Pub Date : 2023-01-01DOI: 10.2220/biomedres.44.209
Miho Kanazashi, Masayuki Tanaka
Electrical stimulation (ES) is effective for disuse-induced muscle atrophy. However, the acute effect of ES on muscle protein synthesis (MPS) and muscle protein breakdown (MPB) remains unclear. We investigated the effect of a single-session ES treatment on mTORC1 signaling, MPS, and MPB in the soleus muscle of 2-week hindlimb unloaded rats. Sprague Dawley rats (n = 12 male) were randomly divided into control (CON) and hindlimb unloaded (HU) groups. After 2 weeks, the right soleus muscle was percutaneously stimulated and underwent supramaximal isometric contractions. The left soleus muscle served as an internal control. We collected soleus muscle samples 6 h after ES. Two weeks of HU decreased p70S6K and S6rp activation, downstream factors for mTORC1 signaling, and SUnSET method-assessed MPS, but increased the LC3-II/I ratio, an indicator of autophagy. ES on disused muscle successfully activated mTORC1 signaling but did not affect MPS. Contrary, ES decreased ubiquitinated proteins expression and LC3B-II/I ratio. HU might affect mTORC1 activation and MPS differently in response to acute ES possibly due to excessive ROS production caused by ES. Our findings suggest that ES applied to disused skeletal muscles may suppress MPB, but its effect on MPS appears to be attenuated.
{"title":"Acute effect of electrical stimulation on muscle protein synthesis and break-down in the soleus muscle of hindlimb unloaded rats.","authors":"Miho Kanazashi, Masayuki Tanaka","doi":"10.2220/biomedres.44.209","DOIUrl":"https://doi.org/10.2220/biomedres.44.209","url":null,"abstract":"<p><p>Electrical stimulation (ES) is effective for disuse-induced muscle atrophy. However, the acute effect of ES on muscle protein synthesis (MPS) and muscle protein breakdown (MPB) remains unclear. We investigated the effect of a single-session ES treatment on mTORC1 signaling, MPS, and MPB in the soleus muscle of 2-week hindlimb unloaded rats. Sprague Dawley rats (n = 12 male) were randomly divided into control (CON) and hindlimb unloaded (HU) groups. After 2 weeks, the right soleus muscle was percutaneously stimulated and underwent supramaximal isometric contractions. The left soleus muscle served as an internal control. We collected soleus muscle samples 6 h after ES. Two weeks of HU decreased p70S6K and S6rp activation, downstream factors for mTORC1 signaling, and SUnSET method-assessed MPS, but increased the LC3-II/I ratio, an indicator of autophagy. ES on disused muscle successfully activated mTORC1 signaling but did not affect MPS. Contrary, ES decreased ubiquitinated proteins expression and LC3B-II/I ratio. HU might affect mTORC1 activation and MPS differently in response to acute ES possibly due to excessive ROS production caused by ES. Our findings suggest that ES applied to disused skeletal muscles may suppress MPB, but its effect on MPS appears to be attenuated.</p>","PeriodicalId":9138,"journal":{"name":"Biomedical Research-tokyo","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41106020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.2220/biomedres.44.245
Qinggen Xiong, Fei Lu, Xiaoming Xie, Wei Zhou
This study mainly used human VSMCs and ECs cultured in vitro to investigate whether exosomes (Exos) are involved in the communication between ECs and VSMCs under hypoxia, and to explore the role and mechanism of ECs-derived exosomes in the abnormal proliferation of VSMCs. VSMCs proliferation and migration were assessed by a series of cell function assays after culturing VSMCs alone or co-culturing ECs under hypoxia or normoxia. Next, exosomes were extracted from ECs under hypoxia or normoxia and characterized. We then introduced ECs-Exos to observe their effects on VSMCs proliferation and migration, and further evaluated the expression of transforming growth factor-beta receptor 1 (TGFBR1) pathway-related proteins. Finally, the effect of ECs-Exos on VSMCs function was evaluated after knocking down TGFBR1 in ECs. VSMCs treated with ECs-Exos exhibited increased proliferation and migration ability in hypoxic environment, and the expression of TGFBR1 pathway-related proteins was upregulated. Administration of ECs-Exos with TGFβ1 knockdown conspicuously reversed the promoting effects of ECs-Exos on cell proliferation and migration under hypoxia. In summary, hypoxia affected the secretion of extracellular vesicles by endothelial cells, which can be internalized by VSMCs and accelerate the abnormal proliferation and migration of VSMCs by delivering TGFBR1.
