Search Results (273)

Alzheimer’s disease (AD) is increasingly recognized as a multifactorial disorder driven by a combination of disruptions in proteostasis and organelle communication. The 2020 Lancet commission reported that approximately 10 million people worldwide were affected by AD in the mid-20th century. AD is the most prevalent cause of dementia. By early 2030, the global cost of dementia is projected to rise by USD 2 trillion per year, with up to 85% of that cost attributed to daily patient care. Several factors have been implicated in the progression of neurodegeneration, including increased oxidative stress, the accumulation of misfolded proteins, the formation of amyloid plaques and aggregates, the unfolded protein response (UPR), and mitochondrial–endoplasmic reticulum (ER) calcium homeostasis. However, the exact triggers that initiate these pathological processes remain unclear, in part because clinical symptoms often emerge gradually and subtly, complicating early diagnosis. Among the early hallmarks of neurodegeneration, elevated levels of reactive oxygen species (ROS) and the buildup of misfolded proteins are believed to play pivotal roles in disrupting proteostasis, leading to cognitive deficits and neuronal cell death. The accumulation of amyloid-β (Aβ) plaques and tau neurofibrillary tangles is a characteristic feature of AD. These features contribute to chronic neuroinflammation, which is marked by the release of pro-inflammatory cytokines and chemokines that exacerbate oxidative stress. Given these interconnected mechanisms, targeting stress-related signaling pathways, such as oxidative stress (ROS) generated in the mitochondria and ER, ER stress, UPR, and cytosolic chaperones, represents a promising strategy for therapeutic intervention. This review focuses on the relationship between stress chaperone responses and organelle function, particularly the interaction between mitochondria and the ER, in the development of new therapies for AD and related neurodegenerative disorders. Full article

In familial Alzheimer’s disease (FAD), presenilin 1 (PSEN1) E280A cholinergic-like neurons (ChLNs) induce aberrant secretion of extracellular amyloid beta (eAβ). How PSEN1 E280A ChLNs-eAβ affects microglial activity is still unknown. We obtained induced microglia-like cells (iMG) from human peripheral blood cells (hPBCs) in a 15-day differentiation process to investigate the effect of bolus addition of Aβ42, PSEN1 E280A cholinergic-like neuron (ChLN)-derived culture supernatants, and PSEN1 E280A ChLNs on wild type (WT) iMG, PSEN1 E280A iMG, and sporadic Alzheimer’s disease (SAD) iMG. We found that WT iMG cells, when challenged with non-cellular (e.g., lipopolysaccharide, LPS) or cellular (e.g., Aβ42, PSEN1 E280A ChLN-derived culture supernatants) microenvironments, closely resemble primary human microglia in terms of morphology (resembling an “amoeboid-like phenotype”), expression of surface markers (Ionized calcium-binding adapter molecule 1, IBA-1; transmembrane protein 119, TMEM119), phagocytic ability (high pHrodo™ Red E. coli BioParticles™ phagocytic activity), immune metabolism (i.e., high generation of reactive oxygen species, ROS), increase in mitochondrial membrane potential (ΔΨm), response to ATP-induced transient intracellular Ca²⁺ influx, cell polarization (cluster of differentiation 68 (CD68)/CD206 ratio: M1 phenotype), cell migration activity according to the scratch wound assay, and especially in their inflammatory response (secretion of cytokine interleukin-6, IL-6; Tumor necrosis factor alpha, TNF-α). We also found that PSEN1 E280A and SAD iMG are physiologically unresponsive to ATP-induced Ca²⁺ influx, have reduced phagocytic activity, and diminished expression of Triggering Receptor Expressed on Myeloid Cells 2 (TREM2) protein, but when co-cultured with PSEN1 E280A ChLNs, iMG shows an increase in pro-inflammatory phenotype (M1) and secretes high levels of cytokines IL-6 and TNF-α. As a result, PSEN1 E280A and SAD iMG induce apoptosis in PSEN1 E280A ChLNs as evidenced by abnormal phosphorylation of protein TAU at residue T205 and cleaved caspase 3 (CC3). Taken together, these results suggest that PSEN1 E280A ChLNs initiate a vicious cycle between damaged neurons and M1 phenotype microglia, resulting in excessive ChLN death. Our findings provide a suitable platform for the exploration of novel therapeutic approaches for the fight against FAD. Full article

