Thermodynamic Work of High-Grade Uterine Prolapse Patients Undergoing Transvaginal Mesh Repair with Total Hysterectomy.

The objective benefit of transvaginal mesh with concomitant total hysterectomy (TVM-HTX) repair to high-grade uterine prolapse (UP) patients has not been fully established. This study aimed to clarify the impact of TVM-HTX on the voiding function of high-grade UP patients by comparing pre- and post-operatively measured pressure-flow and pressure-volume investigations. Urodynamic and thermodynamic studies were conducted on 15 high-grade UP patients (stage III/IV, POP-Q system) who underwent TVM-HTX (January 2019-December 2022) in a tertiary-care university hospital. The parameters analyzed included voiding resistance (Rvod), voiding pressure (Pvod), voiding flow (Fvod), voided volume (Vvod), voiding time (Tvod), and the trajectory-enclosed area of the pressure-volume loop (Apv). Post-operative results showed a significant reduction in Rvod (p < 0.001, N = 15), Pvod (p = 0.021, N = 15), and Apv (p = 0.006, N = 15), along with an increase in Fvod (p = 0.003, N = 15) and a decrease in Tvod (p < 0.001, N = 15). The operation-associated changes in Rvod (ΔRvod) correlated with alterations in Pvod and Fvod (ΔPvod and ΔFvod, r = 0.444, p = 0.004, r = 0.717, p = 0.003, respectively; both N = 15); ΔFvod correlated with the change in Tvod (ΔTvod, r = 0.629, p = 0.012, N = 15) but not with that in ΔVvod (r = 0.166, p = 0.555, N = 15). Changes in Apv (ΔApv) correlated with ΔPvod (r = 0.563, p = 0.029, N = 15) but not with ΔVvod (r = 0.353, p = 0.197, N = 15). Collectively, TVM-HTX reduced the voiding resistance, which improved the voiding efficacy and decreased the pressure gradient required for driving urine flow, thereby lessening the bladder's workload.

Bladder Compliance Dynamics of Pelvic Organ Prolapse in Women Undergoing Robotic-assisted Sacrocolpopexy.

STUDY OBJECTIVE: Although mean/static compliance of bladder filling can be readily assayed via cystometry, a protocol measuring compliance dynamics at a specific stage of bladder filling has not been established in human patients. For patients with pelvic organ prolapse (POP), the objective benefits of robotic-assisted sacrocolpopexy (RSCP) surgical intervention for restoring bladder functions, primarily urine storage, have yet to be established. Also, bladder compliance is a viscoelastic parameter that crucially defines the storage function. Therefore, we aimed to investigate the impact of RSCP on bladder compliance of POP patients using a pressure-volume analysis (PVA), which graphically illustrates bladder compliance. DESIGN: A retrospective pre and postoperative study. SETTING: Multiple hospitals in Taiwan. PATIENTS: Twenty seven female POP patients (stage ≥ II). INTERVENTION: RSCP for POP repair. MEASUREMENTS AND MAIN RESULTS: We retrospectively reviewed the pre- and postoperative PVAs for women with POP who underwent RSCP. The mean compliance of the entire (Cm), the early half (C1/2), and the late half (C2/2) of bladder filling were analyzed as primary outcomes. Changes in intravesical volume (ΔVive) and detrusor pressure (ΔPdet) of bladder filling, ΔPdet in the early (ΔPdet1/2) and late (ΔPdet2/2) filling, and postvoiding residual volume (Vres) were analyzed as secondary outcomes. Compared with the preoperative control, RSCP increased Cm (p = .010, N = 27) and C2/2 (p <.001, N = 27) but negligibly affected C1/2 (p = .457, N = 27). Mechanistically, RSCP decreased ΔPdet (p = .0001, N = 27) without significantly affecting ΔVive (p = .863, N = 27). Furthermore, RSCP decreased the ΔPdet2/2 (p <.001, N = 27) but not ΔPdet1/2 (p = .295, N = 27). CONCLUSIONS: This is the first report on applying PVA in assaying dynamics of bladder compliance in patients with POP. Our results suggest that RSCP improved bladder storage in women with POP since it increased bladder compliance, particularly in the late filling, possibly by restoring the anatomical location and geometric conformation for bladder expansion.

The Transcription Factor Tbx5-Dependent Epigenetic Modification Contributes to Neuropathic Allodynia by Activating TRPV1 Expression in the Dorsal Horn.

