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Glaucoma is an age-related neurodegenerative disorder characterized by retinal ganglion cell (RGC) degeneration and excavation of the optic nerve head (ONH). It is associated with an increase in intraocular pressure (IOP) and progressive decline in the visual field. Reduction in the retrograde axonal transport of neurotrophic factors such as brain-derived neurotrophic factor (BDNF) from the brain to the neuronal cell bodies in retina, has been suggested as one of the key mechanisms underlying selective degeneration of ganglion cells and optic nerve in glaucoma. Multiple studies have indicated that BDNF and its high affinity receptor Tropomyosin receptor kinase B (TrkB) play crucial roles in survival of RGCs and that upregulating BDNF/TrkB signalling using gene therapy can protect the ganglion cells against degeneration. This study corroborates previous findings and demonstrates that glaucoma is associated with downregulation of TrkB downstream signalling and enhanced levels of amyloid β (Aβ 1–42) accumulation in the retina. 7,8 dihydroxyflavone (7,8 DHF) is a TrkB agonist and regular administration of this compound imparted significant protection against loss of GCL density and preserved inner retinal function in experimental glaucoma models. 7,8 DHF treatment stimulated activation of TrkB intracellular signalling as well as ameliorated the increase in the levels of soluble Aβ (1–42) in the retinas of rats and mice exposed to high IOP. The protective effects of 7,8 DHF were also evident in BDNF(+/−) mice indicating that TrkB agonist mediated activation of TrkB signalling was not altered upon BDNF allelic impairment. These data support BDNF/TrkB axis as a promising therapeutic target in glaucoma and highlight that the detrimental effects of high IOP exposure can be compensated by the exogenous administration of a TrkB agonist.

SH2 domain containing tyrosine phosphatase 2 (Shp2; PTPN11) regulates several intracellular pathways downstream of multiple growth factor receptors. Our studies implicate that Shp2 interacts with Caveolin-1 (Cav-1) protein in retinal ganglion cells (RGCs) and negatively regulates BDNF/TrkB signaling. This study aimed to investigate the mechanisms underlying the protective effects of shp2 silencing in the RGCs in glaucomatous conditions. Methods: Shp2 was silenced in the Cav-1 deficient mice and the age matched wildtype littermates using adeno-associated viral (AAV) constructs. Shp2 expression modulation was performed in an acute and a chronic mouse model of experimental glaucoma. AAV2 expressing Shp2 eGFP-shRNA under a strong synthetic CAG promoter was administered intravitreally in the animals' eyes. The contralateral eye received AAV-eGFP-scramble-shRNA as control. Animals with Shp2 downregulation were subjected to either microbead injections or acute ocular hypertension experimental paradigm. Changes in inner retinal function were evaluated by measuring positive scotopic threshold response (pSTR) while structural and biochemical alterations were evaluated through H&E staining, western blotting and immunohistochemical analysis of the retinal tissues. Results: A greater loss of pSTR amplitudes was observed in the WT mice compared to Cav-1-/- retinas in both the models. Silencing of Shp2 phosphatase imparted protection against inner retinal function loss in chronic glaucoma model in WT mice. The functional rescue also translated to structural preservation of ganglion cell layer in the chronic glaucoma condition in WT mice which was not evident in Cav-1-/- mice retinas. Conclusions: This study indicates that protective effects of Shp2 ablation under chronic experimental glaucoma conditions are dependent on Cav-1 in the retina, suggesting in vivo interactions between the two proteins.

Current evidence suggests that exposure to chronically induced intraocular pressure (IOP) leads to neurodegenerative changes in the inner retina. This study aimed to determine retinal proteomic alterations in a rat model of glaucoma and compared findings with human retinal proteomics changes in glaucoma reported previously. We developed an experimental glaucoma rat model by subjecting the rats to increased IOP (9.3 ± 0.1 vs 20.8 ± 1.6 mm Hg) by weekly microbead injections into the eye (8 weeks). The retinal tissues were harvested from control and glaucomatous eyes and protein expression changes analysed using a multiplexed quantitative proteomics approach (TMT-MS3). Immunofluorescence was performed for selected protein markers for data validation. Our study identified 4304 proteins in the rat retinas. Out of these, 139 proteins were downregulated (≤0.83) while the expression of 109 proteins was upregulated (≥1.2-fold change) under glaucoma conditions (P ≤ .05). Computational analysis revealed reduced expression of proteins associated with glutathione metabolism, mitochondrial dysfunction/oxidative phosphorylation, cytoskeleton, and actin filament organisation, along with increased expression of proteins in coagulation cascade, apoptosis, oxidative stress, and RNA processing. Further functional network analysis highlighted the differential modulation of nuclear receptor signalling, cellular survival, protein synthesis, transport, and cellular assembly pathways. Alterations in crystallin family, glutathione metabolism, and mitochondrial dysfunction associated proteins shared similarities between the animal model of glaucoma and the human disease condition. In contrast, the activation of the classical complement pathway and upregulation of cholesterol transport proteins were exclusive to human glaucoma. These findings provide insights into the neurodegenerative mechanisms that are specifically affected in the retina in response to chronically elevated IOP.

