Low-Intensity Electrostimulation Enhances Neuroregeneration and Improves Erectile Function in a Rat Model of Cavernous Nerve Injury

Background: Neurogenic erectile dysfunction (ED) following radical prostatectomy (RP) is a frequent complication often leading to erectile tissue remodeling and permanent ED. Low-intensity electrostimulation (LIES) has been shown to enhance peripheral nerve regeneration, however, its application on cavernous nerves (CN) has never been investigated. Aims: To investigate whether LIES enhances CN regeneration, improves erectile function (EF) recovery, and prevents corpora cavernosal remodeling after CN injury, which is a principal factor for ED following RP. Methods: Adult male Sprague-Dawley rats were divided into Sham, Bilateral Cavernous Nerve Injury (BCNI), and BCNI + LIES (1V, 0.1ms, 12Hz, 1h/day). After 7days, EF was assessed (ICP measurement). Penes and CN were collected formolecular analyses of TGF-beta 1, Il-6, CRP, eNOS, ERK and AKT protein levels in corpus cavernosum (CC), and immunohistological analysis of DHE, total collagen and alpha-SMA in CC and S-100, Tub-III, DAPI, TUNEL, and nNOS in CN. Outcomes: Effects of LIES on EF, erectile tissue remodeling and CN structure. Results: EF was decreased (P < .05) 7 days after BCNI and increased (P < .05) by LIES. Intracavernosal reactive oxygen species (DHE) was increased (P < .05) after BCNI and normalized by LIES. Protein expressions of TGF-beta 1, IL-6, and CRP were increased in the penis (P < .05) after BCNI and normalized by LIES. The alpha-SMA and/or total collagen ratio was decreased (P < .05) after BCNI in the penis and normalized by LIES. Protein expression ratio of p-ERK/ERK and p-AKT/AKT did not change after BCNI but increased (P

Long-term behavioral programming induced by peripuberty stress in rats is accompanied by GABAergic-related alterations in the amygdala

Maria del Carmen Sandi Perez, Stamatina Tzanoulinou, Vandana Veenit

Stress during childhood and adolescence is a risk factor for psychopathology. Alterations in γ-aminobutyric acid (GABA), the main inhibitory neurotransmitter in the brain, have been found following stress exposure and fear experiences and are often implicated in anxiety and mood disorders. Abnormal amygdala functioning has also been detected following stress exposure and is also implicated in anxiety and social disorders. However, the amygdala is not a unitary structure; it includes several nuclei with different functions and little is known on the potential differences the impact of early life stress may have on this system within different amygdaloid nuclei. We aimed here to evaluate potential regional differences in the expression of GABAergic-related markers across several amygdaloid nuclei in adult rats subjected to a peripuberty stress protocol that leads to enhanced basal amygdala activity and psychopathological behaviors. More specifically, we investigated the protein expression levels of glutamic acid decarboxylase (GAD; the principal synthesizing enzyme of GABA) and of GABA-A receptor subunits α2 and α3. We found reduced GAD and GABA-A α3, but not α2, subunit protein levels throughout all the amygdala nuclei examined (lateral, basolateral, basomedial, medial and central) and increased anxiety-like behaviors and reduced sociability in peripubertally stressed animals. Our results identify an enduring inhibition of the GABAergic system across the amygdala following exposure to early adversity. They also highlight the suitability of the peripuberty stress model to investigate the link between treatments targeting the dysfunctional GABAergic system in specific amygdala nuclei and recovery of specific stress-induced behavioral dysfunctions.

Public Library of Science2014

Characterization of the Renin-Angiotensin System in Aged Cavernosal Tissue and its Role in Penile Fibrosis

Maiia Bragina, Babak Ebadi Shirmard, Fabiana Pereira Da Costa Fraga, Nikolaos Stergiopulos, Mikaël Nils Sturny

