Autophagy inhibition plays a protective role against 3, 4-methylenedioxymethamphetamine (MDMA)-induced loss of serotonin transporters and depressive-like behaviors in rats

Autophagy markers, cognitive deficits and depressive symptoms in Parkinson's disease

Depressive symptoms are common in Parkinson's disease (PD). The relationships between autophagy and PD or depression have been documented. However, no studies explored the role of autophagy markers associated with depressive symptoms in PD. Our study aimed to investigate the relationships between autophagy markers, cognitive impairments and depressive symptoms in PD patients. A total of 163 PD patients aged 50-80 years were recruited. Plasma concentrations of autophagy markers (LC3-I, LC3-II and p62/SQSTM1) and glycolipid parameters were measured. Depressive symptoms, cognitive impairments, and motor function were assessed using the Hamilton Depression Rating Scale-17 (HAMD-17), the Montreal Cognitive Assessment (MoCA), and the Movement Disorders Society Unified Parkinson's Rating Scale Part III (MDS-UPDRS-III), respectively. There were no significant differences between depressed and non-depressed PD patients for LC3-I, LC3-II, LC3-II/LC3-I and p62/SQSTM1. After controlling confounding variables, LC3-II/LC3-I showed an independent relationship with depressive symptoms in PD patients (Beta = 10.082, t = 2.483, p = 0.014). Moreover, in depressive PD patients, p62/SQSTM1 was associated with MoCA score (Beta = - 0.002, t = - 2.380, p = 0.020); Further, p62/SQSTM1 was related to naming ability; in addition, p62/SQSTM1 was independently associated with delayed recall (Beta = - 0.001, t = - 2.452, p = 0.017). LC3-II/LC3-I was related to depressive symptoms in PD patients. In depressive PD patients, p62/SQSTM1 was associated with cognitive function, especially naming ability and delayed recall.

Aucubin alleviates methotrexate-induced enteritis in rats by inducing autophagy

One of the toxic side effects of methotrexate (MTX) is enteritis. Aucubin, an iridoid glycoside derived from traditional medicinal herbs, has been proven to have anti-inflammation, anti-apoptosis and anti-oxidation properties. This work explored the effect and mechanism of aucubin in treating MTX-induced enteritis in a rat model. Two doses of aucubin (5 and 10 mg/kg) were adopted for the assessment of its pharmacological activity. We observed that in rats with MTX-induced enteritis, the body weight and small intestinal weight decreased. The intestine barrier was injured, as reflected by pathological examinations and an increase in D-lactate and diamine oxidase concentration in serum. Intestinal inflammation was shown by the observation of macrophages in the intestine and the concentrations of inflammatory cytokines tumour necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in serum. The NLR family pyrin domain containing 3 (NLRP3) inflammasome was shown to be activated by the enhancement of NLRP3, cleaved-caspase 1, IL-18 and IL-1β. Moreover, autophagy was reflected by transmission electron microscopy as slightly induced, along with changes in autophagy-related markers microtubule-associated protein 1 light chain 3 (LC3) and Beclin1. Remarkably, aucubin treatment attenuated the MTX-induced disease activity index increase, intestinal damage, inflammatory response and NLRP3 inflammasome activation, but provoked autophagy. Rapamycin, an autophagy activator, showed similar therapeutic effects to aucubin on MTX-induced enteritis. However, 3-methyladenine, an autophagy inhibitor, reversed the protective effects of aucubin. These findings prompted the hypothesis that aucubin alleviates MTX-induced enteritis by aggravating autophagy. This study might provide evidence for further investigation on the therapeutic role of aucubin in MTX-resulted enteritis.

