Inhibition of RhoA/ROCK Pathway in the Early Stage of Hypoxia Ameliorates Depression in Mice via Protecting Myelin Sheath

AMX0035 Mitigates Oligodendrocyte Apoptosis and Ameliorates Demyelination in MCAO Rats by Inhibiting Endoplasmic Reticulum Stress and Mitochondrial Dysfunction

Post-stroke cognitive impairment (PSCI) is a common complication of strokes and is associated with the demyelination of nerve fibers. AMX0035, a drug currently used to treat motor neuron diseases, may aid in preventing oligodendrocyte apoptosis and alleviating demyelination by targeting the pathways involved in ERS and mitochondrial dysfunction. All animals were randomly divided into four groups: the sham, sham+AMX0035, middle cerebral artery occlusion (MCAO), and MCAO+AMX0035 group. The Morris water maze was used to test cognitive function, and changes in myelin structure in the brain were investigated using transmission electron microscopy (TEM), Luxol fast blue (LFB) staining, and myelin basic protein (MBP) immunofluorescence staining. Western blot was performed to detect proteins associated with ER stress and mitochondrial dysfunction, and double-labeling immunofluorescence was utilized to localize oligodendrocytes and apoptosis-related proteins. Neurological function scores and TTC staining confirmed the successful establishment of the MCAO rat model. The Morris water maze experiment revealed impaired cognitive function in MCAO rats, which significantly improved following the AMX0035 intervention. TEM and LFB staining showed the disrupted myelin structure in the MCAO group, while AMX0035 effectively ameliorated this myelin damage. Immunofluorescence examination and Western blot revealed the decreased expression of MBP in MCAO rats, increasing with AMX0035 treatment. TUNEL staining demonstrated increased cell apoptosis in MCAO rats, which was reduced following AMX0035 therapy. Western blot detected significant increases in proteins associated with the ER stress pathway and proteins linked to mitochondrial dysfunction in the MCAO group, all of which were downregulated after AMX0035 intervention. Double-labeling immunofluorescence staining revealed a significant increase in the number of cytochrome c+ and caspase 12+ oligodendrocyte cells in MCAO rats, which decreased after AMX0035 administration. The activation of ER stress and mitochondrial dysfunction pathways following MCAO led to oligodendrocyte damage and apoptosis. AMX0035 can inhibit these pathways, reduce oligodendrocyte apoptosis, and alleviate demyelination, thereby improving PSCI.

Association Between Red Cell Index and Depressive Symptoms in NHANES (2005-2018): A Cross-sectional Study

BACKGROUND

Physical symptoms and emotional distress, such as melancholy, are common among cancer survivors. Misinterpreting these as normal reactions delays depression diagnosis and worsens prognosis. Patients may hide depressive symptoms during treatment, whereas clinicians and families often dismiss them as expected disease adaptation. Emerging evidence links depression to inflammatory responses and symptoms such as fatigue/cognitive decline to hypoxia, suggesting relevance of the Red Cell Index (RCI).

OBJECTIVE

To identify depression risk factors in cancer survivors and evaluate RCI as a potential biomarker.

METHODS

We included and analyzed 2890 patients from the National Health and Nutrition Examination Survey database in this study. The 9-item Patient Health Questionnaire was used to evaluate the depressive symptoms. We employed multivariable logistic regression and stratified analyses to evaluate the association between RCI and depressive symptoms.

RESULTS

Higher RCI inversely correlated with depression risk in unadjusted analysis, persisting after full adjustment. Subgroup findings were consistent. A significant nonlinear RCI-depression connection was found by dose-response analysis.

CONCLUSIONS

As the RCI increased, the likelihood of depression in patients diagnosed with cancer decreased. Nevertheless, cross-sectional studies can merely establish the link, necessitating further research to validate causality and assess the practicality of clinical use.

IMPLICATIONS FOR PRACTICE

Possible connections between hematological markers and depression symptoms are revealed by this investigation. The RCI-depression correlation offers new perspectives for nursing practice. For cancer survivor care, integrating validated hematological indicators into assessments alongside monitoring physical/psychological symptoms is recommended. Future research should prioritize RCI-depression risk assessment and early interventions in oncology patients.

