• Title/Summary/Keyword: Cell biology

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Purification and Characterization of Mitochondrial Mg2+-Independent Sphingomyelinase from Rat Brain

  • Jong Min Choi;Yongwei Piao;Kyong Hoon Ahn;Seok Kyun Kim;Jong Hoon Won;Jae Hong Lee;Ji Min Jang;In Chul Shin;Zhicheng Fu;Sung Yun Jung;Eui Man Jeong;Dae Kyong Kim
    • Molecules and Cells
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    • v.46 no.9
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    • pp.545-557
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    • 2023
  • Sphingomyelinase (SMase) catalyzes ceramide production from sphingomyelin. Ceramides are critical in cellular responses such as apoptosis. They enhance mitochondrial outer membrane permeabilization (MOMP) through self-assembly in the mitochondrial outer membrane to form channels that release cytochrome c from intermembrane space (IMS) into the cytosol, triggering caspase-9 activation. However, the SMase involved in MOMP is yet to be identified. Here, we identified a mitochondrial Mg2+-independent SMase (mt-iSMase) from rat brain, which was purified 6,130-fold using a Percoll gradient, pulled down with biotinylated sphingomyelin, and subjected to Mono Q anion exchange. A single peak of mt-iSMase activity was eluted at a molecular mass of approximately 65 kDa using Superose 6 gel filtration. The purified enzyme showed optimal activity at pH of 6.5 and was inhibited by dithiothreitol and Mg2+, Mn2+, Ni2+, Cu2+, Zn2+, Fe2+, and Fe3+ ions. It was also inhibited by GW4869, which is a non-competitive inhibitor of Mg2+-dependent neutral SMase 2 (encoded by SMPD3), that protects against cytochrome c release-mediated cell death. Subfractionation experiments showed that mt-iSMase localizes in the IMS of the mitochondria, implying that mt-iSMase may play a critical role in generating ceramides for MOMP, cytochrome c release, and apoptosis. These data suggest that the purified enzyme in this study is a novel SMase.

The TGFβ→TAK1→LATS→YAP1 Pathway Regulates the Spatiotemporal Dynamics of YAP1

  • Min-Kyu Kim;Sang-Hyun Han;Tae-Geun Park;Soo-Hyun Song;Ja-Youl Lee;You-Soub Lee;Seo-Yeong Yoo;Xin-Zi Chi;Eung-Gook Kim;Ju-Won Jang;Dae Sik Lim;Andre J. van Wijnen;Jung-Won Lee;Suk-Chul Bae
    • Molecules and Cells
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    • v.46 no.10
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    • pp.592-610
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    • 2023
  • The Hippo kinase cascade functions as a central hub that relays input from the "outside world" of the cell and translates it into specific cellular responses by regulating the activity of Yes-associated protein 1 (YAP1). How Hippo translates input from the extracellular signals into specific intracellular responses remains unclear. Here, we show that transforming growth factor β (TGFβ)-activated TAK1 activates LATS1/2, which then phosphorylates YAP1. Phosphorylated YAP1 (p-YAP1) associates with RUNX3, but not with TEAD4, to form a TGFβ-stimulated restriction (R)-point-associated complex which activates target chromatin loci in the nucleus. Soon after, p-YAP1 is exported to the cytoplasm. Attenuation of TGFβ signaling results in re-localization of unphosphorylated YAP1 to the nucleus, where it forms a YAP1/TEAD4/SMAD3/AP1/p300 complex. The TGFβ-stimulated spatiotemporal dynamics of YAP1 are abrogated in many cancer cells. These results identify a new pathway that integrates TGFβ signals and the Hippo pathway (TGFβ→TAK1→LATS1/2→YAP1 cascade) with a novel dynamic nuclear role for p-YAP1.

