MnSOD mediated by HSV vectors in the periaqueductal gray suppresses morphine withdrawal in rats

The association between neuropsychiatric effects of substance use and occurrence of endoplasmic reticulum and unfolded protein response: A systematic review

INTRODUCTION

This systematic review aimed to assess the association between neuropsychiatric effects of substance use and occurrence of ER stress and unfolded protein response (UPR) through comprehensive electronic search of existing literature and review of their findings.

METHODS

A comprehensive electronic literature search was carried out on research articles published between 1950 to July 2023 through major databases, such as Scopus, Web of Science, Google Scholar, PubMed, PsycINFO, EMBASE, Medline and Cochrane Library.

RESULTS

A total of 21 research articles were selected for review, which were comprised of sixteen animal studies, four human studies and one study on postmortem human brain samples. The selected studies revealed that alcohol, methamphetamine, cocaine, opioid and kratom exposures contributed to neuropsychiatric effects: such as decline in learning and memory function, executive dysfunction, alcohol, methamphetamine, opioid, and kratom dependence. These effects were associated with activation and persistent of ER stress and UPR with elevation of BiP and CHOP expression and the direction of ER stress is progressing towards the PERK-eIF2α-ATF4-CHOP pathway and neuronal apoptosis and neurodegeneration at various regions of the brain. In addition, regular kratom use in humans also contributed to elevation of p-JNK expression, denoting progress of ER stress towards the IRE1-ASK1-JNK-p-JNK pathway which was linked to kratom use disorder. However, treatment with certain compounds or biological agents could reverse the activation of ER stress.

CONCLUSIONS

The neuropsychiatric effects of alcohol, methamphetamine, cocaine, opioid and kratom use may be associated with persistent ER stress and UPR.

A Narrative Literature Review of the Epidemiology, Etiology, and Treatment of Co-Occurring Panic Disorder and Opioid Use Disorder

OBJECTIVE

Panic disorder is a debilitating psychiatric disorder that often co-occurs with substance use disorders. Given the current opioid epidemic, the high reported rates of comorbid panic disorder and opioid use disorder are particularly concerning. In this narrative review, we describe the literature on panic disorder and opioid use disorder co-occurrence.

METHODS

86 studies, 26 reviews, 2 commentaries, and 5 guidelines pertaining to opioid use disorder, panic disorder, and their comorbidity were identified using all EBSCO databases, PubMed, and Google Scholar.

RESULTS

First, we review epidemiological literature on the prevalence of the comorbid condition above and beyond each disorder on its own. Additionally, we discuss the challenges that complicate the differential diagnosis of panic disorder and opioid use disorder and contribute to difficulties establishing rates of comorbidity. Second, we review three theoretical models that have been proposed to explain high rates of co-occurring panic disorder and opioid use disorder: the precipitation hypothesis, the self-medication hypothesis, and the shared vulnerability hypothesis. Third, we outline how co-occurring panic and opioid use disorder may impact treatment for each condition.

CONCLUSION

Based on findings in the field, we provide recommendations for future research as well as treatment considerations for co-occurring panic and opioid use disorders.

Viral vector-mediated gene therapy for opioid use disorders

Chronic exposure to opioids typically results in adverse consequences. Opioid use disorder (OUD) is a disease of the CNS with behavioral, psychological, neurobiological, and medical manifestations. OUD induces a variety of changes of neurotransmitters/neuropeptides in the nervous system. Existing pharmacotherapy, such as opioid maintenance therapy (OMT) is the mainstay for the treatment of OUD, however, current opioid replacement therapy is far from effective for the majority of patients. Pharmacological therapy for OUD has been challenging for many reasons including debilitating side-effects. Therefore, developing an effective, non-pharmacological approach would be a critical advancement in improving and expanding treatment for OUD. Viral vector mediated gene therapy provides a potential new approach for treating opioid abused patients. Gene therapy can supply targeting gene products directly linked to the mechanisms of OUD to restore neurotransmitter and/or neuropeptides imbalance, and avoid the off-target effects of systemic administration of drugs. The most commonly used viral vectors in rodent studies of treatment of opioid-used disorder are based on recombinant adenovirus (AV), adeno-associated virus (AAV), lentiviral (LV) vectors, and herpes simplex virus (HSV) vectors. In this review, we will focus on the recent progress of viral vector mediated gene therapy in OUD, especially morphine tolerance and withdrawal.

Mitochondrial biogenesis factor PGC-1α suppresses spinal morphine tolerance by reducing mitochondrial superoxide

Opioid use disorders (OUDs) have reached an epidemic level in the United States. The opioid epidemic involves illicit opioid use, prescription opioids for analgesia, counterfeit opioids, new psychoactive substances, and diverted opioids. Opioids remain the last option for the treatment of intractable clinical pain, but chronic use of opioids are limited in part due to antinociceptive/analgesic tolerance. Peroxisome proliferator-activated receptor (PPAR)-gamma coactivator-1alpha (PGC-1α), a mitochondrial biogenesis factor can reduce toxic reactive oxygen species (ROS) that play a role in morphine tolerance (MT). Decreased PGC-1α expression has been shown to contribute to various metabolic disorders or neurodegeneration diseases through increasing ROS. We examined the relationship of PGC-1α and ROS in MT. To induce MT, adult Sprague-Dawley rats received intrathecal morphine for 7 days. Mechanical threshold was measured using the von Frey test and thermal latency was examined using the heat plate test. Expression of PGC-1α in the spinal cord dorsal horn (SCDH) was examined using RT-PCR and western blots. Mitochondrial superoxide was detected using MitoSox Red, a mitochondrial superoxide indicator. The antinociceptive effect of recombinant PGC-1α (rPGC-1α) or Mito-Tempol (a mitochondria-targeted superoxide scavenger) was determined using the von Frey test and hot plate test. Furthermore, we examined the effect of rPGC-1α on mitochondrial superoxide using cultured neurons. Our findings include that: (i) spinal MT decreased the expression of spinal PGC-1α in the SCDH neurons; (ii) rPGC-1α increased mechanical threshold and thermal latency in MT animals; (iii) Mito-Tempol reduced MT behavioral response; (iv) rPGC-1α reduced MT-induced mitochondria-targeted superoxide; and (v) cultured neuronal cells treated with TNFα increased mitochondria-targeted superoxide that can be inhibited by rPGC-1α. The present findings suggest that spinal PGC-1α reduce MT through decreasing mitochondria-targeted superoxide in the SCDH.

Morphine Addiction and Oxidative Stress: The Potential Effects of Thioredoxin-1

Long-term administration of morphine for the management of chronic pain will result in tolerance to its analgesic effect and could even cause drug dependence. Numerous studies have demonstrated significant redox alteration in morphine dependence and addiction. Thioredoxin-1 (Trx-1) play important roles in controlling the cellular redox balance. In recent years, several recent studies have demonstrated that Trx-1 may be a promising novel therapeutic target for morphine addiction. In this article, we firstly review the redox alteration in morphine addiction. We also summarize the expression and the protective roles of Trx-1 in morphine dependence. We further highlight the protection of geranylgeranylacetone (GGA), a noncytotoxic pharmacological inducer of Trx-1, in morphine-induced conditioned place preference. In conclusion, Trx-1 may be very promising for clinical therapy of morphine addiction in the future.