Maria E. Figueiredo-Pereira

Alzheimer′s disease (AD) has long been defined by amyloid-β plaques and hyperphosphorylated tau, yet disease-modifying therapies remain critically limited. Growing evidence reframes AD as a system–level failure driven by early dysregulation of synaptic, metabolic, and neuroimmune pathways, preceding overt protein aggregation and originating in selectively vulnerable circuits, including the locus coeruleus (LC)–hippocampal noradrenergic axis. This complexity underscores the need for therapeutic strategies that engage the disease at a network level, early in its trajectory. To this end, using a machine learning–based systems pharmacology framework for drug repurposing applied to human AD transcriptomic datasets, we identified terazosin (TZ) as a candidate predicted to reverse AD-associated molecular signatures. TZ is an FDA-approved α ₁ –adrenergic receptor antagonist and phosphoglycerate kinase–1 activator. It was administered chronically via the diet (0.5 mg/kg bw/day) to male and female TgF344–AD rats and wild–type littermates from 5 to 11 months of age, preceding overt pathology. Bulk hippocampal RNA sequencing revealed sex–specific transcriptional remodeling in transgenic rats, strongly conserved with human AD datasets. Male TgF344–AD rats exhibited suppression of synaptic and transcriptional maintenance pathways with concurrent activation of metabolic, proteostatic, extracellular matrix, and vascular stress responses; females showed suppression of survival and vascular structural signaling alongside heightened DAM–like immune activation, amyloid-associated stress, and cell death programs. TZ reversed these signatures in a sex–dependent manner: males showed enhanced immune surveillance and reduced proteostasis burden, while females showed reinforcement of synaptic, survival, and metabolic pathways. TgF344–AD rats displayed selective LC–derived hippocampal noradrenergic axonopathy without global neuronal loss. TZ preserved fiber integrity preferentially in females and partially reversed LC vulnerability–associated transcriptional signatures in both sexes. TZ also reduced amyloid–β plaque burden in both sexes, attenuated hyperphosphorylated tau exclusively in females, and induced microglial morphological shifts in males. Finally, TZ restored wild–type spatial learning in transgenic animals, with females appearing to derive the greater cognitive benefit. Together, these findings demonstrate that TZ induced systems-level reprogramming of AD–relevant molecular pathways and preserved vulnerable noradrenergic circuitry in a sex–dependent manner. Moreover, TZ rescued spatial cognition in transgenic rats, with cognitive gains seemingly more pronounced in females. These results support adrenergic–bioenergetic modulation as a translational strategy for early–stage AD and underscore the necessity of sex as a biological variable in disease–modifying treatment development.

