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1

Expression of leptin and long form of leptin receptor genes and proteins in pituitary of cyclic and pregnant pigs

100%

Siawrys G., Kaminski T., Smolinska N., Przala J.

Journal of Physiology and Pharmacology

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2007

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tom 58

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nr 4

Leptin is a multifunctional regulator in numerous tissues, including the pituitary. It is not known, whether the porcine pituitary is a source of leptin synthesis and possesses the leptin receptor protein. It is also unknown, if a relationship exists between expression levels of these proteins in the pituitary and physiological status of sows. Therefore, the aim of the study was 1] to examine, by Western-blotting analysis, the expression levels of leptin and the long form of leptin receptor (OB-Rb) in the porcine anterior (AP) and posterior (NP) pituitary gland during mid- and late-luteal phases of the oestrous cycle (days 10 - 12 and 14 - 16) as well as during two stages of early pregnancy (days 14 - 16 and 30 - 32); and 2] to localise, using in situ hybridisation method (ISH), the expression of leptin and OB-Rb genes in the pituitary gland in the above mentioned stages of the cycle and pregnancy. Western-blotting analysis showed that leptin protein expression in AP was higher in the late-luteal phase than in the mid-luteal phase, while OB-Rb protein expression in both lobes was higher in the mid-luteal phase. In turn, during pregnancy leptin protein content in AP and OB-Rb protein content in NP were more pronounced on days 14 - 16 than on days 30 - 32. Comparison of leptin and OB-Rb protein expression levels in AP between the mid-luteal phase and two periods of pregnancy showed, respectively, stimulation of leptin protein and inhibition of OB-Rb protein expressions during both examined stages of pregnancy. Taking AP from late-luteal phase as the point of reference, it was revealed stimulation of leptin expression during earlier period of pregnancy, whereas on days 30 - 32 of pregnancy both the hormone and its receptor expressions were diminished. In turn, comparison of leptin and OB-Rb protein expression levels in NP between the late-luteal phase and days 14 - 16 or 30 - 32 of pregnancy showed inhibition of leptin protein expression and stimulation of OB-Rb protein expression during pregnancy. Moreover, ISH studies localised leptin and OB-Rb mRNAs expression in the cells of AP as well as NP tissue during the two stages of the cycle and pregnancy. In conclusion, our findings suggest that leptin is produced within the pituitary in the pig and may participate in auto/paracrine manner in the regulation of this gland function during the luteal phase of the oestrous cycle and early pregnancy.

2

Leptin and long form of leptin receptor genes expression in the hypothalamus and pituitary during the luteal phase and early pregnancy in pigs

100%

Kaminski T., Smolinska N., Gajewska A., Siawrys G., Okrasa S., Kochman K., Przala J.

Journal of Physiology and Pharmacology

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2006

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tom 57

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nr 1

Leptin is a polypeptide that plays a key role in the regulation of energy homeostasis and is also linked, among others, to mechanisms controlling reproductive processes. Data concerning the involvement of leptin in controlling reproductive functions at the level of hypothalamus and pituitary in the pig are limited. Therefore, in the present study, an expression of genes coding for leptin and long-form leptin receptor (Ob-Rb) was determined by a semiquantitative reverse transcription polymerase chain reaction (RT-PCR) in the discrete areas of porcine hypothalamus (medial basal hypothalamus - MBH, preoptic area - POA, stalk median eminence - SME) and pituitary (anterior - AP and posterior/neural - NP parts) during the luteal phase of the cycle (days 10-12 and 14-16) and two early stages of pregnancy (days 14-16 and 30-32). Leptin gene expression in MBH was found to be higher in the mid- than in the late-luteal phase, whereas in other structures studied it remained unchanged during these periods. More pronounced differences were noted in expression of Ob-Rb gene, which was increased in MBH, AP and NP during the late-luteal phase in comparison to the mid-luteal one, whilst the relationship in the POA was reversed. In turn, during pregnancy, leptin gene expression in all tested areas of hypothalamus as well as Ob-Rb mRNA content in MBH were higher on days 30-32 than on days 14-16. In contrast, in the anterior pituitary, Ob-Rb gene expression was more pronounced on days 14-16 than during later stage of pregnancy. Comparison of leptin and Ob-Rb mRNA content in studied structures between the mid-luteal phase and days 14-16 of pregnancy revealed inhibition of leptin gene expression in almost all examined tissues (MBH, POA, SME, NP) during early pregnancy whereas Ob-Rb gene expression was inhibited in POA but stimulated in both parts of the pituitary during this stage. In summary, obtained results suggest an involvement of leptin in the regulation of hypothalamic-pituitary axis activity during both the luteal phase of the cycle and early pregnancy in pigs.