Neurodegeneration is the progressive and gradual dysfunction and loss of axons in the central nervous system. It is the main pathological characteristic of chronic and acute neurodegenerative conditions like Alzheimer's disease (AD), Parkinson's disease (PD), and multiple sclerosis (MS). The usual aspects of pathogenesis of disease can be abridged with regards to the downstream implications of uncontrollable protein oligomerization and aggregation from postmitotic cells. The brain structure constantly changes in normal aging without any dysfunction accompanying the structural changes in brain. The decline in cognitive capabilities, for example, processing speed, memory, and functions related to decision making are the sign of healthy aging. The reduction in brain volume in healthy aging is possibly related to neuronal loss at some marginal extent. The following chapter discusses the structural and functional alterations in the brain in ageing and neurodegeneration.

Sphingosine-1-phosphate receptor (S1PR) signaling regulates diverse pathophysiological processes in the central nervous system. The role of S1PR signaling in neurodegenerative conditions is still largely unidentified. Siponimod is a specific modulator of S1P1 and S1P5 receptors, an immunosuppressant drug for managing secondary progressive multiple sclerosis. We investigated its neuroprotective properties in vivo on the retina and the brain in an optic nerve injury model induced by a chronic increase in intraocular pressure or acute N-methyl-D-aspartate excitotoxicity. Neuronal-specific deletion of sphingosine-1-phosphate receptor (S1PR1) was carried out by expressing AAV-PHP.eB-Cre recombinase under Syn1 promoter in S1PR1

Increased amyloid β (Aβ) aggregation is a hallmark feature of Alzheimer’s disease (AD) pathology. The APP/PS1 mouse model of AD exhibits accumulation of Aβ in the retina and demonstrates reduced retinal function and other degenerative changes. The overall molecular effects of AD pathology on the retina remain undetermined. Using a proteomics approach, this study assessed the molecular effects of Aβ accumulation and progression of AD pathology on the retina. Retinal tissues from younger (2.5 months) and older 8-month APP/PS1 mice were analysed for protein expression changes. A multiplexed proteomics approach using chemical isobaric tandem mass tags was applied followed by functional and protein-protein interaction analyses using Ingenuity pathway (IPA) and STRING computational tools. We identified approximately 2000 proteins each in the younger (upregulated 50; downregulated 36) and older set of APP/PS1 (upregulated 85; downregulated 79) mice retinas. Amyloid precursor protein (APP) was consistently upregulated two to threefold in both younger and older retinas (p

Neuroserpin is an axonally secreted serpin that is involved in regulating plasminogen and its enzyme activators, such as tissue plasminogen activator (tPA). The protein has been increasingly shown to play key roles in neuronal development, plasticity, maturation and synaptic refinement. The proteinase inhibitor may function both independently and through tPA-dependent mechanisms. Herein, we discuss the recent evidence regarding the role of neuroserpin in healthy and diseased conditions and highlight the participation of the serpin in various cellular signalling pathways. Several polymorphisms and mutations have also been identified in the protein that may affect the serpin conformation, leading to polymer formation and its intracellular accumulation. The current understanding of the involvement of neuroserpin in Alzheimer’s disease, cancer, glaucoma, stroke, neuropsychiatric disorders and familial encephalopathy with neuroserpin inclusion bodies (FENIB) is presented. To truly understand the detrimental consequences of neuroserpin dysfunction and the effective therapeutic targeting of this molecule in pathological conditions, a cross-disciplinary understanding of neuroserpin alterations and its cellular signaling networks is essential.

