• 한국생물물리학회:학술대회논문집
• /
• 한국생물물리학회 2003년도 정기총회 및 학술발표회
• /
• pp.52-52
• /
• 2003

Junctate is a newly identified integral ER/SR membrane $Ca^{2+}$ binding protein, which is an alternative splicing form of the same gene generating aspartyl $\square$-hydroxylase and junctin. To elucidate the functional role of junctate in heart, transgenic (TG) mice overexpressing mouse cardiac junctate-1 under the control of mouse $\square$$^{~}$ myosin heavy chain promoter were generated. Overexpression of junctate in mouse heart resulted in cardiac hypertrophy, increased fibrosis, bradycardia, arrhythmias and impaired contractility. Overexpression of junctate also led to down-regulation of SERCA2, calsequestrin, calreticulin and RyR, but to up-regulation of NCX and PMCA. The SR $Ca^{2+}$ content decreased and the L-type $Ca^{2+}$ current density and the action potential durations increased in TG cardiomyocytes, which could be the cause for the bradycardia in TG heart. The present work has provided an important example of pathogenesis leading to cardiac hypertrophy and arrhythmia, which was caused by impaired $Ca^{2+}$ handling by overexpression of junctate in heart.n heart.

• 대한의생명과학회지
• /
• 제27권3호
• /
• pp.170-176
• /
• 2021

Thapsigargin (TG), a sarco/endoplasmic reticulum (ER) Ca²⁺-ATPase (SERCA) inhibitor, has been widely used as an agonist for platelet aggregation for decades. In this study, we investigated the effect of TG on the release of lactate dehydrogenase (LDH) for platelets and elucidated its mechanism. Platelet LDH release and platelet aggregation were increased by TG treatment; 1,000 nM of TG induced the complete lysis of platelets. Other agonists such as collagen (2.5 ㎍/mL), thrombin (0.1 U/mL), and ADP (10 mM) did not induce significant platelet LDH release despite platelet aggregation. Finally, we investigated the effects of pharmacological inhibitors on TG-induced platelet aggregation and LDH release. SP600125, a JNK inhibitor, and LY294002, a PI-3K inhibitor, inhibited TG-induced platelet LDH release but not platelet aggregation. Forskolin, an adenylyl cyclase activator, also inhibited LDH release without affecting platelet aggregation by TG. These results suggest that the TG-induced platelet aggregation was accompanied by LDH release but regulated by a different signaling pathway.

• Natural Product Sciences
• /
• 제25권2호
• /
• pp.136-142
• /
• 2019

Ischemia/reperfusion-induced myocardial injury is the main cause of acute myocardial infarction. Dendropanax morbifera $L{\acute{e}}veille$ has been used in traditional medicines for the treatment of various diseases such as headache, infectious diseases, and general debility. However, the effect of extract from D. morbifera (EDM) on myocardial ischemic injury is still unknown. In this study, the effects of EDM on neonatal rat cardiomyocytes with hypoxia/reoxygenation (H/R) injury were investigated. The viability of cardiomyocytes with H (30 min)/R (1 h) decreased; however, treatment with EDM significantly inhibited H/R injury-induced cardiomyocyte death. Further, we observed that reactive oxygen species (ROS) generation and intracellular calcium concentration ($Ca^{2+}{_i}$) were significantly reduced in EDM-treated cardiomyocytes compared with that in H/R-injured positive control. In addition, western blotting results showed that EDM attenuated abnormal changes of RyR2 and SERCA2a genes in hypoxic cardiomyocytes. These results suggest that EDM ameliorates ROS generation and $Ca^{2+}{_i}$ homeostasis to prevent dysregulation of calcium regulatory proteins in the heart, thereby exerting cardioprotective effects and reducing hypoxia-induced cardiomyocyte damage, which verifies the potential use of EDM as a new therapeutic agent for the treatment of myocardial ischemic injury.

• Journal of Microbiology and Biotechnology
• /
• 제33권10호
• /
• pp.1268-1280
• /
• 2023

Echinacoside (ECH) is a naturally occurring phenylethanoid glycoside, isolated from Echinacea angustifolia, and this study aimed to analyze its effect on thermogenesis and its interaction with dopaminergic receptors 1 and 5 (DRD1 and DRD5) in 3T3-L1 white adipocytes and mice models. We employed RT-PCR, immunoblot, immunofluorescence, a staining method, and an assay kit to determine its impact. ECH showed a substantial increase in browning signals in vitro and a decrease in adipogenic signals in vivo. Additionally, analysis of the iWAT showed that the key genes involved in beiging, mitochondrial biogenesis, and ATP-dependent thermogenesis were upregulated while adipogenesis and lipogenesis genes were downregulated. OXPHOS complexes, Ca²⁺ signaling proteins as well as intracellular Ca²⁺ levelswere also upregulated in 3T3-L1 adipocytes following ECH treatment. This was collectively explained by mechanistic studies which showed that ECH mediated the beiging process via the DRD1/5-cAMP-PKA and subsequent downstream molecules, whereas it co-mediated the α1-AR-signaling thermogenesis via the DRD1/5/SERCA2b/RyR2/CKmt pathway in 3T3-L1 adipocytes. Animal experiments revealed that there was a 12.28% reduction in body weight gain after the ECH treatment for six weeks. The effects of ECH treatment on adipose tissue can offer more insights into the treatment of obesity and metabolic syndrome.