Therapeutic effects of methimazole on 3,4-methylenedioxymethamphetamine-induced hyperthermia and serotonergic neurotoxicity

3,4-methylenedioxymethamphetamine (MDMA) is a popular recreational drug, however over 200 studies demonstrate that acute (e.g. hyperthermia, rhabdomyolysis) and chronic (e.g. neurotoxicity) toxicity effects of MDMA were observed in different animals. Methimazole (MMI), an inhibitor of thyroid hormone synthesis, was found to significantly reduce the HSP72 expression of heat stress induced in fibroblasts. Hence, we attempted to understand the effects of MMI on MDMA induced changes in vivo. Male SD rats were randomly divided into four groups as follows:(a) water-saline (b) water-MDMA (c) MMI-saline and (d) MMI-MDMA group. In the temperature analysis test, MMI was found to alleviate MDMA-induced hyperthermia and increase the heat loss index (HLI), revealing its peripheral vasodilation effect. PET experiment suggested that MDMA induced elevated glucose uptake by skeletal muscles, which was resolved by MMI pretreatment. IHC staining (serotonin transporter, SERT) showed the evidence of neurotoxicity caused by MDMA (serotonin fiber loss), which was alleviated by MMI. Furthermore, the animal behaviour test (forced swimming test, FST) showed higher swimming time but lower immobility time in MMI-MDMA and MMI-saline groups. Taken together, treatment of MMI shows benefits such as lowered body temperature, alleviation of neurotoxicity and excited behaviour. However, further investigations should be conducted in the future to provide in-depth evidence for its clinical use.

Blocking coprophagy increases the levels of inflammation and depression in healthy mice as well as mice receiving fecal microbiota transplantation from disease model mice donors

Rodents have been extensively used as animal models in microbiome studies. However, all rodents have a habitual nature called coprophagy, a phenomenon that they self-reinoculate feces into their gastrointestinal tract. Recent studies have shown that blocking coprophagy can alter rodents' diversity of gut microbiota, metabolism, neurochemistry, and cognitive behavior. However, whether rodents' coprophagy behavior affects the levels of inflammation and depression is unclear. In order to address this problem, we first blocked coprophagy in healthy mice. It displayed an increase in the levels of depression, verified by depressive-like behaviors and mood-related indicators, and inflammation, verified by the increased levels of the pro-inflammatory cytokine, in coprophagy-blocked mice. Furthermore, we transplanted fecal microbiota from chronic restraint stress (CRS) depression model mice and lipopolysaccharide (LPS) inflammation model mice to healthy recipient mice, respectively. It showed that the disease-like phenotypes in the coprophagy-blocked group were worse than those in the coprophagy-unblocked group, including severer depressive symptoms and higher levels of pro-inflammatory cytokines (IL-1β, IL-6, TNF-α and IFN-γ) in serum, prefrontal cortex (PFC), and hippocampus (HIP). These findings showed that blocking coprophagy in mice not only increased the levels of inflammation and depression in healthy mice but also aggravated inflammation and depression induced by fecal microbiota from disease donors. The discovery may provide a vital reference for future research involving FMT in rodents.

Silent information regulator 1 mediates H 2 S-inhibited chronic restraint stress-induced depressive-like behaviors by regulating hippocampal autophagy

OBJECTIVES

Our previous study has demonstrated that hydrogen sulfide (H 2 S), a novel gasotransmitter, attenuates excessive autophagy and depressive-like behaviors in chronic restraint stress (CRS)-exposed rats, but the underlying molecular mechanism remains to be elucidated. Silent information regulator 1 (SIRT1), a deacetylase at the consumption of NAD+ plays an important regulatory role in depression. Hence, this study aimed to investigate whether SIRT1 mediates the protective effect of H 2 S on CRS-induced depressive-like behaviors by regulating hippocampal autophagy.

METHODS

Adult male Sprague-Dawley (SD) rats were subjected to CRS (6 h × 28 days) to induce depression-like behavior. Rats were injected with sodium hydrosulfate (NaHS, 100 μmol/kg/d, i.p.), as a donor of H 2 S, alone or in combination with Sirtinol (a SIRT1 inhibitor; 10 nmol, i.c.v.) during CRS process. The depression-like characteristics of rats were assessed by the novelty-suppressed feeding test (NSFT), tail suspension test (TST), forced swimming test (FST) and open field test (OFT). The number of hippocampal autophagosomes was detected by transmission electron microscopy. The expressions of hippocampal autophagy-related proteins were measured by western blotting analysis.