Glaucoma is a trans-synaptic neurodegenerative disease, and the pathological increase in intraocular pressure (IOP) is a major risk factor of glaucoma. High IOP alters microstructure and morphologies of the brain tissue. Since mechanical properties of the brain are sensitive to the alteration of the tissue microstructure, we investigate how varying durations of chronic elevated IOP alter brain mechanical properties. A chronic high IOP rat model was induced by episcleral vein cauterization with subconjunctival injection of 5-Fluorouracil. At 2, 4 and 8 weeks after induction, indentation tests were performed on the brain slices to measure mechanical properties in the hippocampus, lateral geniculate nucleus and occipital lobe of both hemispheres. Meanwhile, the brain’s microstructure was assessed via F-actin and myelin staining. Compared to the blank control group, the Young’s modulus decreased in all three brain regions in the highIOP experimental groups. F-actin fluorescence intensity and myelin area fraction were reduced in the hippocampus, while β-amyloid levels and tau phosphorylation were elevated in the experimental groups. Our study provides insight into Alzheimer’s disease pathogenesis by demonstrating how chronic high IOP alters the brain’s mechanical properties. Full article

(1) Background: Multiple sclerosis (MS) is a biologically highly heterogeneous disease and has poor predictability at diagnosis. Moreover, robust data indicate that early disease activity strongly correlates with future disability. Therefore, there is a need for strong and reliable biomarkers from diagnosis to characterize and identify patients who require highly effective disease-modifying treatments (DMTs). Several biomarkers are promising, particularly neurofilament light chains (NFLs), but the relevance of others is less consolidated. (2) Methods: We evaluated a panel of axonal damage and inflammatory biomarkers in cerebrospinal fluid (CSF) and matched serum obtained from a cohort of 60 newly diagnosed MS patients. Disability at diagnosis, negative prognostic factors, and the initial DMT prescribed were carefully recorded. (3) Results: We observed correlations between different axonal biomarkers: CSF and serum NFL versus CSF total tau; and between the inflammatory marker osteopontin (OPN) and axonal biomarkers CSF p-Tau, CSF total tau, and serum NFL. CSF and serum NFL and total tau, as well as CSF OPN, positively correlated with EDSS at diagnosis. Moreover, CSF and serum NFL levels were increased in patients with gadolinium-enhancing lesions (p = 0.01 and p = 0.04, respectively) and in those treated with highly effective DMT (p = 0.049). Furthermore, CSF OPN and both CSF and serum NFL levels significantly differentiated patients based on EDSS, with a combined ROC AUC of 0.88. We calculated and internally validated biomarker (in particular serum NFL) thresholds that significantly identified patients with higher disability. Finally, CSF OPN levels and dissemination in the spinal cord were significant predictors of EDSS at diagnosis. (4) Conclusions: These preliminary exploratory data confirm the pathological interconnection between inflammation and axonal damage from early disease stages, contributing to early disability. Follow-up data, such as longitudinal disability scores, repeated serum measurements, a healthy control group, and external validation of our results, are needed. We suggest that combining several fluid biomarkers may improve the clinical characterization of patients. Full article

Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are linked by shared genetic mutations and overlapping clinical features, forming a clinical spectrum. This systematic review and meta-analysis analysed 97 studies, including 3212 patients with key ALS/FTD gene mutations, to identify gene-specific behavioural profiles. Chromosome 9 open reading frame 72 (C9orf72) mutations were strongly associated with psychotic symptoms and aggression, while superoxide dismutase 1 (SOD1) mutations had minimal cognitive effects. Progranulin (PGRN) mutations correlated with apathy and hallucinations, microtubule-associated protein tau (MAPT) mutations with disinhibition, and charged multivesicular body protein 2B (CHMP2B) with social impairments. Fused in sarcoma (FUS) mutations caused early sleep disturbances, TANK-binding kinase 1 (TBK1) led to disinhibition, and presenilin 1 and 2 (PSEN1/2) was linked to severe aggression. Prodromal cognitive changes in PGRN, MAPT, and CHMP2B mutations suggested early disease onset. Despite overlapping symptoms and clinical heterogeneity, understanding gene-specific patterns could inform tailored care strategies to enhance the quality of life for ALS and FTD patients. This study calls for refined guidelines integrating genetic behavioural profiles to improve patient and family support. Full article

