Renin-angiotensin system: The underlying mechanisms and promising therapeutical target for depression and anxiety

Anxiolytic effect of alamandine in male transgenic rats with low brain angiotensinogen is dependent on activation of MrgD receptors

Alamandine is a peptide hormone belonging to the renin-angiotensin system (RAS). It acts through the Mas-related G-protein coupled receptor type D, MrgD, which is expressed in different tissues, including the brain. In the present study, we hypothesize that a lack of alamandine, through MrgD, could cause the anxiety-like behavior in transgenic rats with low brain angiotensinogen [TGR(ASrAOGEN)680]. Adult male transgenic rats exhibited a significant increase in the latency to feeding time in the novelty suppressed feeding test and a decrease in the percentage of time and entries in the open arms in the elevated plus maze. These effects were reversed by intracerebroventricular infusion of alamandine. Pretreatment with D-Pro7-Ang-(1-7), a Mas and MrgD receptor antagonist, prevented the anxiolytic effects induced by this peptide. However, its effects were not altered by the selective Mas receptor antagonist, A779. In conclusion, our data indicates that alamandine, through MrgD, attenuates anxiety-like behavior in male TGR(ASrAOGEN)680, which reinforces the importance of the counter-regulatory RAS axis as promising target for the treatment of neuropsychiatric disorders.

Role of brain renin-angiotensin system in depression: A new perspective

Depression is a mood disorder characterized by abnormal thoughts. The pathophysiology of depression is related to the deficiency of serotonin (5HT), which is derived from tryptophan (Trp). Mitochondrial dysfunction, oxidative stress, and neuroinflammation are involved in the pathogenesis of depression. Notably, the renin-angiotensin system (RAS) is involved in the pathogenesis of depression, and different findings revealed that angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) may be effective in depression. However, the underlying mechanism for the role of dysregulated brain RAS-induced depression remains speculative. Therefore, this review aimed to revise the conceivable role of ACEIs and ARBs and how these agents ameliorate the pathophysiology of depression. Dysregulation of brain RAS triggers the development and progression of depression through the reduction of brain 5HT and expression of brain-derived neurotrophic factor (BDNF) and the induction of mitochondrial dysfunction, oxidative stress, and neuroinflammation. Therefore, inhibition of central classical RAS by ARBS and ACEIs and activation of non-classical RAS prevent the development of depression by regulating 5HT, BDNF, mitochondrial dysfunction, oxidative stress, and neuroinflammation.

An antihypertensive drug-AT1 inhibitor attenuated BRCA development promoted by chronic psychological stress via Ang II/PARP1/FN1 pathway

Chronic psychological stress contributes to the occurrence of cancer and activates the renin-angiotensin system (RAS). However, the mechanisms by which RAS promotes the progression of breast cancer (BRCA) under chronic psychological stress are remain unknown. In this study, we observed elevated levels of Angiotensin II (Ang II) in both serum and BRCA tissue under chronic stress, leading to accelerated BRCA growth in a mouse model. An antihypertensive drug, candesartan (an AT1 inhibitor), effectively attenuated Ang II-induced cell proliferation and metastasis. Utilizing mass spectrometry and weighted gene co-expression network analysis (WGCNA), we identified fibronectin 1 (FN1) as the hub protein involved in chronic stress-Ang II/AT1 axis. Focal adhesion pathway was identified as a downstream signaling pathway activated during the progression of chronic stress. Depletion of FN1 significantly attenuated Ang II-induced proliferation and metastasis of BRCA cells. Poly (ADP-ribose) polymerase 1 (PARP1) was found to bind to the DNA promoter of FN1, leading to the transcription of FN1. Ang II upregulated PARP1 expression, resulting in increased FN1 levels. Recombinant FN1 partially restored the progress of BRCA malignancy induced by the Ang II/PARP1 pathway. In vivo, candesartan reversed the progressive effect of chronic psychological stress on BRCA. In clinical samples, Ang II levels in both serum and tumor tissues are higher in stressed patients compared to control patients. Serum Ang II levels were positively correlated with chronic stress indicators. In conclusion, our study demonstrated that chronic psychological stress accelerates the malignancy of BRCA, and the AT1 inhibitor candesartan counteracts these effects by suppressing the Ang II-AT1 axis and the downstream PARP1/FN1/focal adhesion pathway.

Signaling pathways and genetics of brain Renin angiotensin system in psychiatric disorders: State of the art

Along the conventional pathways, Renin-angiotensin system (RAS) plays a key role in the physiology of the CNS and pathogenesis of psychiatric diseases. RAS is a complex regulatory pathway which is composed of several peptides and receptors and comprises two counter-regulatory axes. The classical (ACE1/AngII/AT1 receptor) axis and the contemporary (ACE2/Ang (1-7)/Mas receptor) axis. The genes coding for elements of both axes have been broadly studied. Numerous functional polymorphisms on components of RAS have been identified to serve as informative disease and treatment markers. This review summarizes the role of each peptide and receptor in the pathophysiology of psychiatric disorders (depression, bipolar disorders and schizophrenia), followed by a concise look at the role of genetic polymorphism of the RAS in the pathophysiology of these disorders.