RESULTS

Sirtinol blocked the inhibitory effect of H 2 S on depressive-like behaviors in CRS-exposed rats according to NSFT, TST, FST and OFT. In addition, sirtinol reversed the protective response of H 2 S to CRS-induced excessive autophagy, as proved by the increases in the number of autophagosomes and the expression of Beclin-1 as well as a decrease in the expression of P62 in the hippocampus.

CONCLUSION

These results indicated that SIRT1 contributes to the antidepressant-like function of H 2 S during CRS via reducing hippocampal autophagy.

Oridonin relieves depressive-like behaviors by inhibiting neuroinflammation and autophagy impairment in rats subjected to chronic unpredictable mild stress

Major depressive disorder (MDD) is a severe life-threatening disorder with increasing prevalence. However, the mechanistic interplay between depression, neuroinflammation, and autophagy is yet to be demonstrated. This study investigated the effect of Oridonin on CUMS-induced depression, neuroinflammation, and autophagy impairment. Male 4-week-old Sprague-Dawley rats were subjected to chronic unpredictable mild stress (CUMS), some of which were injected with Oridonin, fluoxetine (FLX), or their combination at different durations of CUMS. CUMS significantly increased the levels of cytokines (IL-1β, IL-18, and caspase-1), reduced autophagy-related protein levels (Beclin-1, p62, Atg5, and LC3B), and caused microglia cells activation. Oridonin prevented and reversed the depressive-like behavior. Furthermore, it has a stronger and longer-lasting antidepressant effect than FLX. And the antidepressant effect of Oridonin in combination with fluoxetine was greater than that of high-dose fluoxetine alone. In addition, Oridonin significantly normalized autophagy-related protein levels, and reduced levels of cytokines by blocking the interaction between NLRP3 and NEK7. Similarly, Oridonin abolished levels of cytokines and reversed autophagy impairment in LPS-activated BV2 cells. All these results supported our hypothesis that Oridonin possesses potent anti-depressive action, which might be mediated via inhibition of neuroinflammation and autophagy impairment by blocking the interaction between NLRP3 and NEK7.

3,4-Methylenedioxymethamphetamine (MDMA) Model: In Vivo 4-[18F]-ADAM PET Imaging

Numerous studies have confirmed that 3,4-Methylenedioxymethamphetamine (MDMA) produces long-lasting changes to the density of the serotonin reuptake transporter (SERT). Amitriptyline (AMI) has been shown to exert neuroprotective properties in neuropathologic injury. Here, we used a SERT-specific radionuclide, 4-[¹⁸F]-ADAM, to assess the longitudinal alterations in SERT binding and evaluate the synergistic neuroprotective effect of AMI in a rat MDMA model. In response to MDMA treatment regimens, SERT binding was significantly reduced in rat brains. Region-specific recovery rate (normalized to baseline) in the MDMA group at day 14 was 71.29% ± 3.21%, and progressively increased to 90.90% ± 7.63% at day 35. AMI dramatically increased SERT binding in all brain regions, enhancing average ~18% recovery rate at day 14 when compared with the MDMA group. The immunochemical staining revealed that AMI markedly increased the serotonergic fiber density in the cingulate and thalamus after MDMA-induction, and confirmed the PET findings. Using in vivo longitudinal PET imaging, we demonstrated that SERT recovery was positively correlated with the duration of MDMA abstinence, implying that lower SERT densities in MDMA-induced rats reflected neurotoxic effects and were (varied) region-specific and reversible. AMI globally accelerated the recovery rate of SERT binding and increased SERT fiber density with possible neuroprotective effects.

