Ultra-early stage lower-grade gliomas: How can we define and differentiate these easily misdiagnosed gliomas through intraoperative molecular diagnosis.

BACKGROUND: Some lower-grade gliomas (LGG) are difficult to distinguish morphologically from glial cell proliferation or inflammatory changes during surgery, leading to a high risk of incorrect diagnosis. It is crucial to differentiate between the two for making surgical decisions. We define these critical cases as "ultra early stage lower-grade gliomas (UES-LGG)". METHODS: We analyzed 11 out of 13 cases diagnosed with "gliosis" or "inflammatory changes" during surgery who tested positive for isocitrate dehydrogenase (IDH). Additionally, we conducted qRT-PCR detection on 35 samples diagnosed with LGG during surgery and analyzed their DNA content within an effective circulating threshold range to infer the critical value between UES-LGG and LGG. We conducted experiments using five standardized samples to infer the limited range of accurate detection of UES-LGG during surgery. RESULTS: In the comparative analysis of 11 samples and 35 samples, it was found that while there was no significant difference in the average DNA detection concentration between the two groups (159.36 ± 83.3 ng/µL and 146.83 ± 122.43 ng/µL), there was a notable statistical variance in the detection threshold for positive mutations (31.78 ± 1.14 and 26.14 ± 2.69, respectively). This suggests that the IDH mutation rate may serve as an indicator for differentiation between the two groups. Subsequently, DNA was extracted from standardized IDH mutant samples and subjected to gradient dilution for detection purposes. The results indicated a consistent increase in detection threshold as detection concentration decreased. When the detection concentration fell below <0.1 ng/µL, it became impossible to carry out effective threshold range detections. To further identify the precise detection interval, we conducted gradient division once again and sought to simulate the functional relationship between DNA copy number and cycle threshold within this interval. The research revealed that when the minimum detection concentration exceeded 250 copies/µL, a 100% detection rate could be achieved. CONCLUSIONS: This article defines UES-LGG as a tumor type easily misdiagnosed in clinical practice due to its extremely low positivity rate during surgery. The popularization of qRT-PCR based intraoperative molecular diagnosis greatly reduces errors caused by manual detection and improves disease detection rates during surgery. It provides a theoretical basis for more accurate surgical plans for surgeons.

Corrigendum: Neuroprotection by upregulation of the major histocompatibility complex class I (MHC I) in SOD1G93A mice.

[This corrects the article DOI: 10.3389/fncel.2023.1211486.].

Sex-specific hypothalamic neuropathology and glucose metabolism in an amyloidosis transgenic mouse model of Alzheimer's disease.

BACKGROUND: Amyloid toxicity and glucose metabolic disorders are key pathological features during the progression of Alzheimer's disease (AD). While the hypothalamus plays a crucial role in regulating systemic energy balance, the distribution of amyloid plaques in the preoptic, anterior, tuberal, and mammillary regions of the hypothalamus in AD mice, particularly across both sexes, remains largely unclear. Our ongoing research aims to explore hypothalamic neuropathology and glucose metabolic disturbances in a well-described APP/PS1 mouse model of AD. RESULTS: Immunocytochemical staining revealed that Old-AD-Female mice exhibited a greater hypothalamic Amyloid ß (Aß) burden than their Old-AD-Male counterparts, with the mammillary bodies showing the most severe accumulation. Analysis of ionized calcium binding adaptor molecule 1 (IBA1) immunoreactivity and Iba1 mRNA indicated differential microgliosis based on sex, while tanycytic territory and ZO-1 tight junction protein expression remained stable in AD mice. Moreover, sex-specific peripheral glucose metabolic parameters (random and fasting blood glucose) seemed to be exacerbated by age. Old AD mice of both sexes exhibited limited hypothalamic activation (c-Fos + cells) in response to blood glucose fluctuations. Hypothalamic Glut 1 expression decreased in young but increased in old female AD mice compared with age-matched male AD mice. Pearson correlation analysis further supported a negative correlation between hypothalamic Aß load and random blood glucose in old AD groups of both genders, shedding light on the mechanisms underlying this amyloidosis mouse model. CONCLUSION: Aged APP/PS1 mice exhibit sex-specific hypothalamic neuropathology and differential glucose metabolism, highlighting distinct pathological mechanisms within each gender.