Nerve injury can induce aberrant changes in the spine; these changes are due to, or at least partly governed by, transcription factors that contribute to the genesis of neuropathic allodynia. Here, we showed that spinal nerve ligation (SNL, a clinical neuropathic allodynia model) increased the expression of the transcription factor Tbx5 in the injured dorsal horn in male Sprague Dawley rats. In contrast, blocking this upregulation alleviated SNL-induced mechanical allodynia, and there was no apparent effect on locomotor function. Moreover, SNL-induced Tbx5 upregulation promoted the recruitment and interaction of GATA4 and Brd4 by enhancing its binding activity to H3K9Ac, which was enriched at the Trpv1 promotor, leading to an increase in TRPV1 transcription and the development of neuropathic allodynia. In addition, nerve injury-induced expression of Fbxo3, which abates Fbxl2-dependent Tbx5 ubiquitination, promoted the subsequent Tbx5-dependent epigenetic modification of TRPV1 expression during SNL-induced neuropathic allodynia. Collectively, our findings indicated that spinal Tbx5-dependent TRPV1 transcription signaling contributes to the development of neuropathic allodynia via Fbxo3-dependent Fbxl2 ubiquitination and degradation. Thus, we propose a potential medical treatment strategy for neuropathic allodynia by targeting Tbx5.

Effect of intra-vaginal electric stimulation on bladder compliance in stress urinary incontinence patients: the involvement of autonomic tone.

Objective: In addition to the well-established advantage that strengthened pelvic musculature increases urethral resistance in stress urinary incontinence (SUI) patients, intra-vaginal electrical stimulation (iVES) has been shown in preclinical studies to improve bladder capacity via the pudendal-hypogastric mechanism. This study investigated whether iVES also benefits bladder storage in SUI patients by focusing on compliance, a viscoelastic parameter critically defining the bladder's storage function, in a clinical study. Moreover, the potential involvement of stimulation-induced neuromodulation in iVES-modified compliance was investigated by comparing the therapeutic outcomes of SUI patients treated with iVES to those who underwent a trans-obturator tape (TOT) implantation surgery, where a mid-urethral sling was implanted without electric stimulation. Patients and methods: Urodynamic and viscoelastic data were collected from 21 SUI patients treated with a regimen combining iVES and biofeedback-assisted pelvic floor muscle training (iVES-bPFMT; 20-min iVES and 20-min bPFMT sessions, twice per week, for 3 months). This regimen complied with ethical standards. Data from 21 SUI patients who received TOT implantation were retrospectively analyzed. Mean compliance (Cm), infused volume (Vinf), and threshold pressure (Pthr) from the pressure-flow/volume investigations were assessed. Results: Compared with the pretreatment control, iVES-bPFMT consistently and significantly increased Cm (18/21; 85%, p = 0.017, N = 21) and Vinf (16/21; 76%, p = 0.046; N = 21) but decreased Pthr (16/21; 76%, p = 0.026, N = 21). In contrast, TOT implantation did not result in consistent or significant changes in Cm, Vinf, or Pthr (p = 0.744, p = 0.295, p = 0.651, respectively; all N = 21). Conclusion: Our results provide viscoelastic and thermodynamic evidence supporting an additional benefit of iVES-bPFMT to bladder storage in SUI patients by modifying bladder compliance, possibly due to the potentiated hypogastric tone, which did not occur in TOT-treated SUI patients.Clinical trial registration: ClinicalTrials.gov, NCT02185235 and NCT05977231.

Lights at night mediate depression-like behavioral and molecular phenotypes in a glucocorticoid-dependent manner in male rats.

Nocturnal light pollution, an underappreciated mood manipulator, disturbs the circadian rhythms of individuals in modern society. Preclinical and clinical studies have suggested that exposure to lights at night (LANs) results in depression-like phenotypes. However, the mechanism underlying the action of LANs remains unclear. Therefore, this study explored the potential influence of LANs on depression-related brain regions by testing brain-derived neurotrophic factor (BDNF), synaptic transmission, and plasticity in male Sprague-Dawley rats. Depression-related behavioral tests, enzyme-linked immunosorbent assays, and intracellular and extracellular electrophysiological recordings were performed. Resultantly, rats exposed to either white or blue LAN for 5 or 21 days exhibited depression-like behaviors. Both white and blue LANs reduced BDNF expression in the medial prefrontal cortex (mPFC) and ventrolateral periaqueductal gray (vlPAG). Moreover, both lights at night (LANs) elevated the plasma corticosterone levels. Pharmacologically, the activation of glucocorticoid receptors mimics the LAN-mediated effects on depression-like behaviors and reduces BDNF levels, whereas the inhibition of glucocorticoid receptors blocks LAN-mediated behavioral and molecular actions. Electrophysiologically, both LANs attenuated the stimulation-response curve, increased the paired-pulse ratio, and decreased the frequency and amplitude of miniature excitatory postsynaptic currents in the vlPAG. In the mPFC, LANs attenuate long-term potentiation and long-term depression. Collectively, these results suggested that white and blue LANs disturbed BDNF expression, synaptic transmission, and plasticity in the vlPAG and mPFC in a glucocorticoid-dependent manner. The results of the present study provide a theoretical basis for understanding the effects of nocturnal light exposure on depression-like phenotypes.