3

The expression of short form of leptin receptor gene during early pregnancy in the pig examined by quantitative real time RT-PCR

100%

Bogacka I., Przala J., Siawrys G., Kaminski T., Smolinska N.

Journal of Physiology and Pharmacology

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2006

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tom 57

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nr 3

The study was conducted to determine gene expression of short form of leptin receptor (OB-Rs) using real time RT-PCR in distinct tissues of the central nervous system (medial basal hypothalamus, preoptic area, stalk median eminence), pituitary and reproductive tract (corpus luteum, ovarian stroma, endometrium, myometrium, and trophoblast) in pigs during luteal phase of the cycle and early gestation. The expression of OB-Rs mRNA in SME did not differ between analyzed stages of the cycle and pregnancy. In anterior pituitary, transcript levels were almost identical in mid- and late-luteal periods, but significantly decreased on 30-32 day of gestation when compared with day 14-16. In posterior pituitary, significantly higher expression was observed in two periods of pregnancy when compared with two stages of luteal phase. In corpus luteum the lowest expression was observed during days 10-12 of the cycle, whereas markedly higher levels were detected in late-luteal stage and gestation. In ovarian stroma the expression of Ob-Rs mRNA was markedly diminished during days 14-16 of the cycle when compared with days: 10-12 of the cycle and 30-32 of pregnancy. The expression of Ob-Rs mRNA in endometrium and myometrium reached the lowest levels on 30-32 day of pregnancy in comparison with earlier stage, 14-16 day. Summarizing, the expression of the short form of leptin receptor mRNA was found in majority of tested tissues including hypothalamus, pituitary and reproductive tract and their levels fluctuated depending on the phase (mid- and late-luteal) of the cycle and the day of pregnancy (early and late stage of implantation).

4

Superactive human leptin antagonist reverses leptin-induced excessive progesterone and testosterone secretion in porcine ovarian follicles by blocking leptin receptors

84%

Gregoraszczuk E. L., Rak A.

Journal of Physiology and Pharmacology

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2015

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tom 66

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nr 1

5

Immunolocalization of leptin receptor and mRNA expression of leptin and estrogen receptors as well as caspases in the chorioallantoic membrane (CAM) of the chicken embryo

84%

Grzegorzewska A. K., Lis W., Sechman A.

Folia Biologica

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2016

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tom 64

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nr 2

6

Leptin is able to stimulate pancreatic enzyme secretion via activation of duodeno-pancreatic reflex and CCK release

84%

Nawrot-Porabka K., Jaworek J., Leja-Szpak A., Palonek M., Szklarczyk J., Konturek S. J., Pawlik W. W.

