Biology subjects

Pacholko, A. G.

Publications and source records attributed to Pacholko, A. G..

3 recordsLinked to original sources

bioRxiv2025

Hypertension-Induced Neurovascular and Cognitive Dysfunction at Single-Cell Resolution

Arterial hypertension is a leading cause of cognitive impairment, attributed to cerebrovascular insufficiency, blood-brain barrier disruption, and white matter damage. However, the molecular mechanisms by which hypertension affects brain cells remain unclear. Using scRNA-seq in a mouse model of hypertension induced by angiotensin II, we mapped neocortical transcriptomic changes before (3 days) and after (42 days) onset of neurovascular and cognitive deficits. Surprisingly, evidence of endothelial transport disruption and senescence, stalled oligodendrocyte differentiation, interneuronal hypofunction and network imbalance emerged after just 3 days. By 42 days, when cognitive impairment becomes apparent, deficits in myelination and axonal conduction, as well as neuronal mitochondrial dysfunction developed. These findings reveal a previously unrecognized early vulnerability of endothelial cells, interneurons, and oligodendrocytes, and provide the molecular bases for the subsequent neurovascular dysfunction and cognitive impairment in hypertension. In addition, the data constitute a valuable resource for future mechanistic studies and therapeutic target validation.

neuroscience↗

bioRxiv2022

Lithium orotate is more potent, effective, and less toxic than lithium carbonate in a mouse model of mania

ObjectiveLithium carbonate (LiCO) is a mainstay therapeutic for the prevention of mood-episode recurrences in bipolar disorder (BD). Unfortunately, its narrow therapeutic index is associated with complications that may lead to treatment non-compliance. Intriguingly, lithium orotate (LiOr) is suggested to possess uptake properties that would allow for reduced dosing and mitigation of toxicity concerns. We hypothesized that due to differences in pharmacokinetics, LiOr is more potent with reduced adverse effects. MethodsDose responses were established for LiOr and LiCO in male and female mice using an amphetamine-induced hyperlocomotion (AIH) model; AIH captures manic elements of BD and is sensitive to a dose-dependent lithium blockade. Next, the relative toxicities of LiOr and LiCO were contrasted after 14 consecutive daily administrations. ResultsLiCO maintained a partial block of AIH at doses of 15 mg/kg or greater in males and 20 mg/kg or greater in females. In contrast, LiOr elicited a near complete blockade at concentrations of just 1.5 mg/kg in both sexes, indicating improved efficacy and potency. Prior application of an organic-anion transporting polypeptide 1A2 (OATP1A2) inhibitor completely blocked the effects of LiOr on AIH while sparing LiCO, suggesting differences in transport between the two compounds. LiCO, but not LiOr, elicited polydipsia in both sexes, elevated serum creatinine levels in males, and increased serum TSH expression in females. ConclusionsLiOr demonstrates superior efficacy, potency, and tolerability to LiCO in both male and female mice as a result of select transport-mediated uptake.

pharmacology and toxicology↗

bioRxiv2019

Acute inflammatory events attenuate high-sucrose diet-induced neurodegenerative processes in reproductively normal female wild-type mice

It is known that diabetic and chronic inflammatory conditions can increase the risk of Alzheimers disease (AD)-like neurodegeneration in isolation. As certain elements of the diabetic/pre-diabetic state may sensitize the brain to inflammatory insult (i.e. excess glucocorticoid activity), there is reason to believe that obesogenic and inflammatory factors may accelerate neurodegeneration in a synergistic manner. Also, given that most AD research utilizes male animal models despite increased prevalence of AD among women, we sought to characterize elements of the established (in males) high-sucrose model of neurodegeneration, for the first time, in reproductively normal (pre-menopausal) female mice. A high-sucrose diet (20% of the drinking water) was combined with systemic intraperitoneal lipopolysaccharide (LPS) injections (0.1 mg/kg; 1x/month over 3 months) over seven months in reproductively normal female wild-type mice (C57Bl/6; n=10/group). Although a deleterious effect was hypothesized, low-dose LPS proved to protect against high sucrose diet-induced pathologies in female wild-type mice. Results from our high-sucrose group confirmed that a high-sucrose diet is a mild model of neurodegeneration in wild-type females, as evidenced by exaggerated glucocorticoid expression, spatial learning deficits, irregularities within the insulin pathway, and increased {beta}-amyloid production and Tau phosphorylation. While LPS had little to no effect in isolation, it exerted a protective influence when added to animals sustained on a high-sucrose diet. Corticosterone homeostasis, and levels of amyloid-{beta} (A{beta}) and pTau were rescued following addition of LPS. The work presented supports a high-sucrose diet as a model of mild neurodegeneration in female mice and highlights a protective role for transient inflammation against dietary-insult that may be sex dependent.

neuroscience↗