Cell Degeneration Research Articles

Exploring the Molecular Interaction Between NR2E3 and NR1D1 in Retinitis Pigmentosa: A Docking and Molecular Dynamics Study

ABSTRACTBackground and AimsRetinitis pigmentosa (RP) is a hereditary retinal disorder that gradually leads to vision loss due to photoreceptor cell degeneration. This study aims to investigate the clinical features and genetic underpinnings of RP within a large Iranian family. Our focus centered on mutations in the NR2E3 gene, which plays a critical role in the development and maintenance of the retina.MethodsTwenty‐five family members showed symptoms of RP, and fourteen of them underwent clinical examinations conducted by geneticists and ophthalmologists. The DNA samples of five individuals diagnosed with RP from the family were subjected to whole‐exome sequencing (WES) as part of the study. The candidate variant identified through WES was subsequently confirmed using bidirectional sequencing in additional family members. Additionally, in silico analysis, including molecular modeling, protein–protein docking, and molecular dynamics simulation (MD), was employed to assess potential pathogenic effects associated with the candidate variants.ResultsOphthalmic examination revealed night blindness, which is a common symptom among affected individuals. Genetic analysis identified a homozygous missense variant (c.934G>A/p.R311Q) in NR2E3 exon 6, which co‐segregates with other affected family members. Furthermore, molecular docking analysis indicated potential disruption in the binding affinity between NR2E3 and NR1D1 proteins. In‐depth, molecular dynamics analysis, considering parameters such as RMSD, RMSF, and hydrogen bonding, revealed notable differences between normal and mutant protein complexes.ConclusionExploring the molecular interaction between NR2E3 and NR1D1 provides new insights into the pathogenic mechanism of the p.R311Q mutation in RP.

Protective effects of Juglans regia oil on lead acetate-induced reprotoxicity in rats: an antioxidant, histological and computational molecular study.

Lead (Pb) is a metal that affects many body systems, primarily the male reproductive system. This study aimed to examine the phytochemical profiling and beneficial effects of Juglans regia oil (JRO) in alleviating lead-induced reprotoxicity-associated oxidative injury in rats. Adult male Wistar rats were randomly divided into four groups as follows: control group received no treatment, Pb group was exposed to 0.344 g kg-1 bw of Pb acetate, Pb + JRO group was co-treated with Pb plus walnut oil (0.9 g kg-1 bw) and JRO group received walnut oil only. Pb-treated rats showed significantly decreased gonado-somatic index, count and viability of sperm. Testosterone levels decreased in Pb-treated animals. Besides, Pb disrupted the oxidative/antioxidative status, the plasmatic lipase activity and testicular Pb content. Furthermore, Pb produced testis histopathological features, especially cell degeneration, atrophy and tubular disarrangement. Co-treatment with JRO was found to be effective for recovering the increased testicular oxidative damage-associated histological features in the Pb group. This was supported by the in silico modeling results. The in silico analyses revealed that JRO compounds bound androgen receptor and RAC-alpha serine/threonine kinase with high affinities, which together with pharmacokinetic properties and molecular interactions satisfactorily support the beneficial in vivo findings in the Pb + JRO group of rats. © 2024 Society of Chemical Industry.

Exploring dysfunctional barrier phenotypes associated with glaucoma using a human pluripotent stem cell-based model of the neurovascular unit.

Glaucoma is a neurodegenerative disease that results in the degeneration of retinal ganglion cells (RGCs) and subsequent loss of vision. While RGCs are the primary cell type affected in glaucoma, neighboring cell types selectively modulate RGCs to maintain overall homeostasis. Among these neighboring cell types, astrocytes, microvascular endothelial cells (MVECs), and pericytes coordinate with neurons to form the neurovascular unit that provides a physical barrier to limit the passage of toxic materials from the blood into neural tissue. Previous studies have demonstrated that these barrier properties may be compromised in the progression of glaucoma, yet mechanisms by which this happens have remained incompletely understood. Thus, the goals of this study were to adapt a human pluripotent stem cell (hPSC)-based model of the neurovascular unit to the study of barrier integrity relevant to glaucoma. To achieve this, hPSCs were differentiated into the cell types that contribute to this barrier, including RGCs, astrocytes, and MVECs, then assembled into an established Transwell®-insert model. The ability of these cell types to contribute to an in vitro barrier model was tested for their ability to recapitulate characteristic barrier properties. Results revealed that barrier properties of MVECs were enhanced when cultured in the presence of RGCs and astrocytes compared to MVECs cultured alone. Conversely, the versatility of this system to model aspects of barrier dysfunction relevant to glaucoma was tested using an hPSC line with a glaucoma-specific Optineurin (E50K) mutation as well as a paired isogenic control, where MVECs then exhibited reduced barrier integrity. To identify factors that could result in barrier dysfunction, results revealed an increased expression of TGFβ2 in glaucoma-associated OPTN(E50K) astrocytes, indicating a potential role for TGFβ2 in disease manifestation. To test this hypothesis, we explored the ability to modulate exogenous TGFβ2 in both isogenic control and OPTN(E50K) experimental conditions. Collectively, the results of this study indicated that the repurposing of this in vitro barrier model for glaucoma reliably mimicked some aspects of barrier dysfunction, and may serve as a platform for drug discovery, as well as a powerful in vitro model to test the consequences of barrier dysfunction upon RGCs in glaucoma.

