Depression caused by long-term stress regulates premature aging and is possibly associated with disruption of circadian rhythms in mice

The impact of life stress on hallmarks of aging and accelerated senescence: Connections in sickness and in health

Chronic stress is a risk factor for numerous aging-related diseases and has been shown to shorten lifespan in humans and other social mammals. Yet how life stress causes such a vast range of diseases is still largely unclear. In recent years, the impact of stress on health and aging has been increasingly associated with the dysregulation of the so-called hallmarks of aging. These are basic biological mechanisms that influence intrinsic cellular functions and whose alteration can lead to accelerated aging. Here, we review correlational and experimental literature (primarily focusing on evidence from humans and murine models) on the contribution of life stress - particularly stress derived from adverse social environments - to trigger hallmarks of aging, including cellular senescence, sterile inflammation, telomere shortening, production of reactive oxygen species, DNA damage, and epigenetic changes. We also evaluate the validity of stress-induced senescence and accelerated aging as an etiopathological proposition. Finally, we highlight current gaps of knowledge and future directions for the field, and discuss perspectives for translational geroscience.

Chronic restraint stress-induced depression-like behavior is mediated by upregulation of melanopsin expression in C57BL/6 mice retina

BACKGROUND

Depression is associated with circadian disturbances in which melanopsin was a key mechanism. Further studies have demonstrated that melanopsin gene variations are associated with some depressive disorders and aberrant light can impair mood through melanopsin-expressing retinal ganglion cells (mRGCs). The goal of this study was to explore the direct relationship between depression and melanopsin.

METHODS

Adult C57BL/6 male mice were physically restrained for 16 h in a 50-ml polypropylene centrifuge tube and all behavioral tests were performed after CRS treatment. Western blot analysis and immunofluorescence were used to detect melanopsin expression in the retina of C57BL/6 mice. And we observed the change of the electrophysiological function and release of glutamate of mRGCs.

RESULTS

The melanopsin expression upregulate in mRGCs of chronic restraint stress (CRS)-treating mice which exhibit depression-like behavior. The frequency of blue light-induced action potentials and light-induced glutamate release mediated by melanopsin also increase significantly. This change of melanopsin is mediated by the CRS-induced glucocorticoid.

CONCLUSIONS

CRS may induce the depression-like behavior in mice via glucocorticoid-melanopsin pathway. Our findings provide a novel mechanistic link between CRS-induced depression and melanopsin in mice.

The sex-dependent response to psychosocial stress and ischaemic heart disease

Stress is an important risk factor for modern chronic diseases, with distinct influences in males and females. The sex specificity of the mammalian stress response contributes to the sex-dependent development and impacts of coronary artery disease (CAD). Compared to men, women appear to have greater susceptibility to chronic forms of psychosocial stress, extending beyond an increased incidence of mood disorders to include a 2- to 4-fold higher risk of stress-dependent myocardial infarction in women, and up to 10-fold higher risk of Takotsubo syndrome-a stress-dependent coronary-myocardial disorder most prevalent in post-menopausal women. Sex differences arise at all levels of the stress response: from initial perception of stress to behavioural, cognitive, and affective responses and longer-term disease outcomes. These fundamental differences involve interactions between chromosomal and gonadal determinants, (mal)adaptive epigenetic modulation across the lifespan (particularly in early life), and the extrinsic influences of socio-cultural, economic, and environmental factors. Pre-clinical investigations of biological mechanisms support distinct early life programming and a heightened corticolimbic-noradrenaline-neuroinflammatory reactivity in females vs. males, among implicated determinants of the chronic stress response. Unravelling the intrinsic molecular, cellular and systems biological basis of these differences, and their interactions with external lifestyle/socio-cultural determinants, can guide preventative and therapeutic strategies to better target coronary heart disease in a tailored sex-specific manner.

The effect of different ammonium to nitrate ratios on antioxidant activity, morpho-physiological and phytochemical traits of Moldavian balm (Dracocephalum moldavica)