Alzheimer’s disease (AD) remains without effective disease-modifying therapies, underscoring the need for interventions that target interconnected molecular and cellular processes driving cognitive decline. Leveraging a cross-species translational framework integrating a progressive rat model of Alzheimer’s disease with human iPSC-derived neurons carrying familial AD mutations, we identify agomelatine (AGO) as a disease-modifying candidate. A clinically used melatonergic agonist and 5-HT _2C serotonergic antagonist, we found that AGO acts as a sex-selective modulator of AD-related neuronal and microglial dysfunction with therapeutic relevance across species. TgF344-AD rats and their wildtype littermates received chronic dietary AGO (∼10 mg/kg/day) from 5 to 11 months of age and underwent hippocampal-dependent spatial learning assessment, quantitative hippocampal histopathology, and bulk RNA sequencing to evaluate the therapeutic effect on cognition, pathology, and molecular mechanisms. Human isogenic iPSC-derived cortical neurons carrying PSEN2 ^N141I or APPV ^717I mutations were treated with 20 µM AGO followed by bulk RNA sequencing, to define AGO-driven transcriptional pathway modulation in AD neurons In TgF344-AD rats, AGO produced robust female-specific benefits. AGO selectively restored hippocampal-dependant cognitive performance in female but not male transgenic rats. These improvements were independent of amyloid burden and instead aligned with reductions in microgliosis and pathogenic AT8-positive tau phosphorylation. Additionally, AGO normalized reactive and amoeboid microglial states exclusively in females and enhanced doublecortin-defined neurogenesis without altering mature NeuN⁺ neuronal density. This coordinated hippocampal stabilization highlights AGO’s capacity to restore plasticity rather than simply suppress pathology. Transcriptomic analyses revealed sex-divergent mechanisms underlying these effects. In females, AGO activated metabolic, oxygen-handling, lipid-processing, neuroimmune, and CREB/IGF-1 signaling pathways while suppressing ER-stress, epigenetic, and ion-channel transcripts, changes consistent with resilience-promoting cellular reprogramming. In males, AGO preferentially modulated mitochondrial redox biology, transcriptional regulators, and extracellular matrix components. Despite these differences, both sexes showed AGO-induced engagement of conserved AD-relevant pathways, including shared induction of synaptic plasticity and hemoglobin/oxygen-transport related genes, suggesting a convergent neuroprotective molecular signature. To translate these findings to a human system, we examined AGO’s effects in PSEN2 ^N141I and APP ^V717I iPSC-derived cortical neurons. Both mutations produced convergent deficits in synaptic integrity, neuronal maturity, trophic signaling, proteostasis, metabolism, and excitability, alongside dysregulated developmental and ECM-remodeling programs. AGO partially reversed these pathogenic transcriptional changes, up-regulating synaptic, metabolic, vesicle-trafficking, and redox-stress resilience genes while suppressing pathological developmental and inflammatory pathways, demonstrating conserved engagement of neuronal recovery programs. Together, these results identify AGO as a promising non-amyloid therapeutic candidate capable of modulating AD-relevant pathways in rodents and human models. The sex-selective efficacy observed in vivo , combined with conserved transcriptional responses across species, underscores the translational relevance of AGO-driven molecular reprogramming in AD.

Neuroinflammation is a key pathological hallmark of Alzheimer’s disease (AD). Investigational and FDA approved drugs targeting inflammation already exist, thus drug repurposing for AD is a suitable approach. BT-11 is an investigational drug that reduces inflammation in the gut and improves cognitive function. BT-11 is orally active and binds to lanthionine synthetase C-like 2 (LANCL2), a glutathione-s-transferase, thus potentially reducing oxidative stress. We investigated the effects of BT-11 long-term treatment on the TgF344-AD rat model of AD. BT-11 (1) reduced spatial memory deficits, and hippocampal Abeta plaque load, and increased neuronal levels in males, and reduced microglia numbers in females, and (2) induced transcriptomic changes in signaling receptor, including G-protein coupled receptor pathways in both males and females, with changes in neurotrophic factors only in males. We detected LANCL2 in hippocampal nuclear and cytoplasmic fractions with potentially different post-translational modifications, suggesting distinct functions based on its subcellular localization. LANCL2 was present in oligodendrocytes, indicating a role in oligodendrocyte function. To our knowledge, these last two findings have not been reported. Overall, our data support that targeting LANCL2 with BT-11 improves cognition and reduces AD-like pathology potentially by modulating G-protein signaling. LANCL2’s localization in oligodendrocytes suggest a possible role oligodendrocyte function that warrants further investigation. Our studies contribute to the field of new immunomodulatory AD therapeutics and establish LANCL2 as a promising therapeutic target meriting further mechanistic investigation.

