Epigenetics of amphetamine-induced sensitization: HDAC5 expression and microRNA in neural remodeling

Neuroimaging of the effects of drug exposure or self-administration in rodents: A systematic review

A systematic review of functional neuroimaging studies on drug (self-) administration in rodents is lacking. Here, we summarized effects of acute or chronic drug administration of various classes of drugs on brain function and determined consistency with human literature. We performed a systematic literature search and identified 125 studies on in vivo rodent resting-state functional magnetic resonance imaging (n = 84) or positron emission tomography (n = 41) spanning depressants (n = 27), opioids (n = 23), stimulants (n = 72), and cannabis (n = 3). Results primarily showed alterations in the striatum, consistent with the human literature. The anterior cingulate cortex and (nonspecific) prefrontal cortex were also frequently implicated. Upregulation was most often found after shorter administration and downregulation after long chronic administration, particularly in the striatum. Importantly, results were consistent across study design, administration models, imaging method, and animal states. Results provide evidence of altered resting-state brain function in rodents upon drug administration, implicating the brain's reward network analogous to human studies. However, alterations were more dynamic than previously known, with dynamic adaptation depending on the length of drug administration.

Role of HDAC5 Epigenetics in Chronic Craniofacial Neuropathic Pain

The information provided from the papers reviewed here about the role of epigenetics in chronic craniofacial neuropathic pain is critically important because epigenetic dysregulation during the development and maintenance of chronic neuropathic pain is not yet well characterized, particularly for craniofacial pain. We have noted that gene expression changes reported vary depending on the nerve injury model and the reported sample collection time point. At a truly chronic timepoint of 10 weeks in our model of chronic neuropathic pain, functional groupings of genes examined include those potentially contributing to anti-inflammation, nerve repair/regeneration, and nociception. Genes altered after treatment with the epigenetic modulator LMK235 are discussed. All of these differentials are key in working toward the development of diagnosis-targeted therapeutics and likely for the timing of when the treatment is provided. The emphasis on the relevance of time post-injury is reiterated here.

Human milk extracellular vesicle miRNA expression and associations with maternal characteristics in a population-based cohort from the Faroe Islands

Human milk plays a critical role in infant development and health, particularly in cognitive, immune, and cardiometabolic functions. Milk contains extracellular vesicles (EVs) that can transport biologically relevant cargo from mother to infant, including microRNAs (miRNAs). We aimed to characterize milk EV-miRNA profiles in a human population cohort, assess potential pathways and ontology, and investigate associations with maternal characteristics. We conducted the first study to describe the EV miRNA profile of human milk in 364 mothers from a population-based mother-infant cohort in the Faroe Islands using small RNA sequencing. We detected 1523 miRNAs with ≥ one read in 70% of samples. Using hierarchical clustering, we determined five EV-miRNA clusters, the top three consisting of 15, 27 and 67 miRNAs. Correlation coefficients indicated that the expression of many miRNAs within the top three clusters was highly correlated. Top-cluster human milk EV-miRNAs were involved in pathways enriched for the endocrine system, cellular community, neurodevelopment, and cancers. miRNA expression was associated with time to milk collection post-delivery, maternal body mass index, and maternal smoking, but not maternal parity. Future studies investigating determinants of human EV-miRNAs and associated health outcomes are needed to elucidate the role of human milk EV-miRNAs in health and disease.

Promotive Role of CircATRNL1 on Chondrogenic Differentiation of BMSCs Mediated by miR-338-3p

AIM

Bone marrow mesenchymal stem cells (BMSCs) are ideal seed cells for tissue engineering cartilage construction. However, the underlying mechanism of it has not been illuminate well. In this study, the effects of circATRNL1 (hsa_circ_0020093) on the differentiation of BMSCs into chondrocytes were investigated.

METHODS

The degrees of chondrogenic differentiation of BMSCs on day 0, 14 and 21 mediums were detected by Alcian blue staining. Expressions of cartilage differentiation related factors SOX9, COL2 and Aggrecan, and circATRNL1 in BMSCs under differentiation were determined by western blot and quantitative real-time polymerase chain reaction (qRT-PCR) as needed. circATRNL1 knockdown or overexpression was performed in BMSCs. Then the viability of BMSCs and cartilage differentiation related factors were separately investigated through MTT assay, qRT-PCR, and western blot. Target gene of circATRNL1 and binding site were predicted using starbase and validated it by dual luciferase reporter. The effect of circATRNL1 and its target gene on chondrogenic differentiation of BMSCs was assessed using Alcian blue staining further.

