Publications by authors named "Ekyune Kim"

The goals of the present study were to develop a simple method for obtain highly purified pig sperm hyaluronidase (pHyase) and to assess its activity, function, and safety. In mammals, sperm-specific glycophosphatidylinositol (GPI)-anchored Hyase assists sperm penetration through the cumulus mass surrounding the egg and aids in the dispersal of the cumulus-oocyte complex. Recently, Purified bovine sperm hyaluronidase (bHyase) has been shown to enhance therapeutic drug transport by breaking down the hyaluronan barrier to the lymphatic and capillary vessels, thereby facilitating tissue absorption.

View Article and Find Full Text PDF

Glycosylphosphatidylinositol-anchored sperm hyaluronidases (HYAL) assist sperm penetration through the cumulus-oocyte complex (COC), but their role in mammalian fertilization remains unclear. Previously, we demonstrated that sperm from HYAL 5 and 7 double-knockout (dKO) mice produced significantly less offspring than sperm from wild-type mice due to defective COC dispersal. However, the HYAL6 gene remained active in the sperm from the dKO mice, indicating that they were not entirely infertile.

View Article and Find Full Text PDF

Glycosylphosphatidylinositol-anchored sperm hyaluronidases have long been believed to assist in sperm penetration through the cumulus-oocyte complex (COC); however, their role in mammalian fertilization remains unclear. Previously, we have shown that hyaluronidase 5 (Hyal5)/Hyal7 double-knockout (dKO) mice produce significantly fewer offspring than their wild-type (WT) counterparts because of defective COC dispersal. Male infertility is mainly caused by a low sperm count.

View Article and Find Full Text PDF

To elucidate the functional role of V-set and immunoglobulin domain-containing 1 (VSIG1) in spermatogenesis and fertilization, we knocked out (KO) VSIG1 in a mouse embryo using CRISPR/Cas9 (Clustered regularly interspaced short palindromic repeat/CRISPR-associated protein 9) -mediated genome editing. Reverse transcription PCR was performed using cDNA synthesized from VSIG1 KO testis RNA. Although Western blot analysis using a specific antibody to VSIG1 confirmed VSIG1 protein defects in the KO mice, hematoxylin-eosin staining analysis was similar in the KO and wild-type mice.

View Article and Find Full Text PDF

is a perennial plant that grows in humid environments across Korea. Its roots are used in traditional Korean medicine to treat several diseases, including diseases of the spleen and skin and several inflammatory pathologies. In this study, different solvent fractions (-hexane, dichloromethane, ethyl acetate, -butanol, and aqueous fractions) from an ethanol extract of roots were evaluated for the presence and composition of anthraquinone compounds and antioxidants by checking for such things as free radical scavenging activity, and electron and proton atom donating ability.

View Article and Find Full Text PDF

Background: Sweet potato is easily propagated by cuttings. But the molecular biological mechanism of adventitious root formation are not yet clear.

Objective: To understand the molecular mechanisms of adventitious root formation from stem cuttings in sweet potato.

View Article and Find Full Text PDF

The glycosylphosphatidylinositol-anchored sperm hyaluronidases (Hyals), sperm adhesion molecule 1 (SPAM1) and HYAL5, have long been believed to assist in sperm penetration through the cumulus-oocyte complex (COC), but their role in mammalian fertilization remains unclear. Previously, we have shown that mouse sperm devoid of either or are still capable of penetrating the COC and that the loss of either or alone does not cause male infertility in mice. In the present study, we found that / double knockout (dKO) mice produced significantly fewer offspring compared with wild-type (WT) mice, and this was due to defective COC dispersal.

View Article and Find Full Text PDF

Hyaluronidases enhance therapeutic drug transport by breaking down the hyaluronan barrier to lymphatic and capillary vessels, facilitating their tissue absorption. Commercially available hyaluronidases are bovine in origin; however, they pose risks such as bovine spongiform encephalopathy. The present study aimed to develop a novel, highly active hyaluronidase and assess its function.

