• The Korean Journal of Physiology and Pharmacology
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• v.27 no.2
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• pp.157-165
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• 2023

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer and current therapeutic strategies are limited in their effectiveness. The expressions of Rab5 and the M2 tumor-associated macrophage marker CD163 in tissues were detected by Western blot. The migration and invasion of cells were determined using a Transwell assay. The expressions of the exosome markers were evaluated by Western blot. The polarization of human macrophages (THP-1) was determined by incubation of THP-1 cells with conditioned medium or exosomes collected from MDA-MB-231 cells with indicated transfections or by a coculture system of THP-1 and MDA-MB-231 cells. The M1 and M2 macrophage markers were evaluated by qRT-PCR. The expression of Rab5 in TNBC was significantly higher than that in normal breast tissue. Rab5 expressions in triple-negative and luminal A breast cancer were higher than those in other molecular subtypes. Higher CD163 expression was observed in triple-negative breast cancer and in triple-negative and luminal B subtypes. Rab5 knockdown suppressed but Rab5 overexpression promoted the migration and invasion capacity of MDA-MB-231 cells. The levels of CD63 and CD9 in the medium of Rab5 knockdown cells were lower than those in control cells, whereas higher levels of CD63 and CD9 were observed in Rab5 overexpression cells. Rab5 knockdown decreased the excretion but did not alter the diameter of the exosomes. Knockdown of Rab5 facilitated the anti-tumor polarization of macrophages, which was partially reversed by Rab5 overexpression. Therefore, Rab5 is expected to be a potential therapeutic target for triple-negative breast cancer.

• Journal of Animal Science and Technology
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• v.64 no.6
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• pp.1024-1034
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• 2022

Identifying effective biomarkers for the diagnosis of male fertility is crucial for improving animal production and treating male infertility in humans. Ras-related proteins (Rab) are associated with morphological and motion kinematic functions in spermatozoa. Moreover, Rab2A, a Rab protein, is a possible male fertility-related biomarker. The present study was designed to identify additional fertility-related biomarkers among the various Rab proteins. First, the expression of Rab proteins (Rab3A, 4, 5, 8A, 9, 14, 25, 27A, and 34A) from 31 duroc boar spermatozoa was measured before and after capacitation; correlation between Rab protein expression and litter size was evaluated by statistical analysis. The results showed that the expression of Rab3A, 4, 5, 8A, 9, and 25 before capacitation and Rab3A, 4, 5, 8A, 9, and 14 after capacitation were negatively correlated with litter size. Moreover, depending on the cutoff values calculated by receiver operating curves, an increase in litter size was observed when evaluating the ability of the Rab proteins to forecast litter size. Therefore, we suggest that Rab proteins may be potential fertility-related biomarkers that could help select superior sires in the livestock industry.

• Biomolecules & Therapeutics
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• v.27 no.6
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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.

• Herbal Formula Science
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• v.28 no.1
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• pp.81-90
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• 2020

Objectives : This study was conducted to investigate the effects of major constituents of Epimedium koreanum Nakai (Icariin, epimedium A, epimedium B, and epimedium C) on melanin synthesis. Methods : We measured melanin contents, tyrosinase activity, and expression of Rab27a in B16F10 cells cultured with Epimedium koreanum Nakai ethanol extract (EKN) and their major constituents. After treatment with H89 and dibutyryl cAMP, which inhibit or promote the activation of PKA, we observed changes in melanin synthesis and tyrosinase activity stimulated by EKN. Results : Among them, EKN and icariin enhanced tyrosinase activity and melanin contents. We confirmed that EKN augmented melanin synthesis via cAMP/PKA pathway. Icariin-induced tyrosinase activity and melanin content were attenuated by PKA inhibitor H89, while melanogenic effect of icariin was further augmented by cAMP analog, dbc AMP. However, icariin did not affect the expression of small GTPase Rab27a involved in melanosome transport. Conclusions : These results suggest that icariin promotes melanogenesis through cAMP/PKA pathway but does not affect small GTPase Rab27a.

• Clinical and Experimental Pediatrics
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• v.57 no.2
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• pp.91-95
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• 2014

Griscelli syndrome type 2 (GS2) is a rare autosomal recessive disease caused by mutations in the RAB27A gene. It is characterized by cutaneous hypopigmentation, immunodeficiency, and hemophagocytic lymphohistiocytosis. We describe 2 brothers who had GS2 with clinically diverse manifestations. The elder brother presented with a purely neurological picture, whereas the younger one presented with fever, pancytopenia, hepatosplenomegaly, and erythema nodosum. Considering that cutaneous hypopigmentation was a common feature between the brothers, genetic analysis for Griscelli syndrome was performed. As the elder sibling had died, mutation analysis was only performed on the younger sibling, which revealed a novel homozygous mutation in the RAB27A gene on chromosome 15 showing a single-base substitution (c.136T>A p.F46I). Both parents were heterozygous for the same mutation. This confirmed the diagnosis of GS2 in the accelerated phase in both siblings. The atypical features of GS2 in these cases are a novel mutation, isolated neurological involvement in one sibling, association with erythema nodosum, and 2 distinct clinical presentations in siblings with the same genetic mutation.