Blue light at night produces stress-evoked heightened aggression by enhancing brain-derived neurotrophic factor in the basolateral amygdala.

Light is an underappreciated mood manipulator. People are often exposed to electronic equipment, which results in nocturnal blue light exposure in modern society. Light pollution drastically shortens the night phase of the circadian rhythm. Preclinical and clinical studies have reported that nocturnal light exposure can influence mood, such as depressive-like phenotypes. However, the effects of blue light at night (BLAN) on other moods and how it alters mood remain unclear. Here, we explored the impact of BLAN on stress-provoked aggression in male Sprague‒Dawley rats, focusing on its influence on basolateral amygdala (BLA) activity. Resident-intruder tests, extracellular electrophysiological recordings, and enzyme-linked immunosorbent assays were performed. The results indicated that BLAN produces stress-induced heightened aggressive and anxiety-like phenotypes. Moreover, BLAN not only potentiates long-term potentiation and long-term depression in the BLA but also results in stress-induced elevation of brain-derived neurotrophic factor (BDNF), mature BDNF, and phosphorylation of tyrosine receptor kinase B expression in the BLA. Intra-BLA microinfusion of BDNF RNAi, BDNF neutralizing antibody, K252a, and rapamycin blocked stress-induced heightened aggressive behavior in BLAN rats. In addition, intra-BLA application of BDNF and 7,8-DHF caused stress-induced heightened aggressive behavior in naïve rats. Collectively, these results suggest that BLAN results in stress-evoked heightened aggressive phenotypes, which may work by enhancing BLA BDNF signaling and synaptic plasticity. This study reveals that nocturnal blue light exposure may have an impact on stress-provoked aggression. Moreover, this study provides novel insights into the BLA BDNF-dependent mechanism underlying the impact of the BLAN on mood.

Protein Arginine Methyltransferase 5 Contributes to Paclitaxel-Induced Neuropathic Pain by Activating Transient Receptor Potential Vanilloid 1 Epigenetic Modification in Dorsal Root Ganglion.

BACKGROUND: Paclitaxel (PTX), which is a first-line chemotherapy drug used to treat various types of cancers, exhibits peripheral neuropathy as a common side effect that is difficult to treat. Protein arginine methyltransferase 5 (PRMT 5) is a key regulator of the chemotherapy response, as chemotherapy drugs induce PRMT5 expression. However, little is known about the PRMT5-mediated epigenetic mechanisms involved in PTX-induced neuropathic allodynia. METHODS: Sprague-Dawley rats were intraperitoneally given PTX to induce neuropathic pain. Biochemical analyses were conducted to measure the protein expression levels in the dorsal root ganglion (DRG) of the animals. The von Frey test and hot plate test were used to evaluate nociceptive behaviors. RESULTS: PTX increased the PRMT5 (mean difference [MD]: 0.68, 95% confidence interval [CI], 0.88-0.48; P < .001 for vehicle)-mediated deposition of histone H3R2 dimethyl symmetric (H3R2me2s) at the transient receptor potential vanilloid 1 ( Trpv1 ) promoter in the DRG. PRMT5-induced H3R2me2s recruited WD repeat domain 5 (WDR5) to increase trimethylation of lysine 4 on histone H3 (H3K4me3) at Trpv1 promoters, thus resulting in TRPV1 transcriptional activation (MD: 0.65, 95% CI, 0.82-0.49; P < .001 for vehicle) in DRG in PTX-induced neuropathic pain. Moreover, PTX increased the activity of NADPH oxidase 4 (NOX4) (MD: 0.66, 95% CI, 0.81-0.51; P < .001 for vehicle), PRMT5-induced H3R2me2s, and WDR5-mediated H3K4me3 in the DRG in PTX-induced neuropathic pain. Pharmacological antagonism and the selective knockdown of PRMT5 in DRG neurons completely blocked PRMT5-mediated H3R2me2s, WDR5-mediated H3K4me3, or TRPV1 expression and neuropathic pain development after PTX injection. Remarkably, NOX4 inhibition not only attenuated allodynia behavior and reversed the above-mentioned signaling but also reversed NOX4 upregulation via PTX. CONCLUSIONS: Thus, the NOX4/PRMT5-associated epigenetic mechanism in DRG has a dominant function in the transcriptional activation of TRPV1 in PTX-induced neuropathic pain.

Melatonin Relieves Paclitaxel-Induced Neuropathic Pain by Regulating pNEK2-Dependent Epigenetic Pathways in DRG Neurons.