Xiaoyaosan Exerts Antidepressant-Like Effect by Regulating Autophagy Involves the Expression of GLUT4 in the Mice Hypothalamic Neurons

Many studies have proven that autophagy plays a pivotal role in the development of depression and it also affects the expression of GLUT4 in the hypothalamus. Xiaoyaosan has been shown to exert antidepressant effects in a variety of ways, but its underlying mechanism by which Xiaoyaosan regulates autophagy as well as GLUT4 in the hypothalamus remains unclear. Thus, in this study, we established a mouse model of depression induced by chronic unpredictable mild stress (CUMS), and set up autophagy blockade as a control to explore whether Xiaoyaosan exerts antidepressant effect by affecting autophagy. We examined the effects of Xiaoyaosan on behaviors exhibited during the open field test, tail suspension test and sucrose preference test, and the changes in autophagy in hypothalamic neurons as well as changes in GLUT4 and the related indicators of glucose metabolism in CUMS-induced depressive mouse model. We found that CUMS- and 3-MA-induced mice exhibited depressive-like behavioral changes, with decreased LC3 expression and increased p62 expression, suggesting decreased levels of autophagy in the mouse hypothalamus. The expression of GLUT4 was also decreased, and it was closely related to the level of autophagy through Rab8 and Rab10. Nevertheless, after the intervention of Xiaoyaosan, the above changes were effectively reversed. These results show that Xiaoyaosan can regulate the autophagy in hypothalamic neurons and the expression of GLUT4 in depressed mice.

Deficient Autophagy in Microglia Aggravates Repeated Social Defeat Stress-Induced Social Avoidance

Major depressive disorder (MDD) is associated with repeated exposure to environmental stress. Autophagy is activated under various stress conditions that are associated with several diseases in the brain. This study was aimed at elucidating the autophagy signaling changes in the prefrontal cortex (PFC) under repeated social defeat (RSD) to investigate the involvement of microglial autophagy in RSD-induced behavioral changes. We found that RSD stress, an animal model of MDD, significantly induced initial autophagic signals followed by increased transcription of autophagy-related genes (Atg6, Atg7, and Atg12) in the PFC. Similarly, significantly increased transcripts of ATGs (Atg6, Atg7, Atg12, and Atg5) were confirmed in the postmortem PFC of patients with MDD. The protein levels of the prefrontal cortical LC3B were significantly increased, whereas p62 was significantly decreased in the resilient but not in susceptible mice and patients with MDD. This indicates that enhanced autophagic flux may alleviate stress-induced depression. Furthermore, we identified that FKBP5, an early-stage autophagy regulator, was significantly increased in the PFC of resilient mice at the transcript and protein levels. In addition, the resilient mice exhibited enhanced autophagic flux in the prefrontal cortical microglia, and the autophagic deficiency in microglia aggravated RSD-induced social avoidance, indicating that microglial autophagy involves stress-induced behavioral changes.

Involvement of the microbiota-gut-brain axis in chronic restraint stress: disturbances of the kynurenine metabolic pathway in both the gut and brain

Emerging evidence suggests that the gut microbiota may interact with the host brain and play pivotal roles in the pathogenesis of neuropsychiatric disorders. However, the mechanism underlying reciprocal interactions along the microbiota-gut-brain axis in depression remains unclear. In this study, a murine model of chronic restraint stress (CRS) was established to investigate the metabolic signaling of tryptophan (Trp) neurotransmission at the intestinal and central levels in depression. The results showed that CRS mice displayed depression- and anxiety-like behaviors. Additionally, kynurenine (Kyn) and its metabolites, an important Trp metabolic pathway, were strongly activated in the brain. Intriguingly, the Kyn toxic signaling was exacerbated in the gut, especially in the colon. Indoleamine 2,3-dioxygenase (IDO), a rate-limiting enzyme responsible for Kyn metabolic pathway initiation, was significantly upregulated in the brain and gut in CRS mice compared with control mice, promoting transfer of Trp metabolic pathway to Kyn signaling. Additionally, administration of IDO inhibitor, 1-methyl-tryptophan (1-MT), partially rescued CRS-induced depression- and anxiety-like changes. Moreover, the enhanced intestinal permeability mediated by CRS allowed toxic metabolites to "leak" into the bloodstream. The microbiome profiles of CRS mice displayed obviously altered taxonomic composition and negative correlations were observed between Enterorhabdus, Parabacteroides and Kyn levels in the brain. Reciprocal crosstalk between the brain and gut was further validated by citalopram treatment, IDO inhibitor and microbiota intervention, which counteracted depression-like behavior, Kyn metabolic signaling and microbiota composition in CRS mice. Meanwhile, Parabacteroides treatment affected Trp metabolism in mouse hippocampus, manifesting as elevated concentration of 5-HT as well as ratio of 5-HT to Trp. These results suggest that long-term stress disrupts Kyn metabolism and endocrine function along the gut-brain axis, accompanied by the disrupted homeostasis of certain microbiota, which collectively contribute to the development of depression-like behavior.

