefit from anti-IL-17-targeted biologics.

Soft and still responsive

Soft Electronics![Figure][1] Soft touch-conductive hydrogel PHOTO: KIM ET AL. Transparent touch screens, from large-panel interactive information maps to advanced cell phones, have become a part of daily life. However, such devices all use hard materials. Kim et al. have developed a soft

Living Radical Polymerization with Alkali and Alkaline Earth Metal Iodides as Catalysts

The generation of an alkyl radical (R•) from an alkyl iodide (R–I) with NaI playing a catalytic role was experimentally demonstrated. This catalytic reaction was exploited as an activation process for living radical polymerization. Alkali metal iodides, NaI, KI, and CsI, and alkaline earth metal iodides, MgI2 and CaI2, were systematically studied as catalysts. 18-crown-6-Ether and a polyether, that is, diethylene glycol dimethyl ether (diglyme), were utilized to solvate these catalysts in hydrophobic monomers. Among the five catalysts, NaI exhibited a particularly high reactivity. The polymer molecular weight and its distribution (Mw/Mn = 1.2−1.4) were well controlled with high conversions (e.g., 80–90%) in reasonably short periods of time (3–6 h) at mild temperatures (60–70 °C) in the polymerizations of methyl methacrylate. NaI is also amenable to styrene, acrylonitrile, and functional methacrylates. In addition to homopolymers, NaI also afforded well-defined block copolymers, chain-end functional polyme...

A simple mechanistic explanation for original antigenic sin and its alleviation by adjuvants.

A large number of published studies have shown that adaptive immunity to a particular antigen, including pathogen-derived, can be boosted by another, cross-reacting antigen while inducing suboptimal immunity to the latter. Although this phenomenon, called original antigenic sin (OAS), was first reported approximately 70 years ago (Francis et al. 1947 Am. J. Public Health 37, 1013-1016 (doi:10.2105/AJPH.37.8.1013)), its underlying biological mechanisms are still inadequately understood (Kim et al. Proc. Natl Acad. Sci. USA 109, 13 751-13 756 (doi:10.1073/pnas.0912458109)). Here, focusing on the humoral aspects of adaptive immunity, I propose a simple and testable mechanism: that OAS occurs when T regulatory cells induced by the first antigen decrease the dose of the second antigen that is loaded by dendritic cells and available to activate naive lymphocytes. I use both a parsimonious mathematical model and experimental data to confirm the deductive validity of this proposal. This model also explains the puzzling experimental observation that administering certain dendritic cell-activating adjuvants during antigen exposure alleviates OAS. Specifically, the model predicts that such adjuvants will attenuate T regulatory suppression of naive lymphocyte activation. Together, these results suggest additional strategies for redeeming adaptive immunity from the destructive consequences of antigenic 'sin'.

Myoblast Fusion: Playing Hard to Get

In Drosophila myoblast fusion, the fusing cell invades another by actin-enriched protrusion. In this issue of Developmental Cell, Kim etal. (2015) examine the myoblast fusion mechanism from the perspective of the "receiving" cell and report that fusion depends on the ability of this cell to stiffen its actomyosin cortex.

ZMP: A Master Regulator of One-Carbon Metabolism

In this issue, Kim etal. (2015) show that ZMP (5-aminoimidazole-4-carboxamide ribonucleotide) binds to and activates a conserved riboswitch to regulate expression of one-carbon metabolism genes.

The Nucleolus Gets the Silent Treatment

In this issue of Cell Stem Cell, Savić etal. (2014) and Kim etal. (2014) provide insight into how global heterochromatin condensation and LIN28 sequestration in embryonic stem cells are independent mechanisms regulating pluripotency in the oft-overlooked nucleolus.

Reinventing the Neural Crest: Direct Reprogramming Makes iNCCs

Aberrant neural crest (NC) development is at the origin of many congenital diseases. Given the limitations inhuman NC cell isolation and expansion, the development of new strategies for NC generation is crucial. In this issue of Cell Stem Cell, Kim etal. (2014) report the direct reprogramming of postnatal fibroblasts into multipotent NC cells.

Iron ERRs with Salmonella.

The hormone hepcidin promotes iron sequestration by macrophages. A recent study by Kim etal. (2014) implicates the orphan receptor ERRγ (estrogen-related receptor γ) in the regulation of hepcidin production and suggests that targeting the ERRγ-hepcidin axis may be beneficial during infection with the facultative intracellular pathogen Salmonella.