The neurohormone melatonin (MLT) demonstrates promising potential in ameliorating neuropathic pain induced by paclitaxel (PTX) chemotherapy. However, little is known about its protective effect on dorsal root ganglion (DRG) neurons in neuropathic pain resulting from the chemotherapeutic drug PTX. Here, PTX-treated rats revealed that intrathecal administration of MLT dose-dependently elevated hind paw withdrawal thresholds and latency, indicating that MLT significantly reversed PTX-induced neuropathic pain. Mechanistically, the analgesic effects of MLT were found to be mediated via melatonin receptor 2 (MT2), as pretreatment with an MT2 receptor antagonist inhibited these effects. Moreover, intrathecal MLT injection reversed the pNEK2-dependent epigenetic program induced by PTX. All of the effects caused by MLT were blocked by pretreatment with an MT2 receptor-selective antagonist, 4P-PDOT. Remarkably, multiple MLT administered during PTX treatment (PTX+MLTs) exhibited not only rapid but also lasting reversal of allodynia/hyperalgesia compared to single-bolus MLT administered after PTX treatment (PTX+MLT). In addition, PTX+MLTs exhibited greater efficacy in reversing PTX-induced alterations in pRSK2, pNEK2, JMJD3, H3K27me3, and TRPV1 expression and interaction in DRG neurons than PTX+MLT. These results indicated that MLT administered during PTX treatment reduced the incidence and/or severity of neuropathy and had a better inhibitory effect on the pNEK2-dependent epigenetic program compared to MLT administered after PTX treatment. In conclusion, MLT/MT2 is a promising therapy for the treatment of pNEK2-dependent painful neuropathy resulting from PTX treatment. MLT administered during PTX chemotherapy may be more effective in the prevention or reduction of PTX-induced neuropathy and maintaining quality.

Pressure-Volume Loop Analysis of Voiding Workload: An Application in Trans-Vaginal Mesh-Repaired Pelvic Organ Prolapse Patients.

Although trans-vaginal mesh (TVM) offers a successful anatomical reconstruction and can subjectively relieve symptoms/signs in pelvic organ prolapse (POP) patients, its objective benefits to the voiding function of the bladder have not been well established. In this study, we investigated the therapeutic advantage of TVM on bladder function by focusing on the thermodynamic workload of voiding. The histories of 31 POP patients who underwent TVM repair were retrospectively reviewed. Cystometry and pressure volume analysis (PVA) of the patients performed before and after the operation were analyzed. TVM postoperatively decreased the mean voiding resistance (mRv, p < 0.05, N = 31), reduced the mean and peak voiding pressure (mPv, p < 0.05 and pPv, p < 0.01, both N = 31), and elevated the mean flow rate (mFv, p < 0.05, N = 31) of voiding. While displaying an insignificant effect on the voided volume (Vv, p < 0.05, N = 31), TVM significantly shortened the voiding time (Tv, p < 0.05, N = 31). TVM postoperatively decreased the loop-enclosed area (Apv, p < 0.05, N = 31) in the PVA, indicating that TVM lessened the workload of voiding. Moreover, in 21 patients who displayed postvoiding urine retention before the operation, TVM decreased the residual volume (Vr, p < 0.01, N = 21). Collectively, our results reveal that TVM postoperatively lessened the workload of bladder voiding by diminishing voiding resistance, which reduced the pressure gradient required for driving urine flow.

BTRX-246040 Acts Through the Ventrolateral Periaqueductal Gray to Exert Antidepressant-Relevant Actions in Mice.

BACKGROUND: BTRX-246040, a nociceptin/orphanin FQ peptide receptor antagonist, is being developed for the treatment of depressive patients. However, the underlying mechanism of this potential antidepressant is still largely unclear. Here, we studied the antidepressant-related actions of BTRX-246040 in the ventrolateral periaqueductal gray (vlPAG). METHODS: The tail suspension test, forced swim test, female urine sniffing test, sucrose preference test, and learned helplessness (LH) combined with pharmacological approaches were employed to examine the antidepressant-like effects and drug effects on LH-induced depressive-like behavior in C57BL/6J mice. Electrophysiological recordings in vlPAG neurons were used to study synaptic activity. RESULTS: Intraperitoneal administration of BTRX-246040 produced antidepressant-like behavioral effects in a dose-dependent manner. Systemic BTRX-246040 (10 mg/kg) resulted in an increased frequency and amplitude of miniature excitatory postsynaptic currents (EPSCs) in the vlPAG. Moreover, slice perfusion of BTRX-246040 directly elevated the frequency and amplitude of miniature EPSCs and enhanced the evoked EPSCs in the vlPAG, which were blocked by pretreatment with the nociceptin/orphanin FQ peptide receptor agonist Ro 64-6198. In addition, intra-vlPAG application of BTRX-246040 produced antidepressant-like behavioral effects in a dose-dependent manner. Moreover, intra-vlPAG pretreatment with 6-cyano-7-nitroquinoxaline-2,3-dione reversed both systemic and local BTRX-246040-mediated antidepressant-like behavioral effects. Furthermore, both systemic and local BTRX-246040 decreased the LH phenotype and reduced LH-induced depressive-like behavior. CONCLUSIONS: The results suggested that BTRX-246040 may act through the vlPAG to exert antidepressant-relevant actions. The present study provides new insight into a vlPAG-dependent mechanism underlying the antidepressant-like actions of BTRX-246040.