Journal of Physiology and Pharmacology. Supplement

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2004

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tom 55

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nr 2

47-57

Leptin, 16- kDa protein produced and secreted from white adipocytes is known to regulate food intake and energy expenditure. Leptin receptors have been detected in the pancreas and it has been shown that systemic application of this protein diminished postprandial pancreatic secretion. Leptin is also produced in the stomach and released into the gastrointestinal lumen but the implication of luminal leptin in the regulation of pancreatic enzyme secretion has not been elucidated. The aim of our study was to evaluate the effects of intraduodenal (i.d.) leptin administration on pancreatic enzyme secretion and to assess the involvent of afferent nerves and CCK in above effects. The secretory studies were carried out on anaesthetized Wistar rats with acute pancreatic fistulae. Leptin was administered to the animals at doses of 0.1 1.0 or 10.0 µg/kg i.d. Tarazepide (2.5 mg/kg i.d.), a CCK1 receptor antagonist, was given to the rats prior to the application of leptin. Rats with capsaicin deactivated sensory nerves were used in part of the study. Samples of pancreatic juice were taken at 15 min intervals to measure the volume flow and protein and amylase concentrations. CCK plasma level was measured by radioimmunoassay (RIA) following administration of leptin to the rats. Intraduodenal administration of leptin (1.0 or 10.0 µg/kg) to the fasted rats significantly and dose-dependently increased pancreatic protein and amylase outputs. Pancreatic secretory responses to leptin were totally abolished by prior capsaicin deactivation of sensory nerves or by pretreatment of the rats with tarazepide. Under basal conditions plasma CCK level averaged about 15.46 ± 1,4 pg/ml. Exogenous leptin, given i.d. at doses of 0.1 1.0 or 10.0 µg/kg i.d. to the rats with intact or capsaicin-deactivated sensory nerves resulted in dose-dependent rise of plasma CCK level, reaching the highest value at the dose of 10.0 µg/kg i.d. We conclude that leptin given i.d. stimulates pancreatic enzyme secretion and this effect could be related to the stimulation of CCK release and activation of duodeno-pancreatic reflexes.

7

Effects of peripheral or central GLP-1 receptor blockade on leptin-induced suppression of appetite

84%

Nowak A., Bojanowska E.

Journal of Physiology and Pharmacology

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2008

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tom 59

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nr 3

501-510

Leptin and glucagon-like peptide-1 (GLP-1) were proved to act in concert to control the activity of feeding centres. Since leptin receptor was identified in the gut endocrine L cells and neurons producing GLP-1, we have checked whether GLP-1 mediates the effects of leptin on feeding and drinking behaviour. To this aim, an intraperitoneal or intracerebroventricular injection of exendin (9 - 39), a GLP-1 antagonist, (50 or 10 µg per rat, respectively) followed by leptin (100 or 5 µg per rat, respectively) was made and 24-hour food intake and body weight changes were measured. Previous injection of exendin (9 - 39) completely abolished the suppressory effect of peripheral leptin on food intake and body weight gain. Moreover, exendin (9 - 39) significantly attenuated the effect of intracerebroventricular leptin on food but not water consumption. It is concluded that intact GLP-1 signalling is necessary to mediate the effect of leptin on food intake in the rat. Conversely, leptin seems to affect the thirst center function independently of GLP-1. Also, these findings produce further evidence for close interactions between long- and short-term factors regulating the activity of feeding centres.

8

mRNA expression and immunocytochemical localization of leptin receptor in the oviduct of the laying hen [Gallus domesticus]

84%

Grzegorzewska A. K., Paczoska-Eliasiewicz H. E., Rzasa J.

Folia Biologica

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2008

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tom 56

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nr 3-4

179-185

9

Placental leptin and its receptor genes expression in pregnancies complicated by type 1 diabetes

84%

Iciek R., Wender-Ozegowska E., Zawiejska A., Mikolajczak P., Mrozikiewicz P. M., Pietryga M., Brazert J.

Journal of Physiology and Pharmacology

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2013

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tom 64

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nr 5

10

Expression of leptin receptor and suppressor of cytokine signaling-3 genes in adenohypophysis of normal-fed and fasted cows

84%

Amstalden M., Spencer T. E., Harms P. G., Williams G. L.

Reproductive Biology

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2005

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tom 05

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nr 2

11

The transcript expression profile of the leptin receptor-coding gene assayed with the oligonucleotide microarray technique - could this be an anorexia nervosa marker?

84%

Janas-Kozik M., Mazurek U., Krupka-Matuszczyk I., Stachowicz M., Glogowska-Ligus J., Wilczok T.

Cellular and Molecular Biology Letters

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2006

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tom 11

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nr 1

Anorexia nervosa is a serious eating disorder with the highest mortality rate of any psychiatric disorder. The DSM-IV classification differentiates two AN types: the restricting type (AN-R) and the binge-eating/purging type (AN-BP). Leptin (LEP) levels can be thought of as a signal to the body of its energy reserves. The leptin receptor (including all its mRNA isoforms) is expressed in many tissues. Our aim was to discover the transcript expression profile of the LEP receptor-coding gene in the peripheral blood mononuclears in AN-R and AN-BP patients. Three young women suffering from Anorexia nervosa (one with AN-BP and two with AN-R) took part in the study, along with three non-anorexic subjects as our reference group. LEP receptor gene expression was examined using the oligonucleotide microarray method (HG-U133A, Affymetrix). The results were normalized using RMAExpress. Next, the accumulation analysis method was used (clustering). Hierarchical clustering resulted in three groups of separate clusters. The first group (cluster I) consisted of AN-R patients. The next group (cluster II) consisted of reference group patients suffering from different psychic disorders not related to eating disorders. Cluster III consisted of two patients — the first with AN-BP and the second with an adaptive disorder.