{"title":"Hypoxia-induced endothelial cell-derived exosome stimulates vascular smooth muscle cell proliferation and migration.","authors":"Qinggen Xiong, Fei Lu, Xiaoming Xie, Wei Zhou","doi":"10.2220/biomedres.44.245","DOIUrl":"10.2220/biomedres.44.245","url":null,"abstract":"<p><p>This study mainly used human VSMCs and ECs cultured in vitro to investigate whether exosomes (Exos) are involved in the communication between ECs and VSMCs under hypoxia, and to explore the role and mechanism of ECs-derived exosomes in the abnormal proliferation of VSMCs. VSMCs proliferation and migration were assessed by a series of cell function assays after culturing VSMCs alone or co-culturing ECs under hypoxia or normoxia. Next, exosomes were extracted from ECs under hypoxia or normoxia and characterized. We then introduced ECs-Exos to observe their effects on VSMCs proliferation and migration, and further evaluated the expression of transforming growth factor-beta receptor 1 (TGFBR1) pathway-related proteins. Finally, the effect of ECs-Exos on VSMCs function was evaluated after knocking down TGFBR1 in ECs. VSMCs treated with ECs-Exos exhibited increased proliferation and migration ability in hypoxic environment, and the expression of TGFBR1 pathway-related proteins was upregulated. Administration of ECs-Exos with TGFβ1 knockdown conspicuously reversed the promoting effects of ECs-Exos on cell proliferation and migration under hypoxia. In summary, hypoxia affected the secretion of extracellular vesicles by endothelial cells, which can be internalized by VSMCs and accelerate the abnormal proliferation and migration of VSMCs by delivering TGFBR1.</p>","PeriodicalId":9138,"journal":{"name":"Biomedical Research-tokyo","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138440302","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Intestinal transport of electrolytes is regulated by the enteric nervous system. Acetylcholine (ACh) is considered the most important neurotransmitter for electrolyte transport in the colon. However, electrolyte transport regulated by ACh is not fully understood in the colon. We investigated the regulation of electrogenic electrolyte transport by cholinergic agonists in the mouse colon by measuring the short-circuit current (Isc) using an Ussing chamber system. Muscarinic stimulation induced transient electrogenic Cl- secretion, and nicotinic stimulation induced electrogenic K+ secretion to the apical side in the normal mouse colon, and these effects were reduced in the colon of mice with food allergy (FA). Administration of prednisolone to mice with FA suppressed mild inflammation in the colon and allergic symptoms and thereby ameliorated the disruption of electrogenic electrolyte transport induced not only by cholinergic pathway activation but also by electrical field stimulation and intracellular cAMP signaling pathway activation in the colon. These results suggest that the electrogenic electrolyte transport function in the colon is impaired by FA-induced colonic inflammation and that the suppression of inflammation ameliorates the dysfunction of electrogenic electrolyte transport in the colon of mice with FA.