Improving yield and secondary metabolites production of medicinal plants through nutrition management recently has been considered. The present study was done to determine the effects of different ammonium (NH₄⁺) to nitrate (NO₃^-) ratios (100:0, 75:25, 50:50, 25:75, 0:100) on morphophysiological, nutrient contents (N, P, K, Ca, and Mg), phenolic compounds (Total phenolics (TPC) and flavonoid (TFC) contents and individual phenolics including chlorogenic acid, rosmarinic acid, gallic acid, cinnamic acid, caffeic acid, rutin, p-Coumaric acid, apigenin, and quercetin by HPLC-DAD), essential oil composition (by GC and GC-MS), and antioxidant capacity (by DPPH and FRAP assays) of Moldavian balm (Dracocephalum moldavica L.) in deep water culture (DWC) system. The highest biomass and morphological traits values of D. moldavica observed in 0:100 ratio of NH₄⁺:NO₃^-. Also, the highest TPC and TFC was earned in plants that supplied with 0:100 ratio of NH₄⁺:NO₃^-. Using the 25:75 ratio of NH₄⁺:NO₃^- caused the highest nutrient contents (N, Ca and Mg) in the leaves. p-Coumaric acid was detected as the major abundant phenolic compound in extracts and the application of 75:25 ratio of NH₄⁺:NO₃ resulted in the highest amounts of p-Coumaric acid, gallic acid, rosmarinic acid, caffeic acid, quercetin, and rutin. The highest antioxidant capacity by both FRAP and DPPH assays was obtained in 75:25 ratio of NH₄⁺:NO₃^-. Also, the highest geranial and geranyl acetate, geraniol, and neral were obtained in 75:25, 25:75, and 50:50 ratios of NH₄⁺:NO₃^-, respectively. Plants supplied with the 0:100 ratio of NH₄⁺:NO₃^-, had the highest total carotenoids, while the highest chlorophyll a and b content gained with 75:25 ratio of NH₄⁺:NO₃^-. These results suggest that the management of N source in nutrient recipe could contribute to enhance of morphophysiological traits, antioxidant activity and phytochemical compounds in Moldavian balm.

Hydroxy-β-sanshool isolated from Zanthoxylum piperitum (Japanese pepper) shortens the period of the circadian clock

We showed that an ethanol extract from Zanthoxylum piperitum can shorten the circadian rhythm at the cellular level and that this activity was due to hydroxy-β-sanshool, a secondary metabolite in this plant. An ethanol extract of Z. piperitum was repeatedly fractionated using solid phase extraction and reverse-phase HPLC, then the circadian rhythms of cells to which the fractions were loaded were monitored using real-time reporter gene assays. We purified one HPLC peak and identified it as hydroxy-β-sanshool using liquid chromatography (LC)-precision-mass spectrometry (MS). This compound shortened the period of Bmal1 and Per2 at the cellular level. Incubation cells for 24 h with hydroxy-β-sanshool resulted in upregulated Per2 promoter activity. Hydroxy-β-sanshool also dose-dependently upregulated expression of the clock genes Bmal1, Per1, Per2 and Cry1 and the clock-controlled oxidative stress responsive genes Gpx1and Sod2.

Quercetin: A Molecule of Great Biochemical and Clinical Value and Its Beneficial Effect on Diabetes and Cancer

Quercetin belongs to the broader category of polyphenols. It is found, in particular, among the flavonols, and along with kaempferol, myricetin and isorhamnetin, it is recognized as a foreign substance after ingestion in contrast to vitamins. Quercetin occurs mainly linked to sugars with the most common compounds being quercetin-3-O-glucoside or as an aglycone, especially in the plant population. The aim of this review is to present a recent bibliography on the mechanisms of quercetin absorption and metabolism, bioavailability, and antioxidant and the clinical effects in diabetes and cancer. The literature reports a positive effect of quercetin on oxidative stress, cancer, and the regulation of blood sugar levels. Moreover, research-administered drug dosages of up to 2000 mg per day showed mild to no symptoms of overdose. It should be noted that quercetin is no longer considered a carcinogenic substance. The daily intake of quercetin in the diet ranges 10 mg-500 mg, depending on the type of products consumed. This review highlights that quercetin is a valuable dietary antioxidant, although a specific daily recommended intake for this substance has not yet been determined and further studies are required to decide a beneficial concentration threshold.

Mitophagy in depression: Pathophysiology and treatment targets

Mitochondria, the 'powerhouse' of eukaryotic cells, play a key role in cellular homeostasis. However, defective mitochondria increase mitochondrial ROS (mtROS) production and cell-free mitochondrial DNA (mtDNA) release, leading to increased inflammation. Mitophagy is a vital pathway, which selectively removes defective mitochondria through the process of autophagy. Thus, an impairment in the mitophagy pathway might trigger the gradual accumulation of defective mitochondria. Accumulating evidence suggest that inflammation and mitochondrial dysfunction are linked to the pathogenesis of depression. In this article, we have reviewed the role of impaired mitophagy as a contributing factor in depression pathophysiology. Further, we have discussed the potential therapeutic interventions aimed at modulating mitophagy in depression.