6-hydroxygenistein attenuates hypoxia-induced injury via activating Nrf2/HO-1 signaling pathway in PC12 cells

4',5,6,7-tetrahydoxyisoflavone (6-hydroxygenistein, 6-OHG) is a hydroxylated derivative of genistein with excellent antioxidant activity, but whether 6-OHG can protect hypoxia-induced damage is unclear. The objective of current study was to evaluate the protective effect and underling mechanism of 6-OHG against hypoxia-induced injury via network pharmacology and cellular experiments. 6-OHG-related and hypoxia injury-related targets were screened by public databases. The intersected targets were used for constructing PPI network and performing GO and KEGG functional analysis. We induced injury in PC12 cells under hypoxia conditions and observed the effects and molecular mechanisms of 6-OHG on cellular damage. Network pharmacological analysis predicted that 6-OHG delayed hypoxia injury by mitigating oxidative stress, inflammatory response and apoptosis. Cellular experiments suggested that 6-OHG treatment mitigated cell damage, enhanced cell viability, reduced ROS production and MDA level, increased SOD and CAT activities and elevated GSH level in PC12 cell exposed to hypoxia. Additionally, 6-OHG treatment reduced the TNF-α and IL-6 levels and elevated the IL-10 content, while downregulated the NF-κB and TNF-α expressions. 6-OHG also inhibited the caspase-3 and - 9 activation and the Bax and cleaved caspase-3 expressions, and elevated the Bcl-2 expression. Moreover, 6-OHG remarkably enhanced Nrf2 nuclear translocation and increased HO-1 expression. Molecular docking also proved the strong binding affinities of 6-OHG with Nrf2 and HO-1. Furthermore, ML385, a specific Nrf2 inhibitor, eliminated the beneficial effects of 6-OHG. In summary, 6-OHG can alleviate hypoxia-induced injury in PC12 cells through activating Nrf2/HO-1 signaling pathway and may be developed as candidate for preventing neuro-damage induced by hypoxia.

Targeting Oligodendrocyte Dynamics and Remyelination: Emerging Therapies and Personalized Approaches in Multiple Sclerosis Management

Multiple sclerosis (MS) is a progressive autoimmune condition that primarily affects young people and is characterized by demyelination and neurodegeneration of the central nervous system (CNS). This in-depth review explores the complex involvement of oligodendrocytes, the primary myelin- producing cells in the CNS, in the pathophysiology of MS. It discusses the biochemical processes and signalling pathways required for oligodendrocytes to function and remain alive, as well as how they might fail and cause demyelination to occur. We investigate developing therapeutic options that target remyelination, a fundamental component of MS treatment. Remyelination approaches promote the survival and differentiation of oligodendrocyte precursor cells (OPCs), restoring myelin sheaths. This improves nerve fibre function and may prevent MS from worsening. We examine crucial parameters influencing remyelination success, such as OPC density, ageing, and signalling pathway regulation (e.g., Retinoid X receptor, LINGO-1, Notch). The review also examines existing neuroprotective and antiinflammatory medications being studied to see if they can assist oligodendrocytes in surviving and reducing the severity of MS symptoms. The review focuses on medicines that target the myelin metabolism in oligodendrocytes. Altering oligodendrocyte metabolism has been linked to reversing demyelination and improving MS patient outcomes through various mechanisms. We also explore potential breakthroughs, including innovative antisense technologies, deep brain stimulation, and the impact of gut health and exercise on MS development. The article discusses the possibility of personalized medicine in MS therapy, emphasizing the importance of specific medicines based on individual molecular profiles. The study emphasizes the need for reliable biomarkers and improved imaging tools for monitoring disease progression and therapy response. Finally, this review focuses on the importance of oligodendrocytes in MS and the potential for remyelination therapy. It also underlines the importance of continued research to develop more effective treatment regimens, taking into account the complexities of MS pathology and the different factors that influence disease progression and treatment.

Nocturnal hypoxia in patients with sleep disorders: exploring its role as a mediator between neurotic personality traits and psychological symptoms

Introduction

Sleep disorders often coexist with personality and psychological issues, alongside nocturnal hypoxia. This study investigates the potential mediating role of nocturnal hypoxia between personality traits and psychological symptoms in individuals with sleep disorders.

Methods

A cohort comprising 171 participants reporting sleep disturbances was recruited from Dalian Seventh People's Hospital. Psychological symptoms were assessed using the Symptom Checklist-90-R (SCL-90-R), while personality traits were evaluated using the Eysenck Personality Questionnaire (EPQ). Nocturnal hypoxia status was determined through overnight polysomnography.