• The Korean Journal of Physiology and Pharmacology
• /
• 제23권6호
• /
• pp.539-547
• /
• 2019

Anoctamin 5 (ANO5)/TMEM16E belongs to a member of the ANO/TMEM16 family member of anion channels. However, it is a matter of debate whether ANO5 functions as a genuine plasma membrane chloride channel. It has been recognized that mutations in the ANO5 gene cause many skeletal muscle diseases such as limb girdle muscular dystrophy type 2L (LGMD2L) and Miyoshi muscular dystrophy type 3 (MMD3) in human. However, the molecular mechanisms of the skeletal myopathies caused by ANO5 defects are poorly understood. To understand the role of ANO5 in skeletal muscle development and function, we silenced the ANO5 gene in C2C12 myoblasts and evaluated whether it impairs myogenesis and myotube function. ANO5 knockdown (ANO5-KD) by shRNA resulted in clustered or aggregated nuclei at the body of myotubes without affecting differentiation or myotube formation. Nuclear positioning defect of ANO5-KD myotubes was accompanied with reduced expression of Kif5b protein, a kinesin-related motor protein that controls nuclear transport during myogenesis. ANO5-KD impaired depolarization-induced $[Ca2^{+}]_i$ transient and reduced sarcoplasmic reticulum (SR) $Ca^{2+}$ storage. ANO5-KD resulted in reduced protein expression of the dihydropyridine receptor (DHPR) and SR $Ca^{2+}-ATPase$ subtype 1. In addition, ANO5-KD compromised co-localization between DHPR and ryanodine receptor subtype 1. It is concluded that ANO5-KD causes nuclear positioning defect by reduction of Kif5b expression, and compromises $Ca^{2+}$ signaling by downregulating the expression of DHPR and SERCA proteins.

• 한국어류학회지
• /
• 제23권1호
• /
• pp.1-9
• /
• 2011

ACP (annealing control primer)를 사용하여 DDRT (differential display reverse transcription)-PCR 방법으로 볼락의 성장단계에 따라 발현량 차이를 나타내는 DEG (differentially expressed gene)를 확보하였다. ACP 120개를 분석하여 18개월령 근육조직에서보다 6개월령 근육조직에서 발현량이 많은 DEG 16개와 6개월령 근육조직에서보다 18개월령 근육조직에서 발현량이 더 많은 DEG22개의 염기서열을 분석하였다. DEG 염기서열을 BLAST 검색한 결과, parvalbumin (PVALB) 등 18개의 유전자(PVALB, NDKB, TPM, TnI, GAPDH, CKM2, factor 2 SERF2, AMPD, TRICA, ARHGAP15, ESD, hsp70, COL1A2, GST, Midllip1, MYL1, SERCA1B, FTH1)와 69~95%의 상동성을 나타냈다. Real time PCR 분석법으로 6개월령 근육조직에서 발현량이 많은 DEG14와 PVALB 유전자의 성장단계별 발현양상을 조사한 결과, 볼락이 성장함에 따라 발현량이 감소하였으며, 특히 PVALB 유전자는 6개월령 이후에는 발현량이 극히 적었다. 6개월령 근육조직에서보다 18 개월령 근육조직에서 발현량에서 많았던 CKM2 유전자는 성장함에 따라 발현량이 계속 증가하였고, 4세 이후에는 발현량이 감소하였다. DEG의 조직특이적 발현양상을 분석한 결과, DEG14는 근육, 간, 신장, 및 비장조직에서 발현되었으며, PVALB 유전자는 근육과 신장조직에서 발현되었고, 간과 비장조직에서는 발현되지 않았다. CKM2 유전자는 근육, 신장 및 비장조직에서 발현되었고, 간 조직에서는 발현되지 않았다. PVALB 유전자의 mRNA 크기는 659 bp 이며, 110개의 아미노산으로 구성되어 있다. Parvalbumin과 CKM2 유전자는 성장속도가 빠른 어류 선발에 이용할 수 있는 분자마커 개발에 활용하고자한다.