Clinical and Structural Parameters in Autosomal Dominant Optic Atrophy Patients: A Cross-Sectional Study Using Optical Coherence Tomography

Background: Autosomal Dominant Optic Atrophy (ADOA) is a hereditary optic neuropathy characterized by retinal ganglion cell degeneration and optic nerve fiber loss. This study examined the correlation between clinical and structural parameters in patients with ADOA using optical coherence tomography (OCT) and explored potential clinical biomarkers. Methods: A cross-sectional, case–control observational study included 27 patients with ADOA and 27 age- and sex-matched healthy controls. Clinical examinations, OCT imaging, and OCT angiography (OCTA) were performed. Statistical analyses were conducted to establish correlations between clinical and OCT parameters. Results: Patients with ADOA exhibited gradual bilateral vision loss, central scotomas, and optic disc pallor. Structural OCT analysis revealed significant reductions in central macular thickness, macular volume, ganglion cell complex (GCC), and peripapillary retinal nerve fiber layer compared with controls. Correlation analysis demonstrated associations between worsening clinical parameters (best corrected visual acuity, Sloan Letters Low Contrast Chart 25%, Pseudoisochromatic Test) and increased OCT damage (structural and OCTA). GCC emerged, at least at exploratory terms, as the most important clinical biomarker in patients with ADOA given its multiple positive functional associations, while OCTA parameters correlated with visual field defects. Conclusions: Our study revealed significant correlations between clinical and structural parameters in patients with ADOA, highlighting the importance of OCT in assessing disease severity. GCC measurement shows promise as a clinical biomarker, aiding in disease monitoring. OCTA parameters offer potential early biomarkers for vascular changes. These findings contribute to understanding ADOA pathophysiology and may improve patient diagnosis and management. Further research is warranted to validate these findings and explore potential therapeutic interventions.

Melatonin attenuates degenerative disc degression by downregulating DLX5 via the TGF/Smad2/3 pathway in nucleus pulposus cells.

Intervertebral disc degeneration (IVDD) is the leading cause of low back pain, and apoptosis plays a key role in its pathogenesis. Distal-less homeobox 5 (Dlx5) has been reported to induce cell apoptosis. Melatonin, as a powerful antiapoptotic agent, has been widely reported. This study aimed to investigate the role of DLX5 in the pathogenesis of IVDD and the potential therapeutic role of melatonin in targeting DLX5 in IVDD. Western blotting, RT-qPCR, immunohistochemistry, si-DLX5, Ex-DLX5, flow cytometry, and immunofluorescence were used to examine the regulatory effect of DLX5 on apoptosis. Therapeutic efficacy was assessed by the intraperitoneal injection of melatonin into IVDD mice. The expression level of DLX5 is significantly increased in IVDD, and the expression levels were positively correlated with the grade of IVDD. DLX5 was significantly upregulated in TNF-α-induced degenerative NP cells. Degenerative NP cells transfected with si-DLX5 exhibited significantly less apoptosis than control cells. Melatonin significantly alleviated IVDD in surgically induced IVDD model mice. The results revealed that the expression of DLX5 was positively correlated with the severity of IVDD and that melatonin ameliorated DLX5-induced apoptosis and extracellular matrix imbalance by inhibiting the TGF-β/Smad signaling pathway. This study may provide therapeutic strategies to alleviate inflammation-induced apoptosis IVDD-associated inflammation-induced apoptosis. DLX5 plays an important role in IVDD progression by promoting apoptosis, and melatonin represents a promising therapeutic strategy for alleviating IVDD-associated inflammation and apoptosis.