Potential Therapeutic Effects of New Ruthenium (III) Complex with Quercetin: Characterization, Structure, Gene Regulation, and Antitumor and Anti-Inflammatory Studies (RuIII/Q Novel Complex Is a Potent Immunoprotective Agent)

The aim of this study was to evaluate the antioxidant and anti-inflammatory effects of the new [Ru(Q)(Cl)2(H2O)2] complex (RuIII/Q). A new vital complex containing quercetin flavonoid compound (Q) with ruthenium (III) ions was synthesized. The molar conductivity of the RuIII/Q complex was measured in dimethylsulfoxide (DMSO) with value 12 (Ω−1 mol−1 cm−1, indicating their non-electrolytic nature. Infrared (FTIR) spectroscopic investigation of the RuIII/Q complex indicated that Q is coordinated as a bidentate with Ru metal ions through the oxygen of carbonyl C(4)=O group and oxygen of phenolic C(3)−O group based on the wavenumber shifts at 1654 and 1335 cm−1 respectively. The electronic (UV−Vis) spectra and the magnetic susceptibility value (1.85 B.M.) revealed that the Ru(III) complex has an octahedral geometry. The average diameter of the RuIII/Q nanoparticles was approximately 7–15 nm according to the transmission electron microscopy. The thermogravimetric study (TG/DTG) indicates that the RuIII/Q compound is quite stable until 300 °C. To assess biological activity, 60 male rats were allocated to six groups, namely control, DG (D-galactose), Q, RuIII/Q, DG plus Q, and DG plus RuIII/Q. Antioxidant enzymes (SOD, CAT, GPx, and GRx), markers of lipid peroxidation (such as MDA), expression of genes (namely Nrf2, Cu-ZnSOD, CAT, GPx, cyto c, P53, Bax, BCl2, caspase-3, and caspase-9 in testicular tissue), glutamate, 4-hydroxynonenal (HNE), GSH, HCY, amyloid beta, and GABA levels were evaluated in brain tissues. Cytokines, such as IL-6 and TNF-α, histological and ultrastructural studies were estimated in both the brain and testicular tissues, while the comet assay was performed in the brain tissue. RuIII/Q administration either alone or combined with DG reduced oxidative injury to normal levels and decreased apoptotic activities. Thus, RuIII/Q inhibited injury in both the testis and brain and reduced oxidative stress in male rats. The (RuIII/Q) complex has a potent ameliorative effect against aging neurotoxicity, reproductive toxicity, and antihepatic cancer activity induced by D-galactose (DG).

Metformin Attenuates the Metabolic Disturbance and Depression-like Behaviors Induced by Corticosterone and Mediates the Glucose Metabolism Pathway

BACKGROUND

Metabolism disturbances are common in patients with depression. The drug metformin has been reported to exhibit antidepressant activity. The purpose of this study was to investigate metabolism disturbances induced by corticosterone (CORT) and determine if metformin can reverse these effects and their accompanying depression-like behaviors.

METHODS

Rats were exposed to corticosterone with or without metformin administration. Depression-like behaviors were tested. Gene expression was confirmed by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot analysis. In addition, the metabolites were quantified by LC-MS/MS analysis.

RESULTS

Metformin attenuated the depression-like behaviors induced by CORT. Furthermore, metformin reversed disturbances in body weight, serum glucose, and triglyceride levels, as well as hepatic TG levels induced by CORT. Metformin normalized the alterations in the expression of glucose metabolism-related genes (PGC-1α, G6pc, Pepck, Gck, PYGL, Gys2, PKLR, GLUT4) and insulin resistance-related genes (AdipoR1, AdipoR2) in the muscles and livers of rats induced by CORT. Metabolomic analysis showed that metformin reversed the effects of CORT on 11 metabolites involved in the pathways of the tricarboxylic acid cycle, glycolysis, and gluconeogenesis (3-phospho-D-glycerate, β-D-fructose 6-phosphate, D-glucose 6-phosphate, and pyruvate).

CONCLUSION

Our findings suggest that metformin can attenuate metabolism disturbances and depression-like behaviors induced by CORT mediating the glucose metabolism pathway.