(2R,6R)-hydroxynorketamine targeting the basolateral amygdala regulates fear memory.

(2R,6R)-Hydroxynorketamine (HNK), a ketamine metabolite, has been proposed as an ideal next-generation antidepressant due to its rapid-acting and long-lasting antidepression-relevant actions. Interestingly, recent studies have shown that (2R,6R)-HNK may have diverse impacts on memory formation. However, its effect on fear memory extinction is still unknown. In the present study, we assessed the effects of (2R,6R)-HNK on synaptic transmission and plasticity in the basolateral amygdala (BLA) and explored its actions on auditory fear memory extinction. Adult male C57BL/6J mice were used in this study. The extracellular electrophysiological recording was conducted to assay synaptic transmission and plasticity. The auditory fear conditioning paradigm was performed to test fear extinction. The results showed that (2R,6R)-HNK at 30 mg/kg increased the number of c-fos-positive cells in the BLA. Moreover, (2R,6R)-HNK enhanced the induction and maintenance of long-term potentiation (LTP) in the BLA in a dose-dependent manner (at 1, 10, and 30 mg/kg). In addition, (2R,6R)-HNK at 30 mg/kg and directly slice perfusion of (2R,6R)-HNK enhanced BLA synaptic transmission. Furthermore, intra-BLA application and systemic administration of (2R,6R)-HNK reduced the retrieval of recent fear memory and decreased the retrieval of remote fear memory. Both local and systemic (2R,6R)-HNK also inhibited the spontaneous recovery of remote fear memory. Taken together, these results indicated that (2R,6R)-HNK could regulate BLA synaptic transmission and plasticity and act through the BLA to modulate fear memory. The results revealed that (2R,6R)-HNK may be a potential drug to treat posttraumatic stress disorder (PTSD) patients.

Rhynchophylline ameliorates cerebral ischemia by improving the synaptic plasticity in a middle cerebral artery occlusion induced stroke model.

INTRODUCTION: Previous studies have documented that rhynchophylline exerts antioxidative and anti-inflammatory effects on ischemic neuronal damage in vitro or in vivo. There is a considerable lack of direct evidence for its role in neural function and neuroplasticity after ischemic stroke. AIMS: This study aims to explore the role of rhynchophylline in middle cerebral artery occlusion (MCAO) induced ischemic stroke model and the potential mechanisms. METHODS: Mice were randomly divided into the following three groups: Sham, MCAO + ddH2O, and MCAO + Rhy(40 mg/kg by oral gavage) groups. Cerebral ischemia was induced by MCAO. Cerebral blood flow was monitored to indicate the success of the ischemic model. The neurological severity score and a series of related behavior tests were performed(after MCAO 3d,7d,14d,21d,28d). Golgi staining and Sholl analysis were used to evaluate the complexity of dendrites and the density of dendritic spines. Immunohistochemistry was used to detect the expression of synapsin I and NeuN. RESULTS: Administration of rhynchophylline for 7 consecutive days after the onset of cerebral ischemia alleviated the sensory-motor functional defects and ameliorated hippocampus-dependent spatial memory injury as well as reduced the infarct volume induced by MCAO. However, golgi staining and sholl analysis showed that rhynchophylline improved dendritic complexity and spine density as well as the synaptic plasticity. Furthermore,the expression of synapsin I and Neun was significantly reduced after cerebral ischemia and rhynchophylline administration ameliorated the loss of synapsin I. CONCLUSION: Rhynchophylline is a promising treatment for ischemic stroke via improving synaptic plasticity and ameliorating the sensory-motor function.

Prelimbic cortex miR-34a contributes to (2R,6R)-hydroxynorketamine-mediated antidepressant-relevant actions.

