• Biomolecules & Therapeutics
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• 제27권6호
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• pp.553-561
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• 2019

Rab25, a member of the Rab11 small GTPase family, is central to achieving cellular polarity in epithelial tissues. Rab25 is highly expressed in epithelial cells of various tissues including breast, vagina, cervix, the gastrointestinal tract, and skin. Rab25 plays key roles in tumorigenesis, mainly by regulating epithelial differentiation and proliferation. However, its role in skin physiology is relatively unknown. In this study, we demonstrated that Rab25 knock-out (KO) mice show a skin barrier dysfunction with high trans-epidermal water loss and low cutaneous hydration. To examine this observation, we investigated the histology and epidermal differentiation markers of the skin in Rab25 KO mice. Rab25 KO increased cell proliferation at the basal layer of epidermis, whereas the supra-basal layer remained unaffected. Ceramide, which is a critical lipid component for skin barrier function, was not altered by Rab25 KO in its distribution or amount, as determined by immunohistochemistry. Notably, levels of epidermal differentiation markers, including loricrin, involucrin, and keratins (5, 14, 1, and 10) increased prominently in Rab25 KO mice. In line with this, depletion of Rab25 with single hairpin RNA increased the expression of differentiation markers in a human keratinocyte cell line, HaCaT. Transcriptomic analysis of the skin revealed increased expression of genes associated with skin development, epidermal development, and keratinocyte differentiation in Rab25 KO mice. Collectively, these results suggested that Rab25 is involved in the regulation of epidermal differentiation and proliferation.

• 한국발생생물학회지:발생과생식
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• 제26권2호
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• pp.71-77
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• 2022

In response to luteinizing hormone (LH), a higher concentration of progesterone (P4) is produced in luteal cells of corpus luteum (CL). Mitochondria are an essential cellular organelle in steroidogenesis. The specific engagement of the concept regarding mitochondrial shaping with early stages of steroidogenesis was suggested in reproductive endocrine cells. Although the specific involvement of GTPase dynamin-related protein 1 (Drp1) with steroidogenesis has been demonstrated in luteal cells of bovine CL in vitro, its actual relationship with ovarian steroidogenesis during the estrous cycle remains unknown. In this study, while Fis1 and Opa1 protein levels did not show significant changes during the estrous cycle, Drp1, Mfn1, and Mfn2 proteins exhibited relatively lower levels at proestrus than at estrus or diestrus. 3β-HSD showed higher levels at proestrus than at estrus or diestrus. In addition, Drp1 phosphorylation (s637) was higher in proestrus than in estrus or diestrus. Immune-positive cells for Drp1, pDrp1 (s637), and 3β-HSD were all localized in the cytoplasm of luteal cells in the CL. The immune-positive cells for 3β-HSD were more frequently seen in the CL at proestrus than at estrus or diestrus. Immunoreactivity for Drp1 in luteal cells at proestrus was weaker than that at estrus or diestrus. However, pDrp1 (s637) immune-positive cells were mostly detected in luteal cells at proestrus. These results imply that steroidogenesis (P4 production) in the CL is closely related to phosphorylation of Drp1 at serine 637. Taken together, this study presents evidence that Drp1 phosphorylation at serine 637 is an important step in steroidogenesis in the CL.

• Molecules and Cells
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• 제44권7호
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• pp.458-467
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• 2021

GPR43 (also known as FFAR2 or FFA2) is a G-protein-coupled receptor primarily expressed in immune cells, enteroendocrine cells and adipocytes that recognizes short-chain fatty acids, such as acetate, propionate, and butyrate, likely to be implicated in innate immunity and host energy homeostasis. Activated GPR43 suppresses the cAMP level and induces Ca²⁺ flux via coupling to Gα_i and Gα_q families, respectively. Additionally, GPR43 is reported to facilitate phosphorylation of ERK through G-protein-dependent pathways and interacts with β-arrestin 2 to inhibit NF-κB signaling. However, other G-protein-dependent and independent signaling pathways involving GPR43 remain to be established. Here, we have demonstrated that GPR43 augments Rho GTPase signaling. Acetate and a synthetic agonist effectively activated RhoA and stabilized YAP/TAZ transcriptional coactivators through interactions of GPR43 with Gα_q/11 and Gα_12/13. Acetate-induced nuclear accumulation of YAP was blocked by a GPR43-specific inverse agonist. The target genes induced by YAP/TAZ were further regulated by GPR43. Moreover, in THP-1-derived M1-like macrophage cells, the Rho-YAP/TAZ pathway was activated by acetate and a synthetic agonist. Our collective findings suggest that GPR43 acts as a mediator of the Rho-YAP/TAZ pathway.