Depression-like behaviors are accompanied by disrupted mitochondrial energy metabolism in chronic corticosterone-induced mice

Stress exerts its negative effects by interference with mitochondrial energy production in rodents, and is able to impair mitochondrial bioenergetics. However, the underlying mechanism that stress hormone impacts depression-like behaviors and mitochondrial energy metabolism is still not well understood. Here, we investigated the changes of depression-like behaviors and mitochondrial energy metabolism induced by chronic corticosterone (CORT). The results showed that after treatment with CORT for 6 weeks, mice displayed depression-like behaviors, which were identified by tail suspension test, forced swimming test and open field test. Then, the livers were isolated and tested by RNA sequencing and metabolome analysis. RNA sequencing showed 354 up-regulated genes and 284 down-regulated genes, and metabolome analysis revealed 280 metabolites with increased abundances and 193 metabolites with reduced abundances in the liver of mice after CORT, which were closely associated with lipid metabolism and oxidative phosphorylation in mitochondria. Based on these findings, the changes of mitochondrial energy metabolism were investigated, and we revealed that CORT condition inhibited glycolysis and fatty acid degradation pathway, and activated synthesis of triacylglycerol, leading to the reduced levels of acetyl-CoA and attenuated TCA cycle. Also, the pathways of NAD⁺ synthesis were inhibited, resulting in the reduced activity of sirtuin 3 (SIRT3). Thus, all of these observations disrupted the function of mitochondria, and led to the decrease of ATP production. Our findings uncover a novel mechanism of stress on depression-like behaviors and mitochondrial energy metabolism in rodents.

Nicotinamide mononucleotide ameliorates the depression-like behaviors and is associated with attenuating the disruption of mitochondrial bioenergetics in depressed mice

BACKGROUND

Nicotinamide mononucleotide (NMN) has been shown to stimulate oxidative phosphorylation in mitochondria and to improve various pathologies in patients and mouse disease models. However, whether NMN mediates mitochondrial energy production and its mechanism of action in depressed animals remain unclear.

METHODS

Mice were subcutaneously injected with corticosterone (CORT; 20 mg/kg) each day for 6 weeks, while another group was given an additional dose of NMN (300 mg/kg) by oral gavage in the last 2 weeks. Then, transcriptome analyses, metabolome analyses and transient gene knockdown in primary mouse cells were performed.

RESULTS

NMN administration alleviated depression-like behavior and the liver weight to body weight ratio in a mouse model of CORT-induced depression. Transcriptome and metabolome analyses revealed that in depressed mice, NMN reduced the mRNA expression of genes involved in fatty acid synthesis, stimulation of β-oxidation and glycolysis, and increased production of acetyl-coenzyme A for the tricarboxylic acid cycle. Importantly, NMN supplementation increased NAD⁺ levels to enhance sirtuin (SIRT)3 activity, thereby improving mitochondrial energy metabolism in the hippocampus and liver of CORT-treated mice. Sirt3knockdown in primary mouse astrocytes reversed the effect of NMN by inhibiting energy production, although it did not affect NAD⁺ synthesis LIMITATIONS: Group sample sizes were small, and only one type of primary mouse cell was used CONCLUSION: These results provide evidence for the beneficial role of NMN in energy production and suggest that therapeutic strategies that increase the level of NMN can be an effective treatment for depression.

Enhancing Catalytic Efficiency of an Actinoplanes utahensis Echinocandin B Deacylase through Random Mutagenesis and Site-Directed Mutagenesis

Echinocandin B deacylase (EBDA), from Actinoplanes utahensis ZJB-08196, is capable of cleaving the linoleoyl group from echinocandin B (ECB), forming the echinocandin B nucleus (ECBN), which is a key precursor of semisynthetic antifungal antibiotics. In the present study, molecular evolution of AuEBDA by random mutagenesis combined with site-directed mutagenesis (SDM) and screening was performed. Random mutagenesis on the wild-type (WT) AuEBDA generated two beneficial substitutions of G287Q, R527V. The "best" variant AuEBDA-G287Q/R527V was obtained by combining G287Q with R527V through SDM, which was most active at 35 °C, pH 7.5, with K_m and v_max values of 0.68 mM and 395.26 U/mg, respectively. Mutation of G287Q/R527V markedly increased the catalytic efficiency k_cat/K_m by 290% compared with the WT-AuEBDA.

The influence of titanium dioxide nanoparticles on their cellular response to macrophage cells

As the most widely application of nanomaterials in biology and medicine, their interaction with biological system and the afterwards cellular responses would be addressed. Here, the agglomerate states of two kinds of TiO₂ NPs in culture medium were characterized and the cluster specific cellular responses in RAW264.7 cells were investigated. Owing to the smaller aggregates and more positively charged surface, 21 nm TiO₂ NPs exhibited higher cytotoxicity, which correlated with their ability to cause damage to mitochondria. While for 35 nm TiO₂ NPs, higher level of cell autophagy and stronger pro-inflammatory immune response were observed, which are responsible for their lower cytotoxicity. These results suggest that physiochemical properties of TiO₂ NPs in culture medium are important factor affecting their cellular response to RAW264.7 cells.