Results

Mediation analysis, conducted using SPSS 23.0, demonstrated that the cumulative time of nocturnal peripheral oxygen saturation (SpO2) < 85% (T85) partially mediated the relationship between neuroticism and various psychological symptoms, including somatization (c=0.207, c'=0.164, a*b=0.043, proportion of mediation 20.8%), interpersonal sensitivity (c=0.360, c'=0.326, a*b=0.034, proportion of mediation 9.6%), depression (c=0.277, c'=0.234, a*b=0.042, proportion of mediation 15.3%), anxiety (c=0.240, c'=0.199, a*b=0.041, proportion of mediation 16.9%), hostility (c=0.241, c'=0.205, a*b=0.036, proportion of mediation 14.9%), phobic anxiety (c=0.271, c'=0.241, a*b=0.030, proportion of mediation 11.1%), and psychoticism (c=0.298, c'=0.266, a*b=0.032, proportion of mediation 10.8%).

Discussion

These findings underscore the potential mediating role of nocturnal hypoxia in the association between neuroticism personality traits and psychological symptoms among individuals with sleep disorders. Our research holds considerable significance in advancing the quest for personalized treatments targeting psychological symptoms in individuals with sleep disorders.

Differential expression of genes in the RhoA/ROCK pathway in the hippocampus and cortex following intermittent hypoxia and high-intensity interval training

Structural neuroplasticity such as neurite extension and dendritic spine dynamics is enhanced by brain-derived neurotrophic factor (BDNF) and impaired by types of inhibitory molecules that induce growth cone collapse and actin depolymerization, for example, myelin-associated inhibitors, chondroitin sulfate proteoglycans, and negative guidance molecules. These inhibitory molecules can activate RhoA/rho-associated coiled-coil containing protein kinase (ROCK) signaling (known to restrict structural plasticity). Intermittent hypoxia (IH) and high-intensity interval training (HIIT) are known to upregulate BDNF that is associated with improvements in learning and memory and greater functional recovery following neural insults. We investigated whether the RhoA/ROCK signaling pathway is also modulated by IH and HIIT in the hippocampus, cortex, and lumbar spinal cord of male Wistar rats. The gene expression of 25 RhoA/ROCK signaling pathway components was determined following IH, HIIT, or IH combined with HIIT (30 min/day, 5 days/wk, 6 wk). IH included 10 3-min bouts that alternated between hypoxia (15% O2) and normoxia. HIIT included 10 3-min bouts alternating between treadmill speeds of 50 cm·s-1 and 15 cm·s-1. In the hippocampus, IH and HIIT significantly downregulated Acan and NgR2 mRNA that are involved in the inhibition of neuroplasticity. However, IH and IH + HIIT significantly upregulated Lingo-1 and NgR3 in the cortex. This is the first time IH and HIIT have been linked to the modulation of plasticity-inhibiting pathways. These results provide a fundamental step toward elucidating the interplay between the neurotrophic and inhibitory mechanisms involved in experience-driven neural plasticity that will aid in optimizing physiological interventions for the treatment of cognitive decline or neurorehabilitation.NEW & NOTEWORTHY Intermittent hypoxia (IH) and high-intensity interval training (HIIT) enhance neuroplasticity and upregulate neurotrophic factors in the central nervous system (CNS). We provide evidence that IH and IH + HIIT also have the capacity to regulate genes involved in the RhoA/ROCK signaling pathway that is known to restrict structural plasticity in the CNS. This provides a new mechanistic insight into how these interventions may enhance hippocampal-related plasticity and facilitate learning, memory, and neuroregeneration.

The role and mechanism of TGF-β1 in the antidepressant-like effects of tetrahydrocurcumin