Exploration of nutritional and bioactive peptide properties in goat meat from various primal cuts during in vitro gastrointestinal digestion and absorption

  • Pichitpon Luasiri;Papungkorn Sangsawad;Jaksuma Pongsetkul;Pramote Paengkoum;Chatsirin Nakharuthai;Saranya Suwanangul;Sasikan Katemala;Narathip Sujinda;Jukkrapong Pinyo;Jarunan Chainam;Chompoonuch Khongla;Supaluk Sorapukdee
    • Animal Bioscience
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    • v.37 no.6
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    • pp.1096-1109
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    • 2024
  • Objective: This research aims to explore the nutritional and bioactive peptide properties of goat meat taken from various primal cuts, including the breast, shoulder, rib, loin, and leg, to produce these bioactive peptides during in vitro gastrointestinal (GI) digestion and absorption. Methods: The goat meat from various primal cuts was obtained from Boer goats with an average carcass weight of 30±2 kg. The meat was collected within 3 h after slaughter and was stored at -80℃ until analysis. A comprehensive assessment encompassed various aspects, including the chemical composition, cooking properties, in vitro GI digestion, bioactive characteristics, and the bioavailability of the resulting peptides. Results: The findings indicate that the loin muscles contain the highest protein and essential amino acid composition. When the meats were cooked at 70℃ for 30 min, they exhibited distinct protein compositions and quantities in the sodium dodecyl sulfate-polyacrylamide gel electrophoresis profile, suggesting they served as different protein substrates during GI digestion. Subsequent in vitro simulated GI digestion revealed that the cooked shoulder and loin underwent the most significant hydrolysis during the intestinal phase, resulting in the strongest angiotensin-converting enzyme (ACE) and dipeptidyl peptidase-IV (DPP-IV) inhibition. Following in vitro GI peptide absorption using a Caco-2 cell monolayer, the GI peptide derived from the cooked loin demonstrated greater bioavailability and a higher degree of ACE and DPP-IV inhibition than the shoulder peptide. Conclusion: This study highlights the potential of goat meat, particularly cooked loin, as a functional meat source for protein, essential amino acids, and bioactive peptides during GI digestion and absorption. These peptides promise to play a role in preventing and treating metabolic diseases due to their dual inhibitory effects on ACE and DPP-IV.

Stomatal Closure due to Water Stress in Plants (수분 스트레스에 의한 식물의 기공 닫힘)

  • Joon Sang Lee
    • Journal of Life Science
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    • v.34 no.6
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    • pp.426-433
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    • 2024
  • The environmental stress that plants are most susceptible to is water stress. Abscisic acid (ABA) is a plant hormone synthesized by plants to counteract environmental stress. The role of stomata in plants is to allow the synthesis of sucrose by absorbing CO2, which greatly affects photosynthetic activity. In addition, stomata are pathways for transpiration, which releases H2O and help establish a water potential gradient that allows plant roots to continuously absorb water and inorganic substances from the soil. Plants have a mechanism to minimize water loss by closing their stomata when exposed to water-stressed environments. The most well-studied hypothesis concerning the mechanism of stomatal closure is the response to water stress. When a plant receives sufficient water, its stomata open during the day and close at night due to its circadian rhythm. In addition, stomatal closure occurs when the concentration of CO2 in the intercellular space increases. However, the mechanism of stomatal closure due to circadian rhythm and increased CO2 concentration in the intercellular space is not well understood. When plants undergo water stress, the increased concentration of ABA in the guard cell cytoplasm induces an increase in Ca2+ concentration, resulting in cytoplasmic depolarization. As a result, the outward K+-channel of the tonoplast and the slow-type anion channels SLAC1 and SLAH3 are activated, releasing K+, Cl-, and malate2-, causing the stomata to close. Therefore, in this paper, the mechanism of stomatal closure caused by water stress was investigated.

Inhibitory Effect of Chloroform Extract of Marine Algae Hizikia Fusifomis on Angiogenesis (Hizikia fusiformis 클로로포름 추출물의 in vitro 및 in vivo 혈관신생 억제 연구)

