• Asian-Australasian Journal of Animal Sciences
• /
• v.33 no.10
• /
• pp.1579-1589
• /
• 2020

Objective: This study was conducted to investigate the roles of LIM kinases (LIMK1 and LIMK2) during porcine early embryo development. We checked the mRNA expression patterns and localization of LIMK1/2 to evaluate their characterization. We further explored the function of LIMK1/2 in developmental competence and their relationship between actin assembly and cell junction integrity, specifically during the first cleavage and compaction. Methods: Pig ovaries were transferred from a local slaughterhouse within 1 h and cumulus oocyte complexes (COCs) were collected. COCs were matured in in vitro maturation medium in a CO2 incubator. Metaphase II oocytes were activated using an Electro Cell Manipulator 2001 and microinjected to insert LIMK1/2 dsRNA into the cytoplasm. To confirm the roles of LIMK1/2 during compaction and subsequent blastocyst formation, we employed a LIMK inhibitor (LIMKi3). Results: LIMK1/2 was localized in cytoplasm in embryos and co-localized with actin in cell-to-cell boundaries after the morula stage. LIMK1/2 knockdown using LIMK1/2 dsRNA significantly decreased the cleavage rate, compared to the control group. Protein levels of E-cadherin and β-catenin, present in adherens junctions, were reduced at the cell-to-cell boundaries in the LIMK1/2 knockdown embryos. Embryos treated with LIMKi3 at the morula stage failed to undergo compaction and could not develop into blastocysts. Actin intensity at the cortical region was considerably reduced in LIMKi3-treated embryos. LIMKi3-induced decrease in cortical actin levels was attributed to the disruption of adherens junction and tight junction assembly. Phosphorylation of cofilin was also reduced in LIMKi3-treated embryos. Conclusion: The above results suggest that LIMK1/2 is crucial for cleavage and compaction through regulation of actin organization and cell junction assembly.

• Journal of Integrative Natural Science
• /
• v.8 no.4
• /
• pp.285-292
• /
• 2015

LIM kinases belong to the serine/Threonine kinase family. The members of the LIM kinase (LIMK) family include LIMK 1 and 2 which are involved in the regulation of actin polymerisation and microtubule disassembly. LIMK1 was shown to be involved in cancer metastasis, while LIMK2 activation promotes cells cycle progression. Since LIMK2 plays a vital role in many disease conditions such as pulmonary hypertension, cancer and viral diseases, and till date there are not much selective inhibitors been reported, LIMK2 becomes an interesting therapeutic target among the kinases. 3D QSAR study was carried out on a series of pyrrolopyrimidines based derivatives as LIMK2 inhibitors. A reasonable CoMFA ($q^2$=0.888; ONC=3; $r^2$=0.974) with good statistical values was developed. The developed model was validated using 1000 runs of boostrapping and was found to be predictable. The results of CoMFA contour map analysis suggested that the bulky substitution at $R_4$ and $R_5$ position are highly desirable to increase the activity. Similarly, positive substitution at $R_3$ position is also required to increase the activity. It is also noted that bulky substitution at $R_1$ position must be avoided. Our results could provide valuable information to enhance the activity of the LIMK2 inhibitors and to design potent pyrrolopyrimidines derivatives.

• The Korean Journal of Physiology and Pharmacology
• /
• v.16 no.3
• /
• pp.159-165
• /
• 2012

Squamous cell carcinoma (SCC) and adenocarcinoma (AC) are the major histological types of non-small cell lung carcinoma (NSCLC). Although both SCCs and ACs have been characterized histologically and clinically, the precise mechanisms underlying their migration and invasion are not yet known. Here, we address the involvement in NSCLC of the p21-associated kinase1 (Pak1)/LIM kinase1 (LIMK1)/cofilin pathway, which recently has been reported to play a critical role in tumor migration and invasion. The Pak1/LIMK1/cofilin pathway was evaluated in tumors from SCC (n=35) and AC (n=35) patients and in SCC- and AC-type cell lines by western blotting, immunohistochemistry, and in vitro migration and invasion assays. The levels of phosphorylated Pak1, LIMK1, and cofilin in lung tumor tissues from SCC patients were increased as compared to normal tissues. In addition, immunohistochemistry showed greater expression of phosphorylated cofilin in SCC tissues. Expression of phosphorylated Pak1 and LIMK1 proteins was also significantly higher in SCC-type cells than in AC-type cells. Moreover, migration and invasion assays revealed that a higher percentage of SCC type cells exhibited migration and invasion compared to AC type cells. Migration was also decreased in LIMK1 knockdown SK-MES-1 cells. These findings suggest that the activation of the Pak1/LIMK1/cofilin pathway could preferentially contribute to greater tumor migration and invasion in SCC, relative to that in AC.