Alzheimer’s disease is a neurodegenerative disorder that leads to progressive memory loss, cognitive decline, and behavioral changes. Despite ongoing research, its exact causes and effective treatments remain elusive. Traditional approaches have focused on symptom management, but breakthroughs in bioinformatics and high-throughput drug screening are offering new pathways to potential therapies. This review highlights our recent efforts to identify novel drug candidates for Alzheimer’s disease by leveraging computational methods and large-scale biological datasets. Our work introduces two key innovations in Alzheimer’s disease research: addressing sex-specific differences and leveraging drug repurposing for accelerated treatment discovery. By combining sex-stratified preclinical data with machine learning and in vivo validation, we improve translational relevance and support precision medicine. Using the TgF344-AD rat model, which mimics human Alzheimer’s disease spatial memory deficits and pathology, we explored the efficacy of various US Food and Drug Administration–approved and investigational drugs. These included ibudilast, timapiprant, RG2833, diazoxide/dibenzoylmethane (combined), and BT-11, which targeted key Alzheimer’s disease–related molecular pathways such as amyloid-beta plaques, Tau tangles, and neuroinflammation. These drugs, at various stages of development, offer hope for not only managing symptoms but also addressing the underlying mechanisms of Alzheimer’s disease. This review underscores the need for a multifaceted approach to Alzheimer’s disease treatment, combining symptom relief with disease modification.

Background: Nearly two-thirds of Alzheimer's disease (AD) patients are women. Therapeutics for women are critical to lowering their elevated risk of developing this major cause of adult dementia. Moreover, targeting epigenetic processes such as histone acetylation that regulate multiple cellular pathways is advantageous given the multifactorial nature of AD. Histone acetylation takes part in memory consolidation, and its disruption is linked to AD. Objective: Determine whether the investigational drug RG2833 has repurposing potential for AD. RG2833 is a histone deacetylase HDAC1/3 inhibitor that is orally bioavailable and permeates the blood-brain-barrier. Methods: RG2833 effects were determined on cognition, transcriptome, and AD-like pathology in 11-month TgF344-AD female and male rats. Treatment started early in the course of pathology when therapeutic intervention is predicted to be most effective. Results: RG2833-treatment of 11-month TgF344-AD rats: (1) Significantly improved hippocampal-dependent spatial memory in females but not males. (2) Upregulated expression of immediate early genes, such as Arc, Egr1 and c-Fos, and other genes involved in synaptic plasticity and memory consolidation in females. Remarkably, out of 17,168 genes analyzed for each sex, no significant changes in gene expression were detected in males at p < 0.05, false discovery rate 1.5. (3) Failed to improve amyloid beta accumulation and microgliosis in female and male TgF344-AD rats. Conclusions: Our study highlights the potential of histone-modifying therapeutics such as RG2833 to improve cognitive behavior and drive the expression of immediate early, synaptic plasticity and memory consolidation genes, especially in female AD patients.

Neuroinflammation is a key pathological hallmark of Alzheimer’s disease (AD). Investigational and FDA approved drugs targeting inflammation already exist, thus drug repurposing for AD is a suitable approach. BT-11 is an investigational drug that reduces inflammation in the gut and improves cognitive function. BT-11 is orally active and binds to lanthionine synthetase C-like 2 (LANCL2), a glutathione-s-transferase, thus potentially reducing oxidative stress. We investigated the effects of BT-11 long-term treatment on the TgF344-AD rat model. BT-11 reduced hippocampal-dependent spatial memory deficits, Aβ plaque load and neuronal loss in males, and mitigated microglia numbers in females. BT-11 treatment led to hippocampal transcriptomic changes in signaling receptor, including G-protein coupled receptor pathways. We detected LANCL2 in hippocampal nuclear and cytoplasmic fractions with potential different post-translational modifications, suggesting distinct functions based on its subcellular localization. LANCL2 was present in oligodendrocytes, showing a role in oligodendrocyte function. To our knowledge, these last two findings have not been reported. Overall, our data suggest that targeting LANCL2 with BT-11 improves cognition and reduces AD-like pathology by potentially modulating G-protein signaling and oligodendrocyte function. Our studies contribute to the field of novel immunomodulatory AD therapeutics, and merit further research on the role of LANCL2 in this disease.

