Disruption of Cdk5-GluN2B complex by a small interfering peptide attenuates social isolation-induced escalated intermale attack behavior and hippocampal oxidative stress in mice

Social isolation has emerged as a significant issue during the COVID-19 pandemic that can adversely impact human mental health and potentially lead to pathological aggression. Given the lack of effective therapeutic interventions for aggressive behavior, alternative approaches are necessary. In this study, we utilized a genetic method combined with a pharmacological approach to identify and demonstrate the crucial role of Cdk5 in escalated intermale attack behavior induced by 2-week social isolation. Moreover, we developed a small peptide that effectively disrupts the interaction between Cdk5 and GluN2B, given the known involvement of this complex in various neuropsychiatric disorders. Administration of the peptide, either systemically or via intrahippocampal injection, significantly reduced oxidative stress in the hippocampus and attenuated intermale attack behavior induced by 2-week social isolation. These findings highlight the previously unknown role of the hippocampal Cdk5-GluN2B complex in social isolation-induced aggressive behavior in mice and propose the peptide as a promising therapeutic strategy for regulating attack behavior and oxidative stress.

Disrupting phosphorylation of Tyr-1070 at GluN2B selectively produces resilience to depression-like behaviors

Drugs targeting N-methyl-D-aspartate receptors (NMDARs) have been approved to treat major depressive disorder (MDD); however, the presence of undesirable psychotomimetic and cognitive side effects may limit their utility. In this study, we show that the phosphorylation levels of the GluN2B subunit at tyrosine (Y) 1070 increase in mice after both acute and chronic restraint stress (CRS) exposure. Preventing GluN2B-Y1070 phosphorylation via Y1070F mutation knockin produces effects similar to those of antidepressants but does not affect cognitive or anxiety-related behaviors in subject mice. Mechanistically, the Y1070F mutation selectively reduces non-synaptic NMDAR currents and increases the number of excitatory synapses in the layer 5 pyramidal neurons of medial prefrontal cortex (mPFC) but not in the hippocampus. Altogether, our study identifies phosphorylation levels of GluN2B-Y1070 in the mPFC as a dynamic, master switch guarding depressive behaviors, suggesting that disrupting the Y1070 phosphorylation of GluN2B subunit has the potential for developing new antidepressants.

Targeting GluN2B/NO Pathway Ameliorates Social Isolation-Induced Exacerbated Attack Behavior in Mice

Exacerbated attack behavior has a profound socioeconomic impact and devastating social consequences; however, there is no satisfactory clinical management available for an escalated attack behavior. Social isolation (SI) is widespread during this pandemic and may exert detrimental effects on mental health, such as causing heightened attack behavior. To explore the therapeutic approaches that alleviate the SI-induced heightened attack behavior, we utilized pharmacological methods targeting the GluN2B/NO signaling pathway during the attack behavior. Ifenprodil and TAT-9C peptide targeting GluN2B showed that the inhibition of GluN2B mitigated the SI-induced escalated attack behavior and the SI-induced aberrant nitric oxide (NO) level in the brain. Additionally, the potentiation of the NO level by L-arginine reversed the effects of the inhibition of GluN2B. Moreover, we showed that high doses of L-NAME and 7-NI and subeffective doses of L-NAME in combination with ifenprodil or TAT-9C or subeffective doses of 7-NI plus ifenprodil or TAT-9C all decreased the SI-induced escalated attack behavior and reduced the NO level, further supporting the idea that GluN2B/NO signaling is a crucial modulator of the escalated attack behavior.

Differential Roles of GluN2B in Two Types of Chemical-induced Long Term Potentiation-mediated Phosphorylation Regulation of GluA1 at Serine 845 in Hippocampal Slices

Synaptic plasticity, such as long term potentiation (LTP) and long term depression (LTD), underlies the cellular mechanism of learning and memory. Chemical-induced LTP (cLTP), which facilitates biochemical analysis of molecular changes in brain slices or neuronal cultures, has been accepted as an in vitro model to explore synaptic plasticity. cLTP, by either forskolin and rolipram (F&R) or glycine, is thought to be dependent on NMDA receptor. However, subunit-specific dependence and regulation of the NMDA receptor in cLTP remain poorly understood. In the present study, we found that phosphorylation level of GluN2B at tyrosine 1472 was modulated by F&R-induced LTP but not by glycine-induced LTP in hippocampal slices. Furthermore, an increased phosphorylation level of GluA1 at serine 845 by F&R-induced LTP rather than glycine-induced LTP was dependent on the activation of GluN2B, which is supported by the results from GluN2B antagonists, small interfering peptide and CRISPR-Cas9-mediated knock out of GluN2B. Taken together, we reveal the significant role of GluN2B in F&R-induced LTP, uncovering the role of GluN2B subunit of NMDA receptor in a specified cLTP.