• BMB Reports
• /
• v.54 no.12
• /
• pp.614-619
• /
• 2021

Hepatitis B virus (HBV) infection is a major cause of hepatocellular carcinoma (HCC), which is a highly aggressive cancer. HBV X protein (HBx), one of four HBV gene products, plays pivotal roles in the development and metastasis of HCC. It has been reported that HBx induces liver cancer cell migration and reorganizes actin cytoskeleton, however the molecular basis for actin cytoskeleton reorganization remains obscure. In this study, we for the first time report that HBx promotes actin polymerization and liver cancer cell migration by regulating calcium modulated protein, calmodulin (CaM). HBx physically interacts with CaM to control the level of phosphorylated cofilin, an actin depolymerizing factor. Mechanistically, HBx interacts with CaM, liberates Hsp90 from its inhibitory partner CaM, and increases the activity of Hsp90, thus activating LIMK1/cofilin pathway. Interestingly, the interaction between HBx and CaM is calcium-dependent and requires the CaM binding motif on HBx. These results indicate that HBx modulates CaM which plays a regulatory role in Hsp90/LIMK1/cofilin pathway of actin reorganization, suggesting a new mechanism of HBV-induced HCC metastasis specifically derived by HBx.

• Journal of Life Science
• /
• v.21 no.10
• /
• pp.1401-1406
• /
• 2011

Morphological changes in immune cells occur due to pathogen infection and natural circulation. T cells produce uropod, filopodia, lamellipodia, and microvilli for inflammation, immunosurvelliance, migration, and diapedesis. Short finger-like microvilli cover the surfaces of circulating mammalian immune cells. The surface features of monocytes and neutrophils are quite different, containing membrane ruffles as their predominant structure. In this study, we present the involvement of actin cytoskeleton regarding T lymphocyte microvilli. From analysis of scanning electron micrographs, Jurkat T lymphocyte microvilli was observed to rapidly disassemble when exposed to the actin-sequestering molecule, cytochalasin D. In contrast to cytochalasin D treatment, we found that median microvillar thickness was enlarged on Jurkat T lymphocytes treated with PMA via Lin-11, Isl-1, Mec-3 Kinase (LIMK) and cofilin signaling. In addition, actin cytoskeleton was involved in polarity formation in EL4 T lymphocytes. These results suggest that microvilli formation or polarity of T lymphocytes are involved in actin cytoskeleton dynamics.

• Proceedings of the Korean Society of Plant Pathology Conference
• /
• 2003.10a
• /
• pp.88.1-88
• /
• 2003

Antogonistic bacteria against Rhizoctonia solani and Pythium spp., causing serious damage to golf course grasses, were isolated from the top soil of several golf courses in Korea. The isolate of Limk0102 was selected as the biological agent by characterization of antifungal activity, large scale preparation, fungicides tolerance and ecological fitness to the targe environment. The isolate was identified as Bacillus subtilis by biochemical and physiological characterization, and 165 rDNA sequence analysis. The bacterial agent was formulated as a granule type by seeding it on fine sand. The formulated agent showed high recovery rate (more than 10$\^$8/ cells/g sand) even after 6 month-storage at room temperature with similar antifungal activity with that of original cells. In vitro, the biological agent successfully exhibited antagonistic performance on bentgrass inoculated with R. solani or Pythium spp. isolated from the diseased grasses on golf courses. Field evaluation on disease control activity and ecological fitness of the agent is now under going on several golf courses.

• Molecular & Cellular Toxicology
• /
• v.4 no.1
• /
• pp.31-44
• /
• 2008

The forced swim test (FST) is the most widely used model for assessing potential antidepressant activity. Although it has been shown that lateral septum is involved with the FST-related behavior, it is not clear whether antidepressant treatments could alter the FST-induced gene expression profile in the lateral septum. In the present study, the gene expression profiles in response to FST and reboxetine pretreatment were observed in the lateral septum of rats. Reboxetine is known as a most selective serotonin norepinephrine reuptake inhibitor. In addition, we compared the changes in gene expression profile between reboxetine response and nonresponse groups, which were determined by counting FST-related behavior. After FST, lateral septum from controls and reboxetine pretreated group were dissected and gene expression profiles were assessed using an Affymetrix microarray system containing 15,923 genes. Various genes with different functions were changed in reboxetine response group compared with reboxetine nonresponse group, In particular, pleiotrophin, orexin receptor 2, serotonin 2A receptor, neuropeptide Y5 receptor and thyroid hormone receptor $\beta$ were decreased in reboxetine response group, but Lim motif-containing protein kinase 1 (Limk1) and histone deacetylase 1 (HDAC1) were increased. Although further studies are required for direct roles of these genes in reboxetine response, the microarray may provide tools to find out potential target genes and signaling pathways in antidepressant response.

• The Transactions of the Korea Information Processing Society
• /
• v.7 no.10
• /
• pp.3210-3218
• /
• 2000

In a IS-95 cellular systm, blocking will occur when the reverse link user interference power reaches a predepermmed level which is set to maintam acceptable signal quality. In this paper, it is assumed that a mobile rdio channel is a shadowing channel and Erlang capacity is calculated for the reverse limk of an imperfect power controlled IS-95 cellular system. the blocking probability is derived using lognornal pproximation and the results according to guassian and lognormal approximation method are compared and analyzed respcctively. Assuming that blocking probability is 1% at the data rate of $R_b$=9.6kbps and $R_b$=14.4kbps, it is shown that Erlang capacity using Iognormal approximation is 13.68 Erlang and 7.08 Erlang and then the approximation erroris occurred about 24.4% and 40.4% inthe garssian approximation, respectively. It is also observed that if the power control becomes periect, the Erlang capacity is increased more 6.99 and 4.21 Erlang than that of the imperfect power control that the power contrl error is 2.5dB, and if voice activity is considered as 10%, the Erlang capacity is increased more 8.21 and 1.25 Erlang than that using non voice activity, respectively.