12

The effect of the polymorphism of leptin [LEP], leptin receptor [LEPR] and osteopontin [OPN] genes on selected reproduction traits of synthetic Line 990 sows

84%

Korwin-Kossakowska A., Kamyczek M., Cieslak D., Pierzchala M., Kuryl J.

Animal Science Papers and Reports

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2002

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tom 20

|

nr 3

13

Leptin concentration in blood and its hypothalamic binding are poorly related with amount of fat and growth rate in pigs

84%

Mackowiak P., Nowak K. W., Kaczmarek P., Szydlowski M., Kamyczek M., Eckert R., Rozycki M., Switonski M.

Journal of Animal and Feed Sciences

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2004

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tom 13

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nr 1

14

Expression of leptin and its receptor in female breast cancer in relation with selected apoptotic markers

67%

Koda M., Sulkowska M., Kanczuga-Koda L., Jarzabek K., Sulkowski S.

Folia Histochemica et Cytobiologica. Supplement

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2007

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tom 45

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nr 1

187-191

15

Ultrastructural response of arcuate nucleus neurons to fasting in aged rats

67%

Kubasik-Juraniec J., Zauszkiewicz-Pawlak A., Kotlarz G., Wozniak M., Knap N.

Folia Morphologica

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2009

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tom 68

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nr 4

218-223

The arcuate nucleus of the hypothalamus (ARH) is involved in the control of energy homeostasis. Leptin — an adipocyte derived hormone — is known to act on the hypothalamic nuclei and thus to control body weight by food intake reduction. Oxidative stress is believed to be implicated in leptin signalling. However, its relevance for leptin-induced signal transduction within ARH remains unclear. The goal of the study was to investigate the effect of fasting on morphological alterations of the neuronal endoplasmic reticulum/Golgi network as well as on the expression of leptin receptors in the arcuate nucleus of aged rats. Male Wistar rats, aged 24 months, were fasted for 96 hours. The control animals were fed ad libitum. Membranous whorls in the ARH neurons were visualized using the electron microscopy technique. Leptin receptors in the membranes of ARH neurons were determined immunohistochemically (IHC), and soluble leptin receptors in the plasma as well as plasma isoprostanes were quantified immunochemically (ELISA). An intense formation of membranous whorls was observed, directly associated with the cisternae of the rough endoplasmic reticulum, as well as lamellar bodies. Interestingly, the whorls were often localized near a well-developed Golgi complex. Moreover, some Golgi complexes displayed an early stage of whorl formation. Groups of residual lipofuscin granules were found in the immediate proximity of the whorls. An increased immunoreactivity with neuronal leptin receptors suggests that hypersensitive neurons may still effectively respond to the fasting serum levels of leptin, mediating ultrastructural transformation of ARH neurons during short- -term fasting. Having observed a significant accumulation of lipofuscin granules and a marked increase of total 8-isoprostane serum level in the fasting rats, we hypothesize that signal transduction within the neurons of ARH is dependent on oxidative stress phenomena. (Folia Morphol 2009; 68, 4: 218–223)

16

Frequency of distribution of leptin receptor gene polymorphism in obstructive sleep apnea patients

67%

Popko K., Gorska E., Wasik M., Stoklosa A., Plywaczewski R., Winiarska M., Gorecka D., Sliwinski P., Demkow U.

Journal of Physiology and Pharmacology. Supplement

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2007

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tom 58

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nr 5

17

Leptin is the modulator of HSP60 gene expression in AR42J cells

67%

Bonior J., Jaworek J., Konturek S. J., Pawlik W. W.