Opa1 and MT-Nd6 mutations induce early mitochondrial changes in the retina and prelaminar optic nerve of hereditary optic neuropathy mouse models

Abstract Hereditary optic neuropathies (HON), including dominant optic atrophy and Leber's hereditary optic neuropathy, are genetic disorders characterized by retinal ganglion cell (RGC) degeneration leading to vision loss, mainly associated with mitochondrial dysfunction. In this study, we analyzed mitochondrial distribution and ultrastructure in the retina and longitudinal optic nerve sections of presymptomatic HON mouse models with Opa1 and Nd6 deficiency to identify early mitochondrial changes. Our results show significant mitochondrial fragmentation and increased mitophagy in Opa1+/- mice, indicating early mitochondrial changes prior to neuronal loss. Conversely Nd6P25L mice exhibited mitochondrial hypertrophy, suggesting an adaptive response to compensate for altered energy metabolism. These pre-symptomatic mitochondrial changes were mainly observed in the unmyelinated portion of the RGC axons, where the transmission of the visual information requires high energy expenditure, constituting the specific point of vulnerability in HON. These findings highlight early focal mitochondrial changes prior to neuronal loss in HON and provide insight into presymptomatic therapeutic approaches.

Glutamylation imbalance impairs the molecular architecture of the photoreceptor cilium.

Microtubules, composed of conserved α/β-tubulin dimers, undergo complex post-translational modifications (PTMs) that fine-tune their properties and interactions with other proteins. Cilia exhibit several tubulin PTMs, such as polyglutamylation, polyglycylation, detyrosination, and acetylation, with functions that are not fully understood. Mutations in AGBL5, which encodes the deglutamylating enzyme CCP5, have been linked to retinitis pigmentosa, suggesting that altered polyglutamylation may cause photoreceptor cell degeneration, though the underlying mechanisms are unclear. Using super-resolution ultrastructure expansion microscopy (U-ExM) in mouse and human photoreceptor cells, we observed that most tubulin PTMs accumulate at the connecting cilium that links outer and inner photoreceptor segments. Mouse models with increased glutamylation (Ccp5-/- and Ccp1-/-) or loss of tubulin acetylation (Atat1-/-) showed that aberrant glutamylation, but not acetylation loss, disrupts outer segment architecture. This disruption includes exacerbation of the connecting cilium, loss of the bulge region, and destabilization of the distal axoneme. Additionally, we found significant impairment in tubulin glycylation, as well as reduced levels of intraflagellar transport proteins and of retinitis pigmentosa-associated protein RPGR. Our findings indicate that proper glutamylation levels are crucial for maintaining the molecular architecture of the photoreceptor cilium.

Immune cell changes in Helicobacter pylori infection-induced glandular epithelial cell damage of the gastric mucosa

Objective The purpose of this study was to investigate the relationship between Helicobacter pylori (H. pylori) infection-induced changes in gastric mucosal immune cells and glandular epithelial cell damage and the histopathological characteristics of these changes. Methods We performed a detailed histomorphometry and immunohistochemical analysis of a total of 1635 H. pylori-infected gastric mucosal specimens. Results Stage-wise features were as follows: Early stage of infection: H. pylori was colonized in the mucous layer, and very few neutrophils were visible in the layer. Gastric surface epithelial cell infection stage: H. pylori specifically and selectively adhered to the cytoplasm of the surface mucous cells, with the presence of a small number of neutrophils, eosinophils, and lymphocytes infiltration, which is termed early immune response. Compensatory mucous neck cell hyperplasia stage: proliferation of stem cells in the deep gastric pit and infiltration of a large number of lymphocytes in the superficial layer of lamina propria were observed, which is termed immune cell mobilization counterinsurgency. Lamina propria lesion stage: excessive upward migration of the proliferative area. Infiltration of a large number of lymphocytes, plasma cells, monocytes, macrophages, and other immune cells was observed in the whole layer of the gastric mucosa, which is termed automatic replication of immune cells. Abnormal proliferative transformation stage: presence of intranuclear milky globular body cells or signet-ring cell-like heterotypic cells at the junction of the gastric pit and the gastric gland, with proliferation of large numbers of immune cells and vacuolar degeneration of immune cells, which is termed the proliferation and degeneration of immune cells. Intraepithelial neoplasia stage: clonal hyperplasia of epithelial cells and immunosuppression. Conclusion For controlling the occurrence and development of gastric cancer and effective immune intervention, it is essential to grasp the relationship between H. pylori infection-induced changes in gastric mucosal immune cells and glandular epithelial cell damage and its histopathological characteristics.