Aptamer-based diagnostic and therapeutic approaches for animal viruses: A review

Animal diseases often have significant consequences due to the unclear and time-consuming diagnosis process. Furthermore, the emergence of new viral infections and drug-resistant pathogens has further complicated the diagnosis and treatment of viral diseases. Aptamers, which are obtained through systematic evolution of ligands by exponential enrichment (SELEX) technology, provide a promising solution as they enable specific identification and binding to targets, facilitating pathogen detection and the development of novel therapeutics. This review presented an overview of aptasensors for animal virus detection, discussed the antiviral activity and mechanisms of aptamers, and highlighted advancements in aptamer-based antiviral research following the COVID-19 pandemic. Additionally, the challenges and prospects of aptamer-based virus diagnosis and treatment research were explored. Although this review was not exhaustive, it offered valuable insights into the progress of aptamer-based antiviral drug research, target mechanisms, as well as the development of novel antiviral drugs and biosensors.

DeepBiomarker2: Prediction of Alcohol and Substance Use Disorder Risk in Post-Traumatic Stress Disorder Patients Using Electronic Medical Records and Multiple Social Determinants of Health

Prediction of high-risk events amongst patients with mental disorders is critical for personalized interventions. We developed DeepBiomarker2 by leveraging deep learning and natural language processing to analyze lab tests, medication use, diagnosis, social determinants of health (SDoH) parameters, and psychotherapy for outcome prediction. To increase the model's interpretability, we further refined our contribution analysis to identify key features by scaling with a factor from a reference feature. We applied DeepBiomarker2 to analyze the EMR data of 38,807 patients from the University of Pittsburgh Medical Center diagnosed with post-traumatic stress disorder (PTSD) to determine their risk of developing alcohol and substance use disorder (ASUD). DeepBiomarker2 predicted whether a PTSD patient would have a diagnosis of ASUD within the following 3 months with an average c-statistic (receiver operating characteristic AUC) of 0.93 and average F1 score, precision, and recall of 0.880, 0.895, and 0.866 in the test sets, respectively. Our study found that the medications clindamycin, enalapril, penicillin, valacyclovir, Xarelto/rivaroxaban, moxifloxacin, and atropine and the SDoH parameters access to psychotherapy, living in zip codes with a high normalized vegetative index, Gini index, and low-income segregation may have potential to reduce the risk of ASUDs in PTSD. In conclusion, the integration of SDoH information, coupled with the refined feature contribution analysis, empowers DeepBiomarker2 to accurately predict ASUD risk. Moreover, the model can further identify potential indicators of increased risk along with medications with beneficial effects.

Interplay of G-proteins and Serotonin in the Neuroimmunoinflammatory Model of Chronic Stress and Depression: A Narrative Review

INTRODUCTION

This narrative review addresses the clinical challenges in stress-related disorders such as depression, focusing on the interplay between neuron-specific and pro-inflammatory mechanisms at the cellular, cerebral, and systemic levels.

OBJECTIVE

We aim to elucidate the molecular mechanisms linking chronic psychological stress with low-grade neuroinflammation in key brain regions, particularly focusing on the roles of G proteins and serotonin (5-HT) receptors.

METHODS

This comprehensive review of the literature employs systematic, narrative, and scoping review methodologies, combined with systemic approaches to general pathology. It synthesizes current research on shared signaling pathways involved in stress responses and neuroinflammation, including calcium-dependent mechanisms, mitogen-activated protein kinases, and key transcription factors like NF-κB and p53. The review also focuses on the role of G protein-coupled neurotransmitter receptors (GPCRs) in immune and pro-inflammatory responses, with a detailed analysis of how 13 of 14 types of human 5-HT receptors contribute to depression and neuroinflammation.

RESULTS

The review reveals a complex interaction between neurotransmitter signals and immunoinflammatory responses in stress-related pathologies. It highlights the role of GPCRs and canonical inflammatory mediators in influencing both pathological and physiological processes in nervous tissue.

CONCLUSION

The proposed Neuroimmunoinflammatory Stress Model (NIIS Model) suggests that proinflammatory signaling pathways, mediated by metabotropic and ionotropic neurotransmitter receptors, are crucial for maintaining neuronal homeostasis. Chronic mental stress can disrupt this balance, leading to increased pro-inflammatory states in the brain and contributing to neuropsychiatric and psychosomatic disorders, including depression. This model integrates traditional theories on depression pathogenesis, offering a comprehensive understanding of the multifaceted nature of the condition.