  • Myeong-Eun Jegal;Yu-Seon Han;Shi-Young Park;Ji-Hyeok Lee;Eui-Yeun Yi;Yung-Jin Kim
    • Journal of Life Science
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    • v.34 no.6
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    • pp.399-407
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    • 2024
  • Angiogenesis is the process by which new blood vessels form from existing blood vessels. This phenomenon occurs during growth, healing, and menstrual cycle changes. Angiogenesis is a complex and multifaceted process that is important for the continued growth of primary tumors, metastasis promotion, the support of metastatic tumors, and cancer progression. Impaired angiogenesis can lead to cancer, autoimmune diseases, rheumatoid arthritis, cardiovascular disease, and delayed wound healing. Currently, there are only a handful of effective antiangiogenic drugs. Recent studies have shown that natural marine products exhibit antiangiogenic effects. In a previous study, we reported that the hexane extract of H. fusiformis (HFH) could inhibit the development of new blood vessels both in vitro and in vivo. The aim of this study was to describe the inhibitory effect of chloroform extracts of H. fusiformis on angiogenesis. To investigate how chloroform extract prevents blood vessel growth, we examined its effects on HUVEC, including cell migration, invasion, and tube formation. In a mouse Matrigel plug assay, H. fusiformis chloroform extract (HFC) also inhibited angiogenesis in vivo. Certain proteins associated with blood vessel growth were reduced after HFC treatment. These proteins include vascular endothelial growth factor (VEGF), mitogen-activated protein kinase (MAPK)/extracellular signal transduction kinase, and serine/threonine kinase 1 (AKT). These studies have shown that the chloroform extract of H. fusiformis can inhibit blood vessel growth both in vitro and in vivo.

Effects of an in vitro vitamin D treatment on the inflammatory responses in visceral adipose tissue from Ldlr-/- mice

  • Deok Hoon Kwon;Jungwon Hwang;Hyeyoung You;Na Young Kim;Ga Young Lee;Sung Nim Han
    • Nutrition Research and Practice
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    • v.18 no.1
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    • pp.19-32
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    • 2024
  • BACKGROUND/OBJECTIVES: Atherosclerosis is associated with increased inflammation in the visceral adipose tissue (VAT). Vitamin D has been reported to modulate the inflammatory responses of stromal vascular cells (SVCs) and adipocytes in adipose tissue, but the role of vitamin D in atherosclerosis biology is unclear. This study examined the effects of in vitro 1,25-dihydroxyvitamin D3 (1,25[OH]2D3) treatment on the inflammatory responses of SVCs and adipocytes from atherosclerotic mice. MATERIALS/METHODS: C57BL/6J (B6) mice were divided randomly into 2 groups and fed a 10% kcal fat control diet (control group, CON) or 41% kcal fat, 0.21% cholesterol (high fat + cholesterol, HFC) diet (obese group, OB), and B6.129S7-Ldlrtm1Her/J (Ldlr-/-) mice were fed a HFC diet (obese with atherosclerosis group, OBA) for 16 weeks. SVCs and adipocytes isolated from VAT were pre-incubated with 1,25(OH)2D3 for 24 h and stimulated with lipopolysaccarides for the next 24 h. Proinflammatory cytokine production by adipocytes and SVCs, the immune cell population in SVCs, and the expression of the genes involved in the inflammatory signaling pathway in SVCs were determined. RESULTS: The numbers of total macrophages and SVCs per mouse were higher in OB and OBA groups than the CON group. The in vitro 1,25(OH)2D3 treatment significantly reduced macrophages/SVCs (%) in the OBA group. Consistent with this change, the production of interleukin-6 and monocyte chemoattractant protein 1 (MCP-1) by SVCs from the OBA group was decreased by 1,25(OH)2D3 treatment. The 1,25(OH)2D3 treatment significantly reduced the toll-like receptor 4 and dual-specificity protein phosphatase 1 (also known as mitogen-activated protein kinase phosphatase 1) mRNA levels in SVCs and MCP-1 production by adipocytes from all 3 groups. CONCLUSIONS: These findings suggest that vitamin D can attribute to the inhibition of the inflammatory response in VAT from atherosclerotic mice by reducing proinflammatory cytokine production.