A Pro-Inflammatory Stimulus versus Extensive Passaging of DITNC1 Astrocyte Cultures as Models to Study Astrogliosis.

Astrogliosis is a process by which astrocytes, when exposed to inflammation, exhibit hypertrophy, motility, and elevated expression of reactivity markers such as Glial Fibrillar Acidic Protein, Vimentin, and Connexin43. Since 1999, our laboratory in Chile has been studying molecular signaling pathways associated with "gliosis" and has reported that reactive astrocytes upregulate Syndecan 4 and αVß3 Integrin, which are receptors for the neuronal glycoprotein Thy-1. Thy-1 engagement stimulates adhesion and migration of reactive astrocytes and induces neurons to retract neurites, thus hindering neuronal network repair. Reportedly, we have used DITNC1 astrocytes and neuron-like CAD cells to study signaling mechanisms activated by the Syndecan 4-αVß3 Integrin/Thy-1 interaction. Importantly, the sole overexpression of ß3 Integrin in non-reactive astrocytes turns them into reactive cells. In vitro, extensive passaging is a simile for "aging", and aged fibroblasts have shown ß3 Integrin upregulation. However, it is not known if astrocytes upregulate ß3 Integrin after successive cell passages. Here, we hypothesized that astrocytes undergoing long-term passaging increase ß3 Integrin expression levels and behave as reactive astrocytes without needing pro-inflammatory stimuli. We used DITNC1 cells with different passage numbers to study reactivity markers using immunoblots, immunofluorescence, and astrocyte adhesion/migration assays. We also evaluated ß3 Integrin levels by immunoblot and flow cytometry, as well as the neurotoxic effects of reactive astrocytes. Serial cell passaging mimicked the effects of inflammatory stimuli, inducing astrocyte reactivity. Indeed, in response to Thy-1, ß3 Integrin levels, as well as cell adhesion and migration, gradually increased with multiple passages. Importantly, these long-lived astrocytes expressed and secreted factors that inhibited neurite outgrowth and caused neuronal death, just like reactive astrocytes in culture. Therefore, we describe two DITNC1 cell types: a non-reactive type that can be activated with Tumor Necrosis Factor (TNF) and another one that exhibits reactive astrocyte features even in the absence of TNF treatment. Our results emphasize the importance of passage numbers in cell behavior. Likewise, we compare the pro-inflammatory stimulus versus long-term in-plate passaging of cell cultures and introduce them as astrocyte models to study the reactivity process.

Dipeptidyl peptidase 4 deficiency improves survival after focal cerebral ischemia in mice and ameliorates microglia activation and specific inflammatory markers.

Dipeptidyl peptidase 4 (DPP4; CD26) is involved in the regulation of various metabolic, immunological, and neurobiological processes in healthy individuals. Observations based on epidemiological data indicate that DPP4 inhibition by gliptins, typically used in patients with diabetes, may reduce the risk for cerebral ischemia and may also improve related outcomes. However, as DPP4 inhibitor application is neither complete nor specific for suppression of DPP4 enzymatic activity and DPP4 has non-enzymatic functions as well, the variety of consequences is a matter of debate. Therefore, we here used DPP4 knock-out (KO) mice to analyze the specific contribution of DPP4 to cellular, immunological, and functional consequences of experimental focal cerebral ischemia. We observed a significantly higher survival rate of DPP4 KO mice after ischemia, which was accompanied by a lower abundance of the pro-inflammatory chemokine CCL2 and reduced activation of Iba1-positive microglia cells in brain tissue of DPP4 KO mice. In addition, after ischemia for 24 h to 72 h, decreased concentrations of CCL5 and CCL12 in plasma and of CCL17 in brain tissue of DPP4 KO mice were observed when compared to wild type mice. Other aspects analyzed, such as the functional Menzies score, astrocyte activation and chemokine levels in plasma and brain tissue were affected by ischemia but appeared to be unaffected by the DPP4 KO genotype. Taken together, experimental ablation of DPP4 functions in mice improves survival and ameliorates aspects of cellular and molecular inflammation after focal cerebral ischemia.

