生物谷綜合報道：人到了老年就會容易健忘,，如何能夠讓大腦細胞一直受到刺激保持記憶能力是科學(xué)家們最關(guān)注的研究課題之一。最近,，美國新澤西州魯特杰斯大學(xué)的幾位科學(xué)家表示,，他們已經(jīng)發(fā)現(xiàn)了一種能夠刺激腦細胞增長的蛋白質(zhì)，模仿這種蛋白質(zhì)的化學(xué)成份制成藥物將可以起到增強記憶的效果,。
上述科學(xué)家表示，這種蛋白質(zhì)富含的化學(xué)成份“cypin”是大腦進行學(xué)習(xí)和記憶存儲時最需要的物質(zhì)之一,，另外其在不同腦細胞之間建立連接方面也扮演著重要的角色,。
科學(xué)家稱，完全可以基于“cypin”研發(fā)出類似的增強記憶藥物,?？茖W(xué)家之一鮑妮-菲雷斯坦教授表示，“cypin”看起來對于腦神經(jīng)細胞之間的細絲狀連接物的增長起著至關(guān)重要的作用,，而這些細絲狀連接物正是記憶形成的原因之一,。她說，當(dāng)神經(jīng)細胞之間無法連接時,，大腦可能就會出現(xiàn)記憶漸漸缺失等癥狀,，最明顯的反映就是老年癡呆病人的癥狀。
菲雷斯坦教授說：“確定‘cypin’的作用以及了解它的工作原理將為治療嚴(yán)重的腦神經(jīng)紊亂打開新的途徑,。‘cypin’可以說是刺激腦神經(jīng)細胞增長的催化劑,，如果說神經(jīng)細胞是一顆樹，‘cypin’就是樹干生長的控制器,。樹干生長越好越枝繁葉茂,，神經(jīng)細胞就能夠接收更多的信息從而增強大腦的記憶能力。”
科學(xué)家表示,，“Cypin”這種化學(xué)成份早在1999年已經(jīng)被發(fā)現(xiàn)，但直到最近才被確認是大腦內(nèi)部一種活躍的生化酶,。
這是1999年發(fā)表在Neuron上的文章：
Neuron. 1999 Nov; 24(3): 659-72.
Cypin: a cytosolic regulator of PSD-95 postsynaptic targeting.
Firestein BL, Firestein BL, Brenman JE, Aoki C, Sanchez-Perez AM, El-Husseini AE, Bredt DS.
Department of Physiology, University of California, San Francisco 94143, USA.
Postsynaptic density 95 (PSD-95/SAP-90) is a membrane associated guanylate kinase (GK) PDZ protein that scaffolds glutamate receptors and associated signaling networks at excitatory synapses. Affinity chromatography identifies cypin as a major PSD-95-binding protein in brain extracts. Cypin is homologous to a family of hydrolytic bacterial enzymes and shares some similarity with collapsin response mediator protein (CRMP), a cytoplasmic mediator of semaphorin III signalling. Cypin is discretely expressed in neurons and is polarized to basal membranes in intestinal epithelial cells. Overexpression of cypin in hippocampal neurons specifically perturbs postsynaptic trafficking of PSD-95 and SAP-102, an effect not produced by overexpression of other PDZ ligands. In fact, PSD-95 can induce postsynaptic clustering of an otherwise diffusely localized K+ channel, Kv1.4. By regulating postsynaptic protein sorting, cypin may influence synaptic development and plasticity.
這是另一個最新相關(guān)報道，最新有關(guān)cypin文章發(fā)表在Nature neurosciences
Rutgers scientists discover protein in brain affects learning and memory
NEW BRUNSWICK/PISCATAWAY, N.J. – Rutgers researchers have discovered what could be the newest target for drugs in the treatment of memory and learning disabilities as well as diseases such as Alzheimer's and fetal alcohol syndrome: a protein known as cypin.
Cypin is found throughout the body, but in the brain it regulates nerve cell or neuron branching. Branching or dendrite growth is an important process in normal brain function and is thought to increase when a person learns. A reduction in branching is associated with certain neurological diseases.
"The identification of cypin and understanding how it works in the brain is particularly exciting since it opens up new avenues for the treatment of serious neurological disorders," said principal investigator Bonnie Firestein, assistant professor of cell biology and neuroscience at Rutgers, The State University of New Jersey. "This paves the way to designing new drugs that could target this protein molecule."
Proteins or the genes that code for them have become the targets of choice for developing precisely focused, effective new drug therapies – one of the outcomes of the many revelations provided by the Human Genome Project.
Firestein first identified and isolated cypin in 1999 during her postdoctoral research. She is currently focusing on how it works in the hippocampus, a structure in the brain associated with the regulation of emotions and memory.
"We knew that cypin existed elsewhere in the body where it performs other functions, but no one knew why it was present in the brain," Firestein. Her new research determined that cypin in the brain works as an enzyme involved in shaping neurons.
"One end of a neuron looks like a tree and, in the hippocampus, cypin controls the growth of its branches," she explained. "An increase in the number of branches provides additional sites where a neuron can receive information that it can pass along, enhancing communication."
Maxine Chen, a graduate student in Firestein's laboratory, helped substantiate the connection between cypin and dendrite growth. When she looked closely at neurons in the lab, she found cypin only in certain neurons – "neurons that tended to be more fuzzy," as she described those with increased dendrites. Stimulating neurons in a dish also produced an increase in the protein overall. This has been shown to increase dendrite growth.
Fellow graduate student Barbara Akum further verified the connection between the protein and branching. She used a new molecular technique developed by Samuel Gunderson, a Rutgers assistant professor of molecular biology and biochemistry. With this new tool, Akum reduced the expression of cypin and observed a consequent decrease in branching.
"We also found something else that is really exciting," said Firestein, referring to the molecular mechanics by which cypin affects dendrite growth. Cypin appears to act as a glue that cements other molecules together into long chain structures that extend through the branches of a dendrite as a skeleton.
"Cypin works on tubulin, a protein that is a structural building block of the dendrite skeleton," explained Firestein. "If you just take our purified protein and mix it with tubulin in a test tube, the cypin on its own will actually cause these skeletal structures to grow."
A paper presenting this research will appear in Nature Neuroscience online beginning (Sunday) Jan. 19.
