The suitability of an animal model to study human diseases heavily relies on the similarity between the two species at the genetic, epigenetic, gene expression and metabolic levels. However, consistent data from different animal models at each level to evaluate this suitability is lacking. With the availability of genome sequences for many mammalian species it is now possible to compare animal models based on the genomic similarities. Here, we compare the coding sequences (CDS) of five mammalian models that include rhesus macaque, marmoset, pig, mouse and rat with those from human. We identified 10,316 conserved CDS across the five organisms and human based on the sequence similarity. Mapping the human disease-associated single nucleotide polymorphisms (SNPs) from these conserved CDS in each species has identified species-specific association with various human diseases. While associations for a disease such as colon cancer were prevalent in multiple model species, pig showed the highest number (117 diseases) of model-specific human disease associations. Based on the percentage of disease-associated SNP-containing genes, marmoset models are well suited to study many human ailments including behavioral and gastrointestinal diseases. Comparison of gene expression levels of the conserved CDS from colon, heart, kidney, lung, skeletal muscle, and spleen tissues in these models showed correlations with human expression levels in a tissue-specific manner. In the gastrointestinal tissues (colon, spleen), the pig showed the highest correlation while mouse displayed a better correlation in the heart and kidney. This study demonstrated genomic as well as tissue-specific expression-based similarity evaluation of five animal models against human that could help investigators select a suitable animal model to study their targeted disease.

In the 21st century, the effects of HIV-associated neurocognitive disorders (HAND) have been significantly reduced in individuals due to the development of antiretroviral therapies (ARTs). However, the growing epidemic of polysubstance use (PSU) has led to concern for the effects of PSU on HIV-seropositive individuals. To effectively treat individuals affected by HAND, it is critical to understand the biological mechanisms affected by PSU including identification of novel markers. To fill this important knowledge gap, we used an in vivo HIV-Transgenic (HIV-Tg) animal model, to investigate the effects of the combined use of chronic methamphetamine (METH) and oxycodone (oxy). RNA-Seq analysis on the striatum - a brain region that is primarily targeted by both HIV and drugs of abuse - identified key differentially expressed markers post-METH and oxy exposure. Furthermore, ClueGO analysis and Ingenuity Pathway Analysis (IPA) revealed crucial molecular and biological functions associated with ATP-activated adenosine receptor, neuropeptide hormone activity, and the oxytocin signaling pathway to be altered between the different treatment groups. The current study further reveals the harmful effects of chronic PSU and HIV infection that can subsequently impact neurological outcomes in polysubstance users with HAND.

Gabapentin (GBP), a GABA analogue, is primarily used as an anticonvulsant to treat partial seizures and neuropathic pain. While a majority of the side effects are associated with the nervous system, emerging evidence suggests a high risk for heart diseases in the patients taking GBP. In the present study, we used a preclinical model of rats to investigate (1) the acute cardiovascular responses to GBP (bolus i.v. injection, 50 mg/kg) and (2) the effects of chronic GBP treatment (i.p. 100 mg/kg/day x 7 days) on cardiovascular function and the myocardial proteome. Under isoflurane-anesthesia, rat blood pressure (BP), heart rate (HR), and left ventricular (LV) hemodynamics were measured using Millar pressure transducers. The LV myocardium and brain cortex were analyzed by proteomics, bioinformatics, and western blot to explore the molecular mechanisms underlying GBP-induced cardiac dysfunction. In experiment (1), we found that i.v. GBP significantly decreased BP, HR, maximal LV pressure, and maximal and minimal dP/dt, whereas it increased IRP-AdP/dt, Tau, systolic, diastolic, and cycle durations (*p < 0.05 and **p < 0.01 vs baseline; n = 4/group). In experiment (2), we found that chronic GBP treatment resulted in hypotension, bradycardia, and LV systolic dysfunction, with no change in plasma norepinephrine. In the myocardium, we identified 109 differentially expressed proteins involved in calcium pathways, cholesterol metabolism, and galactose metabolism. Particularly, we found that calmodulin, a key protein of intracellular calcium signaling, was significantly upregulated by GBP in the heart but not in the brain. In summary, we found that acute and chronic GBP treatments suppressed cardiovascular function in rats, which is attributed to abnormal calcium signaling in cardiomyocytes. These data reveal a novel side effect of GBP independent of the nervous system, providing important translational evidence to suggest that GBP can evoke adverse cardiovascular events by depression of myocardial function.