Astrocytes and the activation of inflammatory factors are associated with depression. Tetrahydrocurcumin (THC), the principal metabolite of natural curcumin, is renowned for its anti-inflammatory properties. In this research, we explored the impact of THC on the expression of inflammatory factors, neurotrophins, and transforming growth factor β1 (TGF-β1) in the prefrontal cortex after chronic restraint stress (CRS) in mice and in lipopolysaccharide (LPS)-induced TNC1 astrocytes. Our findings indicated that THC mitigated the anxiety and depression-like behaviours observed in CRS mice. It also influenced the expression of TGF-β1, p-SMAD3/SMAD3, sirtuin 1 (SIRT1), brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF), inducible nitric oxide synthase (iNOS), and tumour necrosis factor α (TNF-α). Specifically, THC augmented the expressions of TGF-β1, p-SMAD3/SMAD3, SIRT1, BDNF, and GDNF, whilst diminishing the expressions of iNOS and TNF-α in LPS-induced astrocytes. However, when pre-treated with SB431542, a TGF-β1 receptor inhibitor, it nullified the aforementioned effects of THC on astrocytes. Our results propose that THC delivers its anti-depressive effects through the activation of TGF-β1, enhancement of p-SMAD3/SMAD3 and SIRT1 expression, upregulation of BDNF and GDNF, and downregulation of iNOS and TNF-α. This research furnishes new perspectives on the anti-inflammatory mechanism that underpins the antidepressant-like impact of THC.

Role of hypoxic exosomes and the mechanisms of exosome release in the CNS under hypoxic conditions

Hypoxia is characterized by low oxygen levels in the body or environment, resulting in various physiological and pathological changes. The brain, which has the highest oxygen consumption of any organ, is particularly susceptible to hypoxic injury. Exposure to low-pressure hypoxic environments can cause irreversible brain damage. Hypoxia can occur in healthy individuals at high altitudes or in pathological conditions such as trauma, stroke, inflammation, and autoimmune and neurodegenerative diseases, leading to severe brain damage and impairments in cognitive, learning, and memory functions. Exosomes may play a role in the mechanisms of hypoxic injury and adaptation and are a current focus of research. Investigating changes in exosomes in the central nervous system under hypoxic conditions may aid in preventing secondary damage caused by hypoxia. This paper provides a brief overview of central nervous system injury resulting from hypoxia, and aimed to conduct a comprehensive literature review to assess the pathophysio-logical impact of exosomes on the central nervous system under hypoxic conditions.

H2S-RhoA/ROCK Pathway and Glial Cells in Axonal Remyelination After Ischemic Stroke

Ischemic stroke is one of the main reasons of disability and death. Stroke-induced functional deficits are mainly due to the secondary degeneration of the white matter characterized by axonal demyelination and injury of axon-glial integrity. Enhancement of the axonal regeneration and remyelination could promote the neural functional recovery. However, cerebral ischemia-induced activation of RhoA/Rho kinase (ROCK) pathway plays a crucial and harmful role in the process of axonal recovery and regeneration. Inhibition of this pathway could promote the axonal regeneration and remyelination. In addition, hydrogen sulfide (H2S) has the significant neuroprotective role during the recovery of ischemic stroke via inhibiting the inflammatory response and oxidative stress, regulating astrocyte function, promoting the differentiation of endogenous oligodendrocyte precursor cells (OPCs) to mature oligodendrocyte. Among all of these effects, promoting the formation of mature oligodendrocyte is a crucial part of axonal regeneration and remyelination. Furthermore, numerous studies have uncovered the crosstalk between astrocytes and oligodendrocyte, microglial cells and oligodendrocyte in the axonal remyelination following ischemic stroke. The purpose of this review was to discuss the relationship among H2S, RhoA/ROCK pathway, astrocytes, and microglial cells in the axonal remyelination following ischemic stroke to reveal new strategies for preventing and treating this devastating disease.

Myelin sheath injury and repairment after subarachnoid hemorrhage

Subarachnoid hemorrhage (SAH) can lead to damage to the myelin sheath in white matter. Through classification and analysis of relevant research results, the discussion in this paper provides a deeper understanding of the spatiotemporal change characteristics, pathophysiological mechanisms and treatment strategies of myelin sheath injury after SAH. The research progress for this condition was also systematically reviewed and compared related to myelin sheath in other fields. Serious deficiencies were identified in the research on myelin sheath injury and treatment after SAH. It is necessary to focus on the overall situation and actively explore different treatment methods based on the spatiotemporal changes in the characteristics of the myelin sheath, as well as the initiation, intersection and common action point of the pathophysiological mechanism, to finally achieve accurate treatment. We hope that this article can help researchers in this field to further clarify the challenges and opportunities in the current research on myelin sheath injury and treatment after SAH.