Background: The renin-angiotensin system (RAS) plays an important role in erectile function. The RAS contains 2 major axes: one deleterious, composed of ACE-Ang II-AT1 receptor, and another protective, composed of ACE2-Ang-(1-7)-Mas receptor. While aging is a well-known cause for development of male sexual disorders, little is known about local regulation of the RAS in age-related erectile dysfunction (ED). Aim: The present study aimed to assess regulation of the RAS in aging-associated ED rat model and evaluate possible options for disease management through pharmacological modulation of the RAS. Methods: Penile tissues were harvested from 3-, 12-, and 24-month-old Wistar rats. Local expression of major RAS components and ED markers was measured by RT-PCR. Protein expression of RAS components was assessed by western blot. Collagen deposition was measured by Sirius Red and immunohistochemical staining. Evaluation of collagen content was also performed in penile sections of Mas-knockout mice by Sirius Red and Masson's trichrome stainings. Finally, the effect of Ang-(1-7) pretreatment on TGF-beta-induced myofibroblast activation was studied in primary cavernosal and immortalized fibroblasts. Outcomes: Experimental results highlighted the essential role of the RAS in modulation of cavernosal fibrosis. Results: The present study demonstrates local expression of angiotensinogen mRNA alongside with major RAS components, which suggests local autonomous functioning of the RAS within penile tissue. Gene expression analysis revealed strong positive correlation between ACE-Ang II-AT1 axis with markers for inflammation and fibrosis. While corpus cavernosum from 24-month-old rats was characterized by increased collagen deposition, protein expression of ACE, AT1, and Mas was shown to be upregulated in the penile tissue of this group. At the same time, penile sections from Mas-knockout mice (FVB/N background) were also shown to have increased collagen deposition. Finally, it was demonstrated that Ang-(1-7) treatment of primary cavernosal and immor-talized fibroblasts was able to alleviate TGF-beta-induced fibroblast-to-myofibroblast transition. Clinical Translation: The present study suggests Ang-(1-7) treatment as a possible strategy for pharmacological management of fibrosis-associated ED in aging. Strengths & Limitations: The link between the RAS and penile fibrosis, indicated by a holistic screening of different ED markers, was confirmed by in vivo and in vitro data. However, results, presented in the manuscript, need to be further reinforced by human data. Important to note, the main goal of the study was to characterize RAS regulation in aging condition rather than state any causal relationships. Conclusion: Present study characterizes RAS regulation in aging-associated ED and indicates its important role in cavernosal fibrosis. Copyright (C) 2020, International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

ELSEVIER SCI LTD2020

Apelin-13 Protects Corpus Cavernosum Against Fibrosis Induced by High-Fat Diet in an MMP-Dependent Mechanism

Léa Liliane Colette Anguenot, Maiia Bragina, Rafaela Fernandes Da Silva, Augusto Martins Lima, Fabiana Pereira Da Costa Fraga, Nikolaos Stergiopulos, Mikaël Nils Sturny

Background: An increased fibrosis of the corpora cavernosa is a prevalent process that underlies most cases of erectile dysfunction. Apelin, an endogenous circulating peptide, has been documented as an important effector on cardiovascular homeostasis, controlling vascular function and reducing fibrosis in multiple pathological conditions. Recently, initial studies have shown that Apelin, acting through the APJ receptor, also modulates penile erection, however, the role of this system on penile structure and intracorporal collagen remodeling has not been investigated yet. Aims: Here we sought to investigate the effect of chronic Apelin treatment on the corpus cavernosum structure of hyperchOlesterolemic mice. Methods: Apolipoprotein gene-deleted (ApoE(-/-)) mice were fed with a Western diet for 11 weeks and received Apelin-13 (2 mg/kg/day) or vehicle during the last 3 weeks. Penile samples were obtained for histological and biochemical analyses to assess the intracorporal collagen content and key proteins expression. Furthermore, the effect of Apelin-13 was evaluated in cultured NIH3T3 mouse fibroblasts stimulated with TGF-beta. Outcome: Local expression of Apelin-13 in mouse corpus cavernosum and its protective effect against fibrosis. Results: Apelin and APJ receptor were expressed (gene and protein) within the corpus cavernosum of ApoE(-/-) mice, indicating a local modulation of the Apelin system. Interestingly, 3 weeks of Apelin-13 treatment strongly reduced intracavernosal collagen content. In addition, Apelin-13 enhanced total matrix metalloproteinase (MMP) activity in the mice penis, which was associated with an increased protein expression of MMP-1, MMP-3, MMP-8, and MMP-9, while tissue inhibitor of metalloproteinase were unaltered. These beneficial actions were not associated with changes in nNOS or eNOS protein expression, intracavernosal reactive oxygen species content, or atherosclerotic plaque deposition. Additionally, in cultured fibroblast, Apelin-13 inhibited TGF-beta-induced fibroblast to myofibroblast differentiation and collagen production, possibly through the activation of ERK1/2 kinase. Clinical Translation: These results point out Apelin/APJ system as a potential target to treat intracavernosal fibrosis-related disorders. Strength & Limitations: These results provide the first evidence of the Apelin system's positive role on erectile tissue structure/remodeling. Nevertheless, additional functional study addressing erectile response would bring extended validation regarding the relevance of such effect. Conclusion: These results suggest a local modulation of the Apelin system within the corpus cavernosum. Remarkably, Apelin-13 reduced intracavernosal fibrosis in hypercholesterolemic mice by: (i) enhancing MMPs expression and activity; and (ii) inhibiting fibroblast differentiation into myofibroblast. Altogether, these results suggest an essential protective role of Apelin, indicating Apelin/APJ system as a promising candidate for the development of fibrosis-associated erectile dysfunction treatments. Copyright (C) 2021 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

ELSEVIER SCI LTD2021