Antidiabetic Drug Metformin Ameliorates Depressive-Like Behavior in Mice with Chronic Restraint Stress via Activation of AMP-Activated Protein Kinase

Depression is one of the most prevalent neuropsychiatric disorders in modern society. However, traditional drugs, such as monoaminergic agents, have defect showing lag response requiring several weeks to months. Additionally, these drugs have limited efficacy and high resistance rates in patients with depression. Thus, there is an urgent need to develop novel drugs or approaches for the treatment of depression. Here, using biochemical, pharmacological, genetic and behavioral methods, we demonstrate that metformin imparts a fast-acting antidepressant-like effect in naïve mice as well as stressed mice subjected to chronic restraint stress model. Moreover, inhibition of AMP-activated protein kinase (AMPK) activity by compound C or knock down of hippocampal AMPKα occluded the antidepressant-like effect induced by metformin. Our results suggest that metformin may be a viable therapeutic drug for the treatment of stress-induced depression via activation of AMPK.

Phosphorylation of Tyrosine 1070 at the GluN2B Subunit Is Regulated by Synaptic Activity and Critical for Surface Expression of N-Methyl-D-aspartate (NMDA) Receptors

The number and subunit composition of synaptic N-methyl-d-aspartate receptors (NMDARs) play critical roles in synaptic plasticity, learning, and memory and are implicated in neurological disorders. Tyrosine phosphorylation provides a powerful means of regulating NMDAR function, but the underling mechanism remains elusive. In this study we identified a tyrosine site on the GluN2B subunit, Tyr-1070, which was phosphorylated by a proto-oncogene tyrosine-protein (Fyn) kinase and critical for the surface expression of GluN2B-containing NMDARs. The phosphorylation of GluN2B at Tyr-1070 was required for binding of Fyn kinase to GluN2B, which up-regulated the phosphorylation of GluN2B at Tyr-1472. Moreover, our results revealed that the phosphorylation change of GluN2B at Tyr-1070 accompanied the Tyr-1472 phosphorylation and Fyn associated with GluN2B in synaptic plasticity induced by both chemical and contextual fear learning. Taken together, our findings provide a new mechanism for regulating the surface expression of NMDARs with implications for synaptic plasticity.

Resistin level is positively correlated with thrombotic complications in Southern Chinese metabolic syndrome patients

BACKGROUND

The metabolic syndrome (MetS) has been found to be closely related with thrombotic diseases. The mechanism, however, is far from elucidated.

AIM

This study was designed to investigate the relationship between endogenous resistin and thrombosis mediating factors, as well as its potential effects on the gene expression of cardiovascular disease biomarkers.

METHODS

Ninety patients satisfied the MetS criteria, and 55 healthy subjects were recruited as part of a single-center clinical study. Plasma levels of resistin, tissue factor (TF), tissue factor pathway inhibitor (TFPI), tissue plasminogen activator (tPA), plasminogen activator inhibitor-1 (PAI-1) were measured by enzymelinked immunosorbent assays. The effect of resistin on the expression of cardiovascular disease biomarkers in human umbilical vein endothelial cells (HUVEC) was assayed by gene microarray.

RESULTS

1) The average levels of resistin in MetS patients with or without acute myocardial or cerebral infarction were significantly higher than those of the controls. 2) The TF and TFPI increase was higher in MetS with infarction patients than in MetS patients. 3) In MetS with infarction patients, resistin was positively correlated with TF and PAI-1 (r=0.313, p=0.008; r=0.401, p=0.002, respectively). 4) In HUVEC, the microarray showed that apolipoprotein C-I, ACE, tumor necrosis factor receptor superfamily member 1A (TNFRSF1A) and member 5 (CD40) genes expression were dramatically increased by resistin.

CONCLUSION

In patients with MetS, resistin is strongly associated with hypercoagulative and hypofibrinolitic activities. Moreover, resistin may induce thrombotic complications via mediating the lipoprotein metabolism and stimulating inflammation.

[Comparing extended vertical partial laryngectomy and cricohyoidoepiglottopexy in the treatment of laryngeal carcinoma]

OBJECTIVE

To compare the results of extended vertical partial laryngectomy (similar to modified supracricoid partial laryngectomy with cricohyoidoepiglottopexy) and cricohyoidoepiglottopexy in the treatment of laryngeal carcinoma.

METHODS

Retrospectively analyzed on the results and prognosis in patients underwent extended vertical partial laryngectomy and cricohyoidoepiglottopexy between 1998 and 2005. The operation was similar to extended vertical partial laryngectomy. The healthy vocal cord and ventricular band as well as about 1/3 to 2/3 laminas of thyroid cartilage were removed. The healthy cricoarytenoid joint was reserved. The vocal cord, ventricular band, fixed or limitation of motion arytenoid cartilage and 2/3 laminas of thyroid cartilage in ill side were removed. The posteroinferior border of laminas of thyroid cartilage in both sides were reserved. The cricoid was lifted and fixed with hyoid epiglottis directly. Extended vertical partial laryngectomy group consisted of 37 patients with glottic carcinoma (stage T2 16 cases, stage T3 21 cases) and cricohyoidoepiglottopexy group consisted of 34 patients with glottic carcinoma (stage T2 12 cases, stage T3 21 cases, stage T4 1 case).

