P-523 Whole-chromosome aneuploidies revealed by transcriptome of trophectoderm biopsied from human pre-implantation blastocyst

Study question

Whether mRNA transcriptome of biopsied trophectoderm (TE) in human pre-implantation blastocyst can predict embryo karyotype?

Summary answer

mRNA transcriptome of biopsied TE can precisely predict whole-chromosome aneuploidies but not mosaicism or segmental aneuploidies.

What is known already

Karyotype of human pre-implantation blastocyst is well recognized by PGT-A. However, genome can’t demonstrate gene expression level which might infer the development potential of euploidy. Transcriptome of blastocyst by singe-cell RNA-seq has revealed the lineage segregation of human pre-implantation blastocyst. It is not known whether transcriptome of biopsied TE used in PGT-A can infer the karyotype of human pre-implantation blastocyst.

Study design, size, duration

A total of 74 TE samples were biopsied from 26 blastocysts which were donated from patients who underwent PGT at our Reproductive Medicine Center. All of these embryos have been previously diagnosed as aneuploidies (n = 19) or euploidies (n = 7) with monogenic disorder.

Participants/materials, setting, methods

The DNA and mRNA of all biopsied TEs were separated independently using a modified oligo-dT bead capture, followed by PGT-A of DNA and smart2-sequencing of mRNA (G&T-seq). Karyotype of biopsied TEs were confirmed with PGT-A performed in MiSeq system (Illumina) in our PGT laboratory with the use of next-generation sequencing. Data of transcriptome was analyzed using Rstudio and R package InferCNV to predict aneuploidies by referring to euploidies which were inferred with corresponding PGT-A results.

Main results and the role of chance

In human pre-implantation blastocyst, all whole-chromosome aneuploidies could be inferred by transcriptome of biopsied TE, which were consistent with PGT-A result. But chromosomal mosaicism or segmental aneuploidies were hard to be predicted precisely by transcriptome of TE.

Limitations, reasons for caution

The main limitation of this study lies in the inability to retrieve the exact copy number variations from mRNA transcription. Gene expression is in a great imbalance in such an early development of human pre-implantation blastocyst.

Wider implications of the findings

Our data suggest that mRNA transcriptome is enough for prediction of whole-chromosome aneuploidies. The method and value for predicting mosaicism and segmental aneuploidies by transcriptome should be further investigated.

Trial registration number

not applicable

P–523 Whole-chromosome aneuploidies revealed by transcriptome of trophectoderm biopsied from human pre-implantation blastocyst

Study question

Whether mRNA transcriptome of biopsied trophectoderm (TE) in human pre-implantation blastocyst can predict embryo karyotype?

Summary answer

mRNA transcriptome of biopsied TE can precisely predict whole-chromosome aneuploidies but not mosaicism or segmental aneuploidies.

What is known already

Karyotype of human pre-implantation blastocyst is well recognized by PGT-A. However, genome can’t demonstrate gene expression level which might infer the development potential of euploidy. Transcriptome of blastocyst by singe-cell RNA-seq has revealed the lineage segregation of human pre-implantation blastocyst. It is not known whether transcriptome of biopsied TE used in PGT-A can infer the karyotype of human pre-implantation blastocyst.

Study design, size, duration

A total of 74 TE samples were biopsied from 26 blastocysts which were donated from patients who underwent PGT at our Reproductive Medicine Center. All of these embryos have been previously diagnosed as aneuploidies (n = 19) or euploidies (n = 7) with monogenic disorder.

Participants/materials, setting, methods

The DNA and mRNA of all biopsied TEs were separated independently using a modified oligo-dT bead capture, followed by PGT-A of DNA and smart2-sequencing of mRNA (G&T-seq). Karyotype of biopsied TEs were confirmed with PGT-A performed in MiSeq system (Illumina) in our PGT laboratory with the use of next-generation sequencing. Data of transcriptome was analyzed using Rstudio and R package InferCNV to predict aneuploidies by referring to euploidies which were inferred with corresponding PGT-A results.

Main results and the role of chance

In human pre-implantation blastocyst, all whole-chromosome aneuploidies could be inferred by transcriptome of biopsied TE, which were consistent with PGT-A result. But chromosomal mosaicism or segmental aneuploidies were hard to be predicted precisely by transcriptome of TE.

Limitations, reasons for caution

The main limitation of this study lies in the inability to retrieve the exact copy number variations from mRNA transcription. Gene expression is in a great imbalance in such an early development of human pre-implantation blastocyst.

Wider implications of the findings: Our data suggest that mRNA transcriptome is enough for prediction of whole-chromosome aneuploidies. The method and value for predicting mosaicism and segmental aneuploidies by transcriptome should be further investigated.

Trial registration number

Not applicable

Enhanced ZAG production by subcutaneous adipose tissue is linked to weight loss in gastrointestinal cancer patients

Background:

Profound loss of adipose tissue is a hallmark of cancer cachexia. Zinc-α2-glycoprotein (ZAG), a recently identified adipokine, is suggested as a candidate in lipid catabolism.

Methods:

In the first study, eight weight-stable and 17 cachectic cancer patients (weight loss ⩾5% in previous 6 months) were recruited. Zinc-α2-glycoprotein mRNA and protein expression were assessed in subcutaneous adipose tissue (SAT), subcutaneous adipose tissue morphology was examined and serum ZAG concentrations were quantified. In the second cohort, ZAG release by SAT was determined in 18 weight-stable and 15 cachectic cancer patients. The effect of ZAG on lipolysis was evaluated in vitro.

Results:

Subcutaneous adipose tissue remodelling in cancer cachexia was evident through shrunken adipocytes with increased fibrosis. In cachectic cancer patients, ZAG mRNA was upregulated (2.7-fold, P=0.028) while leptin mRNA decreased (2.2-fold, P=0.018); serum ZAG levels were found to be unaffected. Zinc-α2-glycoprotein mRNA correlated positively with weight loss (r=0.51, P=0.01) and serum glycerol levels (r=0.57, P=0.003). Zinc-α2-glycoprotein release by SAT was also elevated in cachectic patients (1.5-fold, P=0.024) and correlated with weight loss (r=0.50, P=0.003). Recombinant ZAG stimulated lipolysis in human adipocytes.