MECHANICAL CHARACTERIZATION OF HOMOGENIZED TI-12MO-13NB AND TI-10MO-20NB ALLOYS

Beta titanium alloys have been developed for biomedical applications due to their outstanding mechanical properties, including low elastic modulus, high strength, excellent fatigue resistance, good ductility, and exceptional corrosion resistance. To enhance safety, the metastable beta titanium alloys Ti-12Mo-13Nb and Ti-10Mo-20Nb have been introduced as alternatives to the traditional Ti-6Al-6V alloy. The Ti-6Al-6V alloy contains vanadium, which is biotoxic and can lead to cell death, and aluminum, which may contribute to neural cell degeneration and accelerate the progression of Alzheimer’s disease. The objective of this work is to explore and present the properties and microstructure of the Ti-12Mo-13Nb and Ti-10Mo-20Nb alloys. Microstructural characterization of these alloys was performed using techniques such as X-ray diffraction and optical microscopy. The mechanical characterization was realized by Vickers hardness and the Young’s modulus was obtained by the nanoidentation technique. Both alloys presented elastic modulus (~90 GPa) lower than the widely used Ti-6Al-4V alloy (135 GPa). The results of the microstructural characterization showed only the presence of the β-Ti phase in the alloys.

Enhanced auditory responses in visual cortex of blind rats using intrinsic optical signal imaging

Functional maturation of the visual cortex is induced by visual experiences during critical periods. Blind animals and humans exhibit improved auditory abilities after losing their vision. Here we investigated the response of the visual cortex to white noise stimuli during the progression of photoreceptor degeneration in a rat model of blindness (Royal College of Surgeons [RCS] (rdy/rdy) rats). Optical coherence tomography of RCS (+/+) rats with normal visual function revealed normal photoreceptor cells, whereas 3-month-old RCS (rdy/rdy) rats demonstrated photoreceptor cell degeneration. Visual cortex responses (VCRs) to a single flash stimulus were negligible in 3-month-old photoreceptor-degenerated rats. However, VCRs with white noise stimuli were significantly increased in blind versus RCS rats (+/+). Slight changes in the intrinsic optical signals of the control rats were observed on the ventral side of the visual cortex. In contrast, responses were markedly increased throughout the visual cortex of RCS (rdy/rdy) rats. These results indicate that the visual cortex rapidly acquires auditory system function over the first 3 months of life and that the entire visual cortex, rather than just the portion close to the auditory cortex, responds to white noise.

BDNF and Cerebellar Ataxia.

Brain-derived neurotrophic factor (BDNF) has been proposed as a treatment for neurodegeneration, including diseases of the cerebellum, where BDNF levels or those of its main receptor, TrkB, are often diminished relative to controls, thereby serving as replacement therapy. Experimental evidence indicates that BDNF signaling countered cerebellar degeneration, sensorimotor deficits, or both, in transgenic ATXN1 mice mutated for ataxin-1, Cacna1a knock-in mice mutated for ataxin-6, mice injected with lentivectors encoding RNA sequences against human FXN into the cerebellar cortex, Kcnj6Wv (Weaver) mutant mice with granule cell degeneration, and rats with olivocerebellar transaction, similar to a BDNF-overexpressing transgenic line interbred with Cacng2stg mutant mice. In this regard, this study discusses whether BDNF is effective in cerebellar pathologies where BDNF levels are normal and whether it is effective in cases with combined cerebellar and basal ganglia damage.