Cryptogenic New-onset Refractory Status Epilepticus with Hyperintensity of T1-weighted Magnetic Resonance Imaging in the Bilateral Basal Ganglia: An Autopsy Report.

We present a 76-year-old man with cryptogenic new-onset refractory status epilepticus (C-NORSE) with an initial abnormal signal in the nucleus accumbens and a remarkable hyperintense signal on T1-weighted magnetic resonance imaging in the bilateral basal ganglia (BG). His status epilepticus did not respond to most anti-epileptic therapies or immunotherapies, and he died of sepsis. An autopsy revealed severe neuronal loss and hypertrophic astrocytes in the BG and limbic system, with no signs of inflammation or malignancy. This case suggests that lesions in the BG may reflect secondary degeneration and predict poor outcomes in C-NORSE.

Modulation of diabetes-related retinal pathophysiology by PTX3.

Diabetic retinopathy (DR) is a common complication of diabetes characterized by vascular pathology and neuroinflammation. Pentraxin 3 (PTX3) is a soluble pattern recognition molecule that functions at the crossroads between innate immunity, inflammation, and tissue remodeling. DR is known to involve inflammatory pathways, although the potential relevance of PTX3 has not been explored. We found that PTX3 protein levels increased in the retina of diabetic mice. Similarly, evaluation of a publicly available transcriptomic human dataset revealed increased PTX3 expression in DR with diabetic macular edema and proliferative retinopathy, when compared to nondiabetic retinas or diabetic retinas without complications. To further understand the role of PTX3 within DR, we employed the streptozotocin-induced diabetes model in PTX3 knockout mice (PTX3KO), which were followed up for 9 mo to evaluate hallmarks of disease progression. In diabetic PTX3KO mice, we observed decreased reactive gliosis, diminished microglia activation, and reduced vasodegeneration, when compared to diabetic PTX3 wild-type littermates. The decrease in DR-associated pathological features in PTX3KO retinas translated into preserved visual function, as evidenced by improved optokinetic response, restored b-wave amplitude in electroretinograms, and attenuated neurodegeneration. We showed that PTX3 induced an inflammatory phenotype in human retinal macroglia, characterized by GFAP upregulation and increased secretion of IL6 and PAI-1. We confirmed that PTX3 was required for TNF-α-induced reactive gliosis, as PTX3KO retinal explants did not up-regulate GFAP in response to TNF-α. This study reveals a unique role for PTX3 as an enhancer of sterile inflammation in DR, which drives pathogenesis and ultimately visual impairment.

High-fat and High-sucrose Diet-induced Hypothalamic Inflammation Shows Sex Specific Features in Mice.

Hypothalamic inflammation underlies diet-induced obesity and diabetes in rodent models. While diet normalization largely allows for recovery from metabolic impairment, it remains unknown whether long-term hypothalamic inflammation induced by obesogenic diets is a reversible process. In this study, we aimed at determining sex specificity of hypothalamic neuroinflammation and gliosis in mice fed a fat- and sugar-rich diet, and their reversibility upon diet normalization. Mice were fed a 60%-fat diet complemented by a 20% sucrose drink (HFHSD) for 3 days or 24 weeks, followed by a third group that had their diet normalized for the last 8 weeks of the study (reverse diet group, RevD). We determined the expression of pro- and anti-inflammatory cytokines, and of the inflammatory cell markers IBA1, CD68, GFAP and EMR1 in the hypothalamus, and analyzed morphology of microglia (IBA-1+ cells) and astrocytes (GFAP+ cells) in the arcuate nucleus. After 3 days of HFHSD feeding, male mice showed over-expression of IL-13, IL-18, IFN-γ, CD68 and EMR1 and reduced expression of IL-10, while females showed increased IL-6 and IBA1 and reduced IL-13, compared to controls. After 24 weeks of HFHSD exposure, male mice showed a general depression in the expression of cytokines, with prominent reduction of TNF-α, IL-6 and IL-13, but increased TGF-ß, while female mice showed over-expression of IFN-γ and IL-18. Furthermore, both female and male mice showed some degree of gliosis after HFHSD feeding for 24 weeks. In mice of both sexes, diet normalization after prolonged HFHSD feeding resulted in partial neuroinflammation recovery in the hypothalamus, but gliosis was only recovered in females. In sum, HFHSD-fed mice display sex-specific inflammatory processes in the hypothalamus that are not fully reversible after diet normalization.

