Neurogenesis pada Perdarahan Intraserebral Spontan

Abstract

Abstrak Perdarahan intraserebral spontan (PIS) adalah salah satu tipe stroke berdarah, akibat ruptur pembuluh darah sehingga darah menggenangi parenkim otak. Mortalitasnya mencapai 34,6% dan hanya 38% yang dapat pulih seperti sediakala atau dengan kecacatan ringan. Pada PIS terjadi cedera primer yaitu kerusakan neuron dan glia secara mekanis yang diikuti oleh deformasi, pelepasan neurotransmitter, disfungsi mitokondria dan depolarisasi membran sel. Selanjutnya terjadi cedera sekunder akibat pemecahan hemoglobin dan faktor koagulasi khususnya trombin. Produk tersebut akan mengaktifkan mikroglia sehingga menghasilkan zat toksik seperti reactive oxygen species (ROS), matrix metalloproteinase (MMP), cyclooksigenase-2, prostaglandin, heme oxygenase-1 (HO-1), faktor komplemen, tumor necrotizing factor α (TNFα), dan interleukin 1β yang mengakibatkan cedera jaringan. Selain cedera, juga terjadi penggantian sel mati melalui proses neurogenesis yaitu pertumbuhan sel punca neural di area subventrikel dan hipokampus. Sel tersebut akan bermigrasi ke area perdarahan karena terjadi perbedaan kadar stromal derived factor-1 (sdf-1) pada kedua area tersebut. Sebanyak 80% sel yang bermigrasi tersebut akan mati sehingga hanya sedikit yang dapat menggantikan sel mati.
Kata Kunci: sel punca neural, habitat, mikroglia, zat toksik

Abstract Spontaneous intracerebral hemorrhage (SICH) is a type of hemorrhagic stroke. There are brain vessels rupture which bleeds into parenchym. Mortality rate of ICH is about 34.6% and only 38% of the patients can be fully recovered. Mechanical disruption will appear by the bleeding as primary injury. The neuron and glia will be deformed, neurotransmitter released, dysfunctional mitochondria and cell membrane depolarization will occur. Primary injury will be followed by secondary injury due to degradation of blood product such as hemoglobin and coagulation factor, especially thrombin. These product will activate microglia resulted in the production of toxic factors i.e. reactive oxygen species (ROS), matrix metalloproteinase (MMP), cyclooksigenase-2 (Cox-2), prostaglandin, heme oxygenase -1 (HO-1), complement factor, tumor necrotizing factor α (TNFα), and interleukin 1β. Furthermore, there is replacement of dead cells by neuroendogenesis proscess, performed by stem cells that normally exist in a special niche in subventricle zone and hippocampus.. The stem cells in the migrates to perihematoma zone attracted by the different concentration of stromal derived factor-1 (SDF-1) between the niche and the peri-hematoma area. But most of the activated cells (80%) will die and only small number survive to replace the dead cells.
Key words: neural stem cells, niche, microglia, toxic subtance