Biometric analysis hand parameters in young adults for prosthetic hand and ergonomic product applications

  • Gkionoul Nteli Chatzioglou;Yelda Pinar;Figen Govsa
    • Anatomy and Cell Biology
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    • v.57 no.2
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    • pp.172-182
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    • 2024
  • This study aimed to evaluate the superficial anatomy, kinesiology, and functions of the hand to reveal its morphometry and apply the findings in various fields such as prosthetic hand and protective hand support product design. We examined 51 young adults (32 females, 19 males) aged between 18-30. Hand photographs were taken, and measurements were conducted using ImageJ software. Pearson correlation analysis was performed to determine the relationship between personal information and the parameters. The results of the measurements showed the average lengths of finger segments: thumb (49.5±5.5 mm), index finger (63.9±4.1 mm), middle finger (70.7±5.2 mm), ring finger (65.5±4.8 mm), and little finger (53.3±4.3 mm). Both females and males, the left index finger was measured longer than the right index finger. The right ring finger was found to be longer than the left in both sexes. Additionally, length differences between fingers in extended and maximally adducted positions were determined: thumb-index finger (56.1±6.2 mm), index-middle finger (10.7±4.1 mm), middle-ring finger (10.8±1.4 mm), and ring-little finger (25.6±2.7 mm). Other findings included the average radial natural angle (56.4°±10.5°), ulnar natural angle (23.4°±7.1°), radial deviation angle (65.2°±8.2°), ulnar deviation angle (51.2°±9.6°), and grasping/gripping angle (49.1°±5.8°). The average angles between fingers in maximum abduction positions were also measured: thumb-index finger (53.4°±6.5°), index-middle finger (17.2°±2.6°), middle-ring finger (14.3°±2.3°), and ring-little finger (32.1°±7.0°). The study examined the variability in the positioning of proximal interphalangeal joints during maximum metacarpophalangeal and proximal interphalangeal flexion, coinciding with maximum distal interphalangeal extension movements. The focal points of our observations were the asymmetrical and symmetrical arches formed by these joints. This study provides valuable hand parameters in young adults, which can be utilized in various applications such as prosthetic design, ergonomic product development, and hand-related research. The results highlight the significance of considering individual factors when assessing hand morphology and function.

Aromadendrin Inhibits Lipopolysaccharide-Induced Inflammation in BEAS-2B Cells and Lungs of Mice

  • Juhyun Lee;Ji-Won Park;Jinseon Choi;Seok Han Yun;Bong Hyo Rhee;Hyeon Jeong Jeong;Hyueyun Kim;Kihoon Lee;Kyung-Seop Ahn;Hye-Gwang Jeong;Jae-Won Lee
    • Biomolecules & Therapeutics
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    • v.32 no.5
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    • pp.546-555
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    • 2024
  • Aromadendrin is a phenolic compound with various biological effects such as anti-inflammatory properties. However, its protective effects against acute lung injury (ALI) remain unclear. Therefore, this study aimed to explore the ameliorative effects of aromadendrin in an experimental model of lipopolysaccharide (LPS)-induced ALI. In vitro analysis revealed a notable increase in the levels of cytokine/chemokine formation, nuclear factor kappa B (NF-κB) activation, and myeloid differentiation primary response 88 (MyD88)/toll-like receptor (TLR4) expression in LPS-stimulated BEAS-2B lung epithelial cell lines that was ameliorated by aromadendrin pretreatment. In LPS-induced ALI mice, the remarkable upregulation of immune cells and IL-1β/IL-6/TNF-α levels in the bronchoalveolar lavage fluid and inducible nitric oxide synthase/cyclooxygenase-2/CD68 expression in lung was decreased by the oral administration of aromadendrin. Histological analysis revealed the presence of cells in the lungs of ALI mice, which was alleviated by aromadendrin. In addition, aromadendrin ameliorated lung edema. This in vivo effect of aromadendrin was accompanied by its inhibitory effect on LPS-induced NF-κB activation, MyD88/TLR4 expression, and signal transducer and activator of transcription 3 activation. Furthermore, aromadendrin increased the expression of heme oxygenase-1/ NAD(P)H quinone dehydrogenase 1 in the lungs of ALI mice. In summary, the in vitro and in vivo studies demonstrated that aromadendrin ameliorated endotoxin-induced pulmonary inflammation by suppressing cytokine formation and NF-κB activation, suggesting that aromadendrin could be a useful adjuvant in the treatment of ALI.

