Lipocalin-2 Deficiency Impairs Thermogenesis and Potentiates Diet-Induced Insulin Resistance in Mice

Lipocalin (LCN) 2 belongs to the lipocalin subfamily of low-molecular mass-secreted proteins that bind small hydrophobic molecules. LCN2 has been recently characterized as an adipose-derived cytokine, and its expression is upregulated in adipose tissue in genetically obese rodents. The objective of this study was to investigate the role of LCN2 in diet-induced insulin resistance and metabolic homeostasis in vivo. Systemic insulin sensitivity, adaptive thermogenesis, and serum metabolic and lipid profile were assessed in LCN2-deficient mice fed a high-fat diet (HFD) or regular chow diet. The molecular disruption of LCN2 in mice resulted in significantly potentiated diet-induced obesity, dyslipidemia, fatty liver disease, and insulin resistance. LCN2(-/-) mice exhibit impaired adaptive thermogenesis and cold intolerance. Gene expression patterns in white and brown adipose tissue, liver, and muscle indicate that LCN2(-/-) mice have increased hepatic gluconeogenesis, decreased mitochondrial oxidative capacity, impaired lipid metabolism, and increased inflammatory state under the HFD condition. LCN2 has a novel role in adaptive thermoregulation and diet-induced insulin resistanc

Value of intraoperative neurophysiological monitoring to reduce neurological complications in patients undergoing anterior cervical spine procedures for cervical spondylotic myelopathy

The primary aim of this study was to conduct a systematic review of reports of patients with cervical spondylotic myelopathy and to assess the value of intraoperative monitoring (IOM), including somatosensory evoked potentials, transcranial motor evoked potentials and electromyography, in anterior cervical procedures. A search was conducted to collect a small database of relevant papers using key words describing disorders and procedures of interest. The database was then shortlisted using selection criteria and data was extracted to identify complications as a result of anterior cervical procedures for cervical spondylotic myelopathy and outcome analysis on a continuous scale. In the 22 studies that matched the screening criteria, only two involved the use of IOM. The average sample size was 173 patients. In procedures done without IOM a mean change in Japanese Orthopaedic Association score of 3.94 points and Nurick score by 1.20 points (both less severe post-operatively) was observed. Within our sub-group analysis, worsening myelopathy and/or quadriplegia was seen in 2.71% of patients for studies without IOM and 0.91% of patients for studies with IOM. Variations persist in the existing literature in the evaluation of complications associated with anterior cervical spinal procedures. Based on the review of published studies, sufficient evidence does not exist to make recommendations regarding the use of different IOM modalities to reduce neurological complications during anterior cervical procedures. However, future studies with objective measures of neurological deficits using a specific IOM modality may establish it as an effective and reliable indicator of injury during such surgeries

Leptin as a critical regulator of hepatocellular carcinoma development through modulation of human telomerase reverse transcriptase

<p>Abstract</p> <p>Background</p> <p>Numerous epidemiological studies have documented that obesity is associated with hepatocellular carcinoma (HCC). The aim of this study was to investigate the biological actions regulated by leptin, the obesity biomarker molecule, and its receptors in HCC and the correlation between leptin and human telomerase reverse transcriptase (hTERT), a known mediator of cellular immortalization.</p> <p>Methods</p> <p>We investigated the relationship between leptin, leptin receptors and hTERT mRNA expression in HCC and healthy liver tissue samples. In HepG2 cells, chromatin immunoprecipitation assay was used to study signal transducer and activator of transcription-3 (STAT3) and myc/mad/max transcription factors downstream of leptin which could be responsible for hTERT regulation. Flow cytometry was used for evaluation of cell cycle modifications and MMP1, 9 and 13 expression after treatment of HepG2 cells with leptin. Blocking of leptin's expression was achieved using siRNA against leptin and transfection with liposomes.</p> <p>Results</p> <p>We showed, for the first time, that leptin's expression is highly correlated with hTERT expression levels in HCC liver tissues. We also demonstrated in HepG2 cells that leptin-induced up-regulation of hTERT and TA was mediated through binding of STAT3 and Myc/Max/Mad network proteins on <it>hTERT </it>promoter. We also found that leptin could affect hepatocellular carcinoma progression and invasion through its interaction with cytokines and matrix mettaloproteinases (MMPs) in the tumorigenic microenvironment. Furthermore, we showed that histone modification contributes to leptin's gene regulation in HCC.</p> <p>Conclusions</p> <p>We propose that leptin is a key regulator of the malignant properties of hepatocellular carcinoma cells through modulation of hTERT, a critical player of oncogenesis.</p

