Experiments were performed to evaluate the efficiency of inhibition of HSP70 gene expressionby antisense oligonucleotides complementary to the mRNA of HSP70 and to test the effects ofinhibition of HSP70 gene expressio...Experiments were performed to evaluate the efficiency of inhibition of HSP70 gene expressionby antisense oligonucleotides complementary to the mRNA of HSP70 and to test the effects ofinhibition of HSP70 gene expression on subsequent embryonic sensitivity to heat shock. Theresults showed that transfection of pre-implantation embryos at 4-cell stage with 5 Mantisense oligo had no effect on in vitro blastocyst development. However, transfection with10 to 40 M antisense oligo had reduced in vitro blastocyst development to 15, 10% and 0; Forthe embryos which exposed to 40 M As arrested at the 16-cell stage, there was no blastocystformation within the heat shock groups. In contrast, transfection had no effect on embryonicsensitivity to heat shock, above 25% of embryos developed to blastocyst stage in controlgroups.展开更多
Fibrillar proteins form structural elements of cells and the extracellular matrix. Pathological lesions, of fibrillar microanatomical structures, or secondary fibrillar changes in globular proteins are well known. A s...Fibrillar proteins form structural elements of cells and the extracellular matrix. Pathological lesions, of fibrillar microanatomical structures, or secondary fibrillar changes in globular proteins are well known. A special group concerns histologically amorphous deposits, amyloid. The major characteristics of amyloid are: apple green birefringence after Congo red staining of histological sections, and non-branching 7–10 nm thick fibrils on electron microscopy revealing a high content of cross beta pleated sheets. About 25 different types of amyloid have been characterised. In animals, AA-amyloid is the most frequent type. Other types of amyloid in animals represent: AIAPP (in cats), AApoAI, AApoAII, localised AL-amyloid, amyloid in odontogenic or mammary tumors and amyloid in the brain. In old dogs Aβ and in sheep APrPsc-amyloid can be encountered. AA-amyloidosis is a systemic disorder with a precursor in blood, acute phase serum amyloid A (SAA). In chronic inflammatory processes AA-amyloid can be deposited. A rapid crystallization of SAA to amyloid fibrils on small beta-sheeted fragments, the ‘amyloid enhancing factor’ (AEF), is known and the AEF has been shown to penetrate the enteric barrier. Amyloid fibrils can aggregate from various precursor proteins in vitro in particular at acidic pH and when proteolytic fragments are formed. Molecular chaperones influence this process. Tissue data point to amyloid fibrillogenesis in lysosomes and near cell surfaces. A comparison can be made of the fibrillogenesis in prion diseases and in enhanced AA-amyloidosis. In the reactive form, acute phase SAA is the supply of the precursor protein, whereas in the prion diseases, cell membrane proteins form a structural source. Aβ-amyloid in brain tissue of aged dogs showing signs of dementia forms a canine counterpart of senile dementia of the Alzheimer type (ccSDAT) in man. Misfolded proteins remain potential food hazards. Developments concerning prevention of amyloidogenesis and therapy of amyloid deposits are shortly commented.展开更多
基金supported financially by National(30270957)Shandong(Y2003D03)Natural Science Foundation of China
文摘Experiments were performed to evaluate the efficiency of inhibition of HSP70 gene expressionby antisense oligonucleotides complementary to the mRNA of HSP70 and to test the effects ofinhibition of HSP70 gene expression on subsequent embryonic sensitivity to heat shock. Theresults showed that transfection of pre-implantation embryos at 4-cell stage with 5 Mantisense oligo had no effect on in vitro blastocyst development. However, transfection with10 to 40 M antisense oligo had reduced in vitro blastocyst development to 15, 10% and 0; Forthe embryos which exposed to 40 M As arrested at the 16-cell stage, there was no blastocystformation within the heat shock groups. In contrast, transfection had no effect on embryonicsensitivity to heat shock, above 25% of embryos developed to blastocyst stage in controlgroups.
文摘Fibrillar proteins form structural elements of cells and the extracellular matrix. Pathological lesions, of fibrillar microanatomical structures, or secondary fibrillar changes in globular proteins are well known. A special group concerns histologically amorphous deposits, amyloid. The major characteristics of amyloid are: apple green birefringence after Congo red staining of histological sections, and non-branching 7–10 nm thick fibrils on electron microscopy revealing a high content of cross beta pleated sheets. About 25 different types of amyloid have been characterised. In animals, AA-amyloid is the most frequent type. Other types of amyloid in animals represent: AIAPP (in cats), AApoAI, AApoAII, localised AL-amyloid, amyloid in odontogenic or mammary tumors and amyloid in the brain. In old dogs Aβ and in sheep APrPsc-amyloid can be encountered. AA-amyloidosis is a systemic disorder with a precursor in blood, acute phase serum amyloid A (SAA). In chronic inflammatory processes AA-amyloid can be deposited. A rapid crystallization of SAA to amyloid fibrils on small beta-sheeted fragments, the ‘amyloid enhancing factor’ (AEF), is known and the AEF has been shown to penetrate the enteric barrier. Amyloid fibrils can aggregate from various precursor proteins in vitro in particular at acidic pH and when proteolytic fragments are formed. Molecular chaperones influence this process. Tissue data point to amyloid fibrillogenesis in lysosomes and near cell surfaces. A comparison can be made of the fibrillogenesis in prion diseases and in enhanced AA-amyloidosis. In the reactive form, acute phase SAA is the supply of the precursor protein, whereas in the prion diseases, cell membrane proteins form a structural source. Aβ-amyloid in brain tissue of aged dogs showing signs of dementia forms a canine counterpart of senile dementia of the Alzheimer type (ccSDAT) in man. Misfolded proteins remain potential food hazards. Developments concerning prevention of amyloidogenesis and therapy of amyloid deposits are shortly commented.