RESULTS

Kaplan-Meier analysis was performed to calculate the survival rates. The three-year cumulative survival rate was 91.7% in extended vertical partial laryngectomy group and 87.5% in cricohyoidoepiglottopexy group respectively. There was no significant difference between the two groups (P > 0.05). The five-year cumulative survival rate was 80.6% in extended vertical partial laryngectomy group and 81.3% in cricohyoidoepiglottopexy group respectively. There was also no significant difference between the two groups (P > 0.05). The decannulation rate was 100% (37/37) in extended vertical partial laryngectomy group and 94.1% (32/34) in cricohyoidoepiglottopexy group respectively. The decannulation time was (14.0 + or - 2.3) days in extended vertical partial laryngectomy group and (19.0 + or - 4.6) days in cricohyoidoepiglottopexy group respectively. The incidence of aspiration was 2.7% (1/37) in modified group and 23.5 (8/34) in cricohyoidoepiglottopexy group respectively evaluated at 8th weeks post-operatively. The evaluation of deglutition disorder was analyzed by Ridit analysis in both groups and the results showed that there was significant difference between the two groups (U = 7.341, P < 0.001). The symptom of aspiration in extended vertical partial laryngectomy group was significant less than in cricohyoidoepiglottopexy group.

CONCLUSIONS

Although the survival rate was not different between the two groups. The preservation of laryngeal function in extended vertical partial laryngectomy group was significant better than in cricohyoidoepiglottopexy group and extended vertical partial laryngectomy.

[Identification of differentially expressed genes in recurrent nasopharyngeal carcinoma and analysis of their chromosomal location]

OBJECTIVE

To identify differentially expressed genes in recurrent nasopharyngeal carcinoma (rNPC) by DNA microarrays, and analyze chromosomal localizations and molecular function by bioinformatics.

METHODS

The primary nasopharyngeal carcinoma (pNPC) tissue samples and rNPC tissue samples were selected, and Affymetrix Gene1.0 ST gene chips were used to identify differential expressed genes in rNPC, and the bioinformatics was used to analyze their chromosomal localizations as well as molecular functions.

RESULTS

A total of 44 genes were identified to be differential expressed in rNPC. Thirty-six genes were down regulated, 8 genes were up regulated. Functional classification of down-regulation genes showed that most genes (10 genes, 27.8%) belonged to the enzyme activity genes, followed by calcium ion binding genes (7 genes, 19.4%), protein binding genes (5 genes, 13.9%), receptor activity genes (4 genes, 11.1%), ATP binding genes (2 genes, 5.6%), transcription factor genes (2 genes, 5.6%), extracellular matrix binding and growth factor binding have 1 gene respectively (each accounted for 2.8%). In addition, the functions of 4 genes (11.1%) were unknown. Functional classification of up-regulation genes showed most genes (3 genes, 37.5%) were unknown, followed enzyme activity genes (2 genes, 25.0%), receptor activity, calcium ion binding and voltage-gated ion channel activity genes have 1 genes respectively (each accounted for 12.5%). These genes were localized randomly on the most the chromosomes, with a majority of them localized on chromosomes 1, 17. Chromosome 1 contained the most differentially expressed genes (10, 22.7%), followed by chromosomes 17 (5, 11.3%).

CONCLUSIONS

The differential expressed genes in rNPC were supposed to be randomly distributed on most chromosomes, but the majorities were found on chromosomes 1, 17. Abnormality in three groups of genes, including in enzyme activity, calcium ion binding and protein binding associate genes, might play important roles in rNPC. Those genes need to be further studied.

Six cases of ectopic ACTH syndrome caused by thymic carcinoid

The ectopic ACTH syndrome (EAS) caused by thymic carcinoid is rare and its diagnosis remains a challenge to the endocrinologist. Here are six cases of EAS with a typical Cushing habitus accompanied by hyperpigmentation and hypokalemia. For all six patients, the high dose (8 mg) dexamethasone suppression test (HDDST) showed lack of suppression, computed tomography (CT) scanning documented anterior mediastinal masses, and the mediastenal tumors removed were confirmed as ACTH secreting thymic carcinoids by positive ACTH and NSE staining. Our data indicate that HDDST chest radiologic imaging and other laboratory examinations will greatly assist in diagnosing the thymic carcinoid-induced EAS at an earlier stage, which will significantly improve the long-term survival of the patient.