MDMA and memory, addiction, and depression: dose-effect analysis

RATIONALE

±3,4-Methylenedioxymethamphetamine (MDMA) is a recreational drug that shows substantial promise as a psychotherapeutic agent. Still, there is some concern regarding its behavioral toxicity, and its dose-effect relationship is poorly understood. We previously explored the role of dose in the cognitive effects of MDMA in a systematic review of existing literature and found no evidence in animals that MDMA impairs memory at low doses (< 3 mg/kg) but mixed results at high doses (≥ 3 mg/kg). Since this review comprised mostly of single-dose studies and an assortment of methodologies, an empirical dose-ranging study on this topic is warranted.

OBJECTIVES

The current study aims to evaluate the conclusion from our systematic review that 3 mg/kg may be the threshold for MDMA-induced amnesia, and to further understand the dose-effect relationship of MDMA on behavioral assays of memory, addiction, and depression.

METHODS

We systematically examined the effects of 0.01 to 10 mg/kg MDMA on Pavlovian fear conditioning; behavioral sensitization, conditioned place preference, and conditioned responding; and the Porsolt forced swim test in mice.

RESULTS

High doses of MDMA (≥ 3 mg/kg) produced amnesia of fear conditioning memory, some evidence of an addictive potential, and antidepressant effects, while low doses of MDMA (≤ 1 mg/kg) had no effect on these behaviors.

CONCLUSIONS

The present dose-ranging study provides further evidence that 3 mg/kg is the threshold for MDMA-induced amnesia. These findings, in addition to our systematic review, demonstrate that careful selection of MDMA dose is critical. High doses (≥ 3 mg/kg) should likely be avoided due to evidence that they can produce amnesia and addiction. Conversely, there is little evidence to suggest that low doses, which are usually administered in clinical studies (approximately 1-2 mg/kg), will lead to these same adverse effects. Ultra-low doses (< 1 mg/kg) are likely even safer and should be investigated for therapeutic effects in future studies.

NLRP3 inflammasome inhibition by histone acetylation ameliorates sevoflurane-induced cognitive impairment in aged mice by activating the autophagy pathway

Age-related cognitive impairment is associated with diminished autophagy and progressively increased neuroinflammation. Histone acetylation has been shown to be a key process in sevoflurane-induced neurobehavioral abnormalities. Here, we investigated whether histone acetylation regulates the interaction between autophagy and the NLRP3 inflammasome in models of sevoflurane-induced cognitive impairment and explored the underlying molecular mechanisms. Aged C57BL/6 J mice and cultured primary hippocampal neurons were exposed to 3% sevoflurane for 2 h. Hippocampal tissue samples and hippocampal neurons were harvested. The processes of histone acetylation and autophagy and the activation of the NLRP3 inflammasome were observed using western blotting, immunofluorescence staining, and transmission electron microscopy. Suberoylanilide hydroxamic acid (SAHA), an inhibitor of histone deacetylases, increased histone H3 and H4 acetylation in both the mouse hippocampus and primary neurons. Concomitantly, sevoflurane upregulated components of the NLRP3 inflammasome (NLRP3, cleaved caspase-1, and IL-1β) by promoting autophagic degradation in the aging brain. Cognitive deficits and inadequate autophagy induced by sevoflurane were reversed and NLRP3 inflammasome activation was inhibited by SAHA. Treatment with 3-MA, an autophagy inhibitor, eliminated the neuroprotective effects of SAHA on improving cognition in mice, activating autophagy and downregulating the NLRP3 inflammasome. Based on these results, histone acetylation activates autophagy plays an important role in inhibiting the activation of the NLRP3 inflammasome to protect the host from excessive neuroinflammation and sevoflurane-induced cognitive dysfunction in the aging brain.