CD44 signaling in Müller cells impacts photoreceptor function and survival in healthy and diseased retinas.

Retinitis pigmentosa (RP), an inherited retinal disease, affects 1,5 million people worldwide. The initial mutation-driven photoreceptor degeneration leads to chronic inflammation, characterized by Müller cell activation and upregulation of CD44. CD44 is a cell surface transmembrane glycoprotein and the primary receptor for hyaluronic acid. It is involved in many pathological processes, but little is known about CD44's retinal functions. CD44 expression is also increased in Müller cells from our Pde6bSTOP/STOP RP mouse model. To gain a more detailed understanding of CD44's role in healthy and diseased retinas, we analyzed Cd44-/- and Cd44-/-Pde6bSTOP/STOP mice, respectively. The loss of CD44 led to enhanced photoreceptor degeneration, reduced retinal function, and increased inflammatory response. To understand the underlying mechanism, we performed proteomic analysis on isolated Müller cells from Cd44-/- and Cd44-/-Pde6bSTOP/STOP retinas and identified a significant downregulation of glutamate transporter 1 (SLC1A2). This downregulation was accompanied by higher glutamate levels, suggesting impaired glutamate homeostasis. These novel findings indicate that CD44 stimulates glutamate uptake via SLC1A2 in Müller cells, which in turn, supports photoreceptor survival and function.

Minimizing Invasiveness in Neurosurgical Osteotomies: A Comparative Histomorphometric Study of Piezoelectric Craniotomy versus High-Speed Drill.

BACKGROUND: Piezoelectric bone cutting has gained popularity in neurosurgical osteotomies due to perceived lower trauma compared to rotary instruments. However, histological confirmation of its decreased aggressiveness is lacking, hindering conclusive proof. This study compares the bony and neuro-meningeal invasiveness of piezoelectric craniotomy with high-speed drill techniques. METHODS: Histological data from 21 sheep undergoing piezoelectric craniotomy and 19 sheep subjected to high-speed electric drill craniotomy were compared. Piezoelectric craniotomy utilized a 0.35 mm micro saw titanium nitride coated. Outcome parameters included the detection of the "smear layer," average osteoblast count per high-power field, and residual bone matrix for bony invasiveness assessment. Parameters for meningeal and brain parenchymal invasiveness included pachymeningeal and leptomeningeal injury, gliosis, and histiocytic infiltration. Statistical significance was determined at P < 0.05. RESULTS: Results showed the Piezo group had fewer frequent smear layers (P <0.001), higher residual bone matrix (P < 0.05), and greater osteoblast counts per high-power field (P < 0.05). Additionally, the Piezo group exhibited lower rates of leptomeningeal injury, cerebral gliosis, and histiocytic infiltration (P < 0.05). CONCLUSIONS: Piezoelectric craniotomy preserves residual osteoblast viability and leptomeningeal integrity while demonstrating lower rates of thermally induced gliosis and histiocytic infiltration compared to high-speed drills. This suggests the piezoelectric osteotome's minimal invasiveness in bone, meningeal, and brain tissue.

Pathological findings in enucleated eyes of patients with neurofibromatosis type 1: report of a case with 15-year follow-up and review of 14 patients in the literature.