[Quality of life, personality, coping style in the patients with advanced laryngeal cancer]

OBJECTIVE

To evaluate the relationship between the life quality of advanced laryngeal squamous cell cancer patients and their personality, coping style and other psychological factors.

METHODS

The life quality were measured for 2 sub-groups of advanced laryngeal cancer patients and the normal control group. The Eysenck personality questionnaire (EPQ), coping style questionnaires (CSQ) and University of Washington-quality of life (UW-QOL) were used for life quality evaluation. The 2 sub-groups of the patients on the worse speech, job and ability (group I), the better speech, job and ability (group II), and normal control.

RESULTS

(1) UW-QOL score: the total, activity, recreation, job and speech scores of group II were significantly higher than those of group I (P < 0.01). Group II was better than group I in appearance (P < 0.05). (2) EPQ score: the P and N scores in group II were lower than that in group I (P < 0.05). The E scores in group II were significantly higher than that in group I (P < 0.01). (3) CSQ score: the problem-saving factor and help-seeking factor in group II were more significantly lower than that in group I (P < 0.01). The self-blaming factor in group II were higher than that in group I (P < 0.05). (4) There was positive correlation between total scores of QOL and the problem-saving factor, help-seeking factor of CSQ, the E scores of EPQ (P < 0.05), there was negative correlation between total scores of QOL and the P scores, the N scores of EPQ (P < 0.05).

CONCLUSIONS

The advanced laryngeal cancer patients of group II have better life quality, and their personalities showed more extroversive, stable feeling, adaptable, mature coping styles. The above characteristics may have good effects on the prognosis of advanced laryngeal cancer.

Inhibition by nociceptin on excitatory non-adrenergic non-cholinergic response in guinea pig airways

AIM

To study the effect of nociceptin (NC), a newly discovered heptadecapeptide, and U-50488H, a kappa-opioid receptor agonist, on excitatory non-adrenergic non-cholinergic (eNANC) constriction responses in guinea pig isolated bronchus.

METHODS

An eNANC response was induced by electric field stimulation (EFS) in the preparation via activation of the sensory nerve terminals. The effect of NC and U-50488H was analyzed on the response.

RESULTS

Nociceptin 0.001 - 0.1 micromol/L inhibited the eNANC constriction which was induced by EFS but not by capsaicin in guinea pig bronchus. The constriction inhibited by NC 0.01 micromol/L was (43 +/- 31) % compared with the control. After pretreatment with naloxone 0.1 micromol/L, the constriction was inhibited by (46 +/- 28) %, without marked change compared with the above figure. IC50 (95 % of confidence limits) was 6.12 (3.8 - 9.9) nmol/L. U-50488H also inhibited the EFS-evoked eNANC constriction and the effect was abolished after pretreatment with naloxone. IC50 (95 % of confidence limits) was 1.08 (0.5 - 2.2) micromol/L. Capsaicin 0.01 - 1 micromol/L caused a cumulative constriction response in the preparation. Moreover, the effect of capsaicin was not affected by pretreatment with NC 0.01 micromol/L or U-50488H 0.1 micromol/L. The constriction induced by exogenous neurokinin A, were also unaffected by treatment with NC 0.01 micromol/L or U-50488H 0.1 micromol/L in isolated bronchus.

CONCLUSION

Nociceptin inhibits EFS-induced eNANC constriction, which is not reversed by naloxone, while U-50488H inhibits EFS-induced eNANC response via activation of opioid receptor in guinea pig airways.

Urinary cations and blood pressure: a collaborative study of 16 districts in China

Relationships between blood pressure and overnight urinary sodium, potassium and calcium were investigated in 3248 subjects from 16 districts in China. Average systolic (SBP) and diastolic (DBP) blood pressures of subjects from northern, middle and southern China were 116/74.2, 114/70.5 and 110.8/69.6 mmHg, respectively. Urinary sodium, potassium and calcium were 55.1, 8.3 and 1.1 mmol/l for the north, 63.6, 9.2 and 1.6 mmol/l for the middle and 50.0, 8.9 and 1.5 mmol/l for the south, respectively. The urinary sodium to potassium ratio was significantly and positively correlated with SBP and DBP in both males and females. Urinary sodium was weakly and positively correlated with SBP only in the north. Females over the age of 50 years were especially sensitive to sodium intake. Urinary calcium was negatively correlated with DBP in both males and females. Urinary calcium (creatinine) was negatively correlated with SBP in males, and with SBP and DBP in the south. Urinary potassium was negatively correlated with SBP and DBP only in the 20-29 year age group. Urinary potassium (creatinine) was negatively correlated with DBP only in the south. Age and body mass index were positively and level of education negatively correlated with blood pressure. Dietary factors for higher blood pressure in northern China were related to higher sodium, lower potassium and possibly lower calcium intake.