Beyond ecstasy: Alternative entactogens to 3,4-methylenedioxymethamphetamine with potential applications in psychotherapy

The last two decades have seen a revival of interest in the entactogen 3,4-methylenedioxy-N-methylamphetamine (MDMA) as an adjunct to psychotherapy, particularly for the treatment of post-traumatic stress disorder. While clinical results are highly promising, and MDMA is expected to be approved as a treatment in the near future, it is currently the only compound in its class of action that is being actively investigated as a medicine. This lack of alternatives to MDMA may prove detrimental to patients who do not respond well to the particular mechanism of action of MDMA or whose treatment calls for a modification of MDMA's effects. For instance, patients with existing cardiovascular conditions or with a prolonged history of stimulant drug use may not fit into the current model of MDMA-assisted psychotherapy, and could benefit from alternative drugs. This review examines the existing literature on a host of entactogenic drugs, which may prove to be useful alternatives in the future, paying particularly close attention to any neurotoxic risks, neuropharmacological mechanism of action and entactogenic commonalities with MDMA. The substances examined derive from the 1,3-benzodioxole, cathinone, benzofuran, aminoindane, indole and amphetamine classes. Several compounds from these classes are identified as potential alternatives to MDMA.

Sinisan Protects Primary Hippocampal Neurons Against Corticosterone by Inhibiting Autophagy via the PI3K/Akt/mTOR Pathway

Objective: Corticosterone causes significant neurotoxicity in primary hippocampal neurons which is associated with depression. Dysfunctional autophagy is implicated in cognitive impairment and depressive-like behavior. The traditional Chinese medicine Sinisan (SNS) is highly effective in clinical treatment of depression. However, the molecular mechanisms underlying therapeutic effects of SNS are unknown. Purpose: The aim of this study was to elucidate the protective effect of SNS and the underlying mechanisms against corticosterone-induced neuronal damage. Study Design: The effects of serum derived from rats containing SNS (or untreated controls) on the expression of autophagy-related molecules in primary rat hippocampal neurons exposed to different concentrations of corticosterone for different intervals were explored. Methods: CCK-8 assay, LDH assay were used to analyze cell viability and LDH activity. Western blot, qRT-PCR, and immunofluorescence assays were used to determine protein and mRNA expression levels of molecules such as LC3, p62, Beclin1, ULK1, PI3K, p-PI3K, Akt p-Akt, mTOR, p-mTOR, p70S6, p-p70S6, 4ebp1 and p-4ebp1. Results: Corticosterone induced a dose- and time-dependent reduction in cellular viability. Moreover, corticosterone (100-400 μM) treatment for 24 h increased LC3-II/LC3-I protein ratio, increased Beclin1 and ULK1 protein expression levels, and decreased p62, PI3K, p-PI3K, p-Akt, p-mTOR, p-p70S6, and p-4ebp1 protein expression levels. Notably, SNS-containing serum reversed corticosterone-induced reduction of neuronal viability, and increased p62, PI3K, p-Akt, p-mTOR, p-p70S6, and p-4ebp1 protein and mRNA expression levels. In addition, SNS-containing serum decreased LC3-II/LC3-I protein ratio, and downregulated Beclin1, and ULK1 protein and mRNA expression in primary hippocampal neurons. Conclusion: SNS protects primary hippocampal neurons against corticosterone-induced neurotoxicity by preventing excessive autophagy through activation of PI3K/AKT/mTOR pathway.