BACKGROUNDS: Iris nodules are frequently noted as clinical manifestations of neurofibromatosis type 1 but the other intraocular manifestations are rare. The purpose of this study is to present a patient with a phthisic eye who underwent enucleation for a cosmetic reason after 15-year follow-up and also to review 14 patients with enucleation described in the literature. CASE PRESENTATION: A 17-year-old man with neurofibromatosis type 1 from infancy underwent the enucleation of phthisic left eye and also had the resection of eyelid subcutaneous mass lesions on the left side for a cosmetic reason. He had undergone four-time preceding surgeries for eyelid and orbital mass reduction on the left side in childhood and had developed total retinal detachment 10 years previously. Pathologically, the enucleated eye showed massive retinal gliosis positive for both S-100 and glial fibrillary acidic protein (GFAP) in the area with involvement of the detached retinal neuronal layer, together with a more fibrotic lesion along the choroid which were, in contrast, negative for both S-100 and GFAP. The choroid, ciliary body, and iris did not show apparent neurofibroma while episcleral neurofibroma was present. LITERATURE REVIEW: In review of enucleated eyes of 14 patients in the literature, buphthalmic eyes with early-onset glaucoma on the unilateral side was clinically diagnosed in 9 patients who frequently showed varying extent of hemifacial neurofibromatosis which involved the eyelid and orbit on the same side. Pathologically, neurofibromas in varying extent were found in the choroid of 12 patients. One patient showed choroidal malignant melanoma on the left side and fusiform enlargement of the optic nerve on the right side suspected of optic nerve glioma. The phthisic eye in another patient showed massive retinal gliosis similar to the present patient. CONCLUSIONS: In summary of the 15 patients with neurofibromatosis type 1, including the present patient, buphthalmic or phthisic eyes with no vision were enucleated for cosmetic reasons and showed choroidal neurofibroma in most patients and massive retinal gliosis in two patients including the present patient.

The dopamine analogue CA140 alleviates AD pathology, neuroinflammation, and rescues synaptic/cognitive functions by modulating DRD1 signaling or directly binding to Abeta.

BACKGROUND: We recently reported that the dopamine (DA) analogue CA140 modulates neuroinflammatory responses in lipopolysaccharide-injected wild-type (WT) mice and in 3-month-old 5xFAD mice, a model of Alzheimer's disease (AD). However, the effects of CA140 on Aß/tau pathology and synaptic/cognitive function and its molecular mechanisms of action are unknown. METHODS: To investigate the effects of CA140 on cognitive and synaptic function and AD pathology, 3-month-old WT mice or 8-month-old (aged) 5xFAD mice were injected with vehicle (10% DMSO) or CA140 (30 mg/kg, i.p.) daily for 10, 14, or 17 days. Behavioral tests, ELISA, electrophysiology, RNA sequencing, real-time PCR, Golgi staining, immunofluorescence staining, and western blotting were conducted. RESULTS: In aged 5xFAD mice, a model of AD pathology, CA140 treatment significantly reduced Aß/tau fibrillation, Aß plaque number, tau hyperphosphorylation, and neuroinflammation by inhibiting NLRP3 activation. In addition, CA140 treatment downregulated the expression of cxcl10, a marker of AD-associated reactive astrocytes (RAs), and c1qa, a marker of the interaction of RAs with disease-associated microglia (DAMs) in 5xFAD mice. CA140 treatment also suppressed the mRNA levels of s100ß and cxcl10, markers of AD-associated RAs, in primary astrocytes from 5xFAD mice. In primary microglial cells from 5xFAD mice, CA140 treatment increased the mRNA levels of markers of homeostatic microglia (cx3cr1 and p2ry12) and decreased the mRNA levels of a marker of proliferative region-associated microglia (gpnmb) and a marker of lipid-droplet-accumulating microglia (cln3). Importantly, CA140 treatment rescued scopolamine (SCO)-mediated deficits in long-term memory, dendritic spine number, and LTP impairment. In aged 5xFAD mice, these effects of CA140 treatment on cognitive/synaptic function and AD pathology were regulated by dopamine D1 receptor (DRD1)/Elk1 signaling. In primary hippocampal neurons and WT mice, CA140 treatment promoted long-term memory and dendritic spine formation via effects on DRD1/CaMKIIα and/or ERK signaling. CONCLUSIONS: Our results indicate that CA140 improves neuronal/synaptic/cognitive function and ameliorates Aß/tau pathology and neuroinflammation by modulating DRD1 signaling in primary hippocampal neurons, primary astrocytes/microglia, WT mice, and aged 5xFAD mice.