Loss of Tyro3 causes anxiety-relevant behavioural changes in female mice

White-matter brain abnormalities have been found across a variety of psychiatric disorders. The extent of white matter pathology is proposed to be predictive of the severity of anxiety disorders. However, it is still unknown whether disruptions of white matter integrity precede, and are sufficient to give rise to, the behavioural symptoms. Interestingly, mood disturbances feature prominently in central demyelinating diseases such as multiple sclerosis. It is unclear whether the greater frequency of neuropsychiatric symptoms is linked to underlying neuropathology. In this study, we characterised male and female Tyro3 knockout (KO) mice using a variety of behavioural paradigms. Anxiety-related behaviours were assessed with the elevated-plus maze and light-dark box. Fear memory processing was assessed using fear conditioning and extinction paradigms. Finally, we assessed immobility time in the Porsolt swim test as a measure of depression-related behavioural despair. Surprisingly, loss of Tyro3 did not lead to manifestation of major shifts in baseline behaviour. We noted significant differences in habituation to novel environments and post-conditioning freezing levels of female Tyro3 KO mice, which are consistent with the female bias in anxiety disorders and could be indicative of maladaptive stress-responses. This study has demonstrated that white matter pathology related to a loss of Tyro3 is associated with pro-anxiety behavioural responses of female mice. Future studies could probe their contribution to increased risk for neuropsychiatric disorders when combined with stressful triggering events.

A focus on Rho/ROCK signaling pathway: An emerging therapeutic target in depression

Depression is the most common mental health disorder worldwide; however, the exact cellular and molecular mechanisms of this major depressive disorder are unclear so far. Experimental studies have demonstrated that depression is associated with significant cognitive impairment, dendrite spine loss, and reduction in connectivity among neurons that contribute to symptoms associated with mood disorders. Rho/Rho-associated coiled-coil containing protein kinase (ROCK) receptors are exclusively expressed in the brain and Rho/ROCK signaling has gained considerable attention as it plays a crucial role in the development of neuronal architecture and structural plasticity. Chronic stress-induced activation of the Rho/ROCK signaling pathway promotes neuronal apoptosis and loss of neural processes and synapses. Interestingly, accumulated evidence has identified Rho/ROCK signaling pathways as a putative target for treating neurological disorders. Furthermore, inhibition of the Rho/ROCK signaling pathway has proven to be effective in different models of depression, which signify the potential benefits of clinical Rho/ROCK inhibition. The ROCK inhibitors extensively modulate antidepressant-related pathways which significantly control the synthesis of proteins, and neuron survival and ultimately led to the enhancement of synaptogenesis, connectivity, and improvement in behavior. Therefore, the present review refines the prevailing contribution of this signaling pathway in depression and highlighted preclinical shreds of evidence for employing ROCK inhibitors as disease-modifying targets along with possible underlying mechanisms in stress-associated depression.

Molecular, Circuit, and Stress Response Characterization of Ventral Pallidum Npas1-Neurons

Altered activity of the ventral pallidum (VP) underlies disrupted motivation in stress and drug exposure. The VP is a very heterogeneous structure composed of many neuron types with distinct physiological properties and projections. Neuronal PAS 1-positive (Npas1+) VP neurons are thought to send projections to brain regions critical for motivational behavior. While Npas1+ neurons have been characterized in the globus pallidus external, there is limited information on these neurons in the VP. To address this limitation, we evaluated the projection targets of the VP Npas1+ neurons and performed RNA-sequencing on ribosome-associated mRNA from VP Npas1+ neurons to determine their molecular identity. Finally, we used a chemogenetic approach to manipulate VP Npas1+ neurons during social defeat stress (SDS) and behavioral tasks related to anxiety and motivation in Npas1-Cre mice. We used a similar approach in females using the chronic witness defeat stress (CWDS). We identified VP Npas1+ projections to the nucleus accumbens, ventral tegmental area, medial and lateral habenula, lateral hypothalamus, thalamus, medial and lateral septum, and periaqueductal gray area. VP Npas1+ neurons displayed distinct translatome representing distinct biological processes. Chemogenetic activation of hM3D(Gq) receptors in VP Npas1+ neurons increased susceptibility to a subthreshold SDS and anxiety-like behavior in the elevated plus maze and open field while the activation of hM4D(Gi) receptors in VP Npas1+ neurons enhanced resilience to chronic SDS and CWDS. Thus, the activity of VP Npas1+ neurons modulates susceptibility to social stressors and anxiety-like behavior. Our studies provide new information on VP Npas1+ neuron circuitry, molecular identity, and their role in stress response.SIGNIFICANCE STATEMENT The ventral pallidum (VP) is a structure connected to both reward-related and aversive brain centers. It is a key brain area that signals the hedonic value of natural rewards. Disruption in the VP underlies altered motivation in stress and substance use disorder. However, VP is a very heterogeneous area with multiple neuron subtypes. This study characterized the projection pattern and molecular signatures of VP Neuronal PAS 1-positive (Npas1+) neurons. We further used tools to alter receptor signaling in VP Npas1+ neurons in stress to demonstrate a role for these neurons in stress behavioral outcomes. Our studies have implications for understanding brain cell type identities and their role in brain disorders, such as depression, a serious disorder that is precipitated by stressful events.