Background/Objectives: We previously demonstrated that nilotinib can sufficiently enter the brain to pharmacologically inhibit discoidin domain receptors (DDR)-1 in patients with Parkinson’s and Alzheimer’s disease. We primarily hypothesized that nilotinib is safe, and may alter disease-related biomarkers to improve, motor, cognitive and/or behavioral features in dementia with Lewy bodies (DLB). Methods: Forty-three participants were randomized 1:1 into nilotinib, 200 mg, or matching placebo in a single-center, phase 2, randomized, double-blind study. Study drug was taken orally once daily for 6 months followed by one-month wash-out. Results: Of 43 individuals enrolled, 14 were women (33%); age (mean ± SD) was 73 ± 8.5 years. Nilotinib was safe and well-tolerated, and more adverse events were noted in the placebo (74) vs. nilotinib (37) groups (p = 0.054). The number of falls were reduced in the nilotinib (six) compared to placebo (21) group (p = 0.006). Cerebrospinal fluid homovanillic acid, a biomarker of dopamine levels, was increased (p = 0.004), while the ratio of pTau181/Aβ42 was reduced (p = 0.034). The Alzheimer’s Disease Assessment Scale—cognition 14 improved by 2.8 pts (p = 0.037), and no differences were observed in Movement Disorders Society–Unified Parkinson’s Disease Rating Scale parts II and III. However, part I (cognition) improved (p = 0.044) in nilotinib compared to placebo. Conclusions: Nilotinib demonstrates favorable safety, biomarkers, and efficacy outcomes in patients with DLB supporting further trials in DLB or advanced Parkinson’s disease with dementia. Full article

Introduction: There is no consensus on managing non-functioning pancreatic neuroendocrine tumors smaller than 2 cm (NF-PANNETs < 2 cm). Therefore, their treatment remains controversial. The aim of this study, by literature review and meta-analysis, is to establish the best management of NF-PANNETs < 2 cm based on overall survival (OS) and cancer-specific survival (CSS). Materials and Methods: An extensive online search was conducted using the MEDLINE, EMBASE, Google Scholar, Scopus, Web of Science, and Cochrane Central databases. All retrospective and prospective studies were included in this study, comparing the outcomes of surgical management vs. conservative management in patients with NF-PANNETs < 2 cm. The pooled odds ratio and 95% CI for survival were calculated. Results: Six studies were included in the quantitative analysis, with 2708 patients managed operatively and 985 managed conservatively. A pooled analysis of all the data demonstrated increased OS in patients managed operatively compared with those managed conservatively at five years (OR = 1.77, 95% CI: 0.96 to 2.58; p = 0.002). In contrast, the meta-analysis did not demonstrate increased CSS in patients undergoing surgical resection compared with conservative management (OR = 1.01, 95% CI: −5.25 to 7.27; p = 0.56). Furthermore, analysis demonstrated a high heterogeneity for OS (Q = 43.98, p < 0.001, tau² = 0.46, I² = 88.63%) and for CSS (Q = 22.81, p < 0.0001, tau² = 1.72, I² = 91.23%). Conclusion: This systematic review and meta-analysis indicated that surgical management of NF-PANNETs < 2 cm improves overall survival (OS) but does not significantly enhance cancer-specific survival (CSS). There is variability in outcomes among studies, and while surgery may help some patients, the lack of clear CSS benefits and associated risks call for individualized decision-making. Therefore, a conservative approach with active surveillance may be more suitable for low-risk patients. Full article

