A analysis group on the Institute of Neurosciences of the University of Barcelona (UBneuro) has led a study describing a brand new molecular mechanism that impacts RNA processing and alters the method of protein synthesis in the brains of Alzheimer’s sufferers. The study, which has been carried out in autopsy samples of sufferers and in animal fashions of the disease, will increase the design of future therapies to handle the therapy of this dementia and different neurological problems.
Cristina Malagelada, who led the study, and Genís Campoy-Campos, its first creator, have printed the paper in Nucleic Acids Research. Malagelada is a professor on the UB’s Faculty of Medicine and Health Sciences and the UBneuro and, along with Campoy-Campos, are members of the Centre for Biomedical Research Network on Neurodegenerative Diseases (CIBERNED).
A brand new operate for the RTP801 protein
Alzheimer’s disease is the commonest kind of dementia and causes a gradual decline in cognition, reminiscence and language expertise, in addition to emotional and psychiatric problems. It is characterised by the buildup of β-amyloid plaques exterior neurons and hyperphosphorylated tau protein inside neurons, which alter mind operate and trigger cell loss of life.
Now, this study reveals a beforehand unknown function for the RTP801 protein, a stress response issue that’s ample in sufferers with neurodegenerative illnesses equivalent to Alzheimer’s disease. According to the findings, this protein can alter the molecular mechanisms that help neuronal survival by affecting the interpretation of RNA into proteins.
Malagelada says that “till now, we knew that the RTP801 protein, which is discovered in hippocampal neurons, was concerned in the pathology of Alzheimer’s, as we printed in a earlier article (Cell Death and Disease, 2021). Back then, we found that ranges of this protein have been considerably elevated in each mouse fashions of Alzheimer’s and in autopsy samples from sufferers, and these values correlated with disease development”.
“On a mechanistic stage, we noticed that lowering RTP801 expression prevented cognitive deficits and irritation, particularly by mitigating the activation of the hippocampal inflammasome, i.e. the equipment that processes cytokines in inflammatory responses and drives gliosis (reactivation and proliferation of glial cells)”, continues the professional.
Why is that this mechanism essential for neuronal well being?
The study describes how the RTP801 issue negatively regulates the exercise of the tRNA ligase complicated(tRNA-LC), which is important for processing RNA molecules. In the context of Alzheimer’s disease, larger ranges of RTP801 can inhibit this complicated and trigger issues in RNA splicing and subsequent manufacturing of related proteins, equivalent to brain-derived neurotrophic issue (BDNF), exacerbating cognitive issues in a mouse mannequin of Alzheimer’s disease.
Campoy-Campos notes that “in this study, we’ve discovered that top ranges of RTP801 intervene with the tRNA ligase complicated, which is chargeable for RNA processing, particularly in the method of ligation of its exons, as soon as the introns have been cleaved. This course of takes place each in the messenger RNA — which comprises the data to construct the protein — and in the switch RNAs, which carry the amino acids to translate it”. The researcher stresses that “this course of is significant for the proper synthesis of proteins on the ribosome, the cell organelles the place the interpretation of RNA into proteins takes place”.
Interestingly, this interplay between RTP801 and the tRNA ligase complicated additionally impacts the RNA binding of a transcription issue known as XBP1s. This issue helps cells deal with stress in the endoplasmic reticulum — an organ fashioned by a set of cisternae and membranous cavities in the cell cytoplasm — and promotes the expression of BDNF, a neurotrophin essential for synaptic transmission, reminiscence and neuronal survival.”
Genís Campoy-Campos, first creator
Altered RNA processing — a consequence of excessive ranges of RTP801 — is extremely detrimental to neurons, disrupting their capacity to synthesize proteins and reply to stress. As Malagelada factors out, this altered RNA processing provides a brand new poisonous element to the hitherto recognized evolution of Alzheimer’s disease. “We now carry to the desk the toxicity of unbound RNAs and its penalties as a brand new neurodegenerative mechanism in Alzheimer’s”, she says.
Boosting future therapies to deal with neurodegenerative illnesses
The discovery of recent features of the RTP801 protein may open up future therapeutic choices to handle the therapy of neurodegenerative pathologies and protect mind operate and neuronal well being. In this sense, Malagelada factors out that “if we will design inhibitors of the RTP801 protein — which we’re at present engaged on — or protect the exercise of the tRNA ligase complicated, we may particularly block essentially the most poisonous features of this issue and protect important neuronal processes”.
The researchers conclude that “this provides a brand new vary of modern therapeutic choices in the context of those neurological problems”.
Source:
Journal reference:
Campoy-Campos, et al. (2024). RTP801 interacts with the tRNA ligase complicated and dysregulates its RNA ligase exercise in Alzheimer’s disease. Nucleic Acids Research. doi.org/10.1093/nar/gkae776.