scholarly journals Modulation of Leptin and Leptin Receptor Expression in Mice Acutely Infected with Neospora caninum

Pathogens ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 587
Author(s):  
Luzia Teixeira ◽  
Alexandra Correia ◽  
Bárbara M. Oliveira ◽  
Ana Pinto ◽  
Paula G. Ferreira ◽  
...  
Keyword(s):  
Leptin Receptor ◽  
Neospora Caninum ◽  
Acute Infection ◽  
Elevated Serum ◽  
Serum Levels ◽  
Receptor Expression ◽  
Transcript Variant ◽  
Mrna Levels ◽  
Caninum Infection ◽  
Innate And Adaptive Immunity

Neospora caninum is an apicomplexan parasite that in cattle assumes particular importance, as it is responsible for abortions reported worldwide. Leptin is an adipokine mainly secreted by adipocytes, which beside its role in maintaining metabolic homeostasis also has important effects in both innate and adaptive immunity. In previous work, we showed that mice chronically infected with N. caninum had elevated serum leptin levels. Here, we sought to assess whether acute infection with N. caninum infection influenced the production of this adipokine as well as leptin receptor mRNA levels. Our results show that acute infection with N. caninum led to decreased leptin serum levels and mRNA expression in adipose tissue. A decrease in leptin receptor transcript variant 1 mRNA (long isoform) and leptin receptor transcript variant 3 mRNA (one of the short isoforms) expression was also observed. An increase in the number of cells staining positive for leptin in the liver of infected mice was observed, although this increase was less marked in Interleukin (IL)-12/IL-23 p40-deficient mice. Overall, our results show that N. caninum infection also influences leptin production during acute infection.

scholarly journals Sustained high expression of multiple APOBEC3 cytidine deaminases in systemic lupus erythematosus

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Danielle Perez-Bercoff ◽  
Hélène Laude ◽  
Morgane Lemaire ◽  
Oliver Hunewald ◽  
Valérie Thiers ◽  
...  
Keyword(s):  
Systemic Lupus Erythematosus ◽  
Cell Death ◽  
Lupus Erythematosus ◽  
Immunosuppressive Treatment ◽  
Elevated Serum ◽  
Serum Levels ◽  
Chronic Inflammatory Disease ◽  
Mrna Levels ◽  
Systemic Lupus ◽  
Inflammatory Conditions

AbstractAPOBEC3 (A3) enzymes are best known for their role as antiviral restriction factors and as mutagens in cancer. Although four of them, A3A, A3B, A3F and A3G, are induced by type-1-interferon (IFN-I), their role in inflammatory conditions is unknown. We thus investigated the expression of A3, and particularly A3A and A3B because of their ability to edit cellular DNA, in Systemic Lupus Erythematosus (SLE), a chronic inflammatory disease characterized by high IFN-α serum levels. In a cohort of 57 SLE patients, A3A and A3B, but also A3C and A3G, were upregulated ~ 10 to 15-fold (> 1000-fold for A3B) compared to healthy controls, particularly in patients with flares and elevated serum IFN-α levels. Hydroxychloroquine, corticosteroids and immunosuppressive treatment did not reverse A3 levels. The A3AΔ3B polymorphism, which potentiates A3A, was detected in 14.9% of patients and in 10% of controls, and was associated with higher A3A mRNA expression. A3A and A3B mRNA levels, but not A3C or A3G, were correlated positively with dsDNA breaks and negatively with lymphopenia. Exposure of SLE PBMCs to IFN-α in culture induced massive and sustained A3A levels by 4 h and led to massive cell death. Furthermore, the rs2853669 A > G polymorphism in the telomerase reverse transcriptase (TERT) promoter, which disrupts an Ets-TCF-binding site and influences certain cancers, was highly prevalent in SLE patients, possibly contributing to lymphopenia. Taken together, these findings suggest that high baseline A3A and A3B levels may contribute to cell frailty, lymphopenia and to the generation of neoantigens in SLE patients. Targeting A3 expression could be a strategy to reverse cell death and the generation of neoantigens.