{"title":"Allergic inflammation disrupts epithelial electrogenic electrolyte transport through cholinergic regulation in the mouse colon.","authors":"Takeshi Yamamoto, Yosuke Katsuki, Yuya Kanauchi, Shusaku Hayashi, Makoto Kadowaki","doi":"10.2220/biomedres.44.31","DOIUrl":"https://doi.org/10.2220/biomedres.44.31","url":null,"abstract":"<p><p>Intestinal transport of electrolytes is regulated by the enteric nervous system. Acetylcholine (ACh) is considered the most important neurotransmitter for electrolyte transport in the colon. However, electrolyte transport regulated by ACh is not fully understood in the colon. We investigated the regulation of electrogenic electrolyte transport by cholinergic agonists in the mouse colon by measuring the short-circuit current (Isc) using an Ussing chamber system. Muscarinic stimulation induced transient electrogenic Cl- secretion, and nicotinic stimulation induced electrogenic K+ secretion to the apical side in the normal mouse colon, and these effects were reduced in the colon of mice with food allergy (FA). Administration of prednisolone to mice with FA suppressed mild inflammation in the colon and allergic symptoms and thereby ameliorated the disruption of electrogenic electrolyte transport induced not only by cholinergic pathway activation but also by electrical field stimulation and intracellular cAMP signaling pathway activation in the colon. These results suggest that the electrogenic electrolyte transport function in the colon is impaired by FA-induced colonic inflammation and that the suppression of inflammation ameliorates the dysfunction of electrogenic electrolyte transport in the colon of mice with FA.</p>","PeriodicalId":9138,"journal":{"name":"Biomedical Research-tokyo","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9145537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tactile perception via whiskers is important in rodent behavior. Whisker trimming during the neonatal period affects mouse behaviors related to both whisker-based tactile cognition and social performance. However, the molecular basis of these phenomena is not completely understood. To solve this issue, we investigated developmental changes in transmitters and metabolites in various brain regions of male mice subjected to bilateral whisker trimming during the neonatal period (10 days after birth [BWT10 mice]). We discovered significantly lower levels of 3-methoxy-4-hydroxyphenyl glycol (MHPG), the major noradrenaline metabolite, in various brain regions of male BWT10 mice at both early/late adolescent stages (at P4W and P8W). However, reduced levels of dopamine (DA) and their metabolites were more significantly identified at P8W in the nuclear origins of monoamine (midbrain and medulla oblongata) and the limbic system (frontal cortex, amygdala, and hippocampus) than at P4W. Furthermore, the onset of social behavior deficits (P6W) was observed later to the impairment of whisker-based tactile cognitive behaviors (P4W). Taken together, these findings suggest that whisker-mediated tactile cognition may contribute toprogressive abnormalities in social behaviors in BWT10 mice accompanied by impaired development of dopaminergic systems.
{"title":"Neonatal bilateral whisker trimming in male mice age-dependently alters brain neurotransmitter levels and causes adolescent onsets of social behavior abnormalities.","authors":"Hiroyasu Murasawa, Hitomi Soumiya, Hiroyuki Kobayashi, Jun Imai, Takahiko Nagase, Hidefumi Fukumitsu","doi":"10.2220/biomedres.44.147","DOIUrl":"https://doi.org/10.2220/biomedres.44.147","url":null,"abstract":"<p><p>Tactile perception via whiskers is important in rodent behavior. Whisker trimming during the neonatal period affects mouse behaviors related to both whisker-based tactile cognition and social performance. However, the molecular basis of these phenomena is not completely understood. To solve this issue, we investigated developmental changes in transmitters and metabolites in various brain regions of male mice subjected to bilateral whisker trimming during the neonatal period (10 days after birth [BWT10 mice]). We discovered significantly lower levels of 3-methoxy-4-hydroxyphenyl glycol (MHPG), the major noradrenaline metabolite, in various brain regions of male BWT10 mice at both early/late adolescent stages (at P4W and P8W). However, reduced levels of dopamine (DA) and their metabolites were more significantly identified at P8W in the nuclear origins of monoamine (midbrain and medulla oblongata) and the limbic system (frontal cortex, amygdala, and hippocampus) than at P4W. Furthermore, the onset of social behavior deficits (P6W) was observed later to the impairment of whisker-based tactile cognitive behaviors (P4W). Taken together, these findings suggest that whisker-mediated tactile cognition may contribute toprogressive abnormalities in social behaviors in BWT10 mice accompanied by impaired development of dopaminergic systems.</p>","PeriodicalId":9138,"journal":{"name":"Biomedical Research-tokyo","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9943307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.2220/biomedres.44.173
Yasuyuki Sasano, Alu Konno, Megumi Nakamura, Akiko Henmi, Miyuki Mayanagi, Mu-Chen Yang, Ikuko Yao
Matrix-assisted laser desorption/ionization imaging mass spectrometry (IMS) is used to comprehensively visualize the spatial distribution of numerous biomolecules. The present study was designed to investigate the distribution of phospholipids in developing rat teeth by IMS to identify the characteristic phospholipid molecules for tooth development, and to evaluate the suitability of tissue preparation methods. Rats at postnatal day 3 were euthanized, and the resected head specimens were either fixed or not fixed with 4% paraformaldehyde (PFA), and decalcified or not decalcified in 10% ethylenediaminetetraacetic acid (EDTA) before being frozen. Subsequently, sections were prepared and mounted on glass slides coated with indium tin oxide, and analyzed by IMS. The mass spectra showed the highest peaks around m/z 706, 732, and 734 in the region of interest. Characteristic localization of signals in the tooth buds was seen around m/z 706 and 732, and a database search indicated that the corresponding molecules were phosphatidylcholines. The signals were localized to the dental papillae and enamel epithelia in the tooth buds. The PFA-fixed specimens with or without EDTA decalcification showed preserved IMS signals, while the non-fixed specimens showed fewer signals. Thus, PFA fixation with EDTA decalcification appears to be suitable for IMS analysis of calcified tissues.