Autism-associated CHD8 controls reactive gliosis and neuroinflammation via remodeling chromatin in astrocytes.

Reactive changes of glial cells during neuroinflammation impact brain disorders and disease progression. Elucidating the mechanisms that control reactive gliosis may help us to understand brain pathophysiology and improve outcomes. Here, we report that adult ablation of autism spectrum disorder (ASD)-associated CHD8 in astrocytes attenuates reactive gliosis via remodeling chromatin accessibility, changing gene expression. Conditional Chd8 deletion in astrocytes, but not microglia, suppresses reactive gliosis by impeding astrocyte proliferation and morphological elaboration. Astrocyte Chd8 ablation alleviates lipopolysaccharide-induced neuroinflammation and septic-associated hypothermia in mice. Astrocytic CHD8 plays an important role in neuroinflammation by altering the chromatin landscape, regulating metabolic and lipid-associated pathways, and astrocyte-microglia crosstalk. Moreover, we show that reactive gliosis can be directly mitigated in vivo using an adeno-associated virus (AAV)-mediated Chd8 gene editing strategy. These findings uncover a role of ASD-associated CHD8 in the adult brain, which may warrant future exploration of targeting chromatin remodelers in reactive gliosis and neuroinflammation in injury and neurological diseases.

Retinal Focal Nodular Gliosis (Vasoproliferative Tumors) Have Varied Clinical Courses Requiring Tailored Management: A Case Series.

Introduction: Retinal focal nodular gliosis (FNG), also known as vasoproliferative tumors (VPTs), are rare, benign vascular tumors associated with exudation with no current consensus on management. Herein, we describe the varied clinical course and management of 3 patients with retinal FNG, one of whom is associated with retinitis pigmentosa. Case Presentations: Case 1 is a 76-year-old female who presented with reduced vision and distortion secondary to a vitreous hemorrhage and epiretinal membrane (ERM) as complications of a known small peripheral retinal FNG. She underwent vitrectomy for the hemorrhage to relieve vascular traction and the ERM peel, and the tumor was kept under observation. Case 2 is a 24-year-old female with genetically uncharacterized retinitis pigmentosa-like phenotype who presented with gradual loss of central vision in one eye due to cystoid macular oedema (CMO). She was found to have two peripheral retinal areas of FNG located inferonasally. Tumors were treated with cryotherapy and adjuvant intraocular steroid implant to control the CMO. Case 3 is a 28-year-old female with retinitis pigmentosa secondary to genetically confirmed variant in CRB1 gene who presented with intractable right eye CMO and localized inferior serous retinal detachment secondary to a large inferotemporal FNG. Her left eye has no light perception vision due to previous extensive serous retinal detachment and anterior segment ischemia. The right eye tumor was managed with multiple rounds of cryotherapy and laser therapy to control the serous detachment. Despite this, the condition progressed and was ultimately treated with plaque brachytherapy. Unfortunately, this resulted in extensive retinal inflammation causing annular tractional retinal detachment which was treated with combined pars plana vitrectomy and scleral buckle. Conclusion: We characterized the retinal phenotype of 3 patients with retinal FNG (VPTs) and found them to have varied clinical courses requiring tailored surgical management. The case associated with retinitis pigmentosa had a known pathogenic variant in Crumbs homolog-1 (CRB1) gene affecting retinal structure and exhibited a more severe clinical course. It is therefore important for patients with retinal dystrophies to undergo thorough peripheral examinations and detect FNG early as they may require prompt, aggressive treatment.

Characterization of an Uncommon Finding in the Basal Nuclei in Beagle Dogs: A Novel Potential Background Lesion in the Canine Brain.