Gray Mold of Grafted Cactus Caused by Botrytis cinerea in Korea

Grafted cactus, produced by grafting two different cactus speciesincluding photosynthetic stocks (mostly Hylocereus trigonus) andnon-photosynthetic scions (usually Gymnocalycium mihanovichiior Chamaecereus silvestrii), is one of the most popular exportingornamental plants, comprising about 70% of the world tradingmarket (Song et al., 2009a, 2009b). Since the grated cactus is culti-vated in greenhouses with warm temperature and high humidityduring the whole growing season, several diseases especially causedby fungi such as Bipolaris cactivora , Colletotrichum gloeosporioides(anamorph of Glomerella cingulata), Fusarium oxysporum, andAlternaria alternata are frequently found in the cactus farms inKorea (Chang et al., 1998; Choi et al., 2010; Hyun et al., 1998; Kimet al ., 2000).A stem disease of G. mihanovichii caused by a fungus wasobserved in 2010 in several greenhouses especially with highhumidity at Goyang, Gyeonggi province, the major cactus-growingarea in Korea. Its occurrence was not prevalent and found mostly inmature (old) cactus plants. Characteristic symptoms were initialblack or brown spots that were enlarged with time to becomeshrunken or water-soaked black lesions at advanced infection stages(Fig. 1A & B). Isolation of fungi and bacteria from the rotten stemsof G. mihanovichii was tried to, but it was fail the isolation of thepreviously known fungal and bacterial pathogens such as B. cacti-vora, C. gloeosporioides, F. oxysporum, A. alternata, and Pecto-bacterium carotivorum (Kim et al., 2007) except seven fungalisolates with identical morphological characteristics. The mycologi-cal characteristics of the fungal isolates were as follows. The fungusformed grayish brown colonies with the production of abundant flator irregular black sclerotia on potato-dextrose agar (PDA) (Fig. 1C).Conidiophores were upright, tall and slender, 8.0 −31.0 µm in width,determinate, hyaline or grayish, branched irregularly in upper portions,bearing clusters of conidia simultaneously on short denticles (Fig.1D). Conidia were one celled, colorless or pale brown, mostlyellipsoid or ovoid, and 8.5−12.3 × 6.3−11.2 µm in size (Fig. 1E).These morphological characteristics of the present isolates coincidewith those of Botrytis cinerea described by Ellis and Waller (1974).To confirm the identification of the fungus, the partial internaltranscribed space (ITS) region of rDNA from the present isolate wasamplified using the primers ITS1 and ITS4 as described by White etal. (1990) and sequenced. The resulting sequences were comparedto the GenBank database using the NCBI BLAST search program.A total of 798 base sequences determined from the ITS DNA were100% identical to those of several Botryotinia fuckeliana (teleo-morph of Botrytis cineria) strains of NCBI accession nos.HM849615.1 HM84, 9047.1 HQ1, 66517.1 and, FN812726.1 in, dicat-ing the causal fungus was confirmed to be B. cinerea . For pathogenicity test, one-year-old stems of G. mihanovichiiwere inoculated with spore suspension (1 × 10

The Effect of Black Tea on Biomarkers of Metabolic Syndrome in High Fat Diet Fed Rats

Te mh bolictae ndrom sy obesndromyl saityr (viseec , ae)l a r e c s i v d by ze i r e t c a r cha , is s ete b 2 dia pe of ty use ca jor maobesity, insulin resistance or diabetes, hypertension, andplasma lipid and lipoprotein abnormalities [Bjorntorp,1991; Kissebah, 1991]. Feeding rats with a high fat dietover a 6-month period results in visceral obesitysyndrome, with development of gross visceral and wholebody obesity, impaired or diabetic glucose tolerance, andlipid and lipoprotein abnormalities [Han et al ., 1997].Other studies have shown that high fat diets increasedvisceral fat accumulation by 50%, but long before thedevelopm grosent f os obeH [ an tysi et al ., 1997; Z hater i etal ., 1997] In view of these findings, high fat diet appearsto induce insulinre sisatnce by a rapid incerase of visceralfat and cause visceral obesity [Kim et al ., 1999; Kim etal ., 2000]. Rodents fed high fat diet rapidly developimpaired intracellular glucose metabolism [Kim et al .,1996], visceral obesity, whole body and skeletal muscleinsulin resistance, hyperinsulinemia, hyperglycemia, andhyperlipidemia. When the high fat diet continuedsufficiently long in genetically susceptible animalsdevelop diabetes [Grundleger et al ., 1982; Han et al .,1997]. These findings suggest that high fat diet-fedrodents develop a visceral obesity syndrome that isequivalent to metabolic syndrome in humans [Carroll etal ., 1996; Han et al ., 1997]. ea prToducts have incerasnglyibeen studied for their possible protective effects againstmetabolic diseases. Recent studies showed beneficial gree osfcetfef n tea on cdiovasra ulcar di prksseileifoasrse [Kuriyama, 2008], and obesity [Zheng et al., 2004], andprotective effects of catechins in green tea on obesity[Bose et al. , 2008], blood cholesterol levels [Lee et al. ,2008; Matsuyama et al., 2008], ulcer [Hamaishi et al. ,006]2 , cancer [Isozaki and Tamura, 2001; Horie et al. ,2005] a, nd metabolic syndrome [Bose et al. , 2008;Ike da,008]2 in animals and humans have been reported.However, there are not many studies on black tea,because black tea has been assumed to contain lessercatechins than green tea. Black tea is prepared byfermenting green tea ( Camellia sinensis) , and catechinsof green tea are converted to other form of polyphenolsduring this process such as theaflavins that haveantioxidant effect [Luczaj and Skrzydlewska, 2004]. Ourprevious study [Jeon et al. , 2005] showed that black teaextract (BTE) had anti-obese effect by mechanismBTE inhibitd e t. c a r t x a e n te ee omr r g f t n e r e f f i d -amyaselactivity rather than lipase activity, but green tea did viceversa. Therefore, this study was undertaken to evaluatethe effect of black tea extract on biomarkers of themetabolic syndrome, and the role of theaflavins in BTE inhibitino on of t high anf i estiviti and lipacmaeasla- y e set feidd rats.