{"title":"Visualization of the localization of phospholipids in developing rat teeth by matrix-assisted laser desorption/ionization imaging mass spectrometry.","authors":"Yasuyuki Sasano, Alu Konno, Megumi Nakamura, Akiko Henmi, Miyuki Mayanagi, Mu-Chen Yang, Ikuko Yao","doi":"10.2220/biomedres.44.173","DOIUrl":"https://doi.org/10.2220/biomedres.44.173","url":null,"abstract":"<p><p>Matrix-assisted laser desorption/ionization imaging mass spectrometry (IMS) is used to comprehensively visualize the spatial distribution of numerous biomolecules. The present study was designed to investigate the distribution of phospholipids in developing rat teeth by IMS to identify the characteristic phospholipid molecules for tooth development, and to evaluate the suitability of tissue preparation methods. Rats at postnatal day 3 were euthanized, and the resected head specimens were either fixed or not fixed with 4% paraformaldehyde (PFA), and decalcified or not decalcified in 10% ethylenediaminetetraacetic acid (EDTA) before being frozen. Subsequently, sections were prepared and mounted on glass slides coated with indium tin oxide, and analyzed by IMS. The mass spectra showed the highest peaks around m/z 706, 732, and 734 in the region of interest. Characteristic localization of signals in the tooth buds was seen around m/z 706 and 732, and a database search indicated that the corresponding molecules were phosphatidylcholines. The signals were localized to the dental papillae and enamel epithelia in the tooth buds. The PFA-fixed specimens with or without EDTA decalcification showed preserved IMS signals, while the non-fixed specimens showed fewer signals. Thus, PFA fixation with EDTA decalcification appears to be suitable for IMS analysis of calcified tissues.</p>","PeriodicalId":9138,"journal":{"name":"Biomedical Research-tokyo","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9943309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.2220/biomedres.44.181
Ryosuke Seino, Hiroto Uno, Hisanori Fukunaga
The cell cycle is a series of events in the process of one cell giving rise to two daughter cells. The mitotic harvesting method, established by Terasima and Tolmach in the 1960s, causes minimal physiological stress on the cells and achieves a high degree of cell cycle synchrony by collecting only mitotic cells from a cultured cell system. The purpose of the present study is to validate the versatility of the mitotic harvesting method using human cervical cell line HeLa cells expressing Fluorescent Ubiquitination-based Cell Cycle Indicators (FUCCI) and to estimate the cell cycle-dependent changes in radiosensitivity in HeLa-FUCCI cells. The image analysis showed that cell cycle synchrony was maintained for at least 24 hours after mitotic cell collection. Also, the clonogenic assay demonstrated changes in radiosensitivity that were cell cycle dependent. These results indicate that the mitotic harvesting method using FUCCI-expressing cells has high versatility in the field of radiation cell biology.