• Biomolecules & Therapeutics
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• v.21 no.5
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• pp.343-348
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• 2013

We investigated the inhibitory effects of hesperidin on melanogenesis. To find melanosome transport inhibitor from natural products, we collected the structural information of natural products from Korea Food and Drug Administration (KFDA) and performed pharmacophore-based in silico screening for Rab27A and melanophilin (MLPH). Hesperidin did not inhibit melanin production in B16F10 murine melanoma cells stimulated with ${\alpha}$-melanocyte stimulating hormone (${\alpha}$-MSH), and also did not affect the catalytic activity of tyrosinase. But, hesperidin inhibited melanosome transport in melanocyte and showed skin lightening effect in pigmented reconstructed epidermis model. Therefore, we suggest that hesperidin is a useful inhibitor of melanosome transport and it might be applied to whitening agent.

• Korea Journal of Cosmetic Science
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• v.1 no.1
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• pp.31-43
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• 2019

Melanosomes are specific melanin-containing intracellular organelles of epidermal melanocytes. In epidermal melanocytes, there are three kinds of key player proteins. Rab27a, melanophilin or Slac2-a and Myosin 5a form a tripartite complex connects the melanosome. Mature melanosomes make movements through the tripartite protein complex along actin filaments.In this study, we found that the haplamine (6-Methoxyflindersine) induced melanosome aggregation around the nucleus in epidermal melanocyte. In an attempt to elucidate the inhibitory effect of haplamine on melanosome transport, effect of haplamineon the expression level of Rab27a, melanophilin and Myosin 5a was measured. The results indicated that haplamine up to 5��M effectively suppressed mRNA and protein expression level of melanophilin.To determine the upstream regulator of melanophilin regulated by haplamine, we checked the level of MITF, c-JUN and USF1. Those are possible transcription factor of melanophilin. Among them,treatment of USF1 siRNA decreased mRNA and protein expression level of USF1 as well as melanophilin. Also, treatment of haplamine decreased mRNA and protein expression level of melanophilin as well as USF1 in a dose-dependent manner. Consequently, we found the inhibitory effect of haplamine on melanosome transport in melan-a melanocyte. Treatment of haplamine reduced melanophilin expression level which is a key protein of melanosome transport. We identified that USF1 could be a major transcription factor of melanophilin regulated by haplamine.

• Food Science and Preservation
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• v.31 no.2
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• pp.227-234
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• 2024

This study was designed to compare the whitening effects of 60% ethanol extracts of Trigonotis radicans var. sericea (TR) and Lactobacillus brevis-fermented T. radicans var. sericea (FTR). Measurement of cytotoxicity in B16-F10 melanoma cells to confirm the whitening effect, FTR showed higher cell viability than TR. FTR showed inhibitory activity on melanin contents similar to the normal group at concentrations of 50 and 100 ㎍/mL. MITF expression was used to confirm the effect on melanogenesis-related protein expression. TR and FTR showed significant concentration-dependent decrease, and FTR showed lower expressions than the normal group at concentrations of 25, 50, and 100 ㎍/mL. Additionally, the mRNA expression of melanogenesis-related genes (MC1R, Rab27a, TGF-β1 and Myo5a) were measured by RT-qPCR to confirm the whitening effect. In MC1R expression at a concentration of 100 ㎍/mL in FTR showed effective inhibitory activities, and in TGF-β1 expression, TR and FTR both showed effective activities compared to normal groups even at low concentrations. Results of myo5a and Rab27a, a similar pattern was shown, and FTR showed effective inhibitory activities at a concentration of 100 ㎍/mL. As a result, FTR had higher whitening effects through bioconversion and is expected to be a good material for whitening functional cosmetics.

• Biomolecules & Therapeutics
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• v.31 no.4
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• pp.466-472
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• 2023

Exon skipping is an efficient technique to inhibit specific gene expression induced by a short-sequence peptide nucleic acid (PNA). To date, there has been no study on the effects of PNA on skin pigmentation. In melanocytes, the tripartite complex is responsible for the transport of mature melanosomes from the nucleus to the dendrites. The tripartite complex is composed of Rab27a, Mlph (Melanophilin), and Myosin Va. Defects in the protein Mlph, a melanosome transport-related protein, are known to cause hypopigmentation. Our study shows that Olipass peptide nucleic acid (OPNA), a cell membrane-permeable PNA, targets exon skipping in the Mlph SHD domain, which is involved in Rab27a binding. Our findings demonstrate that OPNA induced exon skipping in melan-a cells, resulting in shortened Mlph mRNA, reduced Mlph protein levels, and melanosome aggregation, as observed by microscopy. Therefore, OPNA inhibits the expression of Mlph by inducing exon skipping within the gene. These results suggest that OPNA, which targets Mlph, may be a potential new whitening agent to inhibit melanosome movement.

• Biomedical Science Letters
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• v.5 no.1
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• pp.27-40
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• 1999

This study was focused on the evaluation of MarB alongside with MarA for its regulatory effects upon the efflux function of AcrAB pump, which were induced or not, perhaps as a target. Transductions of marR and/or acrAB mutation which were derived from Mar and/or AcrAB mutants of wild type E. coli K-12, respectively, into the multicopy plasmid in wild type E. coli backgrounds or into the chromosome of isogenic parents were done. Minimal inhibitory concentration (MIC) of transduced mutants was compared with their original mutants. This study reports the indirect evidences that suggests a model in which MarB along with MarA have a putative negative regulatory effect upon the efflux function of AcrAB/TolC pump while MarA alone have a positive regulatory effect to the expression of acrRAB operon at transcription level. The target of MarB with MarA for its putative negative regulator might be the AcrAB efflux pump. Another efflux system (s) might be negatively regulated by MarB with MarA, and be involved in the efflux of antibiotics which were otherwise extruded preferentially by AcrAB efflux pump.