Honey and levodopa comparably preserved substantia nigra pars compacta neurons through the modulation of nuclear factor erythroid 2-related factor 2 signaling pathway in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced Parkinson's disease model

  • Fatimo Ajoke Sulaimon;Ruqayyah Yetunde Ibiyeye;Aminu Imam;Aboyeji Lukuman Oyewole;Abubakar Lekan Imam;Monsur Shehu;Sikiru Abayomi Biliaminu;Risikat Eniola Kadir;Gabriel Olaiya Omotoso;Moyosore Salihu Ajao
    • Anatomy and Cell Biology
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    • v.57 no.3
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    • pp.431-445
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    • 2024
  • Parkinson's disease (PD) affects about 8.5 million individuals worldwide. Oxidative and inflammatory cascades are implicated in the neurological sequels, that are mostly unresolved in PD treatments. However, proper nutrition offers one of the most effective and least costly ways to decrease the burden of many diseases and their associated risk factors. Moreover, prevention may be the best response to the progressive nature of PD, thus, the therapeutic novelty of honey and levodopa may be prospective. This study aimed to investigate the neuroprotective role of honey and levodopa against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced oxidative stress. Fifty-four adult male Swiss mice were divided into control and PD model groups of 27 mice. Each third of the control mice either received phosphate buffered saline, honey, or levodopa for 21 days. However, each third of the PD models was either pretreated with honey and levodopa or not pretreated. Behavioral studies and euthanasia were conducted 2 and 8 days after MPTP administration respectively. The result showed that there were significantly (P<0.05) higher motor activities in the PD models pretreated with the honey as well as levodopa. furthermore, the pretreatments protected the midbrain against the chromatolysis and astrogliosis induced by MPTP. The expression of antioxidant markers (glutathione [GSH] and nuclear factor erythroid 2-related factor 2 [Nrf2]) was also significantly upregulated in the pretreated PD models. It is thus concluded that honey and levodopa comparably protected the substantia nigra pars compacta neurons against oxidative stress by modulating the Nrf2 signaling molecule thereby increasing GSH level to prevent MPTP-induced oxidative stress.

Edible mushroom (Pleurotus cornucopiae) extract vs. glibenclamide on alloxan induced diabetes: sub-acute in vivo study of Nrf2 expression and renal toxicity

  • Chinedu Godwin Uzomba;Uchenna Kenneth Ezemagu;Mary-Sonia Ofoegbu;Njoku Lydia;Essien Goodness;Chinedum Emelike;Uchewa Obinna;Alo Joseph Nwafor;Ejikeme Felix Mbajiorgu
    • Anatomy and Cell Biology
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    • v.57 no.3
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    • pp.446-458
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    • 2024
  • The study aims to compare the action of Pleurotus cornucopiae and glibenclamide on alloxan-induced diabetes and ascertain how an aqueous extract of the edible mushroom regulates the expression of nuclear factor erythroid 2-related factor 2 (Nrf2), oxidative stress biomarkers and renal toxicity in a diabetic male Wistar rat model. Twenty-five adult male Wistar rats were randomly grouped into five groups with five rats per. Group 1 and those in the treatment groups received normal feed and water ad libitum. Group 2 received intraperitoneal administration of alloxan monohydrate (150 mg/kg body weight). Group 3 received alloxan monohydrate and glibenclamide (5 mg/kg body weight bwt), group 4 received alloxan monohydrate plus the extract (250 mg/kg bwt) and group 5 received alloxan monohydrate plus the extract (500 mg/kg bwt). The administration of glibenclamide plus the extract was oral for 14 days. Glibenclamide and the extract lowered blood glucose level, catalase, and glutathione peroxidase activities, increased the superoxide dismutase (SOD) activity in rats with alloxan induced diabetes. The extract at 500 mg/kg bwt reduced the plasma urea and sodium concentration in the treated rats. The extract and glibenclamide could detoxify alloxan and restore its induced renal degeneration and glomeruli atrophy, intra renal hemorrhage and inflammation and oxidative biomarkers through activation of Nrf2 expression. The drug glibenclamide and P. cornucopiae have appreciable hypoglycemic activity and potential to restore the normal renal architecture in the rats, hence they offer similar curative effects. Additionally, the extract at 500 mg/kg bwt activated SOD and Nrf2 expression more than glibenclamide in rats with alloxan-induced diabetes.