Degenerative lesions specific to the basal nuclei have not been described as a background finding in Beagle dogs. This report comprises a documentation of seven cases. In the context of a nonclinical safety studies, the authors suggest documenting the lesion descriptively as degeneration neuropil, basal nuclei, bilateral as it is characterized by (1) vacuolation, neuropil; (2) gliosis (astro- and/or microgliosis); and (3) demyelination. This novel lesion is considered a potential new background change for several reasons: (1) It occurred in animals from test item-treated and also vehicle-treated groups; (2) no dose dependency was observed; (3) in one of six affected test item-treated dogs, the given compound was shown not to penetrate the blood-brain barrier; and (4) statistical comparison between the proportions of affected dogs in the treatment and control groups did not yield a statistically significant difference. The etiology remains unknown and is subject to further investigations.

An In Vivo Model of Propionic Acid-Rich Diet-Induced Gliosis and Neuro-Inflammation in Mice (FVB/N-Tg(GFAPGFP)14Mes/J): A Potential Link to Autism Spectrum Disorder.

Evidence shows that Autism Spectrum Disorder (ASD) stems from an interplay of genetic and environmental factors, which may include propionic acid (PPA), a microbial byproduct and food preservative. We previously reported that in vitro treatment of neural stem cells with PPA leads to gliosis and neuroinflammation. In this study, mice were exposed ad libitum to a PPA-rich diet for four weeks before mating. The same diet was maintained through pregnancy and administered to the offspring after weaning. The brains of the offspring were studied at 1 and 5 months postpartum. Glial fibrillary acidic protein (astrocytic marker) was significantly increased (1.53 ± 0.56-fold at 1 M and 1.63 ± 0.49-fold at 5 M) in the PPA group brains. Tubulin IIIß (neuronal marker) was significantly decreased in the 5 M group. IL-6 and TNF-α expression were increased in the brain of the PPA group (IL-6: 2.48 ± 1.25-fold at 5 M; TNF-α: 2.84 ± 1.16-fold at 1 M and 2.64 ± 1.42-fold, at 5 M), while IL-10 was decreased. GPR41 and p-Akt were increased, while PTEN (p-Akt inhibitor) was decreased in the PPA group. The data support the role of a PPA-rich diet in glia over-proliferation and neuro-inflammation mediated by the GPR41 receptor and PTEN/Akt pathway. These findings strongly support our earlier study on the role of PPA in ASD.

Cortical neurodegeneration caused by Psen1 mutations is independent of Aß.

Mutations in the PSEN genes are the major cause of familial Alzheimer's disease, and presenilin (PS) is the catalytic subunit of γ-secretase, which cleaves type I transmembrane proteins, including the amyloid precursor protein (APP) to release Aß peptides. While PS plays an essential role in the protection of neuronal survival, PSEN mutations also increase the ratio of Aß42/Aß40. Thus, it remains unresolved whether PSEN mutations cause AD via a loss of its essential function or increases of Aß42/Aß40. Here, we test whether the knockin (KI) allele of Psen1 L435F, the most severe FAD mutation located closest to the active site of γ-secretase, causes age-dependent cortical neurodegeneration independent of Aß by crossing various Psen mutant mice to the App-null background. We report that removing Aß completely through APP deficiency has no impact on the age-dependent neurodegeneration in Psen mutant mice, as shown by the absence of effects on the reduced cortical volume and decreases of cortical neurons at the ages of 12 and 18 mo. The L435F KI allele increases Aß42/Aß40 in the cerebral cortex while decreasing de novo production and steady-state levels of Aß42 and Aß40 in the presence of APP. Furthermore, APP deficiency does not alleviate elevated apoptotic cell death in the cerebral cortex of Psen mutant mice at the ages of 2, 12, and 18 mo, nor does it affect the progressive microgliosis in these mice. Our findings demonstrate that Psen1 mutations cause age-dependent neurodegeneration independent of Aß, providing further support for a loss-of-function pathogenic mechanism underlying PSEN mutations.

Licochalcone A attenuates NMDA-induced neurotoxicity.

