In situ hybridization reveals transient laminin B-chain expression by individual glial and muscle cells in embryonic leech central nervous system.
Research article published in Journal of neurobiology (1995)
Abstract
Laminin, which strongly stimulates axon outgrowth in vitro, appears transiently within the central nervous system (CNS) in embryos. After CNS injury, laminin reportedly reappears along axonal pathways only in animal species in which central axon regeneration is successful, including the leech Hirudo medicinalis. Although glia have been suspected of making CNS laminin, in adult leeches glia are not required for laminin synthesis and evidently microglia, not present in the early embryo, produce laminin. To determine which embryonic cells make laminin, a 1.2 kb DNA fragment of leech laminin B1 chain, with homology to Drosophila, human, and mouse B1 laminins and rat S laminin, was isolated using reverse-transcription and degenerate polymerase chain reaction (PCR) cloning. In situ hybridization revealed that laminin expression began before embryonic day 8, and by days 8 and 9 it was seen in paired CNS muscle cells. By late day 9, the two neuropil glial cells began to express laminin. Lucifer Yellow dye was injected intracellularly and muscle cells stimulated to contract, confirming the identities of muscle and glial cells. Packet glial cells began to express B1 laminin by embryonic day 12. By day 15, the cells of the perineurial sheath expressed B1 laminin, whereas it was no longer detectable in CNS muscle and glia. The results agree with published immunohistochemistry showing laminin within the CNS among growing axons by day 8, and only later in the perineurial sheath, by which time laminin disappears from within the CNS. Therefore, different cells synthesize laminin in the embryo and during repair in adults.
Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.
Resumen
Laminin, which strongly stimulates axon outgrowth in vitro, appears transiently within the central nervous system (CNS) in embryos. After CNS injury, laminin reportedly reappears along axonal pathways only in animal species in which central axon regeneration is successful, including the leech Hirudo medicinalis.
Por qué esto importa para la hirudoterapia
Este estudio empleó hibridación in situ para caracterizar el patrón temporal y celular de la expresión del gen de la cadena B1 de laminina en el sistema nervioso central embrionario de la sanguijuela Hirudo medicinalis, identificando un fragmento de ADN de 1,2 kb con homología frente a las lamininas B1 de Drosophila, humano y ratón. Los autores encontraron que las células musculares pares del SNC expresaron laminina en los días embrionarios 8–9, seguidas de las células gliales del neuropilo, y que distintos tipos celulares sintetizan laminina durante la embriogénesis en comparación con la reparación del SNC adulto. Este estudio es relevante para el ámbito de ASH en la medida en que avanza en la comprensión fundamental de la biología del desarrollo y regenerativa de Hirudo medicinalis, la especie utilizada principalmente en hirudoterapia. Matización: se trata de un estudio básico de neurociencia del desarrollo que examina la expresión génica de la matriz extracelular en embriones de sanguijuela; no tiene una relación directa con la práctica de la hirudoterapia, con el secretoma de la sanguijuela ni con las aplicaciones clínicas de la terapia con sanguijuelas.
Citación
In situ hybridization reveals transient laminin B-chain expression by individual glial and muscle cells in embryonic leech central nervous system.
Luebke et al. · Journal of neurobiology, 1995
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Añadido a la biblioteca ASH: May 28, 2026 · Última actualización del sitio: 18 de junio de 2026