The ketamine metabolite (2R,6R)-hydroxynorketamine (HNK) has recently been suggested to exert fast-acting antidepressant-relevant actions and was proposed as an ideal next-generation antidepressant. However, the microRNA-mediated mechanism underlying its effects is still unknown. In the present study, we investigated the role of miR-34a in the prelimbic (PL) cortex during (2R,6R)-HNK-mediated antidepressant-like effects. Male (8-10 weeks old) C57BL/6J mice and primary hippocampal cultured neurons were employed. The tests of forced swimming, tail suspension, sucrose preference, and female urine sniffing were used as indices of depressive-like behaviors. (2R,6R)-HNK enhanced miR-34a levels in a time-dependent manner at 1, 24 h, and 3 days in vitro, in a time-dependent manner at 1 and 24 h, and in a dose-dependent manner at 10 and 30 mg/kg in PL. Pretreatment with NBQX or verapamil blocked (2R,6R)-HNK-enhanced miR-34a expression and NBQX pretreatment blocked AMPA-elevated miR-34a levels in vitro. AAV-miR-34a in PL produced antidepression-behavioral effects and rescued stress-induced depressive-like behaviors. Moreover, PL AAV-miR-34a increased the frequency and amplitude of miniature excitatory postsynaptic currents (mEPSCs) and potentiated evoked excitatory postsynaptic currents (EPSCs). Slices incubated with miR-34a mimic acutely enhanced the frequency and amplitude of mEPSCs in the PL. Intra-PL application of miR-34a rapidly produced antidepression-like effects and reversed stress-evoked depressive-like behaviors. Furthermore, intra-PL application of anti-miR-34a attenuated both systemic and local (2R,6R)-HNK-mediated antidepressant-like actions. Collectively, these results suggest that miR-34a in PL plays an antidepression-like role and contributes to the fast-acting antidepressant-relevant actions of (2R,6R)-HNK. The present study provides evidence for a miR-34a-dependent mechanism underlying the fast-acting antidepressant-like actions of (2R,6R)-HNK, indicating a novel role of PL miR-34a in antidepression.

A Novel Role of Claudin-5 in Prevention of Mitochondrial Fission Against Ischemic/Hypoxic Stress in Cardiomyocytes.

BACKGROUND: Downregulation of claudin-5 in the heart is associated with the end-stage heart failure. However, the underlying mechanism ofclaudin-5 is unclear. Here we investigated the molecular actions of claudin-5 in perspective of mitochondria in cardiomyocytes to better understand the role of claudin-5 in cardioprotection during ischemia. METHODS: Myocardial ischemia/reperfusion (I/R; 30 min/24 h) and hypoxia/reoxygenation (H/R; 24 h/4 h) were used in this study. Confocal microscopy and transmission electron microscope (TEM) were used to observe mitochondrial morphology. RESULTS: Claudin-5 was detected in murine heart tissue and neonatal rat cardiomyocytes (NRCM). Its protein level was severely decreased after myocardial I/R or H/R. Confocal microscopy showedclaudin-5 presented in the mitochondria of NRCM. H/R-induced claudin-5 downregulation was accompanied by mitochondrial fragmentation. The mitofusin 2 (Mfn2) expressionwas dramatically decreased while the dynamin-related protein (Drp) 1 expression was significantly increased after H/R. The TEM indicatedH/R-induced mitochondrial swelling and fission. Adenoviral claudin-5 overexpression reversed these structural disintegration of mitochondria. The mitochondria-centered intrinsic pathway of apoptosis triggered by H/R and indicated by the cytochrome c and cleaved caspase 3 in the cytoplasm of NRCMs was also reduced by overexpressing claudin-5. Claudin-5 overexpression in mouse heart also significantly decreased cleaved caspase 3 and the infarct size in ischemic heart with improved systolic function. CONCLUSION: We demonstrated for the first time the presence of claudin-5 in the mitochondria in cardiomyocytes and provided the firm evidence for the cardioprotective role of claudin-5 in the preservation of mitochondrial dynamics and cell fate against hypoxia- or ischemia-induced stress.

Topiramate inhibits offensive aggression through targeting ventrolateral periaqueductal gray.

Topiramate is an approved antiepileptic drug clinically used to treat epilepsy and prevent migraines. Currently, topiramate has been found to be effective in treating aggressive symptoms in neuropsychiatric patients. In preclinical studies, however, the effects and mechanisms of topiramate on offensive aggression are still largely uninvestigated. Our previous studies indicated that glutamatergic transmission in the ventrolateral periaqueductal gray (vlPAG) plays a crucial role in regulating elements of offensive aggressive behaviors. In the present work, we investigated the actions of topiramate on vlPAG glutamatergic transmission and aggressive behaviors in group-housed (GH) and socially isolated (SI) rats. The results suggested that a single injection of topiramate systemically and dose-dependently inhibited elements of offensive aggressive behaviors of both GH and SI rats in the resident-intruder test (RIT), with long-lasting effective time profiles in SI rats. Moreover, systemic single administration of topiramate reduced the frequency and amplitude of miniature excitatory postsynaptic currents (mEPSCs) in the vlPAG. Bath perfusion of topiramate directly decreased the frequency and amplitude of mEPSCs and shortened the amplitude of evoked excitatory postsynaptic currents (EPSCs) in the vlPAG. Furthermore, intra-vlPAG single microinjection of topiramate dose-dependently inhibited offensive aggressive behaviors in GH and SI rats in a time-dependent manner. Additionally, both systemic and local topiramate inhibited offensive aggressive behaviors in a (2R,6R)-hydroxynorketamine (HNK)-dependent rat model. In conclusion, the present results suggest that topiramate exerts anti-aggressive roles through its inhibitory actions on glutamatergic activities in the vlPAG. These preclinical results support topiramate as a candidate drug to treat patients with heightened offensive aggression.