Conclusions:

Zinc-α2-glycoprotein expression and secretion by adipose tissue is enhanced in cachectic cancer patients. Given its lipid-mobilising effect, ZAG may contribute to adipose atrophy associated with cancer cachexia in human beings.

Upregulation of the expression of inflammatory and angiogenic markers in human adipocytes by a synthetic cannabinoid, JTE-907

Inflammation in adipose tissue is a characteristic of obesity and the metabolic syndrome. It is suggested that the endocannabinoid system is involved in the regulation of inflammatory and angiogenic processes within the tissue. Human subcutaneous preadipocytes (Zen Bio) were used as the source of human preadipocytes or adipocytes. Gene expression was examined by RT-PCR and real-time PCR. The secretion of inflammation-related proteins was determined by an ELISA array. In experiments on adipocytes treated at day 14 post-differentiation, JTE-907, a synthetic cannabinoid, upregulated the expression of key inflammatory markers - IL-6, MCP-1 and IL-1 beta - and angiogenic factors - VEGF and ANGPTL4 - at 10 microM after 20 h of treatment, having also increased the expression of TRPV1 at 10 microM. JTE-907 showed no effect after 4 h. The ELISA array showed a 2.6-fold increase in IL-6 protein release. The effect of JTE-907 was inhibited by AM251 (CB1 antagonist), and partially by arachidonyl serotonin (TRPV1 and FAAH antagonist). The CB2 antagonist, AM630, partially upregulated the effect of JTE-907. Preadipocytes fed 14 days after 100% confluence exhibited downregulation of CB1, MCP-1, and IL-1 beta, 20 h after having been exposed to JTE-907. CB1 and TRPV1 receptors participate in the regulation of several inflammatory and angiogenic factors in human adipocytes, indicating their potential value as targets for the treatment of disorders related to obesity.

Macrophage-secreted factors inhibit ZAG expression and secretion by human adipocytes

Zinc-alpha2-glycoprotein (ZAG), a novel adipokine, is downregulated in adipose tissue in obesity, a state characterized by increased adipose tissue macrophage infiltration and chronic low-grade inflammation. This study investigated whether macrophage-secreted factors and TNF-alpha, a major product of macrophages, modulate ZAG expression and secretion by human adipocytes. ZAG was produced primarily by adipocytes, and not by preadipocytes and macrophages. Incubation of preadipocytes with macrophage-conditioned medium for up to 12 days decreased ZAG mRNA and protein release, and the expression of adipogenic markers (PPARgamma and C/EBPalpha). Adipocytes treated with macrophage-conditioned medium for 24h displayed significant reductions in ZAG mRNA and release. Chronic TNF-alpha treatment let to significant decreases in ZAG expression and secretion, but marked upregulation of pro-inflammatory cytokines and chemokines (IL-6, leptin, IL-8, MCP-1 and RANTES) in adipocytes. These findings suggest that macrophage-associated inflammation may play a significant role in the downregulation of ZAG in adipose tissue in obesity.

The adipokine zinc-alpha2-glycoprotein (ZAG) is downregulated with fat mass expansion in obesity

INTRODUCTION

Zinc-alpha2-glycoprotein (ZAG) is a novel adipokine, which may act locally to influence adipocyte metabolism. This study assessed the effect of increased adiposity on ZAG expression in adipose tissue in human subjects. The study also examined the association between ZAG and adiponectin expression in human adipose tissue, and whether ZAG modulates adiponectin secretion by human adipocytes.

METHODS

Adipose tissue (visceral and subcutaneous) was collected from human subjects with a wide range of BMIs. Human Simpson-Golabi-Behmel syndrome (SGBS) adipocytes were used for in vitro studies. ZAG mRNA levels were quantified by real-time PCR and protein by Western blotting.

RESULTS

In human subjects, ZAG mRNA level was negatively correlated with BMI (r = -0.61, P < 0.001, n = 23, visceral; r = -0.6, P < 0.05, n = 14, subcutaneous) and fat mass (r = -0.62, P < 0.01, visceral; r = -0.6, P < 0.05, subcutaneous). Negative associations were also found between ZAG mRNA and insulin resistance parameters including plasma insulin (r = -0.65, P < 0.001, visceral; r = -0.55, P < 0.05, subcutaneous) and homeostasis model of insulin resistance (HOMA-IR) (r = -0.65, P < 0.001, visceral; r = -0.52, P = 0.055, subcutaneous), and C reactive protein (CRP) (r = -0.46, P < 0.05, visceral; r = -0.53, P < 0.05, subcutaneous). However, ZAG mRNA was positively correlated with adiponectin (r = 0.5, P < 0.05, visceral; r = 0.82, P < 0.001, subcutaneous) but negatively associated with leptin mRNA (r = -0.42, P < 0.05, visceral; r = -0.54, P < 0.05, subcutaneous). ZAG secretion by differentiated human adipocytes was abundant. Addition of recombinant ZAG stimulated adiponectin release from human adipocytes.

CONCLUSION

ZAG gene expression in adipose tissue is downregulated with increased adiposity and circulating insulin. ZAG mRNA is positively correlated with adiponectin mRNA, and ZAG enhances adiponectin production by human adipocytes. We suggest that ZAG is linked to obesity and obesity-related insulin resistance.

Downregulation of zinc-{alpha}2-glycoprotein in adipose tissue and liver of obese ob/ob mice and by tumour necrosis factor-alpha in adipocytes

Zinc-alpha2-glycoprotein (ZAG, also listed as AZGP1 in the MGI Database), a lipid-mobilising factor, has recently been suggested as a potential candidate in the modulation of body weight. We investigated the effect of increased adiposity on ZAG expression in adipose tissue and the liver and on plasma levels in obese (ob/ob) mice compared with lean siblings. The study also examined the effect of the pro-inflammatory cytokine tumour necrosis factor-alpha (TNFalpha) on ZAG expression in adipocytes. Zag mRNA levels were significantly reduced in subcutaneous (fourfold) and epididymal (eightfold) fat of ob/ob mice. Consistently, ZAG protein content was decreased in both fat depots of ob/ob mice. In the liver of obese animals, steatosis was accompanied by the fall of both Zag mRNA (twofold) and ZAG protein content (2.5-fold). Plasma ZAG levels were also decreased in obese mice. In addition, Zag mRNA was reduced in epididymal (fivefold) and retroperitoneal (fivefold) adipose tissue of obese (fa/fa) Zucker rats. In contrast to Zag expression, Tnfalpha mRNA levels were elevated in adipose tissue (twofold) and the liver (2.5-fold) of ob/ob mice. Treatment with TNFalpha reduced Zag gene expression in differentiated adipocytes, and this inhibition was chronic, occurring at 24 and 48 h following TNFalpha treatment. It is concluded that ZAG synthesis in adipose tissue and the liver is downregulated, as are its circulating levels, in ob/ob mice. The reduced ZAG production may advance the susceptibility to lipid accumulation in these tissues in obesity, and this could be at least in part attributable to the inhibitory effect of TNFalpha.