Journal of Physiology and Pharmacology. Supplement

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2006

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tom 57

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nr 7

135-143

Leptin, circulating protein involved in the control of body weight and energy expenditure received attention as a modulator of immune response of the organism. Leptin receptors have been detected in the pancreas and experimental studies have shown that leptin protects the pancreas against the damage induced by caerulein overstimulation. Heat shock proteins (HSP) are endogenous proteins produced by various cells exposed to high temperature or to the noxious agents. HSP protect the cells against various environmental and endogenous stressors. The implication of HSP60 in the leptin-induced pancreatic protection has not been examined yet. The aim of this study was: to investigate the changes of HSP60 mRNA signal in the pancreatic AR42J cells subjected to caerulein and leptin. AR42J cells were incubated in standart medium at 37°C for: 0, 1, 3, 5, 12 or 24 h, under basal conditions. Incubation time of 3 h was selected for the next experiments. AR42J cells were incubated in presence of caerulein (10-11, 10-9 or 10-7M), leptin (10-8 or 10-6M), or combination of above. Gene expression for HSP60 was determined by RT-PCR. The mRNA signal for HSP60 has been observed in AR42J pancreatic cells under basal conditions. Incubation of AR42J cells in presence of leptin (10-8 or 10-6M) resulted in the significant increase of gene expression for HSP60 in both groups of AR42J cells. Caerulein stimulation reduced mRNA signal for HSP60. The strongest mRNA signal for HSP60 has been observed after the exposition of AR42J cells to combination of leptin and caerulein. We conclude that: 1. Gene expression for HSP60 has been detected in pancreatic AR42J cells under basal conditions. 2. HSP60 gene expression was significantly increased in pancreatic AR42J cells stimulated by leptin whereas caerulein reduced this signal. 3. The strongest gene expression for HSP60 has been detected in the cells incubated with combination of caerulein and leptin.

18

Aspects of central and peripheral regulation of reproduction in mammals

67%

Wojcik-Gladysz A., Nowak K. W., Pierzchala-Koziec K., Wankowska M., Misztal T., Polkowska J., Nowak M., Kaczmarek P., Gorska T., Szczepankiewicz D., Zubel J.

Reproductive Biology

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2006

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tom 06

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nr Suppl.1

Ograniczanie wyników

Expression of leptin and long form of leptin receptor genes and proteins in pituitary of cyclic and pregnant pigs

Leptin and long form of leptin receptor genes expression in the hypothalamus and pituitary during the luteal phase and early pregnancy in pigs

The expression of short form of leptin receptor gene during early pregnancy in the pig examined by quantitative real time RT-PCR

Superactive human leptin antagonist reverses leptin-induced excessive progesterone and testosterone secretion in porcine ovarian follicles by blocking leptin receptors

Immunolocalization of leptin receptor and mRNA expression of leptin and estrogen receptors as well as caspases in the chorioallantoic membrane (CAM) of the chicken embryo

Leptin is able to stimulate pancreatic enzyme secretion via activation of duodeno-pancreatic reflex and CCK release

Effects of peripheral or central GLP-1 receptor blockade on leptin-induced suppression of appetite

mRNA expression and immunocytochemical localization of leptin receptor in the oviduct of the laying hen [Gallus domesticus]

Placental leptin and its receptor genes expression in pregnancies complicated by type 1 diabetes

Expression of leptin receptor and suppressor of cytokine signaling-3 genes in adenohypophysis of normal-fed and fasted cows

The transcript expression profile of the leptin receptor-coding gene assayed with the oligonucleotide microarray technique - could this be an anorexia nervosa marker?

The effect of the polymorphism of leptin [LEP], leptin receptor [LEPR] and osteopontin [OPN] genes on selected reproduction traits of synthetic Line 990 sows

Leptin concentration in blood and its hypothalamic binding are poorly related with amount of fat and growth rate in pigs

Expression of leptin and its receptor in female breast cancer in relation with selected apoptotic markers

Ultrastructural response of arcuate nucleus neurons to fasting in aged rats

Frequency of distribution of leptin receptor gene polymorphism in obstructive sleep apnea patients

Leptin is the modulator of HSP60 gene expression in AR42J cells

Aspects of central and peripheral regulation of reproduction in mammals