The Ventrolateral Periaqueductal Gray Contributes to Depressive-Like Behaviors in Recovery of Inflammatory Bowel Disease Rat Model.

BACKGROUND: Patients with inflammatory bowel disease (IBD) experience depression, even in the remission phase of IBD symptoms. Although mapping depression-associated brain regions through the gut-brain axis can contribute to understanding the process, the mechanisms remain unclear. Our previous results support the idea that glutamatergic transmission in the ventrolateral periaqueductal gray (vlPAG) mediates stress-induced depression-like behaviors. Thus, we hypothesize that the vlPAG plays a role in regulating depression during remission of IBD. METHODS: We used dextran sulfate sodium (DSS)-induced visceral pain model to evoke depression-like behaviors, assessed by tail suspension test (TST) and sucrose preference test (SPT), and electrophysiological recordings from vlPAG. RESULTS: Symptoms of animals modeling IBD were relieved by replacing DSS solution with normal drinking water, but their depression-like behaviors sustained. Moreover, the impairment of glutamatergic neurotransmission in vlPAG was sustained as well. Pharmacologically, microinfusion of the glutamate receptor 1 (GluR1) antagonist NASPM into vlPAG mimicked the depression-like behaviors. Furthermore, intra-vlPAG application of AMPA and AMPA receptor-mediated antidepressant (2R,6R)-hydroxynorketamine [(2R,6R)-HNK] reversed the DSS-induced depression-like behaviors in the remission phase of visceral abnormalities. CONCLUSION: Our results suggest that vlPAG glutamatergic transmission mediates depression-like behaviors during remission of DSS-induced visceral pain, suggesting that vlPAG mapping to the gut-brain axis contributes to depression during remission of IBD.

Brain-derived neurotrophic factor in the ventrolateral periaqueductal gray contributes to (2R,6R)-hydroxynorketamine-mediated actions.

The ketamine metabolite (2R,6R)-hydroxynorketamine (HNK) has recently been suggested as an ideal antidepressant for treating animal models of depression. However, its effects and mechanisms are subjects of debate. According to our recent studies, (2R,6R)-HNK not only acts as an antidepressant but also produces increased aggression by enhancing glutamatergic transmission in the ventrolateral periaqueductal gray (vlPAG). In the present study, we examined the contribution of brain-derived neurotrophic factor (BDNF) in the vlPAG to the actions of (2R,6R)-HNK. The systemic administration of a single dose of (2R,6R)-HNK produced antidepressant-like effects and increased aggression and further increased the levels of the BDNF protein in the vlPAG. Sustained BDNF RNAi-mediated knockdown or pharmacological inhibition of BDNF signaling in the vlPAG not only mimicked depression-like behaviors but also inhibited aggressive behaviors. The intra-vlPAG application of BDNF rapidly produced antidepressant-like effects and enhanced aggressive behaviors. Moreover, the vlPAG injection of a neutralizing BDNF antibody or the inhibition of BDNF signaling prior to the (2R,6R)-HNK application in the vlPAG blocked (2R,6R)-HNK-mediated actions. Furthermore, sustained vlPAG BDNF knockdown locally attenuated systemic (2R,6R)-HNK-mediated actions. In conclusion, BDNF in the vlPAG might play a role in regulating depression-like behaviors and aggressive behaviors. Moreover, BDNF in the vlPAG might be involved in the (2R,6R)-HNK-mediated antidepressant-like effects and increase in aggression. The present study further implicates a shared mechanism of BDNF and vlPAG signaling for antidepressant treatments and increased aggression.

Decreased Glutamatergic Synaptic Strength in the Periaqueductal Gray Contributes to Maintenance of Visceral Pain in Male Rats with Experimental Pancreatitis.

