Limits...
New Strategy of Functional Analysis of PHGPx Knockout Mice Model Using Transgenic Rescue Method and Cre-LoxP System.

Imai H - J Clin Biochem Nutr (2009)

Bottom Line: Phospholipid hydroperoxide glutathione peroxidase (PHGPx) is an intracellular antioxidant enzyme that directly reduces peroxidized phospholipids.PHGPx is transcribed from one gene into three types of mRNA, mitochondrial, non-mitochondrial and nucleolar PHGPx by alternative transcription.All the spermatocyte-specific PHGPx KO male mice were infertile and displayed a significant decrease in the number of spermatozoa and significant reductions in forward motility by mitochondrial dysfunction of spermatozoa.

View Article: PubMed Central - PubMed

Affiliation: School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane Minato-ku Tokyo 108-8641, Japan.

ABSTRACT
Phospholipid hydroperoxide glutathione peroxidase (PHGPx) is an intracellular antioxidant enzyme that directly reduces peroxidized phospholipids. PHGPx is transcribed from one gene into three types of mRNA, mitochondrial, non-mitochondrial and nucleolar PHGPx by alternative transcription. In this review, we focus on our recent experiments on the regulation of promoter activity of the types of PHGPx and on the novel strategy of functional analysis of a PHGPx knockout mice model using the transgenic rescue method and Cre-LoxP system. PHGPx is especially high in testis and spermatozoa. A deficiency is implicated in human infertility. We established spermatocyte-specific PHGPx knockout (KO) mice using a Cre-loxP system. Targeted disruption of all exons of the PHGPx gene in mice by homologous recombination caused embryonic lethality at 7.5 days post coitum. The PHGPx-loxP transgene rescued PHGPx KO mice from embryonic lethality. These rescued floxed PHGPx mice were mated with spermatocyte specific Cre expressing mice. All the spermatocyte-specific PHGPx KO male mice were infertile and displayed a significant decrease in the number of spermatozoa and significant reductions in forward motility by mitochondrial dysfunction of spermatozoa. These results demonstrate that depletion of PHGPx in spermatozoa may be one of the causes of male infertility in mice and humans.

No MeSH data available.


Related in: MedlinePlus

Depletion of PHGPx gene in spermatocyte causes male infertility with oligoasthenozoospermia in mice. Mice with spermatocyte-specific deletion of the PHGPx gene (A) showed male infertility with two significant conspicuous phenotypes: first, a decreased number of spermatozoa in the epididymis caused by the depletion of spermatogenic cells in seminiferous tubules (B) and second, loss of forward motility of spermatozoa due to hairpin-like bending of the tail in the distal midpiece region (C) and/or mitochondrial dysfunction including mitochondrial membrane potential (D) and ultrastructure (E).
© Copyright Policy - open-access
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2803127&req=5

Figure 8: Depletion of PHGPx gene in spermatocyte causes male infertility with oligoasthenozoospermia in mice. Mice with spermatocyte-specific deletion of the PHGPx gene (A) showed male infertility with two significant conspicuous phenotypes: first, a decreased number of spermatozoa in the epididymis caused by the depletion of spermatogenic cells in seminiferous tubules (B) and second, loss of forward motility of spermatozoa due to hairpin-like bending of the tail in the distal midpiece region (C) and/or mitochondrial dysfunction including mitochondrial membrane potential (D) and ultrastructure (E).

Mentions: We successfully created spermatocyte-specific PHGPx KO mice (Fig. 8). The expression of PHGPx protein in spermatocyte-specific PHGPx KO mice was significantly decreased in testis and epididymal spermatozoa (Fig. 8A), but not in liver, brain and kidney, although the expression of voltage dependent anion channels (VDAC) was not changed. These results demonstrate that PHGPx expression is selectively lost in spermatocytes and spermatozoa of spermatocyte-specific PHGPx KO mice.


New Strategy of Functional Analysis of PHGPx Knockout Mice Model Using Transgenic Rescue Method and Cre-LoxP System.

Imai H - J Clin Biochem Nutr (2009)

Depletion of PHGPx gene in spermatocyte causes male infertility with oligoasthenozoospermia in mice. Mice with spermatocyte-specific deletion of the PHGPx gene (A) showed male infertility with two significant conspicuous phenotypes: first, a decreased number of spermatozoa in the epididymis caused by the depletion of spermatogenic cells in seminiferous tubules (B) and second, loss of forward motility of spermatozoa due to hairpin-like bending of the tail in the distal midpiece region (C) and/or mitochondrial dysfunction including mitochondrial membrane potential (D) and ultrastructure (E).
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2803127&req=5

Figure 8: Depletion of PHGPx gene in spermatocyte causes male infertility with oligoasthenozoospermia in mice. Mice with spermatocyte-specific deletion of the PHGPx gene (A) showed male infertility with two significant conspicuous phenotypes: first, a decreased number of spermatozoa in the epididymis caused by the depletion of spermatogenic cells in seminiferous tubules (B) and second, loss of forward motility of spermatozoa due to hairpin-like bending of the tail in the distal midpiece region (C) and/or mitochondrial dysfunction including mitochondrial membrane potential (D) and ultrastructure (E).
Mentions: We successfully created spermatocyte-specific PHGPx KO mice (Fig. 8). The expression of PHGPx protein in spermatocyte-specific PHGPx KO mice was significantly decreased in testis and epididymal spermatozoa (Fig. 8A), but not in liver, brain and kidney, although the expression of voltage dependent anion channels (VDAC) was not changed. These results demonstrate that PHGPx expression is selectively lost in spermatocytes and spermatozoa of spermatocyte-specific PHGPx KO mice.

Bottom Line: Phospholipid hydroperoxide glutathione peroxidase (PHGPx) is an intracellular antioxidant enzyme that directly reduces peroxidized phospholipids.PHGPx is transcribed from one gene into three types of mRNA, mitochondrial, non-mitochondrial and nucleolar PHGPx by alternative transcription.All the spermatocyte-specific PHGPx KO male mice were infertile and displayed a significant decrease in the number of spermatozoa and significant reductions in forward motility by mitochondrial dysfunction of spermatozoa.

View Article: PubMed Central - PubMed

Affiliation: School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane Minato-ku Tokyo 108-8641, Japan.

ABSTRACT
Phospholipid hydroperoxide glutathione peroxidase (PHGPx) is an intracellular antioxidant enzyme that directly reduces peroxidized phospholipids. PHGPx is transcribed from one gene into three types of mRNA, mitochondrial, non-mitochondrial and nucleolar PHGPx by alternative transcription. In this review, we focus on our recent experiments on the regulation of promoter activity of the types of PHGPx and on the novel strategy of functional analysis of a PHGPx knockout mice model using the transgenic rescue method and Cre-LoxP system. PHGPx is especially high in testis and spermatozoa. A deficiency is implicated in human infertility. We established spermatocyte-specific PHGPx knockout (KO) mice using a Cre-loxP system. Targeted disruption of all exons of the PHGPx gene in mice by homologous recombination caused embryonic lethality at 7.5 days post coitum. The PHGPx-loxP transgene rescued PHGPx KO mice from embryonic lethality. These rescued floxed PHGPx mice were mated with spermatocyte specific Cre expressing mice. All the spermatocyte-specific PHGPx KO male mice were infertile and displayed a significant decrease in the number of spermatozoa and significant reductions in forward motility by mitochondrial dysfunction of spermatozoa. These results demonstrate that depletion of PHGPx in spermatozoa may be one of the causes of male infertility in mice and humans.

No MeSH data available.


Related in: MedlinePlus