[Postoperative acute pancreatitis: our experience and review of the literature]

AIM

Acute postoperative pancreatitis is a rare event, but, at the same time, it represents one of the most frightening complications, because it is associated with high mortality risk.

METHODS

From January 1985 to December 2005, we observed 30 cases (12 males, 18 females) of acute postoperative pancreatitis. Twenty cases of low and medium gravity have been treated with only medical therapy, 10 cases, instead, have requested surgical therapy (necrosectomy and application of abdominal drains in 7 cases, necrosectomy and ileostomy in 1 case, necrosectomy and colostomy in 1 case, ligation of pancreatic vessels in 1 case of haemorrhagic pancreatitis).

RESULTS

In the form of low and medium gravity, fast and pharmacological support (somatostatin and gabexate mesilate) are enough to resolve the event. In the form of high gravity the early surgical treatment has represented the clinical solution in 7 patients, while 3 others patients have died for septic and metabolic complication.

CONCLUSIONS

Still today acute postoperative pancreatitis represents a frightening complication associated with high mortality risk that the surgeon has to treat with great care to avoid each bilio-pancreatic injury.

Adipose atrophy in cancer cachexia: morphologic and molecular analysis of adipose tissue in tumour-bearing mice

Extensive loss of adipose tissue is a hallmark of cancer cachexia but the cellular and molecular basis remains unclear. This study has examined morphologic and molecular characteristics of white adipose tissue in mice bearing a cachexia-inducing tumour, MAC16. Adipose tissue from tumour-bearing mice contained shrunken adipocytes that were heterogeneous in size. Increased fibrosis was evident by strong collagen-fibril staining in the tissue matrix. Ultrastructure of 'slimmed' adipocytes revealed severe delipidation and modifications in cell membrane conformation. There were major reductions in mRNA levels of adipogenic transcription factors including CCAAT/enhancer binding protein alpha (C/EBPalpha), CCAAT/enhancer binding protein beta, peroxisome proliferator-activated receptor gamma, and sterol regulatory element binding protein-1c (SREBP-1c) in adipose tissue, which was accompanied by reduced protein content of C/EBPalpha and SREBP-1. mRNA levels of SREBP-1c targets, fatty acid synthase, acetyl CoA carboxylase, stearoyl CoA desaturase 1 and glycerol-3-phosphate acyl transferase, also fell as did glucose transporter-4 and leptin. In contrast, mRNA levels of peroxisome proliferators-activated receptor gamma coactivator-1alpha and uncoupling protein-2 were increased in white fat of tumour-bearing mice. These results suggest that the tumour-induced impairment in the formation and lipid storing capacity of adipose tissue occurs in mice with cancer cachexia.

Large-scale studies of the Leu72Met polymorphism of the ghrelin gene in relation to the metabolic syndrome and associated quantitative traits

AIM

Recently, low-frequency polymorphisms in the coding region of the ghrelin gene were suggested to be involved in the aetiology of obesity and to modulate glucose-induced insulin secretion in different ethnic study groups. The objective of the present large study was to investigate whether the Leu72Met polymorphism of the ghrelin gene associates with features of the metabolic syndrome (MS) in the Danish population.

METHODS

The variant was examined, using PCR-RFLP, in the DanMONICA cohort, a population-based sample of 2413 subjects. The metabolic syndrome was defined using the National Cholesterol Education Program-Adult Treatment Panel III (NCEP-ATPIII) criteria.

RESULTS

The allelic frequency of the Met72 allele was 8.6%[6.3-10.9%] in the MS group and 7.8%[7.0-8.6%] among subjects classified as not having the MS (NS). Similarly, there were no significant differences across the three groups of genotypes with respect to any of the examined variables, including BMI, waist circumference, fasting serum lipids, plasma glucose, serum insulin and HOMA estimates of insulin resistance and insulin secretion.

CONCLUSION

In conclusion, the Leu72Met polymorphism of the ghrelin gene is not associated with the metabolic syndrome or related quantitative traits in the Danish population.

[Early vs conservative treatment of acute cholecystitis. Personal experience and review of the literature]

AIM

The aim of this retrospective study was to compare the results of early cholecystectomy and conservative treatment in acute cholecystitis.

METHODS

From January 1998 to December 2002, 134 patients were admitted to our Department with the diagnosis of acute cholecystitis. Eighty-nine patients (66%, Group 1) were cured with conservative treatment (i.e. fast, broad-spectrum antibiotics, fluid and analgesic drugs), 45 patients (34%, Group 2) were submitted to early cholecystectomy. The 2 groups were matched for age, sex, laboratory results and echographic findings.

RESULTS

The morbidity was 32.5% in Group 1 versus 15.5% in Group 2 (p < 0.05). Mean hospital stay was 18 days in Group 1 as compared to 10.5 days in Group 2 (p < 0.05). At follow-up (12 months) the mean period before starting again a normal working and social life was 57 days in Group 1 and 33 days in Group 2.

CONCLUSIONS

The results of this study showed that early cholecystectomy was the gold standard in the treatment of acute cholecystitis, since it reduces morbidity, hospital stay and absence from working and social life in a statistically important way.