Visceral pain originating from chronic inflammation of the pancreas is often intractable and difficult to manage clinically. However, the pathogenesis of the central nervous system underlying visceral pain is still poorly understood. The aim of the present study was to investigate the role of the midbrain ventrolateral periaqueductal gray (vlPAG) in a rat model of chronic visceral pain induced by pancreatitis. In the present study, we used a well-established rat model of chronic pancreatitis induced by tail vein injection of dibutyltin dichloride (DBTC). To assess the DBTC-induced visceral pain, we examined the abdominal withdrawal by von Frey filament test. We further studied the synaptic transmission in the vlPAG by whole-cell patch-clamp electrophysiological recordings. Rats receiving DBTC injection exhibited a significantly increased withdrawal frequency to mechanical stimulation of the abdomen compared to rats injected with vehicle. Interestingly, compared to rats injected with vehicle, we found that neurons dissected from DBTC-treated rats exhibited a significantly decreased synaptic strength, which was revealed by a diminishedα-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid/N-methyl-d-aspartic acid (AMPA/NMDA) ratio in the vlPAG. Moreover, our results further demonstrated that neurons obtained from DBTC-treated rats displayed a higher paired-pulse ratio, as well as less frequent and smaller amplitudes of miniature excitatory postsynaptic currents in the vlPAG compared to rats injected with vehicle. Furthermore, intra-vlPAG microinjection of AMPA alleviated DBTC-induced abdominal hypersensitivity. Taken together, our findings suggest that diminished glutamatergic synaptic strength via both presynaptic and postsynaptic mechanisms in the midbrain vlPAG is associated with DBTC-induced abdominal hypersensitivity. In addition, activation of AMPA receptors in the vlPAG alleviates DBTC-induced abdominal hypersensitivity.

Ketamine metabolite (2R,6R)-hydroxynorketamine enhances aggression via periaqueductal gray glutamatergic transmission.

(2R,6R)-hydroxynorketamine (HNK), a metabolite of ketamine, has recently been suggested to be a potent antidepressant for treating animal depression and has rapid-onset and long-lasting action through potentiating glutamatergic transmission. However, its other effects are still unclear. In the present study, we tested the effects of (2R,6R)-HNK on offensive aggression. A resident-intruder (RI) test was used as the main model to test elements of offensive aggression, including threats and bites. Electrophysiological recordings in the ventrolateral periaqueductal gray (vlPAG) were used to measure the functions of glutamatergic synaptic transmission. A single systemic injection of (2R,6R)-HNK, but not (2S,6S)-HNK, increased elements of offensive aggression, including threats and bites, in a dose-dependent manner with long-lasting action. Moreover, (2R,6R)-HNK increased the input-output curve, the AMPA-mediated current, and the frequency and amplitude of miniature excitatory postsynaptic currents (mEPSCs) and decreased the paired-pulse ratio (PPR) in the vlPAG. Furthermore, intra-vlPAG application of (2R,6R)-HNK increased aggressive and biting behaviors, which were abolished by an intra-vlPAG pretreatment with the AMPA receptors antagonist, CNQX. Notably, the intra-vlPAG CNQX pretreatment eliminated systemic (2R,6R)-HNK-enhanced aggressive and biting behaviors. The results of this suggest that (2R,6R)-HNK evokes offensive aggression by increasing vlPAG glutamatergic transmission. Although (2R,6R)-HNK is currently suggested to be effective for treating depression, its side effect of increasing offensive aggression should be a subject of concern in future drug development and therapy.

Analysis of oral microbiota in patients with obstructive sleep apnea-associated hypertension.

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is an independent risk factor for hypertension (HTN). The oral microbiota plays a pathophysiological role in cardiovascular diseases; however, there are few reports directly investigating and identifying the organisms involved in OSAHS-related HTN. Therefore, this study aimed to identify those organisms. We obtained 139 oral samples and determined the microbiome composition using pyrosequencing and bioinformatic analyses of the 16S rRNA. We examined the fasting levels of cytokines and homocysteine in all participants and analyzed the correlations between the oral microbiota and homocysteine levels. We determined the molecular mechanism underlying HTN by investigating the genetic composition of the strains in the blood. We detected higher relative abundances of Porphyromonas and Aggregatibacter and elevated proinflammatory cytokines in patients with OSAHS of varying severity compared with individuals without OSAHS; however, the two organisms were not measured in the blood samples from all participants. High levels of specific Porphyromonas bacteria were detected in patients with OSAHS with and without HTN, whereas the relative abundance of Aggregatibacter was negatively correlated with the homocysteine level. The receiver operating characteristic curve analysis of controls and patients with OSAHS resulted in area under the curve values of 0.759 and 0.641 for patients with OSAHS with or without HTN, respectively. We found that the predictive function of oral microbiota was different in patients with OSAHS with and without HTN. However, there was no direct invasion by the two organisms causing endothelial cell injury, leading to speculation regarding the other mechanisms that may lead to HTN. Elucidating the differences in the oral microbiome will help us understand the pathogenesis of OSAHS-related HTN.