• 대한예방한의학회지
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• 제27권2호
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• pp.35-48
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• 2023

Objective : We studied prognostic biomarkers discovery for lung cancer based on the pattern identification for the personalized Korean medicine. Methods : Using 30 tissue samples, we performed a whole exome sequencing to examine the genetic differences among three groups. Results : The exome sequencing identified among 23,490 SNPs germline variants, 12 variants showed significant frequency differences between Xu and Stasis groups (P<0.0005). As similar, 18 and 10 variants were identified in analysis for Xu vs. Gentleness group and Stasis vs. Gentleness group, respectively (P<0.001). Our exome sequencing also found 8,792 lung cancer specific variants and among the groups identified 6, 34, and 12 variants which showed significant allele frequency differences in the comparison groups; Xu vs. Stasis, Xu vs. Gentleness group, and Stasis vs. Gentleness group. As a result of PCA analysis, in germline data set, Xu group was divided from other groups. Analysis using somatic variants also showed similar result. And in gene ontology analysis using pattern identification variants, we found genes like as FUT3, MYCBPAP, and ST5 were related to tumorigenicity, and tumor metastasis in comparison between Xu and Stasis. Other significant SNPs for two were responsible for eye morphogenesis and olfactory receptor activity. Classification of somatic pattern identification variants showed close relationship in multicellular organism reproduction, anion-anion antiporter activity, and GTPase regulator activity. Conclusions : Taken together, our study identified 40 variants in 29 genes in association with germline difference of pattern identification groups and 52 variants in 47 genes in somatic cancer tissues.

• Animal Bioscience
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• 제37권3호
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• pp.461-470
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• 2024

Objective: The objective of this study was to investigate the genetic diversity, population structure and whole-genome selection signatures of Luxi cattle to reveal its genomic characteristics in terms of meat and carcass traits, skeletal muscle development, body size, and other traits. Methods: To further analyze the genomic characteristics of Luxi cattle, this study sequenced the whole-genome of 16 individuals from the core conservation farm in Shandong region, and collected 174 published genomes of cattle for conjoint analysis. Furthermore, three different statistics (pi, F_st, and XP-EHH) were used to detect potential positive selection signatures related to selection in Luxi cattle. Moreover, gene ontology and Kyoto encyclopedia of genes and genomes pathway enrichment analyses were performed to reveal the potential biological function of candidate genes harbored in selected regions. Results: The results showed that Luxi cattle had high genomic diversity and low inbreeding levels. Using three complementary methods (pi, F_st, and XP-EHH) to detect the signatures of selection in the Luxi cattle genome, there were 2,941, 2,221 and 1,304 potentially selected genes identified, respectively. Furthermore, there were 45 genes annotated in common overlapping genomic regions covered 0.723 Mb, including PLAG1 zinc finger (PLAG1), dedicator of cytokinesis 3 (DOCK3), ephrin A2 (EFNA2), DAZ associated protein 1 (DAZAP1), Ral GTPase activating protein catalytic subunit alpha 1 (RALGAPA1), mediator complex subunit 13 (MED13), and decaprenyl diphosphate synthase subunit 2 (PDSS2), most of which were enriched in pathways related to muscle growth and differentiation and immunity. Conclusion: In this study, we provided a series of genes associated with important economic traits were found in positive selection regions, and a scientific basis for the scientific conservation and genetic improvement of Luxi cattle.