Diurnal changes in hypothalamic neuropeptide and SOCS-3 expression: effects of lactation and relationship with serum leptin and food intake

Rats normally eat about 85% of their food at night. Lactation increases food intake 3- to 4-fold, but the diurnal pattern of food intake persists. The mechanisms responsible for the diurnal and lactation-induced changes in food intake are still unresolved, hence we have further investigated the possible roles of serum leptin and hypothalamic expression of neuropeptide Y (NPY), agouti-related peptide (AgRP) and pro-opiomelanocortin (POMC) in rats. Suppressor of cytokine signalling-3 (SOCS-3) acts as a feedback inhibitor of leptin signalling in the hypothalamus, hence changes in expression of SOCS-3 were also investigated. Changes in expression of NPY, AgRP or POMC alone could not account for the diurnal changes in intake and their alteration by lactation. However, there were increased AgRP mRNA:POMC mRNA ratios at night and also during lactation, which were very similar to estimated changes in food intake. Such changes in expression may result in dominance of the orexigenic AgRP peptide over the appetite-suppressing POMC-derived peptides, and so could contribute to the hyperphagia in these states. Diurnal and lactation-related changes in the AgRP mRNA:POMC mRNA ratio and food intake are not due to changes in leptin alone. However, hypoleptinaemia, possibly through increased expression of NPY, may contribute to the hyperphagia of lactation. In the dark, expression of SOCS-3 was decreased in non-lactating rats; lactation decreased SOCS-3 expression in both light and dark phases. However, such changes are likely to enhance the ability of leptin-responsive neurones to transmit the leptin signal, and so are unlikely to contribute to either the nocturnal increase in appetite or the hyperphagia of lactation.

Lactation modulates diurnal expression profiles of specific leptin receptor isoforms in the rat hypothalamus

We investigated the effects of lactation on diurnal changes in serum leptin and hypothalamic expression of the leptin receptor isoforms, Ob-Ra, -Rb, -Rc, -Re and -Rf in rats. In non-lactating rats, serum leptin concentration was increased at night while hypothalamic mRNA levels of Ob-Rb, -Rc and -Re decreased; by contrast, expression of Ob-Ra and Ob-Rf was unchanged at night. There were significant negative correlations between serum leptin and mRNA expression of Ob-Rb (P<0.001) and Ob-Re (P<0.05), which were independent of time of day. In lactating rats, the nocturnal rise in serum leptin was attenuated. Daytime hypothalamic Ob-Rb mRNA levels were significantly lower than in non-lactating controls, and the normal nocturnal decreases in expression of Ob-Rb, -Rc and -Re were lost. The relationship between serum leptin and Ob-Re expression was not changed by lactation. Lactation had no effect on the expression of Ob-Ra mRNA in the hypothalamus. Decreased daytime Ob-Rb expression could lead to reduced hypothalamic sensitivity to leptin, and thus contribute to increased daytime appetite in lactating rats. Moreover, maintaining high levels of Ob-Re expression could, by increasing hypothalamic leptin-binding protein concentration and reducing local leptin bioavailability, further accentuate hyperphagia. Thus, selective changes in expression of specific isoforms of the leptin receptor may contribute to the hyperphagia of lactation in rats.

Weight loss in tumour-bearing mice is not associated with changes in resistin gene expression in white adipose tissue

Resistin, a product of white adipose tissue, is postulated to induce insulin resistance in obesity and regulate adipocyte differentiation. The aim of this study was to examine resistin gene expression in adipose tissue from mice bearing the MAC16 adenocarcinoma, which induces cancer cachexia with marked wasting of adipose tissue and skeletal muscle mass. MAC16-bearing mice lost weight progressively over the period following tumour transplantation, while the weight of control mice remained stable. Leptin mRNA in gonadal fat was 50 % lower in MAC16 mice than in controls (p < 0.05). Plasma insulin concentrations were also significantly lower in the MAC16 group (p < 0.05). However, resistin mRNA level in gonadal fat in MAC16 mice was similar to controls (94 % of controls). Thus, despite severe weight loss and significant falls in leptin expression and insulin concentration, resistin gene expression appears unchanged in white adipose tissue of mice with MAC16 tumour. Maintenance of resistin production may help inhibit the formation of new adipocytes in cancer cachexia.

Expression of uncoupling proteins-1, -2 and -3 mRNA is induced by an adenocarcinoma-derived lipid-mobilizing factor

The abnormalities of lipid metabolism observed in cancer cachexia may be induced by a lipid-mobilizing factor produced by adenocarcinomas. The specific molecules and metabolic pathways that mediate the actions of lipid-mobilizing factor are not known. The mitochondrial uncoupling proteins-1, -2 and -3 are suggested to play essential roles in energy dissipation and disposal of excess lipid. Here, we studied the effects of lipid-mobilizing factor on the expression of uncoupling proteins-1, -2 and -3 in normal mice. Lipid-mobilizing factor isolated from the urine of cancer patients was injected intravenously into mice over a 52-h period, while vehicle was similarly given to controls. Lipid-mobilizing factor caused significant reductions in body weight (-10%, P=0.03) and fat mass (-20%, P<0.01) accompanied by a marked decrease in plasma leptin (-59%, P<0.01) and heavy lipid deposition in the liver. In brown adipose tissue, uncoupling protein-1 mRNA levels were elevated in lipid-mobilizing factor-treated mice (+96%, P<0.01), as were uncoupling proteins-2 and -3 (+57% and +37%, both P<0.05). Lipid-mobilizing factor increased uncoupling protein-2 mRNA in both skeletal muscle (+146%, P<0.05) and liver (+142%, P=0.03). The protein levels of uncoupling protein-1 in brown adipose tissue and uncoupling protein-2 in liver were also increased with lipid-mobilizing factor administration (+49% and +67%, both P=0.02). Upregulation by lipid-mobilizing factor of uncoupling proteins-1, -2 and -3 in brown adipose tissue, and of uncoupling protein-2 in skeletal muscle and liver, suggests that these uncoupling proteins may serve to utilize excess lipid mobilized during fat catabolism in cancer cachexia.

Muscle UCP-3 mRNA levels are elevated in weight loss associated with gastrointestinal adenocarcinoma in humans

The mitochondrial uncoupling proteins-2 and -3 are putative mediators of thermogenesis and energy expenditure. We measured the mRNA levels of uncoupling proteins-2 and -3 in skeletal muscle from 12 gastrointestinal adenocarcinoma patients, of whom six had stable weight and six had lost 2-18 kg, and from six healthy controls undergoing elective surgery. Uncoupling proteins-3 mRNA levels were significantly higher in the muscle of the cancer patients with weight loss (2.2 +/- 0.47 arbitrary units) compared both with controls (0.39 +/- 0.20) and with cancer patients who had not lost weight (0.47 +/- 0.23; P<0.02). Uncoupling proteins-2 mRNA levels did not differ significantly between groups. Elevations in muscle uncoupling proteins-3 activity may enhance energy expenditure and this in turn could contribute to tissue catabolism.