Psychological characteristics of religious delusions

Purpose Religious delusions are common and are considered to be particularly difficult to treat. In this study we investigated what psychological processes may underlie the reported treatment resistance. In particular, we focused on the perceptual, cognitive, affective and behavioural mechanisms held to maintain delusions in cognitive models of psychosis, as these form the key treatment targets in cognitive behavioural therapy. We compared religious delusions to delusions with other content. Methods Comprehensive measures of symptoms and psychological processes were completed by 383 adult participants with delusions and a schizophrenia spectrum diagnosis, drawn from two large studies of cognitive behavioural therapy for psychosis. Results Binary logistic regression showed that religious delusions were associated with higher levels of grandiosity (OR 7.5; 95 % CI 3.9–14.1), passivity experiences, having internal evidence for their delusion (anomalous experiences or mood states), and being willing to consider alternatives to their delusion (95 % CI for ORs 1.1–8.6). Levels of negative symptoms were lower. No differences were found in delusional conviction, insight or attitudes towards treatment. Conclusions Levels of positive symptoms, particularly anomalous experiences and grandiosity, were high, and may contribute to symptom persistence. However, contrary to previous reports, we found no evidence that people with religious delusions would be less likely to engage in any form of help. Higher levels of flexibility may make them particularly amenable to cognitive behavioural approaches, but particular care should be taken to preserve self-esteem and valued aspects of beliefs and experiences

Gender Dimorphism in Skeletal Muscle Leptin Receptors, Serum Leptin and Insulin Sensitivity

To determine if there is a gender dimorphism in the expression of leptin receptors (OB-R170, OB-R128 and OB-R98) and the protein suppressor of cytokine signaling 3 (SOCS3) in human skeletal muscle, the protein expression of OB-R, perilipin A, SOCS3 and alpha-tubulin was assessed by Western blot in muscle biopsies obtained from the m. vastus lateralis in thirty-four men (age = 27.1±6.8 yr) and thirty-three women (age = 26.7±6.7 yr). Basal serum insulin concentration and HOMA were similar in both genders. Serum leptin concentration was 3.4 times higher in women compared to men (P<0.05) and this difference remained significant after accounting for the differences in percentage of body fat or soluble leptin receptor. OB-R protein was 41% (OB-R170, P<0.05) and 163% (OB-R128, P<0.05) greater in women than men. There was no relationship between OB-R expression and the serum concentrations of leptin or 17β-estradiol. In men, muscle OB-R128 protein was inversely related to serum free testosterone. In women, OB-R98 and OB-R128 were inversely related to total serum testosterone concentration, and OB-R128 to serum free testosterone concentration. SOCS3 protein expression was similar in men and women and was not related to OB-R. In women, there was an inverse relationship between the logarithm of free testosterone and SCOS3 protein content in skeletal muscle (r = −0.46, P<0.05). In summary, there is a gender dimorphism in skeletal muscle leptin receptors expression, which can be partly explained by the influence of testosterone. SOCS3 expression in skeletal muscle is not up-regulated in women, despite very high serum leptin concentrations compared to men. The circulating form of the leptin receptor can not be used as a surrogate measure of the amount of leptin receptors expressed in skeletal muscles

Leptin Administration Favors Muscle Mass Accretion by Decreasing FoxO3a and Increasing PGC-1α in ob/ob Mice

Absence of leptin has been associated with reduced skeletal muscle mass in leptin-deficient ob/ob mice. The aim of our study was to examine the effect of leptin on the catabolic and anabolic pathways regulating muscle mass. Gastrocnemius, extensor digitorum longus and soleus muscle mass as well as fiber size were significantly lower in ob/ob mice compared to wild type littermates, being significantly increased by leptin administration (P<0.001). This effect was associated with an inactivation of the muscle atrophy-related transcription factor forkhead box class O3 (FoxO3a) (P<0.05), and with a decrease in the protein expression levels of the E3 ubiquitin-ligases muscle atrophy F-box (MAFbx) (P<0.05) and muscle RING finger 1 (MuRF1) (P<0.05). Moreover, leptin increased (P<0.01) protein expression levels of peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α), a regulator of muscle fiber type, and decreased (P<0.05) myostatin protein, a negative regulator of muscle growth. Leptin administration also activated (P<0.01) the regulators of cell cycle progression proliferating cell nuclear antigen (PCNA) and cyclin D1, and increased (P<0.01) myofibrillar protein troponin T. The present study provides evidence that leptin treatment may increase muscle mass of ob/ob mice by inhibiting myofibrillar protein degradation as well as enhancing muscle cell proliferation