{"title":"Validation of mitotic harvesting method with human cervical carcinoma HeLa cells expressing fluorescent ubiquitination-based cell cycle indicators for radiation research.","authors":"Ryosuke Seino, Hiroto Uno, Hisanori Fukunaga","doi":"10.2220/biomedres.44.181","DOIUrl":"10.2220/biomedres.44.181","url":null,"abstract":"The cell cycle is a series of events in the process of one cell giving rise to two daughter cells. The mitotic harvesting method, established by Terasima and Tolmach in the 1960s, causes minimal physiological stress on the cells and achieves a high degree of cell cycle synchrony by collecting only mitotic cells from a cultured cell system. The purpose of the present study is to validate the versatility of the mitotic harvesting method using human cervical cell line HeLa cells expressing Fluorescent Ubiquitination-based Cell Cycle Indicators (FUCCI) and to estimate the cell cycle-dependent changes in radiosensitivity in HeLa-FUCCI cells. The image analysis showed that cell cycle synchrony was maintained for at least 24 hours after mitotic cell collection. Also, the clonogenic assay demonstrated changes in radiosensitivity that were cell cycle dependent. These results indicate that the mitotic harvesting method using FUCCI-expressing cells has high versatility in the field of radiation cell biology.","PeriodicalId":9138,"journal":{"name":"Biomedical Research-tokyo","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41106680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study aimed to explore the potential roles of fractalkine/CX3CR1, primarily expressed in vascular endothelial cells and has recently been identified in dental pulp cells at sites of pulp tissue inflammation, not only in inflammation but also in pulp hard tissue formation. To this end, cultured human dental pulp cells were grown in 10% FBS-supplemented α-MEM. Fractalkine was introduced to the culture, and COX-2 and dentin sialophosphoprotein (DSPP) expression levels were evaluated via western blotting. Real-time PCR was used to examine BMP-2 and Osterix mRNA expression. Calcified nodule formation was evaluated with Alizarin red staining. Results revealed that fractalkine increased COX-2 protein expression, calcified nodule formation, and BMP-2 and Osterix mRNA expression in a concentration- and time-dependent manner. DSPP protein expression also increased upon fractalkine addition. This effect of fractalkine on expression of DSPP protein was inhibited in the presence of the CX3CR1 inhibiter ADZ8797. In conclusion, our findings suggest a dual role for fractalkine in promoting pulp inflammation via COX-2 production and contributing to pulp hard tissue formation by stimulating the expression of hard tissue formation markers.
{"title":"Fractalkine's dual role in inflammation and hard tissue formation in cultured human dental pulp cells.","authors":"Natsuko Gomyo-Furuya, Naoto Kamio, Takahiro Watanabe, Tomomi Hayama, Joji Fukai, Kosei Kuramochi, Kento Nakanishi, Arata Watanabe, Tatsu Okabe, Kiyoshi Matsushima","doi":"10.2220/biomedres.44.257","DOIUrl":"10.2220/biomedres.44.257","url":null,"abstract":"<p><p>This study aimed to explore the potential roles of fractalkine/CX3CR1, primarily expressed in vascular endothelial cells and has recently been identified in dental pulp cells at sites of pulp tissue inflammation, not only in inflammation but also in pulp hard tissue formation. To this end, cultured human dental pulp cells were grown in 10% FBS-supplemented α-MEM. Fractalkine was introduced to the culture, and COX-2 and dentin sialophosphoprotein (DSPP) expression levels were evaluated via western blotting. Real-time PCR was used to examine BMP-2 and Osterix mRNA expression. Calcified nodule formation was evaluated with Alizarin red staining. Results revealed that fractalkine increased COX-2 protein expression, calcified nodule formation, and BMP-2 and Osterix mRNA expression in a concentration- and time-dependent manner. DSPP protein expression also increased upon fractalkine addition. This effect of fractalkine on expression of DSPP protein was inhibited in the presence of the CX3CR1 inhibiter ADZ8797. In conclusion, our findings suggest a dual role for fractalkine in promoting pulp inflammation via COX-2 production and contributing to pulp hard tissue formation by stimulating the expression of hard tissue formation markers.</p>","PeriodicalId":9138,"journal":{"name":"Biomedical Research-tokyo","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138440247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Silibinin is a flavonolignan isolated from milk thistle (Silybum marianum). Silibinin has been reported to possess multiple biological activities; however, its effect on melanogenesis remains unclear. This study investigated the effect of silibinin on melanogenesis in melanoma cells and the associated molecular mechanism. Our findings demonstrated that silibinin markedly increased melanin content in murine B16-F1 and human HMV-II melanoma cells. Silibinin activated intracellular tyrosinase activity and expression of tyrosinase, tyrosinase-related protein (TRP)-1, TRP-2, and microphthalmia-associated transcription factor (MITF). Furthermore, silibinin enhanced the phosphorylation of cyclic AMP-responsive element-binding protein (CREB), protein kinase A (PKA), and p38 mitogen-activated protein kinase (MAPK) but not of Akt and extracellular signal-regulated kinase (ERK). The specific PKA (H-89) and p38 (SB203580) inhibitors significantly attenuated silibinin-mediated melanin synthesis. These results suggest that silibinin is an effective stimulator of melanogenesis through upregulation of the protein expression of melanogenic enzymes activated by the PKA and p38 pathways, leading to CREB phosphorylation and MITF expression. Therefore, silibinin may have potential for use in the treatment of hypopigmentation disorders.