Cachexia in MAC16 adenocarcinoma: suppression of hunger despite normal regulation of leptin, insulin and hypothalamic neuropeptide Y

Weight loss normally stimulates hunger, through mechanisms that include falls in circulating leptin and insulin, leading to stimulation of hypothalamic neuropeptide Y (NPY). Here, we investigated the leptin, insulin and NPY to clarify why hunger is suppressed in mice with severe cachexia due to the MAC16 adenocarcinoma. MAC16-bearing mice progressively lost weight (19% below controls) and fat (- 61%) over 16 days after tumour transplantation, while total food intake fell by 10%. Pair-fed mice showed less wasting, with final weight being 9% and fat mass 25% below controls. Plasma leptin fell by 85% in MAC16 and 51% in pair-fed mice, in proportion to loss of fat. Plasma insulin was also reduced by 49% in MAC16 and 53% in pair-fed groups. Hypothalamic leptin receptor (OB-Rb) mRNA was significantly increased in both MAC16 (+ 223%) and pair-fed (+192%) mice. Hypothalamic NPY mRNA was also significantly raised in MAC16 (+152%) and pair-fed (+ 99%) groups, showing negative correlations with plasma leptin and insulin, and a positive association with OB-Rb mRNA. In MAC16-induced cachexia, leptin production and hypothalamic OB-Rb and NPY expression are regulated appropriately in response to fat depletion. Therefore, suppression of hunger is probably due to tumour products that inhibit NPY transport or release, or that interfere with neuronal targets downstream of NPY.

The hypothalamus and the control of energy homeostasis: different circuits, different purposes

The hypothalamus regulates many aspects of energy homeostasis, adjusting both the drive to eat and the expenditure of energy in response to a wide range of nutritional and other signals. It is becoming clear that various neural circuits operate to different degrees and probably serve specific functions under particular conditions of altered feeding behaviour. This review will discuss this functional diversity by illustrating hypothalamic neurones that express neuropeptide Y (NPY), the melanocortin-4 receptor (MC4-R) and the orexins. NPY neurones in the arcuate nucleus (ARC) release NPY, a powerful inducer of feeding and obesity, in the paraventricular nucleus (PVN) and the lateral hypothalamic area (LHA). ARC-NPY neurones are inhibited by leptin and insulin and become overactive when levels of these hormones fall during undernutrition. They may function physiologically to protect against starvation. With disruption of the inhibitory leptin signals due to gene mutations, the NPY neurones are overactive, which contributes to hyperphagia and obesity in the ob/ob and db/db mice and fa/fa Zucker rat. The MC4-R is activated by alpha-melanocyte-stimulating hormone [alpha-MSH; a cleavage product of pro-opiomelanocortin (POMC), which is expressed in the other ARC neurones] and inhibits feeding. This effect is antagonised by agouti gene-related peptide (AGRP), which is coexpressed by the ARC-NPY neurones only. Activation of MC4-R, possibly mediated by blockade of AGRP release, appears to restrain overeating of a palatable diet. This response may be programmed by a transient rise in leptin soon after presentation of palatable food, and rats that fail to do this will overeat and become obese. Orexin-A and -B (corresponding to hypocretins 1 and 2) are expressed in specific LHA neurones. These have extensive reciprocal connections with many areas involved in appetite control, including the nucleus of the solitary tracts (NTS), which relays vagal afferent satiety signals from the viscera. Orexin neurones also have close anatomical connections with LHA glucose-sensitive neurones. Orexin-A induces acute feeding but does not cause obesity. Orexin neurones are stimulated by hypoglycaemia partly via the NTS and inhibited by food ingestion. These neurones may therefore be involved in the severe hyperphagia of hypoglycaemia and short-term control of feeding.

Increased gene expression of brown fat uncoupling protein (UCP)1 and skeletal muscle UCP2 and UCP3 in MAC16-induced cancer cachexia

Weight loss in cancer cachexia is attributable to decreased food intake and/or enhanced energy expenditure. We investigated the roles of the uncoupling proteins (UCPs) UCPI, -2, and -3 in a murine model of cachexia, the MAC16 adenocarcinoma. Weight fell to 24% below that of non-tumor-bearing controls (P < 0.01) 18 days after MAC16 inoculation, with significant reductions in fat-pad mass (-67%; P < 0.01) and muscle mass (-20%; P < 0.01). Food intake was 26-60% lower (P < 0.01) than in controls on days 17-18. Non-tumor-bearing mice, pair-fed to match MAC16-induced hypophagia, showed less weight loss (10% below controls, P < 0.01; 16% above MAC-16, P < 0.01) and smaller decreases in fat-pad mass (21% below controls, P < 0.01). Core temperature in MAC16 mice was significantly lower (-2.4 degrees C, P < 0.01) than in controls, and pair-feeding had no effect. MAC16 mice showed significantly higher UCP1 mRNA levels in brown adipose tissue (BAT) than in controls (+63%, P < 0.01), and pair-feeding had no effect. UCP2 and -3 expression in BAT did not differ significantly between groups. By contrast, UCP2 mRNA levels in skeletal muscle were comparably increased in both MAC16 and pair-fed groups (respectively, 183 and 163% above controls; both, P < 0.05), with no significant difference between these two groups. Similarly, UCP3 mRNA was significantly higher than controls in both MAC16 (+163%, P < 0.05) and pair-fed (+253%, P < 0.01) groups, with no significant difference between the two experimental groups. Overexpression of UCP1 in BAT in MAC16-bearing mice may be an adaptive response to hypothermia, which is apparently induced by tumor products; increased thermogenesis in BAT could increase total energy expenditure and, thus, contribute to tissue wasting. Increased UCP2 and -3 expression in muscle are both attributable to reduced food intake and may be involved in lipid utilization during lipolysis in MAC16-induced cachexia.