Memory impairment is a defining characteristic of Alzheimer’s disease (AD), with amnesia often appearing as its earliest symptom. Given the multifactorial nature of AD pathogenesis, this study investigates the multi-target therapeutic potential of sobrerol (coded as NRM-331) in a scopolamine-induced amnesia mouse model, focusing specifically on its effects in ameliorating memory deficits and enhancing neuronal plasticity. Sixty male C57BL/6NCrljOri mice were divided into six groups (10 mice/group): vehicle control (CTL, saline), scopolamine (SPA, 10 mg/kg/day), Aricept (APT, 2 mg/kg/day), and three treatment groups receiving NRM-331 at doses of 40, 80, and 100 mg/kg/day. Several behavioral tests were conducted, including the Y-maze test, passive avoidance test, and Morris water maze test. Additionally, biochemical assays were performed in serum (to measure Aß 1-40 and Aß 1-42) and in the brain (to assess ACh and AChE levels), along with histopathological examination of the brain using Nissl staining and p-tau IHC. No significant change was observed in the Y-maze test or the acquisition trial of the passive avoidance test. However, improvements were noted in the retention trial of the passive avoidance test and the Morris water maze test (including escape latency, swim distance, and number of platform crossed) for the NRM-331 groups compared to the SPA group. Serum levels of Aß 1-40 and Aß 1-42 decreased in the NRM-331 groups compared to the SPA group. In the brain, levels of ACh significantly increased, while AChE levels significantly decreased compared to the SPA group. The number of neuronal cells improved in the CA1, CA3, and DG regions of the hippocampus, as indicated by Nissl staining. A significant reduction in p-tau accumulation was also observed in the NRM-331 groups. In conclusion, NRM-331 demonstrated an anti-amnesic effect by enhancing hippocampal cholinergic signaling, alongside exhibiting anti-tau and anti-Aβ synthesis properties. These therapeutic effects suggest that NRM-331 significantly mitigates memory impairment induced by SPA through a neuroprotective mechanism. Full article