Revisiting PD: Unraveling the brain-first and body-first perspectives

Parkinson’s disease (PD) has undergone significant advancements in diagnosis and treatment over the past century, with apparent dopaminergic cell degeneration on dopamine transporter scans and a strong response to medication being key features. However, the etiology remains complex, involving various pathogenic mechanisms beyond alpha-synuclein accumulation. The recent brain-first versus body-first hypothesis, emerging from advances in functional imaging and clinical symptom clustering, suggests distinct starting points of alpha-synuclein pathology-either in the brain or the body, with subsequent spread via neural connections. This theory, exemplified by the alpha-synuclein origin site and connectome (SOC) model, proposes that body-first PD may originate in the enteric nervous system and spread to the brain, while brain-first PD starts within the central nervous system, such as the olfactory bulb or amygdala. While the SOC model offers valuable insights into the progression of PD, it raises several controversies. Critics argue that the model may oversimplify the disease’s complexity, failing to account for overlapping symptoms and the varying progression rates observed in different subtypes. Furthermore, there are concerns about the lack of longitudinal data and the potential for reclassification of PD subtypes over time. Despite these challenges, the ongoing development of imaging techniques that reflect in-vivo pathology holds promise for resolving these controversies and advancing the selection of patients for disease-modifying therapies.

Exploring Therapeutic Strategies: The Relationship between Metabolic Disorders and FOXO Signalling in Alzheimer's Disease.

Alzheimer's disease is an ailment that is linked with the degeneration of the brain cells, and this illness is the main cause of dementia. Metabolic stress affects the activity of the brain in AD via FOXO signaling. The occurrence of AD will significantly surge as the world's population ages, along with lifestyle changes perceived in current decades, indicating a main contributor to such augmented prevalence. Similarly, metabolic disorders of current adulthood, such as obesity, stroke, and diabetes mellitus, have been observed as the risk-causing factors of AD. Environmental influences induce genetic mutations that result in the development of several diseases. Metabolic disorders develop when individuals are exposed to an environment where food is easily accessible and requires minimal energy expenditure. Obesity and diabetes are among the most significant worldwide health concerns. Obesity arises because of an imbalance between the amount of energy consumed and the amount of energy expended, which is caused by both behavioral and physiological factors. Obesity, insulin resistance syndrome, hypertension, and inflammation are factors that contribute to the worldwide risk of developing diabetes mellitus and neurodegenerative diseases. FOXO transcription factors are preserved molecules that play an important part in assorted biological progressions, precisely in aging as well as metabolism. Apoptosis, cell division and differentiation, oxidative stress, metabolism, and lifespan are among the physiological processes that the FOXO proteins are adept at controlling. In this review, we explored the correlation between signaling pathways and the cellular functions of FOXO proteins. We have also summarized the intricate role of FOXO in AD, with a focus on metabolic stress, and discussed the prospect of FOXO as a molecular link between AD and metabolic disorders.

Histopathological Description of Mouse Liver in a Sepsis Model Infected with Escherichia coli Treated with Paederia foetida L. Leaf Extract for Sepsis Prevention

The leaf of Paederia foetida L. is one type of medicinal plant that can be used as a preventive medicine for sepsis. This plant contains secondary metabolites such as alkaloids, flavonoids, triterpenoids, saponins, and other active compounds. The objective of this study was to determine the histopathological description of the liver in a mouse sepsis model infected with E. coli, with the administration of Paederia foetida L. leaf extract for sepsis prevention, and to ascertain the influence and effective dosage of the leaf extract as a preventive measure against liver histopathology in the sepsis model induced by E. coli. The method employed was a Completely Randomized Design (CRD). The study used 24 male white mice divided into 6 (six) groups. Data analysis was conducted using One Way ANOVA. The results of the study revealed the histopathological profile of liver cell degeneration in group PI (100mg/kg BW) at 20.79%±0.03, group PII (200mg/kg BW) at 21.63%±0.02, and group PIII (500mg/kg BW) at 9.08%±0.02. Necrosis rates were observed in group PI (100mg/kgBW) at 22.62%±0.04, group PII (200mg/kg BW) at 17.63%±0.02, and group PIII (500mg/kg BW) at 6.05%±0.02. The presence of polymorphonuclear leukocytes (PMN) was detected in group PI (100mg/kgBW) at 39.56%±0.03, group PII (200mg/kgBW) at 28.05%±0.02, and group PIII (500mg/kg BW) at 18.45%±0.03. The test results showed a significant effect of P. foetida L. leaf extract as a preventive measure against liver histopathology in the mouse sepsis model infected with E. coli, with significant values for necrosis (p=0.000), cell degeneration (p=0.000), and PMN (p=0.000). The most effective dosage of P. foetida L. leaf extract as a preventive measure against liver histopathology in the mouse sepsis model infected with E. coli was the dosage used in group PIII (500mg/kgBW).