The effect of moxonidine on feeding and body fat in obese Zucker rats: role of hypothalamic NPY neurones

The antihypertensive agent moxonidine, an imidazoline Ii-receptor agonist, also induces hypophagia and lowers body weight in the obese spontaneously hypertensive rat, but the central mediation of this action and the neuronal pathways that moxonidine may interact with are not known. We studied whether moxonidine has anti-obesity effects in the genetically-obese and insulin-resistant fa/fa Zucker rat, and whether these are mediated through inhibition of the hypothalamic neuropeptide Y (NPY) neurones. Lean and obese Zucker rats were given moxonidine (3 mg kg(-1) day(-1)) or saline by gavage for 21 days. Moxonidine decreased food intake throughout by 20% in obese rats (P<0.001) and by 8% in lean rats (P<0.001), and reduced weight gain that final body weight was 15% lower in obese (P<0.001) and 7% lower in lean (P<0.01) rats than their untreated controls. Plasma insulin and leptin levels were decreased in moxonidine-treated obese rats (P<0.01 and P<0.05), but unchanged in treated lean rats. Uncoupling protein-1 gene expression in brown adipose tissue was stimulated by 40-50% (P< or =0.05) in both obese and lean animals given moxonidine. Obese animals given moxonidine showed a 37% reduction in hypothalamic NPY mRNA levels (P = 0.01), together with significantly increased NPY concentrations in the paraventricular nucleus (P<0.05), but no changes in the arcuate nucleus or other nuclei; this is consistent with reduced NPY synthesis in the arcuate nucleus and blocked release of NPY in the paraventricular nucleus. In lean animals, moxonidine did not affect NPY levels or NPY mRNA. The hypophagic, thermogenic and anti-obesity effects of moxonidine in obese Zucker rats may be partly due to inhibition of the NPY neurones, whose inappropriate overactivity may underlie obesity in this model.

Hyperphagia in cold-exposed rats is accompanied by decreased plasma leptin but unchanged hypothalamic NPY

Chronic cold exposure stimulates sympathetically driven thermogenesis in brown adipose tissue (BAT), resulting in fat mobilization, weight loss, and compensatory hyperphagia. Hypothalamic neuropeptide Y (NPY) neurons are implicated in stimulating food intake in starvation, but may also suppress sympathetic outflow to BAT. This study investigated whether the NPY neurons drive hyperphagia in rats that have lost weight through cold exposure. Rats exposed to 4 degrees C for 21 days weighed 14% less than controls maintained at 22 degrees C (P < 0.001). Food intake increased after 3 days and remained 10% higher thereafter (P < 0.001). Increase BAT activity was confirmed by 64, 96, and 335% increases in uncoupling protein-1 mRNA at 2, 8, and 21 days. Plasma leptin decreased during prolonged cold exposure. Cold-exposed rats showed no significant changes in NPY concentrations in any hypothalamic regions or in hypothalamic NPY mRNA at any time. We conclude that the NPY neurons are not activated during cold exposure. This is in contrast with starvation-induced hyperphagia, but is biologically appropriate since enhanced NPY release would inhibit thermogenesis causing potentially lethal hypothermia. Other neuronal pathways must therefore mediate hyperphagia in chronic cold exposure.

Direct stimulation of BAT thermogenesis does not affect hypothalamic neuropeptide Y

Acute cold exposure which significantly stimulated thermogenesis in brown adipose tissue (BAT), also increased neuropeptide Y (NPY) levels in its hypothalamic sites of release without affecting NPY synthesis, suggesting that NPY release is acutely inhibited. To clarify whether these changes in NPY are the cause or consequence of BAT activation, we studied whether hypothalamic NPY and NPY mRNA levels in rats were affected by acute intraperitoneal injection of the beta 3-adrenoceptor agonist BRL 35135 (500 micrograms/kg), which directly activates BAT thermogenesis. BRL 35135 treatment doubled BAT uncoupling protein mRNA levels (p < 0.05), and increased core temperature by 0.4 degree C (p < 0.05), but neither hypothalamic regional NPY levels nor hypothalamic NPY mRNA levels were affected by BRL 35135. This suggests that the NPY changes induced by cold exposure are not the result of BAT activation, and is consistent with the hypothesis that decreased NPY release during cold exposure might disinhibit the sympathetic innervation that drives BAT thermogenesis.

Increased feeding in fatty Zucker rats by the thiazolidinedione BRL 49653 (rosiglitazone) and the possible involvement of leptin and hypothalamic neuropeptide Y

1. The thiazolidinedione BRL 49653 (rosiglitazone) induces hyperphagia and weight gain in obese, insulin-resistant fatty Zucker rats but not in lean insulin-sensitive rats. We investigated whether these responses might involve neuropeptide Y (NPY), leptin and insulin. 2. BRL 49653 (1 mg kg(-1) day(-1), orally) was given for 7 or 20 days to fatty and lean Zucker and Wistar rats. 3. In lean rats of either strain, BRL 49653 had no effect on food intake, body weight, plasma insulin and corticosterone, NPY or NPY mRNA levels. 4. Fatty rats given BRL 49653 showed a 30% increase in food intake and accelerated body weight gain (both P<0.01) after 7 and 20 days, but without significant changes in regional hypothalamic NPY or NPY mRNA levels. 5. Plasma leptin levels were twice as high in untreated fatty Zucker rats as in lean rats (P<0.01), but were unaffected by BRL 49653 given for 20 days. However, BRL 49653 reduced insulin levels by 42% and increased corticosterone levels by 124% in fatty rats (both P<0.01). 6. Hyperphagia induced in fatty Zucker rats by BRL 49653 does not appear to be mediated by either a fall in circulating leptin levels or increased activity of hypothalamic NPYergic neurones. The fall in plasma insulin and/or rise in corticosterone levels during BRL 49653 treatment may be involved, consistent with the postulated role of these hormones in the control of food intake.

