Biology subjects

Kabbani, N.

Publications and source records attributed to Kabbani, N..

4 recordsLinked to original sources

bioRxiv2024

Proteomic Analysis of Dorsal Root Ganglia in a Mouse Model of Paclitaxel-Induced Neuropathic Pain

Paclitaxel is a chemotherapy drug widely used for the treatment of various cancers based on its ability to potently stabilize cellular microtubules and block division in cancer cells. Paclitaxel-based treatment, however, accumulates in peripheral system sensory neurons and leads to a high incidence rate (over 60%) of chemotherapy induced peripheral neuropathy. Using an established preclinical model of paclitaxel-induced peripheral neuropathy (PIPN), we examined proteomic changes in dorsal root ganglia (DRG) of adult male mice that were treated with paclitaxel (8 mg/kg, at 4 injections every other day) relative to vehicle-treated mice. High throughput proteomics based on liquid chromatography electrospray ionization mass spectrometry identified 165 significantly altered proteins in lumbar DRG. Gene ontology enrichment and bioinformatic analysis revealed an effect of paclitaxel on pathways for mitochondrial regulation, axonal function, and inflammatory purinergic signaling as well as microtubule activity. These findings provide insight into molecular mechanisms that can contribute to PIPN in patients.

neuroscience↗

bioRxiv2024

Ribosome-Associated Vesicles promote activity-dependent local translation

Local protein synthesis in axons and dendrites underpins synaptic plasticity. However, the composition of the protein synthesis machinery in distal neuronal processes and the mechanisms for its deployment to local translation sites remain unclear. Here, we employed a multi-scale imaging approach combining cryo-electron tomography, volume electron microscopy, and live-cell imaging to identify endoplasmic reticulum-derived Ribosome-Associated Vesicles (RAVs) as a dynamic platform for moving ribosomes to distal processes and promoting activity-dependent local translation. We demonstrate that neuronal stimulation triggers compartment-specific RAV responses: dendrites accumulate stationary RAVs at sites of enhanced translation, while axons accelerate RAV transport. Real-time imaging of translation at single mRNA resolution reveals that RAVs boost local translation output compared to RAV-independent mechanisms. These findings establish RAVs as specialized platforms that integrate activity-dependent signals with local protein synthesis, providing a mechanistic framework for understanding how neurons achieve precise spatiotemporal control of protein synthesis.

neuroscience↗

bioRxiv2023

The human acetylcholinesterase c-terminal T30 peptide activates neural growth through an alpha 7 nicotinic acetylcholine receptor mTOR pathway

Acetylcholinesterase (AChE) is a highly conserved enzyme responsible for the regulation of acetylcholine signaling within the brain and periphery. AChE has also been shown to participate in non-enzymatic activity and contributing to development and aging. In particular, enzymatic cleavage of the carboxy terminal region of the synaptic AChE isoform, AChE-T, is shown to generate a bioactive T30 peptide that binds to the 7 nicotinic acetylcholine receptor (nAChR) at synapses. Here, we explore intracellular mechanisms of T30 signaling within the human cholinergic neural cell line SH-SY5Y using high performance liquid chromatography (HPLC) coupled to electrospray ionization mass spectrometry (ESI-MS/MS). Proteomic analysis of cells exposed to (100nM) T30 for 3-days reveals significant changes within proteins important for cell growth. Specifically, bioinformatic analysis identifies proteins that converge onto the mammalian target of rapamycin (mTOR) pathway signaling. Functional experiments confirm that T30 regulates neural cell growth via mTOR signaling and 7 nAChR activation. In addition, T30 was found promote mTORC1 pro-growth signaling through an increase in phosphorylated elF4E, and a decrease in autophagy LC3B-II level. Taken together, our findings define mTOR as a novel pathway activated by the T30 cleavage peptide of AChE and suggest a role for mTOR signaling in cholinergic aspects of brain development, as well as disease.

neuroscience↗

bioRxiv2021

Mechanisms of Coupling between Angiotensin Converting Enzyme 2 and Nicotinic Acetylcholine Receptors

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), an RNA virus encapsulated by a spike (S) glycoprotein envelope, binds with high affinity to angiotensin converting enzyme 2 (ACE2) during cell entry of a susceptible host. Recent studies suggest nicotinic acetylcholine receptors (nAChRs) play a role in functional ACE2 regulation and nicotine may contribute to the progression of coronavirus disease 2019 (COVID-19). Here, we present evidence for coupling between ACE2 and nAChR through bioinformatic analysis and cell culture experiments. Following molecular and structural protein comparison of over 250 ACE2 vertebrate orthologues, a region of human ACE2 at positions C542-L554 was identified to have sequence similarity to nAChR-binding neurotoxin and rabies virus glycoproteins (RBVG). Furthermore, experiments conducted in PC12 cells indicate a potential for physical interaction between ACE2 and 7 nAChR proteins. Our findings support a model of nAChR involvement in in COVID-19.

neuroscience↗