Stress and signaling pathways regulating autophagy: From behavioral models to psychiatric disorders

Autophagy is a process of degradation and recycling of cytoplasmatic components by the lysosomes. In the central nervous system (CNS), autophagy is involved in cell surveillance, neuroinflammation, and neuroplasticity. Neuropsychiatric conditions are associated with functional disturbances at molecular and cellular levels, causing significant impairments in cell homeostasis. Additionally, emerging evidence supports that dysfunctions in autophagy contribute to the pathophysiology of neurological diseases. However, the studies on autophagy in psychiatric disorders are highly heterogeneous and have several limitations, mainly to assess causality and determine the autophagy flux in animals and human samples. Besides, the role of this mechanism in non-neuronal cells in the CNS is only recently being explored. Thus, this review summarizes and discusses the changes in the autophagy pathway in animal models of psychiatric disorders and the limitations underlying the significant findings. Moreover, we compared these findings with clinical studies. Understanding the involvement of autophagy in psychiatric conditions, and the limitation of our current models may contribute to the development of more effective research approaches and possibly pharmacological therapies.

Delayed treatment with an autophagy inhibitor 3-MA alleviates the progression of hyperuricemic nephropathy

Autophagy is a cell self-renewal process that relies on the degradation of the cytoplasmic proteins or organelles of lysosomes and is associated with development of numerous diseases. However, the therapeutic effect of autophagy inhibition on hyperuricemic nephropathy (HN) and the underlying mechanisms are still unknown. Here, we investigated the effect of delayed treatment with 3-methyladenine (3-MA), a specific autophagy inhibitor, on the development of HN in a rat model. Administration of 3-MA at 21 days following after uric acid injury protected kidney from hyperuricemic-related injuries, as demonstrated by improving renal dysfunction and architecture damage, blocking Beclin-1 and LC3II/I and decreasing the number of autophagic vacuoles. Late treatment with 3-MA was also effective in attenuating renal fibrosis as evidenced by reducing ECM protein deposition, blocking epithelial-to-mesenchymal transition (EMT) and decreasing the number of renal epithelial cells arrested at the G2/M phase of cell cycle. Injury to the kidney resulted in increased expression of TGFβ receptor I, and phosphorylation of Smad3, 3-MA significantly abrogated all these responses. Moreover, inhibition of autophagy suppressed mitochondrial fission, downregulated the expression of Dynamin-related protein 1 (Drp-1), Cofilin and F-actin, and alleviated cell apoptosis. Finally, 3-MA effectively blocked STAT3 and NF-κB phosphorylation and suppressed infiltration of macrophages and lymphocytes as well as release of multiple profibrogenic cytokines/chemokines in the injured kidney. Taken together, these findings indicate that hyperuricemia-induced autophagy is critically involved in the activation of renal fibroblasts, EMT, mitochondrial fission and apoptosis of tubular epithelial cells and development of renal fibrosis. Thus, this study provides evidence for autophagy inhibitors as the treatment of HN patients.

Is There a Role of Autophagy in Depression and Antidepressant Action?

Autophagy has been recognized as evolutionary conserved intracellular pathway that ensures energy, organelle, and protein homeostasis through lysosomal degradation of damaged macromolecules and organelles. It is activated under various stress situations, e.g., food deprivation or proteotoxic conditions. Autophagy has been linked to several diseases, more recently also including stress-related diseases such as depression. A growing number of publications report on the role of autophagy in neurons, also referred to as "neuronal autophagy" on the one hand, and several studies describe effects of antidepressants-or of compounds that exert antidepressant-like actions-on autophagy on the other hand. This minireview highlights the emerging evidence for the involvement of autophagy in the pathology and treatment of depression and discusses current limitations as well as potential avenues for future research.