• Animal Bioscience
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• 제37권4호
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• pp.576-590
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• 2024

Objective: The objective of this study was to identify genes associated with 305-day milk yield (MY) and fat yield (FY) that also influence the adaptability of the Thai multibreed dairy cattle population to tropical conditions. Methods: A total of 75,776 imputed and actual single nucleotide polymorphisms (SNPs) from 2,661 animals were used to identify genomic regions associated with MY and FY using the single-step genomic best linear unbiased predictions. Fixed effects included herd-year-season, breed regression, heterosis regression and calving age regression effects. Random effects were animal additive genetic and residual. Individual SNPs with a p-value smaller than 0.05 were selected for gene mapping, function analysis, and quantitative trait loci (QTL) annotation analysis. Results: A substantial number of QTLs associated with MY (9,334) and FY (8,977) were identified by integrating SNP genotypes and QTL annotations. Notably, we discovered 17 annotated QTLs within the health and exterior QTL classes, corresponding to nine unique genes. Among these genes, Rho GTPase activating protein 15 (ARHGAP15) and catenin alpha 2 (CTNNA2) have previously been linked to physiological traits associated with tropical adaptation in various cattle breeds. Interestingly, these two genes also showed signs of positive selection, indicating their potential role in conferring tolerance to trypanosomiasis, a prevalent tropical disease. Conclusion: Our findings provide valuable insights into the genetic basis of MY and FY in the Thai multibreed dairy cattle population, shedding light on the underlying mechanisms of tropical adaptation. The identified genes represent promising targets for future breeding strategies aimed at improving milk and fat production while ensuring resilience to tropical challenges. This study significantly contributes to our understanding of the genetic factors influencing milk production and adaptability in dairy cattle, facilitating the development of sustainable genetic selection strategies and breeding programs in tropical environments.

• BMB Reports
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• 제57권6호
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• pp.293-298
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• 2024

Microtubule acetylation has been shown to regulate actin filament dynamics by modulating signaling pathways that control actin organization, although the precise mechanisms remain unknown. In this study, we found that the downregulation of microtubule acetylation via the disruption ATAT1 (which encodes α-tubulin N-acetyltransferase 1) inhibited the expression of RhoA, a small GTPase involved in regulating the organization of actin filaments and the formation of stress fibers. Analysis of RHOA promoter and chromatin immunoprecipitation assays revealed that C/EBPβ is a major regulator of RHOA expression. Interestingly, the majority of C/EBPβ in ATAT1 knockout (KO) cells was found in the nucleus as a 27-kDa fragment (referred to as C/EBPβ^p27) lacking the N-terminus of C/EBPβ. Overexpression of a gene encoding a C/EBPβ^p27-mimicking protein via an N-terminal deletion in C/EBPβ led to competitive binding with wild-type C/EBPβ at the C/EBPβ binding site in the RHOA promoter, resulting in a significant decrease of RHOA expression. We also found that cathepsin L (CTSL), which is overexpressed in ATAT1 KO cells, is responsible for C/EBPβ^p27 formation in the nucleus. Treatment with a CTSL inhibitor led to the restoration of RHOA expression by downregulation of C/EBPβ^p27 and the invasive ability of ATAT1 KO MDA-MB-231 breast cancer cells. Collectively, our findings suggest that the downregulation of microtubule acetylation associated with ATAT1 deficiency suppresses RHOA expression by forming C/EBPβ^p27 in the nucleus through CTSL. We propose that CTSL and C/EBPβ^p27 may represent a novel therapeutic target for breast cancer treatment.

• Parasites, Hosts and Diseases
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• 제62권3호
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• pp.281-293
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• 2024