Alzheimer’s disease (AD) is the major form of dementia prevalent in older adults and with a high incidence in females. Identification of early biomarkers is essential for preventive intervention to delay its progression. Furthermore, due to its multifactorial nature, a multi-target approach could be therapeutically beneficial. Our studies included 4- (pre-pathology) and 11-month (mild-pathology) TgF344-AD rats, a transgenic Alzheimer’s model that exhibits age-dependent AD progression. We identified two potential early biomarker genes for AD, early growth response 2 (EGR2) and histone 1H2AA (HIST1H2AA), in the hippocampus of 4-month females. Out of 17,168 genes analyzed by RNA sequencing, expression of these two genes was significantly altered in 4-month TgF344-AD rats compared to wild-type littermates. We also evaluated co-treatment with diazoxide (DZ), a potassium channel activator, and dibenzoylmethane (DIB), which inhibits eIF2α-P activity, on TgF344-AD and wild-type rats. DZ/DIB-treatment mitigated spatial memory deficits and buildup of hippocampal Aβ plaques and tau PHF in 11-month TgF344-AD rats but had no effect on wild-type littermates. To our knowledge, this preclinical study is the first to report EGR2 and HIST1H2AA as potential AD biomarkers in females, and the benefits of DZ/DIB-treatment in AD. Evaluations across multiple AD-related models is warranted to corroborate our findings.

Nearly two-thirds of patients with Alzheimer’s are women. Identifying therapeutics specific for women is critical to lowering their elevated risk for developing this major cause of adult dementia. Moreover, targeting epigenetic processes that regulate multiple cellular pathways is advantageous given Alzheimer’s multifactorial nature. Histone acetylation is an epigenetic process heavily involved in memory consolidation. Its disruption is linked to Alzheimer’s. Through our computational studies, we predicted that the investigational drug RG2833 (N-[6-(2-aminoanilino)-6-oxohexyl]-4-methylbenzamide) has repurposing potential for Alzheimer’s. RG2833 is a histone deacetylase HDAC1/3 inhibitor that is orally bioavailable and permeates the blood-brain-barrier. We investigated the RG2833 therapeutic potential in TgF344-AD rats, which are a model of Alzheimer’s that exhibits age-dependent progression, thus mimicking this aspect of Alzheimer’s patients that is difficult to establish in animal models. We investigated the RG2833 effects on cognitive performance, gene expression, and AD-like pathology in 11-month TgF344-AD female and male rats. A total of 89 rats were used: wild type n = 45 (17 females, 28 males), and TgF344-AD n = 44 (24 females, 20 males)] across multiple cohorts. No obvious toxicity was detected in the TgF344-AD rats up to 6 months of RG2833-treatment starting at 5 months of age administering the drug in rodent chow at ∼30mg/kg of body weight. We started treatment early in the course of pathology when therapeutic intervention is predicted to be more effective than in later stages of the disease. The drug-treatment significantly mitigated hippocampal-dependent spatial memory deficits in 11-month TgF344-AD females but not in males, compared to wild type littermates. This female sex-specific drug effect has not been previously reported. RG2833-treatment failed to ameliorate amyloid beta accumulation and microgliosis in female and male TgF344-AD rats. However, RNAseq analysis of hippocampal tissue from TgF344-AD rats showed that drug-treatment in females upregulated the expression of immediate early genes, such as Arc, Egr1 and c-Fos, and other genes involved in synaptic plasticity and memory consolidation. Remarkably, out of 17,168 genes analyzed for each sex, no significant changes in gene expression were detected in males at P < 0.05, false discovery rate < 0.05, and fold-change ≥ 1.5. Our data suggest that histone modifying therapeutics such as RG2833 improve cognitive behavior by modulating the expression of immediate early, neuroprotective and synaptic plasticity genes. Our preclinical study supports that RG2833 has therapeutic potential specifically for female Alzheimer’s patients. RG2833 evaluations using other AD-related models is necessary to confirm our findings.