The present Perspective analyzes the remarkable evolution of the Amyloid Cascade Hypothesis 2.0 (ACH2.0) theory of Alzheimer’s disease (AD) since its inception a few years ago, as reflected in the diminishing role of amyloid-beta (Aβ) in the disease. In the initial iteration of the ACH2.0, Aβ-protein-precursor (AβPP)-derived intraneuronal Aβ (iAβ), accumulated to neuronal integrated stress response (ISR)-eliciting levels, triggers AD. The neuronal ISR, in turn, activates the AβPP-independent production of its C99 fragment that is processed into iAβ, which drives the disease. The second iteration of the ACH2.0 stemmed from the realization that AD is, in fact, a disease of the sustained neuronal ISR. It introduced two categories of AD—conventional and unconventional—differing mainly in the manner of their causation. The former is caused by the neuronal ISR triggered by AβPP-derived iAβ, whereas in the latter, the neuronal ISR is elicited by stressors distinct from AβPP-derived iAβ and arising from brain trauma, viral and bacterial infections, and various types of inflammation. Moreover, conventional AD always contains an unconventional component, and in both forms, the disease is driven by iAβ generated independently of AβPP. In its third, the current, iteration, the ACH2.0 posits that proteolytic production of Aβ is suppressed in AD-affected neurons and that the disease is driven by C99 generated independently of AβPP. Suppression of Aβ production in AD seems an oxymoron: Aβ is equated with AD, and the later is inconceivable without the former in an ingrained Amyloid Cascade Hypothesis (ACH)-based notion. But suppression of Aβ production in AD-affected neurons is where the logic leads, and to follow it we only need to overcome the inertia of the preexisting assumptions. Moreover, not only is the generation of Aβ suppressed, so is the production of all components of the AβPP proteolytic pathway. This assertion is not a quantum leap (unless overcoming the inertia counts as such): the global cellular protein synthesis is severely suppressed under the neuronal ISR conditions, and there is no reason for constituents of the AβPP proteolytic pathway to be exempted, and they, apparently, are not, as indicated by the empirical data. In contrast, tau protein translation persists in AD-affected neurons under ISR conditions because the human tau mRNA contains an internal ribosomal entry site in its 5′UTR. In current mouse models, iAβ derived from AβPP expressed exogenously from human transgenes elicits the neuronal ISR and thus suppresses its own production. Its levels cannot principally reach AD pathology-causing levels regardless of the number of transgenes or the types of FAD mutations that they (or additional transgenes) carry. Since the AβPP-independent C99 production pathway is inoperative in mice, the current transgenic models have no potential for developing the full spectrum of AD pathology. What they display are only effects of the AβPP-derived iAβ-elicited neuronal ISR. The paper describes strategies to construct adequate transgenic AD models. It also details the utilization of human neuronal cells as the only adequate model system currently available for conventional and unconventional AD. The final alteration of the ACH2.0, introduced in the present Perspective, is that AβPP, which supports neuronal functionality and viability, is, after all, potentially produced in AD-affected neurons, albeit not conventionally but in an ISR-driven and -compatible process. Thus, the present narrative begins with the “omnipotent” Aβ capable of both triggering and driving the disease and ends up with this peptide largely dislodged from its pedestal and retaining its central role in triggering the disease in only one, although prevalent (conventional), category of AD (and driving it in none). Among interesting inferences of the present Perspective is the determination that “sporadic AD” is not sporadic at all (“non-familial” would be a much better designation). The term has fatalistic connotations, implying that the disease can strike at random. This is patently not the case: The conventional disease affects a distinct subpopulation, and the basis for unconventional AD is well understood. Another conclusion is that, unless prevented, the occurrence of conventional AD is inevitable given a sufficiently long lifespan. This Perspective also defines therapeutic directions not to be taken as well as auspicious ways forward. The former category includes ACH-based drugs (those interfering with the proteolytic production of Aβ and/or depleting extracellular Aβ). They are legitimate (albeit inefficient) preventive agents for conventional AD. There is, however, a proverbial snowball’s chance in hell of them being effective in symptomatic AD, lecanemab, donanemab, and any other “…mab” or “…stat” notwithstanding. They comprise Aβ-specific antibodies, inhibitors of beta- and gamma-secretase, and modulators of the latter. In the latter category, among ways to go are the following: (1) Depletion of iAβ, which, if sufficiently “deep”, opens up a tantalizing possibility of once-in-a-lifetime preventive transient treatment for conventional AD and aging-associated cognitive decline, AACD. (2) Composite therapy comprising the degradation of C99/iAβ and concurrent inhibition of the neuronal ISR. A single transient treatment could be sufficient to arrest the progression of conventional AD and prevent its recurrence for life. Multiple recurrent treatments would achieve the same outcome in unconventional AD. Alternatively, the sustained reduction/removal of unconventional neuronal ISR-eliciting stressors through the elimination of their source would convert unconventional AD into conventional one, preventable/treatable by a single transient administration of the composite C99/iAβ depletion/ISR suppression therapy. Efficient and suitable ISR inhibitors are available, and it is explicitly clear where to look for C99/iAβ-specific targeted degradation agents—activators of BACE1 and, especially, BACE2. Directly acting C99/iAβ-specific degradation agents such as proteolysis-targeting chimeras (PROTACs) and molecular-glue degraders (MGDs) are also viable options. (3) A circumscribed shift (either upstream or downstream) of the position of transcription start site (TSS) of the human AβPP gene, or, alternatively, a gene editing-mediated excision or replacement of a small, defined segment of its portion encoding 5′-untranslated region of AβPP mRNA; targeting AβPP RNA with anti-antisense oligonucleotides is another possibility. If properly executed, these RNA-based strategies would not interfere with the protein-coding potential of AβPP mRNA, and each would be capable of both preventing and stopping the AβPP-independent generation of C99 and thus of either preventing AD or arresting the progression of the disease in its conventional and unconventional forms. The paper is interspersed with “validation” sections: every conceptually significant notion is either validated by the existing data or an experimental procedure validating it is proposed. Full article