We previously reported that leukotriene B₄ (LTB₄) contained in Trichomonas vaginalis-derived secretory products (TvSP) play an essential role in interleukin-8 (IL-8) production in human mast cell line (HMC-1 cells) via LTB₄ receptor (BLT)-mediated Nuclear Factor-kappa B (NF-κB) activation. Dynamin, a GTPase, has been known to be involved in endocytosis of receptors for signaling of production of cytokine or chemokines. In the present study, we investigated the role of dynamin-mediated BLT1 endocytosis in TvSP-induced IL-8 production. When HMC-1 cells were transfected with BLT1 or BLT2 siRNA, TvSP-induced IL-8 production was significantly inhibited compared with that in cells transfected with control siRNA. In addition, pretreatment of HMC-1 cells with a dynamin inhibitor (Dynasore) reduced IL-8 production induced by TvSP or LTB₄. TvSP- or LTB₄-induced phosphorylation of NF-κB was also attenuated by pretreatment with Dynasore. After exposing HMC-1 cells to TvSP or LTB₄, BLT1 was translocated from the intracellular compartments to the plasma membrane within 30 min. At 60 min after stimulation with TvSP or LTB₄, BLT1 remigrated from the cell surface to intracellular areas. Pretreatment of HMC-1 cells with dynamin-2 siRNA blocked internalization of BLT1 induced by TvSP or LTB₄. Co-immunoprecipitation experiments revealed that dynamin-2 strongly interacted with BLT1 60 min after stimulation with TvSP or LTB₄. These results suggest that T. vaginalis-secreted LTB₄ induces IL-8 production in HMC-1 cells via dynamin 2-mediated endocytosis of BLT1 and phosphorylation of NF-κB.

• 분석과학
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• 제24권6호
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• pp.527-532
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• 2011

IQGAP1은 세포 내에서 암세포화, 세포이동과 같은 다양한 기능을 수행하고 있으며, $Ca^{2+}$-비의존성 calmodulin (CaM) 결합 단백질로 잘 알려져 있다. IQGAP1내에는 IQ부위가 4 번 반복해서 나타나는데, 이 부위가 IQGAP1의 CaM 결합에 중요한 역할을 한다고 알려져 있다. 이전의 연구를 통해 4개의 IQ 부위 모두 $Ca^{2+}$/CaM과의 결합에 관여하고, IQ3와 IQ4는 $Ca^{2+}$이 결합되지 않는 상태의 CaM인 proCaM 결합에 관여 한다고 알려져 있다. 그러나, 이러한 각각의 IQ 부위와의 결합성이 CaM과 직접적인 결합인지, 아니면 다른 단백질이 매개하는 간접적인 결합인지 알려져 있지 않았다. 따라서, 본 연구에서는 IQGAP1의 각각의 IQ 부위와 CaM의 결합성을 직접적으로 알아보기 의해 in vitro에서 조사해 보았다. 그 결과, 흥미롭게도 이전의 결과와는 다르게 4개의 IQ 부위 중에서 IQ3는 의미있는 $Ca^{2+}$-비의존성 CaM결합성이 있음을 알게 되었고, IQ1는 약한 $Ca^{2+}$-의존성 CaM 결합성이 있음을 알게 되었다. 반면에, 다른 IQ 부위들은 CaM과의 결합력이 약하거나 없음을 확인하였다. 또한, 기존의 IQ 부위 이외에 IQ(2.7-3)과 IQ(3.5-4.4) 부위가 의미있는 CaM 결합성이 있음을 확인하게 되었다. 따라서, 본 연구 결과 CaM이 IQGAP1을 기존의 보고와는 다른 방식으로 조절할 수 있을 가능성이 있음을 알게 되었고, 새로운 결합 부위 동정을 통해 IQGAP1과 CaM의 결합이 미치는 생리학적인 의미를 연구할 수 있는 토대를 마련하였다.

• Journal of Nutrition and Health
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• 제53권1호
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• pp.1-12
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• 2020

본 연구에서는 고혈당으로 인해 유발되는 당뇨병성 신장병증의 대표적인 증상인 사구체 경화증을 완화시키는 nobiletin의 효능에 대해 알아보고자 하였다. 신장 세포인 HRMC를 이용하여 고혈당에서의 세포외 기질 축적 단백질의 발현과 경화에 관여하는 신호 전달 억제 효능을 확인한 결과 nobiletin은 고혈당의 자극에 의해 증가하는 섬유화 단백질인 collagen IV, fibronectin 그리고 CTGF의 발현을 억제하였으며, 여기에 관여하는 TGF-β1-Src-caveolin-1 신호 전달 경로를 통해 사구체 경화증을 억제하는 것을 확인하였다. 따라서 nobiletin은 고혈당으로 유도된 당뇨병성 신장병증에 있어 사구체 경화증을 예방하는 기능성 성분으로서의 활용 가능성을 확인하였다.