Baicalin Ameliorates Corticosterone-Induced Depression by Promoting Neurodevelopment of Hippocampal via mTOR/GSK3 β Pathway

OBJECTIVE

To investigate the role of hippocampal neurodevelopment in the antidepressant effect of baicalin.

METHODS

Forty male Institute of Cancer Research mice were divided into control, corticosterone (CORT, 40 mg/kg), CORT+baicalin-L (25 mg/kg), CORT+baicalin-H (50 mg/kg), and CORT+fluoxetine (10 mg/kg) groups according to a random number table. An animal model of depression was established by chronic CORT exposure. Behavioral tests were used to assess the reliability of depression model and the antidepressant effect of baicalin. In addition, Nissl staining and immunofluorescence were used to evaluate the effect of baicalin on hippocampal neurodevelopment in mice. The protein and mRNA expression levels of neurodevelopment-related factors were detected by Western blot analysis and real-time polymerase chain reaction, respectively.

RESULTS

Baicalin significantly ameliorated the depressive-like behavior of mice resulting from CORT exposure and promoted the development of dentate gyrus in hippocampus, thereby reversing the depressive-like pathological changes in hippocampal neurons caused by CORT neurotoxicity. Moreover, baicalin significantly decreased the protein and mRNA expression levels of glycogen synthase kinase 3 β (GSK3 β), and upregulated the expression levels of cell cycle protein D1, p-mammalian target of rapamycin (mTOR), doublecortin, and brain-derived neurotrophic factor (all P<0.01). There were no significant differences between baicalin and fluoxetine groups (P>0.05).

CONCLUSION

Baicalin can promote the development of hippocampal neurons via mTOR/GSK3 β signaling pathway, thus protect mice against CORT-induced neurotoxicity and play an antidepressant role.

Sortilin deletion in the prefrontal cortex and hippocampus ameliorates depressive-like behaviors in mice via regulating ASM/ceramide signaling

Major depressive disorder (MDD) is a common psychiatric disorder characterized by persistent mood despondency and loss of motivation. Although numerous hypotheses have been proposed, the possible pathogenesis of MDD remains unclear. Several recent studies show that a classic transporter protein, sortilin, is closely associated with depression. In the present study, we investigated the role of sortilin in MDD using a well-established rodent model of depression. Mice were subjected to chronic unpredictable mild stress (CUMS) for 6 weeks. We showed that the expression levels of sortilin were significantly increased in the prefrontal cortex and hippocampus of CUMS mice. The depressive-like behaviors induced by CUMS were alleviated by specific knockdown of sortilin in the prefrontal cortex and hippocampus. We revealed that sortilin facilitated acid sphingomyelinase (ASM)/ceramide signaling, which activated RhoA/ROCK2 signaling, ultimately causing the transformation of dendritic spine dynamics. Specific overexpression of sortilin in the prefrontal cortex and hippocampus induced depressive-like behaviors, which was mitigated by injection of ASM inhibitor SR33557 (4 µg/μL) into the prefrontal cortex and hippocampus. In conclusion, sortilin knockdown in the prefrontal cortex and hippocampus plays an important role in ameliorating depressive-like behavior induced by CUMS, which is mainly evidenced by decreasing the trafficking of ASM from the trans-Golgi network to the lysosome and reducing the ceramide levels. Our results provide a new insight into the pathology of depression, and demonstrate that sortilin may be a potential therapeutic target for MDD.