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder characterized by cognitive decline, memory impairment, and synaptic dysfunction. The accumulation of amyloid beta (Aβ) plaques and hyperphosphorylated tau protein leads to neuronal dysfunction, neuroinflammation, and glial cell activation. Emerging evidence suggests that peripheral insulin resistance and chronic inflammation, often associated with type 2 diabetes (T2D) and obesity, promote increased proinflammatory cytokines, oxidative stress, and immune cell infiltration. These conditions further damage the blood–brain barrier (BBB) integrity and promote neurotoxicity and chronic glial cell activation. This induces neuroinflammation and impaired neuronal insulin signaling, reducing glucose metabolism and exacerbating Aβ accumulation and tau hyperphosphorylation. Indeed, epidemiological studies have linked T2D and obesity with an increased risk of developing AD, reinforcing the connection between metabolic disorders and neurodegeneration. This review explores the relationships between peripheral insulin resistance, inflammation, and BBB dysfunction, highlighting their role in glial activation and the exacerbation of AD pathology. Full article

Adipose-derived mesenchymal stem cells (ADSCs) have exhibited promising therapeutic potential in Alzheimer’s disease (AD), although the underlying mechanisms remain poorly understood. Previously established Alzheimer’s disease neuron models derived from Ts21-induced pluripotent stem cells (Ts21-iPSCs) have been shown to exhibit progressive amyloid beta accumulation during neuronal differentiation. In this study, we employed a Transwell co-culture system to investigate the interaction between neurons derived from Ts21-iPSCs and ADSCs. Our findings revealed that co-culture with ADSCs significantly enhanced the survival rate of AD neurons. Proteomics analysis identified significant upregulation of left–right determination factor 2 (LEFTY2) protein in the co-culture medium. Supplementation with 2 nM LEFTY2 markedly improved the survival and growth of AD neurons. Furthermore, LEFTY2 effectively downregulates the expression of apolipoprotein E4 and amyloid beta 1–42, along with attenuating phosphorylated tau231 levels in AD neurons. These results suggest the potential of LEFTY2 as a promising therapeutic candidate for Alzheimer’s disease. Full article

Background/Objectives: Frailty screening is essential in primary care for the early identification of vulnerable older adults. PRISMA-7 is a widely used screening tool, but Item 2 (“Are you male?”) introduces potential sex bias and overestimates frailty in men. PRISMA-6, a modified version that excludes Item 2, might provide a more equitable alternative. This study evaluates PRISMA-6’s alignment with the Clinical Frailty Scale (CFS) and its impact on sex-specific frailty classification. Methods: A cross-sectional study was conducted in 142 general practices across South Tyrol, including 9190 general practice patients aged ≥75 years. Frailty was assessed using PRISMA-7, PRISMA-6, and the CFS. Correlations between tools were calculated using Kendall’s Tau-b, whereas Fisher’s z-test was used to compare differences in alignment. The frailty prevalence and odds ratios were stratified according to sex and age. Results: PRISMA-6 showed a stronger correlation with the CFS (τ = 0.492) than PRISMA-7 (τ = 0.308, z = −10.2, p < 0.001). This effect was pronounced in men (z = −9.8, p < 0.001), whereas no difference was observed in women (z = 0.00, p = 1.000). PRISMA-6 reduced the frailty detection rate in men and was more closely aligned with the CFS. Conclusions: PRISMA-6 demonstrated improved alignment with the CFS and reduced sex bias compared to PRISMA-7. However, its use as a screening tool for men requires prospective validation in diverse settings. PRISMA-6 shows promise as a reliable and equitable frailty screening tool and should be considered for use in future studies, particularly in primary care settings, while awaiting further prospective validation. Full article