Background Severe acute respiratory syndrome (SARS) has been initiating pandemics since the beginning of the century. In December 2019, the world was hit again by a devastating SARS episode that has so far infected almost four million individuals worldwide, with over 200,000 fatalities having already occurred by mid-April 2020, and the infection rate continues to grow exponentially. SARS coronavirus 2 (SARS-CoV-2) is a single stranded RNA pathogen which is characterised by a high mutation rate. It is vital to explore the mutagenic capability of the viral genome that enables SARS-CoV-2 to rapidly jump from one host immunity to another and adapt to the genetic pool of local populations. Methods For this study, we analysed 2301 complete viral sequences reported from SARS-CoV-2 infected patients. SARS-CoV-2 host genomes were collected from The Global Initiative on Sharing All Influenza Data (GISAID) database containing 9 genomes from pangolin-CoV origin and 3 genomes from bat-CoV origin, Wuhan SARS-CoV2 reference genome was collected from GeneBank database. The Multiple sequence alignment tool, Clustal Omega was used for genomic sequence alignment. The viral replicating enzyme, 3-chymotrypsin-like cysteine protease (3CLpro) that plays a key role in its pathogenicity was used to assess its affinity with pharmacological inhibitors and repurposed drugs such as anti-viral flavones, biflavanoids, anti-malarial drugs and vitamin supplements. Results Our results demonstrate that bat-CoV shares > 96% similar identity, while pangolin-CoV shares 85.98% identity with Wuhan SARS-CoV-2 genome. This in-depth analysis has identified 12 novel recurrent mutations in South American and African viral genomes out of which 3 were unique in South America, 4 unique in Africa and 5 were present in-patient isolates from both populations. Using state of the art in silico approaches, this study further investigates the interaction of repurposed drugs with the SARS-CoV-2 3CLpro enzyme, which regulates viral replication machinery. Conclusions Overall, this study provides insights into the evolving mutations, with implications to understand viral pathogenicity and possible new strategies for repurposing compounds to combat the nCovid-19 pandemic.

Additional file 2: Table S2. SARS-CoV and SARS-CoV-2 sequence alignment of 3CLPro shares around 95% similarity.

Purpose: Biopharmaceutics classification system (BCS) class IV compounds, exhibits least oral bioavailability, low solubility and intestinal permeability among all pharmaceutical classes of drugs. Thus, these drugs need more compatible and efficient delivery system. Since, their solubility in various medium, remains a limitation so, polymeric nano coacervates based drug loading with modified approach for them may prove to be a solution ahead. Therefore, in present study Chitosan is opted for encapsulating the BCS class IV drug (Hydrochlorothiazide) to attain better stability, enhanced permeability and lower toxicity. Methods: For this study, Hydrochlorothiazide (HCTZ) was opted for formulating chitosan based nano-coacervate system. Results: Optimized HCTZ nanocoacervates exhibited the average particle size of 91.39 ± 0.75 nm with Poly-dispersity index score of 0.159 ± 0.01, indicating homogeneity of colloidal solution. Zeta potential and encapsulation efficiency of HCTZ nanocoacervates were recorded as -18.9 ± 0.8 mV and 76.69 ± 0.82 % respectively. Further, from TEM and SEM evaluation the average particle size for the same were found in conformity (35-50 nm), with almost spherical morphology. Also, the EDX (Electron Dispersive X-ray) spectrometry and FT – IR analysis of optimized formulation indicated the balanced chemical composition and interaction between the polymeric molecules. The HCTZ nano coacervates showed the linear diffusion profile through the dialysis membrane. Conclusion: We can conclude from the present study that the optimized HCTZ nano coacervates may prove to be a suitable potential option for effective delivery of BCS class IV drugs.

Catechin hydrate (CH), is an important phyto compound, reported to have potential therapeutic activity for prevention and treatment of various central nervous system (CNS) disorders. However, its therapeutic action is limited by their low oral bioavailability, poor stability and intestinal absorption, therefore, development of a targeted nanoparticle based carrier system which can overcome its physicochemical limitations and can enhance its biological activity is required. The objective of the present study was to formulate nanoparticle based formulation by ionic gelation method for catechin hydrate. Result and conclusion: After optimising the formulation by statistical tool, further, characterization results showed zeta average particle size of 68.76 ± 1.72 nm along with polydispersibility index of 0.174 ± 0.81 and zeta potential of -5.32 mV. Moreover, TEM analysis also confirmed its nanometric size range (range of 61. 8- 128nm) and FT – IR scan showed no bond formation between polymers and loaded extract (CH). The in vitro compound release kinetics showed a typical linear diffusion profile and cytotoxicity analysis done on NB41A3 cell lines results exhibited the cell viability of 89.5 ± 0.25% in catechin loaded nanoparticles (CH NP’s) whereas, it is 82.7 ± 0.34% in CH indicating negligible toxicity in nanoparticle based formulation. The stability testing was done for CH NP’s after 8 weeks, and results revealed minimal degradation of catechin. Lastly, the antioxidant activities estimated through DPPH (2, 2 – Diphenyl-1-picrylhydrazyl-hydrate), Nitric oxide (NO) and Hydrogen peroxide (H 2 O 2 ) scavenging assays revealed that CH NP’s have higher and prolonged antioxidant activity in comparison with CH.

