Tunicamycin induces depression-like behaviors in male rats, accompanied by initiated chaperon-mediated autophagy and decreased synaptic protein expression in the hippocampus.

BACKGROUND AND AIM: Endoplasmic reticulum (ER) stress participates in the occurrence and development of depression, but the underlying mechanism is not fully understood. This study aimed to investigate the behavioral performance and intracerebral molecular changes in an ER stress model of male rats. METHODS: Intrahippocampal injection of tunicamycin (TM) was performed on male rats as a model of ER stress. The body weight was determined, and behavioral tests, including sucrose preference test (SPT), open field test (OFT), and forced swimming test (FST), were performed to evaluate depressive and anxiety-like phenotypes within 8 days after injection. The levels of chaperone-mediated autophagy (CMA), synaptic proteins, and neuroinflammation related factors in this model were measured via real-time quantitative PCR and Western blot analysis. RESULTS: Intrahippocampal injection of TM (2 or 1 µg) induced depression-like behaviors in rats, as indicated by the reduced body weight, sucrose preference in SPT, central time in OFT, and increased immobility time in FST. The mRNA and protein levels of GRP78, ATF4, CHOP, LAMP2A, IL-1ß, IL-6, and TNF-α were significantly increased, while the expressions of MEF2D, PSD95, SYN, p-CREB (Ser133), and BDNF were significantly decreased in the hippocampus in the model group compared with the sham group. CONCLUSIONS: These results confirmed that intrahippocampal injection of TM was a valid method to induce an ER stress rat model with depression-like behaviors accompanied by decreased synaptic protein expression and neuroinflammation. The alteration in CMA-related proteins in this ER stress depression model indicated the involvement of CMA in the development of depression.

Social isolation after chronic unpredictable mild stress perpetuates depressive-like behaviors, memory deficits and social withdrawal via inhibiting ERK/KEAP1/NRF2 signaling.

BACKGROUND: Social withdrawal in patients with depression can aggravate depressive symptoms. However, few studies focus on the behavioral changes of social isolation after CUMS. NRF2 had been reported to be down-regulated after CUMS. But whether NRF2 participates in behavioral changes induced by social isolation after CUMS remains unclear. This study aims to develop a new model combined social isolation with CUMS, and investigate whether such behavioral changes are related to NRF2 signaling. METHODS: This study included two stages. In Stage 1, rats were subjected to 4-week CUMS and CUMS-susceptible rats were selected. In Stage 2, the CUMS-susceptible rats received 4-week social isolation or social support. Behavioral tests were carried out to observe behavioral changes, including sucrose preference test, forced swimming test, open field test, novel object recognition and social interaction test. QRT-PCR, western blot and immunofluorescence staining detected the ERK/KEAP1/NRF2 signaling. RESULTS: CUMS-susceptible rats exhibited depressive-like behaviors accompanied by the down-regulated ERK/KEAP1/NRF2 signaling in hippocampus. In Stage 2, compared with 4-week social support (group CUMSG), 4-week social isolation (group CUMSI) perpetuated the depressive-like behaviors, memory deficits and social withdrawal in CUMS-susceptible rats, as well as lower levels of p-ERK, NRF2, p-NRF2, HO-1 and NQO1, and the higher levels of KEAP1 in hippocampus. CONCLUSION: These findings suggested that social isolation after CUMS perpetuated depressive-like behaviors, memory deficits and social withdrawal via inhibiting ERK/KEAP1/NRF2 signaling. This study provided molecular evidence for the effects of post-stress social isolation on mental health, and the antioxidant stress signaling might be a target to rescue these.

Ion polarisation-assisted hydrogen-bonded ferroelectrics in liquid crystalline domains.

An alkylamide-substituted (-NHCOC10H21) hydrogen-bonded dibenzo[18]crown-6 derivative (1) was prepared to stabilise the ionic channel structure in a discotic hexagonal columnar (Colh) liquid crystal. The introduction of simple M+X- salts such as Na+PF6 - and K+I- into the ionic channel of 1 enhanced the ionic conductivity of the Colh phase of the M+·(1)·X- salts, with the highest ionic conductivity reaching ∼10-6 S cm-1 for K+·(1)·I- and Na+·(1)·PF6 - at 460 K, which was approximately 5 orders of magnitude higher than that of 1. The introduction of non-ferroelectric 1 into the ferroelectric N,N',N''-tri(tetradecyl)-1,3,5-benzenetricarboxamide (3BC) elicited a ferroelectric response from the mixed Colh phase of (3BC) x (1)1-x with x = 0.9 and 0.8. The further doping of M+X- into the ferroelectric Colh phase of (3BC)0.9(1)0.1 enhanced the ferroelectric polarisation assisted by ion displacement in the half-filled ionic channel for the vacant dibenzo[18]crown-6 of (3BC)0.9[(M+)0.5·(1)·(X-)0.5]0.1.