Background: Diabetic kidney disease (DKD) represents a chronic microvascular complication with diabetes, affecting around one-third of diabetic individuals. Despite current therapies, progression to end-stage kidney disease remains a challenge. Abnormal hyperphosphorylation of the Tau protein is implicated in various age-related diseases. This study aimed to explore the link between renal Tau protein hyperphosphorylation and kidney damage in type 2 diabetes mellitus (T2DM). Methods: Sprague Dawley rats were administered lithium chloride (LiCl), an inhibitor of a glycogen synthase kinase-3 (GSK3) inhibitor known to reduce Tau hyperphosphorylation. LiCl was administered either daily or every other day at a dosage of 1 mmol/kg. The effects of LiCl on kidney function were assessed through proteinuria, the kidney-to-bodyweight ratio, inflammation, fibrosis, and TGF-β1 expression levels. Results: Diabetic rats exhibited increased proteinuria, renal hypertrophy, inflammation, fibrosis, and elevated TGF-β1 expression. Lithium chloride treatment reduced kidney hypertrophy, inflammation, and fibrosis, indicating that Tau hyperphosphorylation contributes to the pathogenesis of DKD. LiCl also regulated TGF-β1 expression, which was associated with improved renal outcomes. Conclusions: The inhibition of Tau hyperphosphorylation by lithium chloride offers a potential therapeutic strategy for mitigating kidney damage in diabetic kidney disease. This study proposes LiCl as a novel treatment approach to attenuate DKD progression. Full article

The assembly of amyloidogenic proteins and peptides into toxic oligomeric and fibrillar aggregates is closely connected to the onset and progression of more than 50 protein diseases, such as Alzheimer’s disease, Parkinson’s disease, prion disease, and type 2 diabetes, to name only a few. Considerable research efforts at identifying the therapeutic strategies against these maladies are currently focused on preventing and inhibiting pathogenic protein aggregation by various agents. Plant-based extracts and compounds have emerged as promising sources of potential inhibitors due to their dual role as nutraceuticals as part of healthy diets and as specific pharmaceuticals when administered at higher concentrations. In recent decades, several plant extracts and plant-extracted compounds have shown potential to modulate protein aggregation. An ever-growing body of research on plant-based amyloid inhibitors requires a detail analysis of existing data to identify potential knowledge gaps. This review summarizes the recent progress in amyloid inhibition using 17 flavonoids, 11 polyphenolic non-flavonoid compounds, 23 non-phenolic inhibitors, and 59 plant extracts, with the main emphasis on directly modulating the fibrillation of four amyloid proteins, namely amyloid-β peptide, microtubule-associated protein tau, α-synuclein, and human islet amyloid polypeptide. Full article

Climate change significantly stresses cold-adapted and stenothermic plant species in high-altitude mountain ecosystems. The diverse plant species at elevations ranging from 1324 to 2527 m above mean sea level (AMSL) provide an ideal setting for investigating these impacts in the Al-Baha Highlands, Saudi Arabia. Therefore, this study has three aims: first, to estimate vegetation cover in 2023 and its relationship with environmental factors; second, to analyze long-term trends (1991–2023) in key spectral indices, including the normalized difference vegetation index (NDVI), normalized difference vegetation water index (NDWI), normalized difference open water index (NDWIw), and land surface temperature (LST), using the Kendall tau-b method; and third, to model ecological stress via a generalized additive model (GAM) and assess its impact on vegetation. We utilized Landsat 5/7/8 (C2 SR T1) for spectral indices and the Copernicus DEM for topographic and hydrological analysis. The results indicate significant roles of LST, elevation, and distance from seasonal streams in shaping vegetation patterns (p < 2 × 10⁻¹⁶). There were negative trends in the NDVI (91.66 km²), NDWI (138 km²), and NDWIw (804 km²) (p < 0.05), whereas the LST exhibited positive trends (116.15 km²) (p < 0.05). The GAM achieved high predictive accuracy (R² = 0.979), capturing nonlinear relationships between the predictors and the stress score. Severe ecological stress occurred in high-altitude zones (>1700 m AMSL) on south-facing slopes due to increased LST and declining NDWI, impacting species such as Juniperus procera. Hypothesis testing was used to assess variations in the NDVI, its long-term trends, and ecological stress between highland and lower-elevation areas, revealing highly significant differences (p < 2.2 × 10⁻¹⁶). This study provides novel insights into ecological stress dynamics in relation to altitude and slope aspects, offering actionable recommendations for sustainable ecosystem management, including targeted reforestation and water resource optimization to mitigate stress and preserve biodiversity. Full article