Neurodegenerative disorders (NDs) are a diverse group of disorders characterized by selective and progressive loss of neural systems that cause dysfunction of the central nervous system (CNS). The examples of NDs include Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), Parkinson's disease (PD), and Huntington's disease (HD). The aggregated proteins block or disrupt the normal proteosomal turnover, autophagy, and become abnormally modified with time, generating toxicity via pathways thereby resulting in neurodegeneration and neuron death. The chapter highlights the understanding in the areas of AD, PD, HD as illustrative of major research so as to define the key factors and events in the improvement of NDs. It defines the physiological functioning of neural transmission (presynaptic, postsynaptic activity) at neural signaling pathway, then the dynamics of neuronal dysfunctioning and its molecular mechanism. Further, it also discusses the progression from synaptic dysfunction to transmission failure followed by NDs.

Objective: Anxiety and depression are disorders which are related with reuptake of monoamine neurotransmitter serotonin. Escitalopram (ETP) which is an hydrophobic antidepressant, an SSRI (selective serotonin reuptake inhibitor), and s-enantiomer of citalopram is exclusively used and due to its extensive hepatic metabolism, reduced drug efficacy and potential side effects, has less therapeutic index therefore, present study is focused on developing and characterizing chitosan based nanoparticles by ionic gelation method for Escitalopram oxalate (ETP). Materials and Methods: The nanoparticles were prepared by ionic gelation method using chitosan and tripolyphosphate. The formulated nanoparticles were optimized and further characterized by various techniques like particle size, zeta potential analysis, TEM, SEM, EDX, rheological parameters and FT-IR techniques. Also, in vitro drug diffusion was studied to evaluate its pattern of drug release. Result and Discussion: The optimized ETP loaded nanoparticles were made with chitosan: tripolyphosphate (1:1.5) ratio, showing particle size range of 60 – 115nm, with polydispersity index of 0.117, which was further confirmed by TEM analysis whereas; zeta potential was estimated to be -1.89mV. The SEM EDX scans showed almost smooth morphology of the same.The FT – IR results confirmed that there is no interaction between the polymers and drug molecules. The in vitro drug release study using dialysis membrane showed sustained drug release pattern of ETP nanoparticles. Conclusion: ETP loaded chitosan nanoparticles were prepared successfully from ionic gelation method, suggesting a comparatively suitable option for treatment of disease with fewer side effects and increased affinity of drug.

Summary Essential hypertension remains a major modifiable risk factor for cardiovascular diseases (CVD) despite important advances in our understanding of its pathophysiology and the availability of effective treatment strategies. Available evidences and researches favour the utility of non selective beta-adrenergic receptor blocking agents. Propranolol belongs to this class and is indicated for treatment of hypertension. Owing to its low bioavailability (26%) and extensive hepatic metabolism, reduction in absorption and elaborative side effects in patients, it is not assumed as an ideal drug candidate for oral drug delivery. Hence, it would be beneficial if it is given through an alternate route, bypassing gastro- intestinal degradation, for faster therapeutic effect, enhanced bioavailability and less dosage. To address these issues, transmucosal nasal drug delivery promises as an interesting alternative. The objective of this study was to develop propranolol nanoparticles for transmucosal nasal drug delivery through ionic gelation method. The Particle size analysis, zeta potential, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) studies confirmed a nanometric size range of nanoparticles below 200 nm, with nearly spherical morphology. Moreover, rheological parameters indicated a good stability of the optimised nanoparticle formulation. In-vitro drug release and cytotoxicity results showed sustained release of the drug till 24 hours along with less cytotoxicity.

Chemoprevention of cancer with conventional therapeutic approach has shown severe side effects along with high possibility of recurrence of the same. This results in decreased therapeutic efficacy of the chemotherapeutic agents used currently. Therefore, to reduce their ill effects, an alternative gateway for cancer treatment and prevention needs to be explored. The natural, plant-based anticancer compounds are proving to be a substantial target in replacing the common approaches which employs chemical drugs. The natural compounds derived from various medicinal plants like vinca alkaloids, cyanidin, curcumin, fisetin, rosmarinic acid, etc. have already been documented with a remarkable antineoplastic property. The aim of the chapter is to focus on the various phytocompounds and their mechanism of action to treat the tumorigenic growth accompanied with the drug delivery system. Furthermore, the limitations and barriers associated with the formulation of phytocompounds and their possible enhanced therapeutic efficiency by nanoparticle-based drug delivery mechanics are also discussed.