View Article and Find Full Text PDF

Hyaluronidases are a family of enzymes that catalyse the breakdown of hyaluronic acid, which is abundant in the extracellular matrix and cumulus oocyte complex. To investigate the activity of recombinant bovine sperm hyaluronidase 1 (SPAM1) and determine the effect of the Asn-X-Ser/Thr motif on its activity, the bovine SPAM1 open reading frame was cloned into the mammalian expression vector pCXN2 and then transfected to the HEK293 cell line. Expression of recombinant bovine hyaluronidase was estimated using a hyaluronidase activity assay with gel electrophoresis.

View Article and Find Full Text PDF

The main pathological hallmark of Alzheimer's disease is the deposition of amyloid-beta (Aβ) peptides in the brain. Aβ has been widely used to mimic several aspects of Alzheimer's disease. However, several characteristics of amyloid-induced Alzheimer's disease pathology are not well established, especially in mice.

View Article and Find Full Text PDF

A well-characterized sperm specific protein of the Member of immunoglobulin superfamily, IZUMO1, has crucial role in fertilization by mediating sperm binding to the egg plasma membrane in the mouse. However little is known about IZUMO1 in bovine. Here, we describe the molecular cloning and expression analysis of bovine IZUMO1 (bIZUMO1).

View Article and Find Full Text PDF

Although sperm hyaluronidase is thought to play an important role in mammalian fertilization, the molecular function underlying these steps remains largely unknown. In mouse models, sperm-specific SPAM1 and HYAL5 hyaluronidase are believed to function in both sperm penetration of the cumulus matrix and sperm-ZP binding. However, gene-targeting studies for SPAM1 or HYAL5 show that hyaluronidases are not essential for fertilization, despite the fact that exogenous hyaluronidase can disrupt the cumulus matrix.

View Article and Find Full Text PDF

Shiga toxin (STx) belongs to the AB(5) toxin family and is transiently localized in the periplasm before secretion into the extracellular milieu. While producing outer membrane vesicles (OMVs) containing only A subunit of the toxin (STxA), we created specific STx1B- and STx2B-deficient mutants of E. coli O157:H7.

View Article and Find Full Text PDF

The retromer complex, which mediates retrograde transport from endosomes to the trans-Golgi network, is a heteropentameric complex that contains a multifunctional cargo recognition heterotrimer consisted of the vacuolar protein sorting (Vps) subunits Vps26, Vps29, and Vps35. In mammals, there are two different isoforms of Vps26, Vps26a and Vps26b, that localize to the endosome, and to the plasma membrane, respectively. To elucidate the biological significance of the Vps26b isoform, we generated Vps26b knockout mice and studied their molecular, histological, and behavioral phenotypes.

View Article and Find Full Text PDF

V-set and immunoglobulin domain containing 1 (VSIG1) is a newly discovered member of the junctional adhesion molecule (JAM) family; it is encoded by a gene located on human chromosome X and preferentially expressed in a variety of cancers in humans. Little is known about its physiological function. To determine the role(s) of VSIG1 in mammalian spermatogenesis, we first generated a specific antibody against mouse VSIG1 and examined the presence and localization of the protein in tissues.

View Article and Find Full Text PDF

The leptin receptor (LEPR) is a crucial regulatory protein that interacts with Leptin. In our analysis of LEPR, novel AluJb-derived alternative transcripts were identified in the genome of the rhesus monkey. In order to investigate the occurrence of AluJb-derived alternative transcripts and the mechanism underlying exonization events, we conducted analyses using a number of primate genomic DNAs and adipose RNAs of tissue and primary cells derived from the crab-eating monkey.

View Article and Find Full Text PDF

Shiga toxins (STx) are secreted extracellularly through the outer membrane vesicles (OMVs) of Escherichia coli O157:H7. In an attempt to produce STxA-deficient OMVs from E. coli O157:H7, site-specific deletions of the stx1A and stx2A subunit genes were carried out.

