Preclinical Studies on Mechanisms Underlying the Protective Effects of Propranolol in Traumatic Brain Injury: A Systematic Review.

Traumatic brain injury (TBI) is a leading cause of mortality and morbidity amongst trauma patients. Its treatment is focused on minimizing progression to secondary injury. Administration of propranolol for TBI maydecrease mortality and improve functional outcomes. However, it is our sense that its use has not been universally adopted due to low certainty evidence. The literature was reviewed to explore the mechanism of propranolol as a therapeutic intervention in TBI to guide future clinical investigations. Medline, Embase, and Scopus were searched for studies that investigated the effect of propranolol on TBI in animal models from inception until June 6, 2023. All routes of administration for propranolol were included and the following outcomes were evaluated: cognitive functions, physiological and immunological responses. Screening and data extraction were done independently and in duplicate. The risk of bias for each individual study was assessed using the SYCLE's risk of bias tool for animal studies. Three hundred twenty-three citations were identified and 14 studies met our eligibility criteria. The data suggests that propranolol may improve post-TBI cognitive and motor function by increasing cerebral perfusion, reducing neural injury, cell death, leukocyte mobilization and p-tau accumulation in animal models. Propranolol may also attenuate TBI-induced immunodeficiency and provide cardioprotective effects by mitigating damage to the myocardium caused by oxidative stress. This systematic review demonstrates that propranolol may be therapeutic in TBI by improving cognitive and motor function while regulating T lymphocyte response and levels of myocardial reactive oxygen species. Oral or intravenous injection of propranolol following TBI is associated with improved cerebral perfusion, reduced neuroinflammation, reduced immunodeficiency, and cardio-neuroprotection in preclinical studies.

Cerebrovascular dysfunction and depressive symptoms in preclinical models: insights from a scoping review.

Although existing literature supports associations between cerebrovascular dysfunction and the emergence of depression and depressive symptoms, relatively little is known about underlying mechanistic pathways that may explain potential relationships. As such, an integrated understanding of these relationships in preclinical models could provide insight into the nature of the relationship, basic mechanistic linkages, and areas in which additional investment should be targeted. This scoping review was conducted in MEDLINE, EMBASE, and Scopus to outline the relationship between depressive symptoms and cerebrovascular dysfunction in preclinical animal models with an additional focus on the areas above. From 3,438 articles initially identified, 15 studies met the inclusion criteria and were included in the review. All studies reported a positive association between the severity of markers for cerebrovascular dysfunction and that for depressive symptoms in rodent models and this spanned all models for either pathology. Specific mechanistic links between the two such as chronic inflammation, elevated vascular oxidant stress, and altered serotonergic signaling were highlighted. Notably, almost all studies addressed outcomes in male animals, with a near complete lack of data from females, and there was little consistency in terms of how cerebrovascular dysfunction was assessed. Across nearly all studies was a lack of clarity for any "cause and effect" relationship between depressive symptoms and cerebrovascular dysfunction. At this time, it is reasonable to conclude that a correlative relationship clearly exists between the two, and future investigation will be required to parse out more specific aspects of this relationship.NEW & NOTEWORTHY This scoping review presents a structured evaluation of all relevant existing literature linking cerebral vasculopathy to depressive symptom emergence in preclinical models. Results support a definite connection between vascular dysfunction and depressive symptoms, highlighting the importance of chronic elevations in inflammation and oxidant stress, and impaired serotonergic signaling. The review also identified significant knowledge gaps addressing male versus female differences and limited clear mechanistic links between cerebral vasculopathy and depressive symptoms.

Assessments of Perfusion, Blood Flow, and Vascular Structure in Ambulatory Subjects: Guidance for Translational Research Scientists.

Research involving human subjects in ambulatory settings is a critical link in the chain comprising translational research, spanning preclinical research to human subject and patient cohort studies. There are presently a wide array of techniques and approaches available to investigators wishing to study blood flow, perfusion, and vascular structure and function in human subjects. In this multi-sectioned review, we discuss capillaroscopy, carotid intima-media thickness, flow-mediated dilation, laser Doppler flowmetry, near-infrared spectroscopy, peripheral arterial tonometry, pulse wave velocity, retinal fundus imaging, and vascular plethysmography. Each section contains a general overview and the physical basis of the technique followed by a discussion of the procedures involved and the necessary equipment, with attention paid to specific requirements or limitations. Subsequently, we detail which aspects of vascular function can be studied with a given technique, the analytical approach to the collected data, and the appropriate application and limitation(s) to the interpretation of the data collected. Finally, a modified scoping review provides a summary of how each assessment technique has been applied in previous studies. It is anticipated that this review will provide an efficient source of information and insight for preclinical investigators seeking to add translational aspects to their research programs.

A systematic review and in silico study of potential genetic markers implicated in cases of overactive bladder.

OBJECTIVE: The contribution of genetic factors to the presence of an overactive bladder is recognized. This study aimed to (1) assemble and synthesize available data from studies assessing differential gene expression in patients with overactive bladder vs controls without overactive bladder and (2) determine possible correlations and functional pathways between genes. DATA SOURCES: We searched PubMed, Ovid or Medline, and Wiley Cochrane Central Register of Controlled Trials databases between January 1, 2000, and December 15, 2021. STUDY ELIGIBILITY CRITERIA: Studies were included if gene expression was detected and quantified using molecular approaches performed on human bladder tissue specimens directly and excluded if the gene expression analysis was carried out from blood and urine specimens alone. METHODS: A systematic review was completed to identify publications that reported differently expressed gene candidates among patients with overactive bladder vs healthy individuals. Gene networking connections and pathway analysis were performed employing Metascape software, where inputs were identified from our systematic review of differentially expressed genes in overactive bladder. RESULTS: A total of 9 studies were included in the final analysis and 11 genes were identified as being up-regulated (purinergic receptor P2X 2 [P2RX2], smoothelin [SMTN], growth-associated protein 43 [GAP43], transient receptor potential cation channel subfamily M member 8 [TRPM8], cadherin 11 [CDH1], gap junction protein gamma 1 [GJC1], cholinergic receptor muscarinic 2 [CHRM2], cholinergic receptor muscarinic 3 [CHRM3], and transient receptor potential cation channel subfamily V member 4 [TRPV4]) or down-regulated (purinergic receptor P2X 2 [P2RX3] and purinergic receptor P2X 5 [P2RX5]) in patients with overactive bladder. Gene network analysis showed that genes are involved in chemical synaptic transmission, smooth muscle contraction, blood circulation, and response to temperature stimulus. Network analysis demonstrated a significant genetic interaction between TRPV4, TRPM8, P2RX3, and PR2X2 genes. CONCLUSION: Outcomes of this systematic review highlighted potential biomarkers for treatment efficacy and have laid the groundwork for developing future gene therapies for overactive bladder in clinical settings.