Редактирование: HSPB2

Heat shock protein beta-2 (HspB2) (DMPK-binding protein) (MKBP)

==Publications==

{{medline-entry
|title=[[CRYAB]] and [[HSPB2]] deficiency alters cardiac metabolism and paradoxically confers protection against myocardial ischemia in aging mice.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/17873008
|abstract=The abundantly expressed small molecular weight proteins, [[CRYAB]] and [[HSPB2]], have been implicated in cardioprotection ex vivo. However, the biological roles of [[CRYAB]]/[[HSPB2]] coexpression for either ischemic preconditioning and/or protection in situ remain poorly defined. Wild-type (WT) and age-matched ( approximately 5-9 mo) [[CRYAB]]/[[HSPB2]] double knockout (DKO) mice were subjected either to 30 min of coronary occlusion and 24 h of reperfusion in situ or preconditioned with a 4-min coronary occlusion/4-min reperfusion x 6, before similar ischemic challenge (ischemic preconditioning). Additionally, WT and DKO mice were subjected to 30 min of global ischemia in isolated hearts ex vivo. All experimental groups were assessed for area at risk and infarct size. Mitochondrial respiration was analyzed in isolated permeabilized cardiac skinned fibers. As a result, DKO mice modestly altered heat shock protein expression. Surprisingly, infarct size in situ was reduced by 35% in hearts of DKO compared with WT mice (38.8  /- 17.9 vs. 59.8  /- 10.6% area at risk, P < 0.05). In DKO mice, ischemic preconditioning was additive to its infarct-sparing phenotype. Similarly, infarct size after ischemia and reperfusion ex vivo was decreased and the production of superoxide and creatine kinase release was decreased in DKO compared with WT mice (P < 0.05). In permeabilized fibers, ADP-stimulated respiration rates were modestly reduced and calcium-dependent ATP synthesis was abrogated in DKO compared with WT mice. In conclusion, contrary to expectation, our findings demonstrate that [[CRYAB]] and [[HSPB2]] deficiency induces profound adaptations that are related to 1) a reduction in calcium-dependent metabolism/respiration, including ATP production, and 2) decreased superoxide production during reperfusion. We discuss the implications of these disparate results in the context of phenotypic responses reported for [[CRYAB]]/[[HSPB2]]-deficient mice to different ischemic challenges.
|mesh-terms=* Aging
* Animals
* Female
* HSP27 Heat-Shock Proteins
* Heat-Shock Proteins
* Male
* Mice
* Mice, Knockout
* Myocardial Ischemia
* Myocardium
* alpha-Crystallin B Chain

|full-text-url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3683980
}}
{{medline-entry
|title=Ischemia-induced increase of stiffness of alphaB-crystallin/[[HSPB2]]-deficient myocardium.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/16217658
|abstract=The two small heat shock proteins (sHSPs), alphaB-crystallin and [[HSPB2]], have been shown to translocate within a few minutes of cardiac ischemia from the cytosol to myofibrils; and it has been suggested that their chaperone-like properties might protect myofibrillar proteins from unfolding or aggregation during stress conditions. Further evidence of an important role for HSPs in muscle function is provided by the fact that mutations of the alphaB-crystallin gene cause myopathy and cardiomyopathy. In the present study, we subjected isolated papillary muscles of alphaB-crystallin/[[HSPB2]]-deficient mice to simulated ischemia and reperfusion. During ischemia in alphaB-crystallin/[[HSPB2]]-deficient muscles, the development of contracture started earlier and reached a higher value compared to the wildtype mice. The recovery of contracture of alphaB-crystallin/[[HSPB2]]-deficient muscles was also attenuated during the simulated reperfusion period. However, twitch force was not significantly altered at any time of the experiment. This suggests that during ischemic insults, alphaB-crystallin/[[HSPB2]] may not be important for the contraction process itself, but rather serve to maintain muscular elasticity.
|mesh-terms=* Animals
* Gene Deletion
* Gene Expression Regulation
* HSP27 Heat-Shock Proteins
* Heat-Shock Proteins
* Longevity
* Mice
* Myocardial Contraction
* Myocardial Ischemia
* Myocardial Reperfusion Injury
* Myocardium
* Weight Loss
* alpha-Crystallin B Chain

|full-text-url=https://sci-hub.do/10.1007/s00424-005-1488-1
}}
{{medline-entry
|title=AlphaB-crystallin in lens development and muscle integrity: a gene knockout approach.
|pubmed-url=https://pubmed.ncbi.nlm.nih.gov/11687538
|abstract=To study the role of alphaB-crystallin (alphaB) in the developing lens and its importance in lens structure and function. Gene targeting in embryonic stem cells was used to generate mouse lines in which the alphaB gene and its protein product were absent. Gene structure and expression were characterized by genomic Southern blot, immunoblot, and Northern blot analyses, and two-dimensional gel electrophoresis. The gene knockout mice were screened for cataract with slit lamp biomicroscopy, and dissected lenses were examined with dark-field microscopy. Lenses and other tissues were analyzed by standard histology and immunohistochemistry. Chaperone activity was determined by heating lens homogenate supernatants and measuring absorbance changes. In an unexpected result, lenses in the alphaB gene knockout mice developed normally and were remarkably similar to wild-type mouse lenses. All the other crystallins were present. The thermal stability of a lens homogenate supernatant was mildly compromised, and when oxidatively stressed in vivo with hyperbaric oxygen, the knockout lenses reacted similarly to wild type. In targeting the alphaB gene, the adjacent [[HSPB2]] gene, which is not expressed in the lens, was also disrupted. Loss of alphaB and/or [[HSPB2]] function leads to degeneration of some skeletal muscles. AlphaB is not essential for normal development of a transparent lens in the mouse, and therefore is more dispensable to the lens than the closely related alphaA-crystallin. It may play a small role in maintaining transparency throughout life. alphaB and/or the closely related [[HSPB2]] is required to maintain muscle cell integrity in some skeletal muscles.
|mesh-terms=* Aging
* Animals
* Bacterial Proteins
* Blotting, Northern
* Blotting, Southern
* Crystallins
* Electrophoresis, Gel, Two-Dimensional
* Gene Deletion
* Heat-Shock Proteins
* Kyphosis
* Lens, Crystalline
* Mice
* Mice, Knockout
* Molecular Chaperones
* Muscle, Skeletal
* Muscular Dystrophies
* Oxidative Stress
* RNA, Messenger


}}