{"title":"Silibinin promotes melanogenesis through the PKA and p38 MAPK signaling pathways in melanoma cells.","authors":"T. Uto, Tomoe Ohta, Koki Katayama, Y. Shoyama","doi":"10.2220/biomedres.43.31","DOIUrl":"https://doi.org/10.2220/biomedres.43.31","url":null,"abstract":"Silibinin is a flavonolignan isolated from milk thistle (Silybum marianum). Silibinin has been reported to possess multiple biological activities; however, its effect on melanogenesis remains unclear. This study investigated the effect of silibinin on melanogenesis in melanoma cells and the associated molecular mechanism. Our findings demonstrated that silibinin markedly increased melanin content in murine B16-F1 and human HMV-II melanoma cells. Silibinin activated intracellular tyrosinase activity and expression of tyrosinase, tyrosinase-related protein (TRP)-1, TRP-2, and microphthalmia-associated transcription factor (MITF). Furthermore, silibinin enhanced the phosphorylation of cyclic AMP-responsive element-binding protein (CREB), protein kinase A (PKA), and p38 mitogen-activated protein kinase (MAPK) but not of Akt and extracellular signal-regulated kinase (ERK). The specific PKA (H-89) and p38 (SB203580) inhibitors significantly attenuated silibinin-mediated melanin synthesis. These results suggest that silibinin is an effective stimulator of melanogenesis through upregulation of the protein expression of melanogenic enzymes activated by the PKA and p38 pathways, leading to CREB phosphorylation and MITF expression. Therefore, silibinin may have potential for use in the treatment of hypopigmentation disorders.","PeriodicalId":9138,"journal":{"name":"Biomedical Research-tokyo","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2022-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45388504","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Doi, Tomoyuki Hioki, Junko Tachi, K. Ueda, R. Matsushima‐Nishiwaki, H. Iida, S. Ogura, O. Kozawa, H. Tokuda
Bone fracture is an important trauma frequently encountered into emergency medicine as well as orthopedics reflecting an aging society. Oncostatin M, an inflammatory cytokine produced by osteal macrophages, has been considered to play a crucial role in fracture healing. Macrophage colony-stimulating factor (M-CSF) secreted from osteoblasts is essential in osteoclastgenesis, and the secretion is stimulated by transforming growth factor-β (TGF-β). The aim of this study is to elucidate the effects of oncostatin M on the TGF-β-induced M-CSF synthesis in osteoblast-like MC3T3-E1 cells and the underlying mechanisms. Oncostatin M attenuated the TGF-β-stimulated M-CSF release and the mRNA expressions. SMAD3 inhibitor SIS3, p38 MAP kinase inhibitor SB203580, MEK1/2 inhibitor PD98059, and SAPK/JNK inhibitor SP600125 significantly suppressed the M-CSF release. Oncostatin M suppressed the TGF-β-induced phosphorylation of p44/p42 MAP kinase and SAPK/JNK, but failed to affect the phosphorylation of SMAD3 and p38 MAP kinase. Oncostatin M attenuated the TGF-β-stimulated vascular endothelial growth factor (VEGF) release and the TGF-β-induced mRNA expressions of VEGF. These results strongly suggest that oncostatin M downregulates TGF-β signaling upstream of p44/p42 MAP kinase and SAPK/JNK, but not SMAD 2/3 and p38 MAP kinase, in osteoblasts, leading to the attenuation of M-CSF synthesis. Our findings might provide a new therapeutic strategy for the acceleration of fracture healing process.
