China
Africa
Explore chapters and articles related to this topic
Pharmacological Management of Amyotrophic Lateral Sclerosis
Published in Sahab Uddin, Rashid Mamunur, Advances in Neuropharmacology, 2020
Shalini Mani, Chahat Kubba, Tanya Sharma, Manisha Singh
Neurons lengthen their axons in excess of extensive distances during developing connections with other synaptic neurons. Proteins involved in guiding the axon may control the progression of axon guidance. These proteins can play a function in attracting or repelling axons thus guide them to a definite area or stopping them from rising into unsuitable regions, correspondingly. Recently several report sustain the testing theory that abnormal expression or function of axon guiding proteins such as ephrins, semaphorins, slits, and netrins usually implicated in curating and maintaining circuits of motor neuron may bring on pathological variations in circuits of motor neuron (Hollis, 2015). Interestingly, pathological variations occurring in nerve terminals and motor axons are found to lead degeneration of motor neurons and associated clinical abnormalities (Fischer et al., 2004). It can be inferred from this discovery that the disease development may begin at the nerve endings and ultimately grow toward the body of the neuronal cell. Numerous diverse molecules responsible for guiding the axons changed expressions in patients of ALS. Thus single-nucleotide polymorphisms (SNPs) in genes expressing proteins for axon guidance may important for diagnosis of ALS (Lesnick et al., 2008). After realizing the importance of these proteins, recently the cell replacement strategies have been designed for corrections of the degenerating motor system of these patients (Silva and Yu, 2008).
Cortical Plasticity: Growth of New Connections Can Contribute to Reorganization
Published in Mark J Rowe, Yoshiaki Iwamura, Somatosensory Processing: From Single Neuron to Brain Imaging, 2001
Sherre L. Florence, Jon H. Kaas
Finally, there also appear to be growth inhibitors that may counteract the facilitory action of neurotrophic factors. A class of molecules have been identified that repulse growing axon tips (for review see Schwab, 1996). The role of these inhibitors during development appears to be axon guidance, like ‘Do Not Enter’ signs for growing axons. Elimination of myelin, where some of the inhibitory factors exist, led to highly aberrant growth of corticospinal axons in young rats (for review see Schwab, 1996). In the adult brain the role of growth inhibitors seems to the stabilization of existing connections. For example, Schwab and colleagues (see Schwab, 1996) showed that elimination of myelin resulted in considerable collateral sprouting.
The concept revolution of gut barrier: from epithelium to endothelium
Published in International Reviews of Immunology, 2021
Song Liu, Peng Song, Feng Sun, Shichao Ai, Qiongyuan Hu, Wenxian Guan, Meng Wang
Another study by Detmar et al. compared the transcriptional profiles between vascular endothelial cells (BEC) and lymphatic endothelial cells (LEC) [12]. They isolated CD31+ CD45- podoplanin- (BEC) and CD31+ CD45- podoplanin+ (LEC) from healthy murine colon. We retrieved the raw data of their whole transcriptional analysis from GSE22034 in Gene Expression Omnibus (GEO) of National Center for Biotechnology Information (NCBI), and conducted Gene Ontology (GO) analysis using Limma [13] and clusterProfiler packages [14] in R software (version 3.5.3). Figure 2 illustrated representative pathways and corresponding genes between BEC and LEC in murine colon. As shown in Figure 2A, extracellular structure organization was the most significant biological process, extracellular matrix was the most significant cellular component, and extracellular matrix structural constituent was the most significant molecular function. A series of molecular binding functions (including cell adhesion molecule binding, integrin binding, collagen binding, etc.) were associated with the function of GVB. Figure 2B illustrated significant genes that associated with representative categories of biological process, including axon guidance, cell-substrate adhesion, circulatory system process, etc. The number of genes in each category fluctuated between 20 to 30 as indicated by the size of black dots.
Proteomic examination of the neuroglial secretome: lessons for the clinic
Published in Expert Review of Proteomics, 2020
Jong-Heon Kim, Ruqayya Afridi, Won-Ha Lee, Kyoungho Suk
Another recent study reported the differential secretion of astrocyte-derived extracellular cargo (ADEVs) in response to treatment with various cytokines [23]. Rat primary astrocytes were subjected to inflammatory stimulus (ATP/IL-1β) or an anti-inflammatory stimulus (IL-10) and ADEVs secreted by the astrocytes were collected after 2 hr of treatment. The proteins in the ADEVs were analyzed using a tandem mass tag-based proteomic technique. The study found the differential secretions of five distinct proteins in response to IL-1β treatment, including complement component 3 (C3), prothymosin alpha (PTMA), and lysyl oxidase (LOX), which may be responsible for stimulating the peripheral immune response. In comparison to IL-1β, ATP-treated astrocytes secreted ribosomal protein L10 (RPL10) and neuropilin and tolloid like 1 (NETO1) differentially. These molecules play important roles in axon guidance and synaptogenesis. The study implies a stimulus-dependent role of astrocytes mediated by secreted proteins, which is important for regulating physiological and detrimental functions in response to the respective stimuli.
Understanding intrinsic survival and regenerative pathways through in vivo and in vitro studies: implications for optic nerve regeneration
Published in Expert Review of Ophthalmology, 2021
To accomplish optic nerve regeneration, multimodal approaches are required (Figure 1). After injury, axons and dendrites are also degenerated and cannot regenerate under the existing physiological conditions. One reason for the failure of optic nerve regeneration is the inactivation of intrinsic survival and regenerative pathways of RGCs, and the presence of an inhibitory environment for axonal regeneration in the CNS (Figure 1). To overcome these barriers, multimodal strategies, i.e. neuroprotection, axonal elongation, axonal guidance, and reconstitution of the optic nerve circuit, are required. Although the regeneration ratio is still low, some regenerating axons can already reach the target cells in the brain cortex [56] and partly recover function by mixing with multiple strategies. To improve the regenerating ratio, multiple neuroprotective therapies may be required to increase survival cells after damage. Adequate axon guidance is the most difficult and the final stage but the mechanisms of repulsion and attraction of axon guidance have been identified. One possible strategy to overcome axon growth inhibitors in the CNS may be an electrical stimulation [56]. The electrical stimulation may, in part, mimic neuronal physiological activities for damaged neurons and stabilize the growth cones formation in the healthy condition. The similar physiological healthy activities of regenerating neurons may be a clue to overcome inhibitory environment for optic nerve regeneration in the CNS. Taken together, increasing intrinsic regenerative abilities, multiple neuroprotective strategies, and maintain the physiological neuronal activities may be required for realizing optic nerve regeneration in the CNS after injury.