Exposure to jet lag aggravates depression-like behaviors and age-related phenotypes in rats subject to chronic corticosterone

Our previous finding demonstrated that chronic corticosterone (CORT) may be involved in mediating the pathophysiology of premature aging in rats. Frequent jet lag increases the risk for many diseases, including obesity and type 2 diabetes, and is associated with the aging processes. However, the effect of jet lag on CORT-induced depression and its association with aging phenotypes remain unclear. In this study, the rats were exposed to both CORT and jet lag treatment, and the differences were analyzed and compared to rats with single CORT treatment. Our results showed that jet lag treatment aggravated CORT-induced depression-like behavior evidenced by sucrose intake test, forced swimming test, and open field test. Additionally, this treatment aggravated the shortening of telomeres, which possibly resulted in decreased telomerase activity, and downregulated the expression of telomere-binding factor 2 (TRF2) and telomerase reverse transcriptase compared to that in CORT rats, as revealed by quantitative real-time-polymerase chain reaction and western blot analysis, respectively. The shortening of telomeres may have been caused by increased oxidative stress, which was associated with the inhibition of sirtuin 3. Exposure to jet lag also aggravated the degeneration of mitochondrial functions, as shown by the decreases in the mRNA expression of COX1, ND1, and Tfam. Our findings provide physiological evidence that jet lag exposure may worsen stress-induced depression and age-related abnormalities.

C9-13 chlorinated paraffins cause immunomodulatory effects in adult C57BL/6 mice

Short-chain chlorinated paraffins (SCCPs, C_10-13) were listed as persistent organic pollutants (POPs) by the Stockholm Convention in 2017 and pose extensive exposure risks to humans. To our knowledge, there have been no studies reporting the immmunomodulatory effects of SCCPs until now. C₉-CPs have also been shown to be present in the environment. In this study, adult male C57BL/6 mice were exposed to 1, 10, or 100 mg/kg/d C_9-13-CPs by gavage for 28 d. The results showed that compared to those of the controls, exposure to C_9-13-CPs led to increased spleen weight, delimited germinal centers, enhanced energy metabolism, and elevated glutathione content, but no variation in the malonaldehyde level in the spleen was observed. Exposure to C_9-13-CPs also increased the populations of splenic lymphocytes, T lymphocytes, NK cells, and the ratio of the CD3⁺/CD19⁺ subsets and CD4⁺/CD8⁺ subsets compared to those of the controls. RNA-seq revealed 424 differentially expressed genes (DEGs) (fold change ≥ 1.5, FDR < 0.05) in the spleen between the control group and the 100 mg/kg/d C_9-13-CPs-treated group. KEGG analysis demonstrated that folate biosynthesis, pathways in cancer and thyroid hormone signaling were the three most significantly enriched pathways, and despite not reaching statistical significance, some immune-related pathways were also enriched in the KEGG functional enrichment analysis, including the chemokine signaling pathway (FDR < 0.0584), the NF-κB signaling pathway (FDR < 0.0663), Th17 cell differentiation (FDR < 0.0839), and the Jak-STAT signaling pathway. Moreover, compared to those of the controls, exposure to C_9-13-CPs enhanced the Concanavalin A (Con A)-stimulated cultured splenocyte proliferation, while the exposure showed no effect on the splenocyte proliferation that was stimulated by lipopolysaccharides (LPS). Taken together, these results demonstrated that subacute exposure to C_9-13-CPs could have immunomodulatory effects in mice. The present study helps to provide an understanding of the comprehensive health risks posed by C_9-13-CPs.

Antioxidant Activities of Quercetin and Its Complexes for Medicinal Application

Quercetin is a bioactive compound that is widely used in botanical medicine and traditional Chinese medicine due to its potent antioxidant activity. In recent years, antioxidant activities of quercetin have been studied extensively, including its effects on glutathione (GSH), enzymatic activity, signal transduction pathways, and reactive oxygen species (ROS) caused by environmental and toxicological factors. Chemical studies on quercetin have mainly focused on the antioxidant activity of its metal ion complexes and complex ions. In this review, we highlight the recent advances in the antioxidant activities, chemical research, and medicinal application of quercetin.