RESULTS

The degrees of chondrogenic differentiation of BMSCs were increased with time. Expressions of SOX9, COL2 and Aggrecan as well as circATRNL1 were enhanced during chondrogenic differentiation. Furthermore, overexpression of circATRNL1 enhanced BMSCs proliferation, SOX9, COL2 and Aggrecan expressions and the degree of chondrogenic differentiation of BMSCs. Further research showed that circATRNL1 targeted miR-338-3p. MiR-338-3p inhibited differentiation of BMSCs into cartilage but overexpression of circATRNL1 reversed it.

CONCLUSION

CircATRNL1 is beneficial to BMSCs differentiation into cartilage by regulating miR-338-3p, which may be a new mechanism of action in the treatment of cartilage repair.

Role of epigenetic regulatory enzymes in animal models of mania induced by amphetamine and paradoxical sleep deprivation

It is known that bipolar disorder has a multifactorial aetiology where the interaction between genetic and environmental factors is responsible for its development. Because of this, epigenetics has been largely studied in psychiatric disorders. The present study aims to evaluate the effects of histone deacetylase inhibitors on epigenetic enzyme alterations in rats or mice submitted to animal models of mania induced by dextro-amphetamine or sleep deprivation, respectively. Adult male Wistar rats were subjected to 14 days of dextro-amphetamine administration, and from the eighth to the fourteenth day, the animals were treated with valproate and sodium butyrate in addition to dextro-amphetamine injections. Adult C57BL/6 mice received 7 days of valproate or sodium butyrate administration, being sleep deprived at the last 36 hr of the protocol. Locomotor and exploratory activities of rats and mice were evaluated in the open-field test, and histone deacetylase, DNA methyltransferase, and histone acetyltransferase activities were assessed in the frontal cortex, hippocampus, and striatum. Dextro-amphetamine and sleep deprivation induced hyperactivity and increased histone deacetylase and DNA methyltransferase activities in the animal's brain. Valproate and sodium butyrate were able to reverse hyperlocomotion induced by both animal models, as well as the alterations on histone deacetylase and DNA methyltransferase activities. There was a positive correlation between enzyme activities and number of crossings for both models. Histone deacetylase and DNA methyltransferase activities also presented a positive correlation between theirselves. These results suggest that epigenetics can play an important role in BD pathophysiology as well as in its treatment.

The molecular neurobiology of chronic pain-induced depression

The increasing number of individuals with comorbidities poses an urgent need to improve the management of patients with multiple co-existing diseases. Among these comorbidities, chronic pain and mood disorders, two long-lasting disabling conditions that significantly reduce the quality of life, could be cited first. The recent development of animal models accelerated the studies focusing on the underlying mechanisms of the chronic pain and depression/anxiety comorbidity. This review provides an overview of clinical and pre-clinical studies performed over the past two decades addressing the molecular aspects of the comorbid relationship of chronic pain and depression. We thus focused on the studies that investigated the molecular characteristics of the comorbid relationship between chronic pain and mood disorders, especially major depressive disorders, from the genetic and epigenetic point of view to key neuromodulators which have been shown to play an important role in this comorbidity.

Immunological effects of iron oxide nanoparticles and iron-based complex drug formulations: Therapeutic benefits, toxicity, mechanistic insights, and translational considerations

Nanotechnology offers several advantages for drug delivery. However, there is the need for addressing potential safety concerns regarding the adverse health effects of these unique materials. Some such effects may occur due to undesirable interactions between nanoparticles and the immune system, and they may include hypersensitivity reactions, immunosuppression, and immunostimulation. While strategies, models, and approaches for studying the immunological safety of various engineered nanoparticles, including metal oxides, have been covered in the current literature, little attention has been given to the interactions between iron oxide-based nanomaterials and various components of the immune system. Here we provide a comprehensive review of studies investigating the effects of iron oxides and iron-based nanoparticles on various types of immune cells, highlight current gaps in the understanding of the structure-activity relationships of these materials, and propose a framework for capturing their immunotoxicity to streamline comparative studies between various types of iron-based formulations.

A Molecular Code for Imprinting Drug-Cue Associations

Previous studies suggest that nuclear histone deacetylase HDAC5 has a dynamic relationship with drug-induced behavioral neuroadaptations. The new work by Taniguchi et al. (2017) suggests that targets of nuclear HDAC5 mediate the behavioral effects of rewarding drugs via regulation of cocaine-associated stimuli.