RESUMEN
Increased expression of the 3.1 isoform of the KCNH2 potassium channel has been associated with cognitive dysfunction and with schizophrenia, yet little is known about the underlying pathophysiological mechanisms. Here, by using in vivo wireless local field potential recordings during working memory processing, in vitro brain slice whole-cell patching recordings and in vivo stereotaxic hippocampal injection of AAV-encoded expression, we identified specific and delayed disruption of hippocampal-mPFC synaptic transmission and functional connectivity associated with reductions of SERPING1, CFH, and CD74 in the KCNH2-3.1 overexpression transgenic mice. The differentially expressed genes in mice are enriched in neurons and microglia, and reduced expression of these genes dysregulates the complement cascade, which has been previously linked to synaptic plasticity. We find that knockdown of these genes in primary neuronal-microglial cocultures from KCNH2-3.1 mice impairs synapse formation, and replenishing reduced CFH gene expression rescues KCNH2-3.1-induced impaired synaptogenesis. Translating to humans, we find analogous dysfunctional interactions between hippocampus and prefrontal cortex in coupling of the fMRI blood oxygen level-dependent (BOLD) signal during working memory in healthy subjects carrying alleles associated with increased KCNH2-3.1 expression in brain. Our data uncover a previously unrecognized role of the truncated KCNH2-3.1 potassium channel in mediating complement activation, which may explain its association with altered hippocampal-prefrontal connectivity and synaptic function. These results provide a potential molecular link between increased KCNH2-3.1 expression, synapse alterations, and hippocampal-prefrontal circuit abnormalities implicated in schizophrenia.
Asunto(s)
Activación de Complemento/fisiología , Canal de Potasio ERG1/metabolismo , Memoria a Corto Plazo/fisiología , Animales , Encéfalo/metabolismo , Disfunción Cognitiva/genética , Activación de Complemento/inmunología , Canal de Potasio ERG1/genética , Femenino , Hipocampo/metabolismo , Humanos , Imagen por Resonancia Magnética , Masculino , Trastornos de la Memoria/fisiopatología , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Plasticidad Neuronal/fisiología , Neuronas/metabolismo , Corteza Prefrontal/metabolismo , Esquizofrenia/genética , Esquizofrenia/metabolismo , Transmisión Sináptica/fisiología , Lóbulo Temporal/metabolismoRESUMEN
Synthetic biology is an interdisciplinary field that brings together engineering and biology concepts alongside the arts and social sciences to develop solutions to pressing problems in our world. The education of students entering this field has relied on a diverse set of pedagogical methods to accomplish this goal. One non-profit group, iGEM-the International Genetically Engineered Machine competition, has been a driver of students' awareness of synthetic biology for the last 20 years giving many young researchers their first experience in the field of synthetic biology. Dissemination of synthetic biology concepts by iGEM has occurred through several programs including a webinar series started during the 2020 COVID pandemic. The iGEM webinar series successfully engaged students by taking inspiration from synthetic biology programs in Europe, North America, and Asia that had themselves evolved alongside iGEM. The webinar designers modeled the content after their experiences in iGEM as well as their academic courses, pedagogy, and mentoring experiences. This series has produced globally accessible pedagogy for both technical synthetic biology knowledge and the communication skills necessary to build and communicate synthetic biology projects. The hope is that this series functions as a lasting blueprint that can be used by future educators in synthetic biology and other disciplines to reduce barriers that students face when attempting to enter cutting edge fields.
RESUMEN
The deposition of fibrillated human islet ß-cell peptide islet amyloid polypeptide (hIAPP) into amyloid plaques is characteristic of the pathogenesis of islet cell death during type 2 diabetes. We investigated the effects of the neuroendocrine secretory proteins 7B2 and proSAAS on hIAPP fibrillation in vitro and on cytotoxicity. In vitro, 21-kDa 7B2 and proSAAS blocked hIAPP fibrillation. Structure-function studies showed that a central region within 21-kDa 7B2 is important in this effect and revealed the importance of the N-terminal region of proSAAS. Both chaperones blocked the cytotoxic effects of exogenous hIAPP on Rin5f cells; 7B2 generated by overexpression was also effective. ProSAAS and 7B2 may perform a chaperone role as secretory anti-aggregants in normal islet cell function and in type 2 diabetes.