This study investigates the effect of Licochalcone A (Lico-A), a flavonoid from licorice roots known for its anti-inflammatory, anti-cancer, and antioxidant properties, on NMDA-induced neurotoxicity in primary cultured rat hippocampal neurons. The study measured cell survival following NMDA and Lico-A exposure, revealing that Lico-A at a 2.5 µg/ml significantly improved cell viability, countering the detrimental effects of NMDA. The study also analyzed synaptic changes by examining both postsynaptic density 95 (PSD95) and synaptophysin-targeted imaging, showing that Lico-A treatment resulted in a significant increase in synaptic puncta, contrasting with the reduction observed under NMDA exposure. Furthermore, levels of phosphorylated mixed lineage kinase domain-like pseudokinase (P-MLKL) and phosphorylated receptor-interacting serine/threonine-protein kinase 3 (P-RIP3), key necroptosis regulators, were measured using Western blotting. The results showed an increase in P-MLKL and P-RIP3 in neurons exposed to NMDA, which was reduced following Lico-A treatment. The response of astrocyte and microglia was also evaluated by immunostaining for glial fibrillary acidic protein (GFAP), ionized calcium-binding adaptor molecule 1 (IBA-1) and tumor necrosis factor alpha (TNF-α). These markers exhibited heightened expression in the NMDA group, which was substantially reduced by Lico-A treatment. These findings suggest that Lico-A has neuroprotective effects against NMDA-induced neurotoxicity, potentially contributing to synaptic preservation, inhibition of neuronal necroptosis, and modulation of glial activation. Therefore, Lico-A shows promise as a neuroprotective agent for conditions associated with NMDA-related neurotoxicity.

JR5558 mice are a reliable model to investigate subretinal fibrosis.

Subretinal fibrosis is a major untreatable cause of poor outcomes in neovascular age-related macular degeneration. Mouse models of subretinal fibrosis all possess a degree of invasiveness and tissue damage not typical of fibrosis progression. This project characterises JR5558 mice as a model to study subretinal fibrosis. Fundus and optical coherence tomography (OCT) imaging was used to non-invasively track lesions. Lesion number and area were quantified with ImageJ. Retinal sections, wholemounts and Western blots were used to characterise alterations. Subretinal lesions expand between 4 and 8 weeks and become established in size and location around 12 weeks. Subretinal lesions were confirmed to be fibrotic, including various cell populations involved in fibrosis development. Müller cell processes extended from superficial retina into subretinal lesions at 8 weeks. Western blotting revealed increases in fibronectin (4 wk and 8 wk, p < 0.001), CTGF (20 wks, p < 0.001), MMP2 (12 wks and 20 wks p < 0.05), αSMA (12 wks and 20 wks p < 0.05) and GFAP (8 wk and 12 wk, p ≤ 0.01), consistent with our immunofluorescence results. Intravitreal injection of Aflibercept reduced subretinal lesion growth. Our study provides evidence JR5558 mice have subretinal fibrotic lesions that grow between 4 and 8 weeks and confirms this line to be a good model to study subretinal fibrosis development and assess treatment options.

Retinal Reactive Astrocytic Tumor and Astrocytic hamartomas in patient with Neurofibromatosis type 1: Case Report and Literature review.

INTRODUCTION: Neurofibromatosis type I, also known as Von Recklinghausen disease, is a common phakomatosis affecting 1 in 2500-3000 live births; it may be associated with several common ocular findings, including Lisch nodules, plexiform neurofibromas, optic pathway gliomas, retinal astrocytic hamartomas and choroidal nodules. CASE DESCRIPTION: This report illustrates clinical evidence of simultaneous presence of retinal reactive astrocytic tumor (RRAT) and two retinal astrocytic hamartomas (RAH) in a 15 y/o patient with NF1, referred to our attention because of an asymptomatic fundus mass in his right eye of recent onset. CONCLUSION: This case, in addition to considering NF1 as one of the ocular conditions associated with secondary RRAT, underlines the importance of early referral and continuous ophthalmological follow-up in preventing possible complications that could cause significant visual impairment in patients with NF1.