Effects of RhoA on depression-like behavior in prenatally stressed offspring rats

Depression is a common mental disease that can lead to suicide when severe. Exposure to prenatal stress (PS) can lead to depression-like behavior in offspring, but the mechanism is unclear. RhoA (Ras homology family member A) plays an important role in stress-induced changes in synaptic plasticity, participating in the development of depression by activating the downstream effector ROCK (Rho-associated protein kinase). This study explored the influence in the expression of RhoA and downstream molecules ROCK1/2 in prenatally stressed rats, and the effect of RhoA inhibitor simvastatin on depression-like behavior induced by PS. Depression-like behavior in offspring was detected by sucrose preference test, forced swimming test, and open-field test. The mRNA and protein expression of RhoA and ROCK1/2 in the hippocampus and prefrontal cortex of offspring rats were detected by qRT-PCR and western blotting, respectively. Our results showed that PS causes depression-like behavior in offspring rats, associated with elevated expression of RhoA, ROCK1/2 in the hippocampus and prefrontal cortex. After administration of simvastatin to PS rats, the expression of RhoA and ROCK2 was significantly reduced, alleviating depression-like behavior. Our study demonstrated that RhoA participates in the depression-like behavior in prenatally stressed offspring rats, which may be a potential target for antidepressant therapy.

Baicalin coadministration with lithium chloride enhanced neurogenesis via GSK3β pathway in corticosterone induced PC-12 cells

Accumulating studies suggest that hippocampal neurogenesis plays a crucial role in the pathological mechanism of depression. As a classic antidepressant, lithium chloride can play an antidepressant role by inhibiting GSK3β and promoting neurogenesis. Correspondingly, baicalin is a compound extracted from natural plants, which shows potential antidepressant effect, however, whether baicalin exerts antidepressant effects by promoting neurogenesis still needs further investigation. In the current study, we established an in vitro depression model through corticosterone induced PC-12 cells, and explored the potential mechanism of baicalin's antidepressant effect by comparing it with lithium chloride alone and the coadministration with lithium chloride. We used CCK-8 assay, EdU staining and cell cycle analysis to evaluate the state of cell survival and cell proliferation. The protein expression levels of neurodevelopmental related factors DCX, BDNF, and the GSK3β pathway-related proteins and mRNA were detected by Western blot and Real-time PCR. The results showed that baicalin could decrease the expression level of GSK3β, while upregulate the expression level of DCX, BDNF, Cyclin D1-CDK4/6, thus promoted cell proliferation and survival in CORT induced PC-12 cells. Moreover, this effect was enhanced when baicalin and lithium chloride were coadministration. Taking the above results together, we conclude that baicalin can promote the proliferation and development of PC-12 cells by regulating GSK3β pathway, so as to reverse the depressive-like pathological changes induced by corticosterone.

Inhibition of ROCK2 kinase activity improved behavioral deficits and reduced neuron damage in a DEACMP rat model

The main pathological changes that occur in delayed encephalopathy after acute carbon monoxide poisoning (DEACMP) are extensive demyelination of brain white matter and neuron damage. Previous studies suggested that demyelination and neuron injury are related to activating the Rho/ROCK signaling pathway. Inhibition of the Rho/ROCK signaling pathway can alleviate neuron injury and promote myelin repair. This study utilized a DEACMP model in which rats were prepared by space injection of CO gas intraperitoneally (CO group), and the association between the Rho/ROCK signaling pathway and DEACMP was investigated. The ROCK2 kinase inhibitor Y-27632 was used to prevent the effects of the DEACMP model to elucidate its protective mechanism. The results demonstrated that the cognitive and motor functions were significantly impaired, and the GFAP, NSE, RhoA, and ROCK2 protein levels were significantly increased in the CO group within three weeks after the model was established. After Y-27632 intervention, the cognitive and motor functions of the CO+Y-27632 group were significantly improved within three weeks after the model was established. In the CO+Y-27632 group, the RhoA, ROCK2, GFAP, and NSE (indicating neuron injury) protein levels decreased significantly, and the MBP protein levels (indicating myelin repair) increased significantly within three weeks after the model was established. These results suggested that the pathogenesis of DEACMP was associated with activation of the Rho/ROCK pathway and that Y-27632 inhibited ROCK2 kinase activity in the CO exposed rats, resulting in improved behavioral deficits, reduced neuron damage, and promotion of myelin repair. Therefore, Y-27632 might be a potentially effective drug for the treatment of DEACMP-induced brain damage.

WITHDRAWN: Anti-inflammatory role and mechanism of microRNA-92b-3p in the progression of hypoxic pulmonary hypertension

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