Effect of Particle Size on Physical Properties, Dissolution, In Vitro Antioxidant Activity, and In Vivo Hepatoprotective Properties of Tetrastigma hemsleyanum Diels et Gilg Powders

Objective: The aim of this study was to analyze the effects of different particle sizes of Tetrastigma hemsleyanum Diels et Gilg (TDG) powders on physical properties, dissolution, in vitro antioxidant activity, and in vivo hepatoprotective properties. Methods: The particle size of TDG coarse powders (TDG-CP), TDG fine powders (TDG-FP), and TDG micro powders (TDG-MP) were measured by a laser particle size analyzer. The physical properties were measured according to the latest version of the Chinese Pharmacopoeia (Committee Chinese Pharmacopoeia 2020). The content of the total flavonoids, total polysaccharides, kaempferol-3-O-rutinoside, and rutin of TDG powders were determined using the NaNO2-Al (NO3)3 colorimetric method, the sulphate-phenol colorimetric method, and HPLC, respectively. In vitro dissolution and antioxidant activity were determined by the paddle method in phosphate buffer (pH 6.8) and the DPPH radical scavenging method, respectively. In addition, the liver tissue pathology was evaluated by hematoxylin and eosin staining (H&E), and the AST and ALT activities were measured by automatic biochemical analyzer. The superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) activities were measured by using commercial analysis kits. Results: As the particle size decreases, the fluidity of TDG powders decreased and the porosity increased. In addition, there were no significant differences in physical properties between low temperature pulverized powders and room temperature pulverized powders. The final dissolution rates of the four bioactive ingredients in TDG-MP were found to be 85.06%, 85.61%, 83.88%, and 83.26%, respectively, whereas in TDG-CP, the dissolution rates were significantly lower at 18.79%, 17.96%, 22.46%, and 24.35%. The EC50 values of TDG-CP, TDG-FP, and TDG-MP on DPPH scavenging activity were 0.82, 0.31, and 0.10 mg/mL, respectively. The AST and ALT activities of the TDG-FP group and the TDG-MP group were significantly decreased and the SOD, CAT, and GSH activities were significantly increased when compared with that of the model group. The inflammatory cell infiltration and vacuolar degeneration of liver cells in the TDG-FP group and the TDG-MP group were significantly improved. Conclusions: The particle size of TDG powders had a significant effect on the physical properties and in vivo bioactivity. TDG pulverized to a fine particle size or smaller is a promising approach for clinical applications with improved physicochemical and biological properties.

A Comprehensive Protocol for Microbead-Induced Ocular Hypertension in Mice.

Glaucoma is a common optic neuropathy characterized by degeneration of retinal ganglion cells (RGCs). Elevated intraocular pressure (IOP), that is, ocular hypertension, is the primary modifiable risk factor for glaucoma and the primary characteristic of most preclinical glaucoma models. Extensive genotype and phenotype diversity at relatively low cost and high accessibility makes laboratory mice an excellent preclinical model for glaucoma. The microbead occlusion model was introduced in 2010 as an inducible model of ocular hypertension in mice and is now one of the most extensively utilized models of rodent glaucoma. Subsequent modifications of the microbead model increased the magnitude and duration of IOP elevation, primarily through modification of injection materials. Despite its popularity, accessibility of the model is hindered by procedural consistency between users. Here we outline an updated and comprehensive protocol for execution of the microbead model that is focused on improving surgical and outcome measure consistency and on enabling single experimenter execution.

Retinal Ganglion Cell Transplantation: Differentiation and Quantification Strategies.

Glaucoma is a leading cause of irreversible blindness worldwide. Current treatments focus on reducing intraocular pressure but cannot restore lost visual function once it is lost due to retinal ganglion cell (RGC) degeneration and death. Recent advances suggest that transplantation of stem cell-derived RGCs could offer new therapeutic approaches for glaucoma and vision restoration. Here, we present a detailed protocol for differentiating human RGCs from embryonic stem cells using both three-dimensional retinal organoid and two-dimensional culture approaches. Following differentiation, we describe methods for isolating and purifying retinal ganglion cells from these cultures and their subsequent transplantation into the mouse retina, with careful monitoring and postoperative care to ensure successful integration. Finally, we describe a quantitative method for assessing transplantation outcomes involving confocal imaging of retinal flat-mounts and custom ImageJ and MATLAB scripts to map and analyze the spatial distribution of donor RGCs within the host retina. Altogether, this approach provides a robust framework for exploring RGC transplantation as a potential therapy for vision loss in glaucoma and other optic neuropathies.