Sex differences in associations between maternal deprivation and alterations in hippocampal calcium-binding proteins and cognitive functions in rats.

BACKGROUND AND OBJECTIVE: Adverse early-life experiences have been suggested as one of the key contributors to neurodevelopmental disorders, such that these experiences influence brain development, cognitive ability and mental health. Previous studies indicated that hippocampal levels of the calcium-binding proteins calretinin (CALR) and calbindin-D28k (CALB) changed in response to maternal deprivation (MD), a model for adverse early-life experiences. We investigated the effects of MD on hippocampal CALR and CALB protein levels and cognitive behaviors, and explored whether these effects were sex-related. METHODS: From postnatal day 2 (PND-2) to PND-14, rat pups in the MD group were separated from their mothers for 3 h/day for comparison with pups raised normally (control). To determine hippocampal CALR and CALB levels, fluorescent immunostaining of hippocampal sections and Western blot analysis of hippocampal tissues were employed at various timepoints (PND-21, -25, -30, -35 and -40). Behavioral and cognitive changes were determined by open field test (PND-21) and Morris water maze (PND-25). RESULTS: Western blot analysis showed changes in the hippocampal CALR and CALB levels in both male and female MD groups, compared with controls. The open field test showed reduced exploration only in male MD groups but not female MD groups. The Morris water maze tests indicated that MD caused spatial memory impairment both in male and female rats, but there was a sex difference in CALR and CALB levels. CONCLUSIONS: Male rats are relatively more vulnerable to MD stress than female rats, but both male and female rats demonstrate spatial learning impairment after exposure to MD stress. Sex difference in CALR and CALB levels may reveal the different mechanisms behind the behavioral observations.

Military experience helps setting reasonable personality characteristics but does not alter the criminal behavior-related impression of negative parental experience and alcoholism in a Chinese population.

Personalities are determined by convergent factors, including physical environment, culture, special experience, and heredity. It has been shown that abuse of substance and alcohol among individuals with personality disorders predict criminality (Glenn and Raine, 2014; Hernandez-Avila et al., 2000). Thus, it is important to clarify the relationship between psychological characteristics and valence of criminal practice, even in the population without substance abuse. Here, we focused on a population with military experience in Shaanxi province of China to screen the psychological characteristics and correlate these characteristics to criminal behaviors. The study population included incarcerated veterans, incarcerated civilians, and three groups of military troops with different lengths of active duty history (<1 month, 1 year, and 2 years). We used the MAST (Michigan Alcoholism Screening Test), EMBU (Egna Minnen av Barndoms Uppfostran), and 16PF (Sixteen Personality Factor Questionnaire) for the screening purpose. Eight hundred seventy-five valid packets of questionnaires were collected during November 2014-January 2015. Comparison of the mean scores was used to evaluate the difference among the five groups. Incarcerated veterans and incarcerated civilians shared the alcohol abuse-relevant characteristics, including negative parental attitudes during their childhood and decreased emotional stability. Compared to the incarcerated civilians, incarcerated veterans scored higher in emotional stability, self-reliance, and perfectionism, but a lower score in apprehension. Personality characteristics associated with criminal behavior of incarcerated veterans seem to be unrelated to their military service per se as evidenced by the control groups. Conversely, military service may benefit the personnel characteristics even in the incarcerated veteran population.

Noble metal/functionalized cellulose nanofiber composites for catalytic applications.

In this study, cellulose acetate nanofibers (CANFs) with a mean diameter of 325 ± 2.0 nm were electrospun followed by deacetylation and functionalization to produce anionic cellulose nanofibers (f-CNFs). The noble metal nanoparticles (RuNPs and AgNPs) were successfully decorated on the f-CNFs by a simple wet reduction method using NaBH4 as a reducing agent. TEM and SEM images of the nanocomposites (RuNPs/CNFs and AgNPs/CNFs) confirmed that the very fine RuNPs or AgNPs were homogeneously dispersed on the surface of f-CNFs. The weight percentage of the Ru and Ag in the nanocomposites was found to be 13.29 wt% and 22.60 wt% respectively; as confirmed by SEM-EDS analysis. The metallic state of the Ru and Ag in the nanocomposites was confirmed by XPS and XRD analyses. The usefulness of these nanocomposites was realized from their superior catalytic activity. In the aerobic oxidation of benzyl alcohol to benzaldehyde, the RuNPs/CNFs system gave a better yield of 89% with 100% selectivity. Similarly, the AgNPs/CNFs produced an excellent yield of 99% (100% selectivity) in the aza-Michael reaction of 1-phenylpiperazine with acrylonitrile. Mechanism has been proposed for the catalytic systems.