{"title":"Oncostatin M reduces the synthesis of macrophage-colony stimulating factor stimulated by TGF-β via suppression of p44/p42 MAP kinase and JNK in osteoblasts.","authors":"T. Doi, Tomoyuki Hioki, Junko Tachi, K. Ueda, R. Matsushima‐Nishiwaki, H. Iida, S. Ogura, O. Kozawa, H. Tokuda","doi":"10.2220/biomedres.43.41","DOIUrl":"https://doi.org/10.2220/biomedres.43.41","url":null,"abstract":"Bone fracture is an important trauma frequently encountered into emergency medicine as well as orthopedics reflecting an aging society. Oncostatin M, an inflammatory cytokine produced by osteal macrophages, has been considered to play a crucial role in fracture healing. Macrophage colony-stimulating factor (M-CSF) secreted from osteoblasts is essential in osteoclastgenesis, and the secretion is stimulated by transforming growth factor-β (TGF-β). The aim of this study is to elucidate the effects of oncostatin M on the TGF-β-induced M-CSF synthesis in osteoblast-like MC3T3-E1 cells and the underlying mechanisms. Oncostatin M attenuated the TGF-β-stimulated M-CSF release and the mRNA expressions. SMAD3 inhibitor SIS3, p38 MAP kinase inhibitor SB203580, MEK1/2 inhibitor PD98059, and SAPK/JNK inhibitor SP600125 significantly suppressed the M-CSF release. Oncostatin M suppressed the TGF-β-induced phosphorylation of p44/p42 MAP kinase and SAPK/JNK, but failed to affect the phosphorylation of SMAD3 and p38 MAP kinase. Oncostatin M attenuated the TGF-β-stimulated vascular endothelial growth factor (VEGF) release and the TGF-β-induced mRNA expressions of VEGF. These results strongly suggest that oncostatin M downregulates TGF-β signaling upstream of p44/p42 MAP kinase and SAPK/JNK, but not SMAD 2/3 and p38 MAP kinase, in osteoblasts, leading to the attenuation of M-CSF synthesis. Our findings might provide a new therapeutic strategy for the acceleration of fracture healing process.","PeriodicalId":9138,"journal":{"name":"Biomedical Research-tokyo","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2022-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46053933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yuuki Horii, Kanako Okadera, Shingo Miyawaki, T. Shiina, Y. Shimizu
Torpor, a state of lowered body temperature due to active reduction of the metabolic rate, has potential medical benefits. The aim of this study was to establish a novel laboratory animal that enter torpor without imposing complex conditions. When house musk shrews (Suncus murinus) were kept at an ambient temperature of 24°C, most of the animals did not enter daily torpor. However, when the ambient temperature was lowered to below 20°C, all of the shrews showed torpor in the absence of fasting and short-day photoperiod. The shrews that were exposed to a stepwise decrease in ambient temperature from 24°C to 8°C entered torpor even after returning them to a room kept at 24°C. In conclusion, this study indicates that Suncus murinus may be a suitable model animal for elucidating the mechanism of daily torpor. Elucidation of the mechanisms of torpor by using this model may be useful for inducing a state of artificial hibernation in various species including humans.
{"title":"Suncus murinus as a novel model animal that is suitable for elucidating the mechanism of daily torpor.","authors":"Yuuki Horii, Kanako Okadera, Shingo Miyawaki, T. Shiina, Y. Shimizu","doi":"10.2220/biomedres.43.53","DOIUrl":"https://doi.org/10.2220/biomedres.43.53","url":null,"abstract":"Torpor, a state of lowered body temperature due to active reduction of the metabolic rate, has potential medical benefits. The aim of this study was to establish a novel laboratory animal that enter torpor without imposing complex conditions. When house musk shrews (Suncus murinus) were kept at an ambient temperature of 24°C, most of the animals did not enter daily torpor. However, when the ambient temperature was lowered to below 20°C, all of the shrews showed torpor in the absence of fasting and short-day photoperiod. The shrews that were exposed to a stepwise decrease in ambient temperature from 24°C to 8°C entered torpor even after returning them to a room kept at 24°C. In conclusion, this study indicates that Suncus murinus may be a suitable model animal for elucidating the mechanism of daily torpor. Elucidation of the mechanisms of torpor by using this model may be useful for inducing a state of artificial hibernation in various species including humans.","PeriodicalId":9138,"journal":{"name":"Biomedical Research-tokyo","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2022-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48454338","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}