Role of hypothalamic neuropeptide Y neurons in the defective thermogenic response to acute cold exposure in fatty Zucker rats

The fatty Zucker rat has impaired heat production and fails to mount an adequate thermogenic response to cold exposure, partly because of decreased sympathetic drive to thermogenesis in brown adipose tissue. Neuropeptide Y, synthesized in neurons of the hypothalamic arcuate nucleus and released in the paraventricular nucleus, stimulates feeding and inhibits brown adipose tissue activity. The neuropeptide Y neurons are overactive in fatty Zucker rats and are thought to contribute to hyperphagia, reduced energy expenditure and obesity. We have examined the relationship between thermogenic activity in brown adipose tissue (measured as uncoupling protein messenger RNA levels) and hypothalamic neuropeptide Y and neuropeptide Y messenger RNA levels in response to cold exposure (4 degrees C) for 2.5 and 18 h, in fatty and lean Zucker rats. In lean Zucker rats, cold exposure at 4 degrees C for 2.5 and 18 h significantly increased uncoupling protein messenger RNA levels by 3.5-fold (P<0.01) and 3.3-fold (P<0.01), respectively, compared with warm-maintained controls. Exposure to cold for 18 h also increased neuropeptide Y concentrations in the paraventricular nucleus (P<0.01) and ventromedial nucleus (P<0.001) in lean rats, with no change in neuropeptide Y messenger RNA after either 2.5 or 18 h. By contrast, fatty Zucker rats showed no significant changes in uncoupling protein messenger RNA (P>0.05) at either duration of cold exposure. There were also no significant changes in neuropeptide Y levels in any region nor in neuropeptide Y messenger RNA, with cold exposure for either period (P>0.05). In lean rats, cold exposure therefore stimulates brown fat uncoupling protein messenger RNA and also increases neuropeptide Y concentrations in its hypothalamic sites of release. We suggest that increased brown fat thermogenic capacity induced by cold in lean rats may be mediated, at least in part, by decreased neuropeptide Y release in the paraventricular nucleus, resulting in its accumulation in this site. Defective thermogenic responses in fatty rats may result from central dysregulation of brown adipose tissue due to sustained and non-suppressible overactivity of hypothalamic neuropeptide Y neurons.

[Determinaion of artificial synthetic pigment in the drug by reflection spectrophotometry]

Solid phase spectrophotometry is a new, simple, fast and sensitive trace analytical method. In this report, it is presented a method that the polyamide was used for the absorbence and the reflectances absorbances were measured directly with remodelled the colorimetric cell. Not only the trace inorganic ion can be analysed by the solid phase method, but also the artificial synthetic pigment in the drug can be determined, the results are satisfied.

Interactions between leptin and hypothalamic neuropeptide Y neurons in the control of food intake and energy homeostasis in the rat

Leptin acts on the brain to inhibit feeding, increase thermogenesis, and decrease body weight. Neuropeptide Y (NPY)-ergic neurons of the hypothalamic arcuate nucleus (ARC) that project to the paraventricular nuclei (PVN) and dorsomedial nuclei (DMH) are postulated to control energy balance by stimulating feeding and inhibiting thermogenesis, especially under conditions of energy deficit. We investigated whether leptin's short-term effects on energy balance are mediated by inhibition of the NPY neurons. Recombinant murine leptin (11 microg) injected into the lateral ventricle of fasted adult Wistar rats inhibited food intake by 20-25% between 2 and 6 h after administration, compared with saline-treated controls (P < 0.05). Uncoupling protein mRNA levels in brown adipose tissue (BAT) rose by 70% (P < 0.01). Leptin treatment significantly reduced NPY concentrations by 20-50% (P < 0.05) in the ARC, PVN, and DMH and significantly decreased hypothalamic NPY mRNA levels (0.61 +/- 0.02 vs. 0.78 +/- 0.03 arbitrary units; P < 0.01). A second study examined changes in leptin during 5 days' intracerebroventricular NPY administration (10 microg/day), which induced sustained hyperphagia and excessive weight gain. In NPY-treated rats, leptin mRNA levels in epididymal fat were comparable to those in saline-treated controls (0.94 +/- 0.17 vs. 1.0 +/- 0.28 arbitrary units; P > 0.1), but plasma leptin levels were significantly higher (4.88 +/- 0.66 vs. 2.85 +/- 0.20 ng/ml; P < 0.01). Leptin therefore acts centrally to decrease NPY synthesis and NPY levels in the ARC-PVN projection; reduced NPY release in the PVN may mediate leptin's hypophagic and thermogenic actions. Conversely, NPY-induced obesity results in raised circulating leptin concentrations. Leptin and the NPY-ergic ARC-PVN neurons may interact in a homeostatic loop to regulate body fat mass and energy balance.

Angiotensin receptors in myometrium and myometrial vessels from uteri of women during the follicular and luteal phases of the menstrual cycle and in late pregnancy

1. Receptors for angiotensin II were identified and characterized in membrane fractions from myometrial samples obtained at non-pregnant hysterectomy in women of reproductive age. Specific binding was also measured in paired samples of vascular and "vessel-free' myometrium. 2. A single class of high-affinity receptor sites was identified in the total myometrial preparations (n = 10), with a median equilibrium dissociation constant (Kd) of 0.122 nmol/l (range 0.065-0.465 nmol/l) and concentration of receptor sites (Bmax) of 149 fmol/mg protein (range 105-435 fmol/mg). Receptor characterization studies using losartan (an angiotensin type 1 receptor antagonist) and PD123177 (an angiotensin type 2 receptor antagonist) showed the myometrium to contain almost entirely type 2 receptors. 3. The median Kd and Bmax for specific angiotensin II binding in isolated myometrial vessel homogenates were 0.086 nmol/l (range 0.060-0.433) and 260 fmol/mg protein (range 197-737 fmol/mg) respectively. Vascular specific binding density was always higher in dissected out myometrial vessels than in paired vessel-free myometrium (median 372 compared with 120 fmol/mg protein; n = 20; P < 0.001). The specific binding in the paired samples was strongly correlated (r = 0.8904, P < 0.0001). 4. The specific binding of 125I-labelled angiotensin II in "vessel-free' myometrium was higher in samples from the follicular phase than in samples from the luteal phase (median 144 compared with 37 fmol/mg; P < 0.02). A similar trend was found in the vessels themselves, but this failed to reach statistical significance (459 compared with 225 fmol/mg; P = 0.051). 5. It is suggested that the down-regulation of the angiotensin type 2 receptors in the luteal (secretory) phase is a preparation for pregnancy, removing an inhibitory factor to uterine growth and vascularization and allowing greater prostacyclin synthesis.