INTRODUCTION: Alzheimer’s disease (AD) is a multifactorial disease for which therapeutic efficacy should benefit from a multi-target approach. Thus, we evaluated a combined chronic treatment with diazoxide (DZ) and dibenzoylmethane (DIB). DZ is a potassium channel activator. DIB counteract eIF2α-P-driven stress responses. The individual therapeutic benefits of each drug on attenuating neurodegeneration and apoptosis were previously examined, but not as a combined treatment. METHODS: We evaluated the efficacy of chronic DZ/DIB treatment on TgF344-AD rats (Tg-AD) at 4- and 11-months of age and wild-type littermates. Spatial working memory was assessed with the radial 8-arm maze, and AD pathology by immunohistochemistry. We used RNA sequencing for transcriptome analysis. RESULTS: DZ/DIB-treatment mitigated the spatial memory deficits as well as the buildup of hippocampal Aβ plaques and tau PHF exhibited by 11-month Tg-AD rats. The DZ/DIB-treatment had no effect on wild-type littermates. We did not detect AD-related deficits in untreated 4-month Tg-AD rats, but DZ/DIB-treatment altered their transcriptome. DZ/DIB-treatment of 4-month Tg-AD rats upregulated several genes normally downregulated in AD and/or aging. Expression of two potential early biomarkers for AD, EGR2 (early growth response 2) and HISIT1H2AA (histone H2AA), were also altered by the DZ/DIB treatment in 4-month Tg-AD rats. The treatment reduced levels of eIF2α, a protein involved in abnormal translational repression and a contributing factor to neuronal loss. DISCUSSION: This preclinical study represents the first report on the combined DZ/DIB-treatment. Besides the benefits of this treatment on spatial memory and AD pathology, we identified two potential early AD biomarkers. Furthermore, the DZ/DIB-treatment prevented downregulation of genes associated with AD and/or aging. Overall, our results strongly support that the combination DZ/DIB-treatment mitigates AD pathology. Evaluations across multiple AD-related models are warranted to further corroborate that the DZ/DIB combination is a candidate treatment for AD. Highlights: DZ/DIB treatment improves cognitive deficits and AD pathology in TgF344-AD rats EGR2 and HISIT1H2AA genes are potential early AD biomarkers in TgF344-AD rats DZ/DIB treatment of 4-month TgF344-AD rats blocks downregulation of AD/aging genes RESEARCH IN CONTEXT: 1. Systematic Review: We reviewed the literature using traditional sources (e.g., PubMed) to assess the status of DZ and DIB treatment individually in preclinical studies in animal models. To our knowledge there is no data with this chronic combined treatment. 2. Interpretation: Treatment takes advantage of a polypharmacological approach to AD therapeutics, considering the multifactorial nature of AD. DZ and DIB individually have been successful in mitigating hippocampal AD pathology but their combined effects were unknown, particularly in a rodent model that shows a more complete disease progression that incorporates aging as a risk factor. The effects of the treatment go beyond previous data in individual DZ and DIB treatment, supporting the need for combination drug treatments to treat a multifactorial disorder. 3. Future Directions: Investigate the potential of DZ/DIB treatment to stop the progression or ameliorate AD pathology when administered at a later age, when pathology is first detected. Graphical

We investigated the relevance of the prostaglandin D2 pathway in Alzheimer’s disease, because prostaglandin D2 is a major prostaglandin in the brain. Thus, its contribution to Alzheimer’s disease merits attention, given the known impact of the prostaglandin E2 pathway in Alzheimer’s disease. We used the TgF344-AD transgenic rat model because it exhibits age-dependent and progressive Alzheimer’s disease pathology. Prostaglandin D2 levels in hippocampi of TgF344-AD and wild-type littermates were significantly higher than prostaglandin E2. Prostaglandin D2 signals through DP1 and DP2 receptors. Microglial DP1 receptors were more abundant and neuronal DP2 receptors were fewer in TgF344-AD than in wild-type rats. Expression of the major brain prostaglandin D2 synthase (lipocalin-type PGDS) was the highest among 33 genes involved in the prostaglandin D2 and prostaglandin E2 pathways. We treated a subset of rats (wild-type and TgF344-AD males) with timapiprant, a potent highly selective DP2 antagonist in development for allergic inflammation treatment. Timapiprant significantly mitigated Alzheimer’s disease pathology and cognitive deficits in TgF344-AD males. Thus, selective DP2 antagonists have potential as therapeutics to treat Alzheimer’s disease.