Impact of 6-OHDA injection and microtrauma in the rat substantia nigra on local brain amyloid beta protein concentrations in the affected area.

Amyloid beta peptides (Aβ) are key indicators of Alzheimer's disease and are also linked to cognitive decline in Parkinson's disease (PD) and other neurodegenerative disorders. This study explored the accumulation of Aβ in a standard 6-Hydroxydopamine (6-OHDA) model of PD. We unilaterally injected 6-OHDA into the substantia nigra of Wistar rats to induce dopaminergic cell degeneration and death, a characteristic of PD. The goal was to detect Aβ protein in tissues and blood vessels showing inflammation or degeneration from the 6-OHDA injection. Our results showed that 6-OHDA injection produced a statistically significant rise in Aβ concentration at the injection site 60 minutes after injection, which was slightly reduced 24 hours post-injection but still significantly higher than in controls. We also tried Gp120 injection in the same zone but it only produced effects comparable to control needle trauma. The presence of Aβ in tissues and blood vessel walls after injection was confirmed through ELISA tests and was supported by immunohistochemical staining of injection areas. We found that the increased Aβ concentration was visible in and around blood vessels and inside blood vessel walls, and also, to a lesser extent in some cells, most probably neurons, in the area. This research highlights the connection between dopaminergic cell poisoning and the accumulation of Aβ, offering insights into the progression of PD to cognitive disorders and dementia.

Novel goose parvovirus in naturally infected ducks suffering from locomotor disorders: Molecular Detection, Histopathological examination, Immunohistochemical signals, and Full genome sequencing

In this study, we investigated the pathological effect of novel goose parvovirus (NGPV) infection on the skeletal muscle, brain, and intestine of naturally affected ducks suffering from locomotor dysfunction as a new approach for deeper understanding of such clinical form. For this purpose, a total of 97 diseased ducks, representing 24 flocks of different duck breeds (14-75 days old), were clinically examined. 72 tissue pools of intestine, brain, and skeletal muscle samples were submitted for molecular identification. Typical clinical signs among the examined ducks suggested the parvovirus infection. Regarding postmortem examination, all examined ducks showed muscle emaciation (100%) either accompanied by congestion (34%) or paleness (66%). Slight congestion, either in the brain (82.5%) or intestine (75.25%), was predominantly detected. Based on molecular identification, the intestine had the highest percentage of positive detection (91.7%), followed by the skeletal muscle (70.8%), and the brain (20.8%). The main histopathological alterations were myofiber atrophy and degeneration, marked enteritis accompanied by lymphocytic infiltration in the lamina propria and submucosa, while the affected brains showed vasculitis, diffuse gliosis, and Purkinje cell degeneration in the cerebellum. Next generation sequencing further confirmed the presence of a variant strain of goose parvovirus (vGPV) that is globally known as NGPV and closely related to Chinese NGPV isolates. Using immunohistochemistry, the NGPV antigen was positively detected in the muscle fibres, enterocytes, and Purkinje cells in the cerebellum. These findings provided proof of the involvement of virus replication in the locomotor disorders linked to NGPV infection in ducks.

Unraveling the Effects of SARS-CoV-2 on Dementia: A Comprehensive Study

Since late 2019, a pandemic caused by SARS-CoV-2, a highly contagious coronavirus, has jeopardized human and public health. Neurodegeneration and structural brain diseases produce dementia, which is developing rapidly. Strong evidence of COVID-19 brain abnormalities as neurotrophic viruses impair neurological systems. Neuron and glial cell degeneration can affect nerve transmission and brain function. Damage to these brain components raises dementia risk. Multiple studies linked SARS-CoV-2 to dementia. This manuscript contains selective data. This study aims to review the findings and suggest strategies to improve SARS-Covid dementia management. The study makes use of medical research databases like Google Scholar, PubMed, Medline, and Embase. Furthermore, information is also collected by recognized health organizations and government agencies. COVID-19 can produce neuropsychological deficits, agitation, confusion, inattention, and disorientation. Thus, SARS can worsen dementia and neurodegeneration. This article summarizes COVID-19's effects on dementia patients from several sources. The focus on existing treatments for affected patients ties the two.