Relationships between hypothalamic neuropeptide Y and food intake in the lactating rat

NPYergic neurons in the hypothalamic arcuate nucleus (ARC) that project to the paraventricular nucleus (PVN) are postulated to regulate food intake and energy balance. This projection is overactive in lactation and is thought to drive hyperphagia in this condition. We have explored further the relationship between hypothalamic NPY and food intake in lactation and tested the hypothesis that hypoinsulinemia is the stimulus to NPY neuronal activity. Compared with nonlactating controls (n = 10), freely fed lactating rats (n = 9) showed significantly increased (p < 0.05) NPY levels in the ARC and medial preoptic area (MPO), but there was no significant increase in whole hypothalamic NPY mRNA levels. Lactating rats (n = 8) that were restricted to control rats' food intake for 3 days showed generally higher hypothalamic NPY levels, with significantly higher concentrations than controls (p < 0.05) in the ARC, MPO, PVN, and lateral hypothalamic area (LHA); NPY mRNA levels were also significantly increased (p < 0.05). Across all three experimental groups, there was a significant inverse correlation between plasma insulin concentration and hypothalamic NPY mRNA levels (r = -0.39, p < 0.01). We conclude that the ARC-PVN projection is overactive in lactation and that this is not a consequence of hyperphagia. Hypoinsulinemia may stimulate these neurons, as it is thought to do in other conditions of energy deficit.

Dissociation of hypothalamic NPY from BAT uncoupling protein mRNA in rats exposed to 24 h thermoneutrality

Neuropeptide Y (NPY) is increasingly considered to be involved in the central regulation of energy balance. Our previous studies suggest that hypothalamic NPY neurons of the arcuatoparaventricular (ARC-PVN) projection are inhibited in association with the marked increases in brown adipose tissue (BAT) thermogenesis and uncoupling protein (UCP) gene expression in rats exposed to cold. We therefore hypothesized that the NPYergic ARC-PVN system would be activated in a thermoneutral environment, when energy expenditure falls to a minimum, and that this activation could mediate the fall in BAT activity. We measured regional hypothalamic NPY concentrations, hypothalamic NPY receptor binding, and NPY mRNA together with UCP mRNA levels in rats exposed to thermoneutrality (29 degrees C) for 24 h. At thermoneutrality, UCP mRNA levels fell to 42% of those in controls maintained at 22 degrees C, but there were no significant changes in hypothalamic NPY or NPY mRNA levels or in NPY receptor binding. We conclude that the fall in UCP mRNA expression occurring under short-term thermoneutral condition is mediated by neuroendocrine mechanisms other than increased activity of hypothalamic NPY neurons.

Nicotine administration reduces neuropeptide Y and neuropeptide Y mRNA concentrations in the rat hypothalamus: NPY may mediate nicotine's effects on energy balance

Neuropeptide Y (NPY) is synthesized in arcuate (ARC) neurons which project principally to the paraventricular nucleus (PVN). NPY injected into the PVN causes hyperphagia, reduced energy expenditure and eventually obesity, effects which are opposed by nicotine. We aimed to investigate whether nicotine's effects on energy balance might be mediated by inhibition of hypothalamic NPYergic neurons. Nicotine or saline was given for 1 or 12 days using osmotic minipumps, and additional groups of rats were food-restricted to the intake of the nicotine-treated groups to allow for the effects of hypophagia on hypothalamic NPY. One day's nicotine treatment (12 mg/kg/day) reduced food intake by 30% (P < 0.001) and body weight by 2% (P < 0.01 vs. controls). NPY mRNA levels were significantly reduced by 40% (P < 0.05) and NPY concentrations fell significantly by 33% in the ARC and PVN (both P < 0.01). Matched food restriction also reduced NPY levels significantly in the ARC and PVN (P < 0.02 vs. controls) but had no effect on NPY mRNA. 12 days' nicotine treatment (12 mg/kg/day) lowered cumulative food intake by 8% (P = 0.02) and body weight by 10% (P < 0.05). NPY mRNA levels rose by 40% (P < 0.05), while NPY levels again fell in the ARC and PVN (both P < 0.05). Food restriction, which induced weight loss comparable with that during nicotine treatment, increased NPY mRNA to levels that were 100% above controls (P < 0.01) and also significantly higher than in the nicotine-treated group (P < 0.05). Food restriction also reduced NPY peptide levels in the PVN (P < 0.02), but did not affect those in the ARC. In addition, 12 days' nicotine treatment significantly reduced plasma insulin levels compared with controls (P < 0.05). We suggest that nicotine may inhibit NPY synthesis in the hypothalamus, independently of any effects due to altered energy balance. Reduced activity of NPYergic neurons in the ARC-PVN projection may mediate the effects of nicotine on energy balance.

Methamphetamine- and apomorphine-induced changes in spontaneous motor activity using a new system to detect and analyze motor activity in mice

A new system was devised to detect animal spontaneous motor activity in more detail, and methamphetamine- and apomorphine-induced changes in spontaneous motor activity were analyzed using this system. The system consists of a doughnut-shaped cage with 36 units of detectors. Scanning of each detector unit was three-dimensionally carried out, and then scanning data were fed into a personal computer. These steps were completed within 0.1 sec and repeated. Spontaneous motor activity was analyzed as changes in parameters, such as total activity, locomotor activity, vertical activity (the number of rearings and the rearing time), motion time, and average speed. Regarding dependence on the dosages of methamphetamine and apomorphine, the time courses of changes in total activity and locomotor activity markedly differed from those for changes in vertical activity. Changes in the numbers of rearings and rearing time induced by 2 mg/kg methamphetamine peaked 40-80 min after administration, whereas those in other parameters did so 15-25 min after. Three mg/kg apomorphine-induced changes in total activity and locomotor activity showed two peaks 10-15 and 40-50 min after administration, respectively. At the same dosage, apomorphine markedly increased rearing time with slight but not significant effects on the number of rearings. These effects peaked 20-30 min after administration. These results indicate this system to be quite useful to detect and analyze drug-induced changes in spontaneous motor activity.

Serum dehydroepiandrosterone sulphate and pubertal development in Chinese girls

Serum dehydroepiandrosterone sulphate (DHEAS), estradiol (E2), luteinizing hormone (LH) and follicle stimulating hormone (FSH) were measured by radioimmunoassay in 170 healthy school girls from 7-16 years old. Blood samples from postmenarcheal girls were taken on days 6-10 of the menstrual cycle. Bone age, height, weight, breast and pubic hair development were also investigated. Of the four hormones measured, serum DHEAS displayed the earliest elevation, at 7 years and upwards. A significant DHEAS increment at chronological age 13 years was observed. Girls with earlier menarche had higher DHEAS level than girls having later menarche. Serum DHEAS levels also correlated with bone age, height, weight, subcutaneous fat and pubertal stages. The results suggest that adrenal androgen might be involved in the initiation of puberty and female maturation.