View Article and Find Full Text PDF

To develop low endotoxic and multi-immunogenic outer membrane vesicles (OMVs), a deletion mutant of the msbB gene in Salmonella enterica serovar Typhimurium (S. Typhimurium) was used as a source of low endotoxic OMV, and an expression vector of the canine parvovirus (CPV) VP2 epitope fused to the bacterial OmpA protein was constructed and transformed into the Salmonella deltaAmsbB mutant. In a lethality test, BALB/c mice injected intraperitoneally with the Salmonella deltaAmsbB mutant survived for 7 days, whereas mice injected intraperitoneally with the wild type survived for 3 days.

View Article and Find Full Text PDF

In an effort to devise a safer and more effective vaccine delivery system, outer membrane vesicles (OMVs) were engineered to have properties of intrinsically low endotoxicity sufficient for the delivery of foreign antigens. Our strategy involved mutational inactivation of the MsbB (LpxM) lipid A acyltransferase to generate OMVs of reduced endotoxicity from Escherichia coli (E. coli) O157:H7.

View Article and Find Full Text PDF

Although sperm entry into the oocyte-cumulus complex and subsequent sperm penetration through the cumulus matrix to reach the oocyte zona pellucida are essential for mammalian fertilization, the molecular mechanism remains controversial. Previously, we have shown that mouse sperm lacking SPAM1 are capable of penetrating the cumulus matrix despite a delayed dispersal of cumulus cells. We also have identified another sperm hyaluronidase, HYAL5, as a candidate enzyme involved in sperm penetration through the cumulus.

View Article and Find Full Text PDF

Fertilin, a heterodimeric protein complex composed of ADAM1 and ADAM2 located on the sperm surface, is involved in sperm-egg interaction. In our study, we examined the physiological processing and subcellular localization of M. fascicularis ADAM2 during spermatogenesis in the testis and epididymal tract.

View Article and Find Full Text PDF

In the mouse, ADAM3, a well-characterized testis-specific protein of the A disintegrin and metalloprotease (ADAM) family, has a crucial role in fertilization by mediating sperm binding to the egg zona pellucida. However, little is known about ADAM3 in other species, such as domestic pigs. We have identified porcine ADAM3 and analyzed the protein.

View Article and Find Full Text PDF

A family of vacuolar protein sorting (Vps) proteins, which are components of mammalian retromer complex, has been studied in the mouse. Vps26a is known as a retromer component that plays an important role in embryonic development: however, its cell-type expression and precise role remain to be elucidated. In this study, we identified a new isoform of Vps26a, called Vps26aT, which was expressed specifically in the mouse testis.

View Article and Find Full Text PDF

Mammalian fertilization requires sperm to penetrate the cumulus mass and egg zona pellucida prior to fusion with the egg. Although sperm penetration through these physical barriers is essential, the molecular mechanism has not yet been completely elucidated. In addition to sperm motility, hyaluronan-hydrolyzing and proteolytic enzymes of sperm have been suggested to participate in the penetration events.

View Article and Find Full Text PDF

Fertilin, a heterodimeric protein complex composed of alpha (ADAM1) and beta (ADAM2) subunits on the sperm surface, is believed to mediate adhesion and fusion between the sperm and egg plasma membranes. Here we have shown that mutant male mice lacking ADAM1b are fertile and that the loss of ADAM1b results in no significant defect in sperm functions such as migration from the uterus into oviduct, binding to egg zona pellucida, and fusion with zona pellucida-free eggs. ADAM1b-deficient epididymal sperm showed a severe reduction of ADAM2 on the cell surface, despite the normal presence of ADAM2 in testicular germ cells.

View Article and Find Full Text PDF

A PHP Error was encountered

Severity: Warning

Message: fopen(/var/lib/php/sessions/ci_sessionao2di4mnfk2c7rrba3k9e7f237j3vmob): Failed to open stream: No space left on device

Filename: drivers/Session_files_driver.php

Line Number: 177

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: session_start(): Failed to read session data: user (path: /var/lib/php/sessions)

Filename: Session/Session.php

Line Number: 137

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once