scholarly journals Thrombopoietin in Patients With Congenital Thrombocytopenia and Absent Radii: Elevated Serum Levels, Normal Receptor Expression, But Defective Reactivity to Thrombopoietin

Blood ◽  
1997 ◽  
Vol 90 (2) ◽  
pp. 612-619 ◽  
Author(s):  
Matthias Ballmaier ◽  
Harald Schulze ◽  
Gabriele Strauβ ◽  
Klara Cherkaoui ◽  
Nicole Wittner ◽  
...  
Keyword(s):  
Elevated Serum ◽  
Signal Transduction Pathway ◽  
Adenosine Diphosphate ◽  
Serum Levels ◽  
Receptor Expression ◽  
Healthy Controls ◽  
Transduction Pathway ◽  
Platelet Response ◽  
Tar Syndrome

The pathophysiology of thrombocytopenia in the syndrome of thrombocytopenia with absent radii (TAR) is not yet understood. We examined thrombopoietin (TPO) serum levels and the in vitro reactivity of platelets to TPO in five patients affected with TAR syndrome. We found elevated TPO serum levels in all patients tested, excluding a TPO production defect as cause for thrombocytopenia in TAR syndrome. In addition, we found similar expression of the TPO receptor c-Mpl on the surface of platelets from TAR patients (5 of 5) and a similar molecular weight of the receptor as compared with healthy controls (4 of 4). Platelet response to adenosine diphosphate or thrombin receptor agonist peptide SFLLRN (TRAP) was normal in TAR patients. However, in contrast to results with healthy controls we could show absence of in vitro reactivity of platelets from TAR patients to recombinant TPO as measured by testing TPO synergism to adenine diphosphate and TRAP in platelet activation. TPO induced tyrosine phosphorylation of platelet proteins was completely absent (3 of 4) or markedly decreased (1 of 4). Our results indicate that defective megakaryocytopoiesis/thrombocytopoiesis in TAR syndrome is not caused by a defect in TPO production but a lack of response to TPO in the signal transduction pathway of c-Mpl.

scholarly journals Serum and Tissue Expression Levels of Leptin and Leptin Receptor Are Putative Markers of Specific Feline Mammary Carcinoma Subtypes

2021 ◽  
Vol 8 ◽  
Author(s):  
Andreia Gameiro ◽  
Catarina Nascimento ◽  
Ana Catarina Urbano ◽  
Jorge Correia ◽  
Fernando Ferreira
Keyword(s):  
Mammary Carcinoma ◽  
Leptin Receptor ◽  
Elevated Serum ◽  
Disease Free Survival ◽  
Serum Levels ◽  
Her2 Positive ◽  
Serum Leptin ◽  
Expression Levels ◽  
Luminal B ◽  
Feline Mammary Carcinoma

Obesity is an established risk factor for breast cancer in post-menopausal women, being associated with elevated serum levels of leptin. Although overweight is a common condition in cat, the role of leptin and its receptor in feline mammary carcinoma remains unsettled. In this study, serum leptin and leptin receptor (ObR) levels were investigated in 58 cats with mammary carcinoma and compared with those of healthy animals, as were the expression levels of leptin and ObR in tumor tissues. The results showed that the Free Leptin Index is significantly decreased in cats with mammary carcinoma (p = 0.0006), particularly in those with luminal B and HER2-positive tumors, and that these animals also present significantly lower serum leptin levels (p < 0.0001 and p < 0.005, respectively). Interestingly, ulcerating tumors (p = 0.0005) and shorter disease-free survival (p = 0.0217) were associated to serum leptin levels above 4.17 pg/mL. In contrast, elevated serum ObR levels were found in all cats with mammary carcinoma (p < 0.0001), with levels above 16.89 ng/mL being associated with smaller tumors (p = 0.0118), estrogen receptor negative status (p = 0.0291) and increased serum levels of CTLA-4 (p = 0.0056), TNF-α (p = 0.0025), PD-1 (p = 0.0023), and PD-L1 (p = 0.0002). In tumor samples, leptin is overexpressed in luminal B and triple-negative carcinomas (p = 0.0046), whereas ObR is found to be overexpressed in luminal B tumors (p = 0.0425). Altogether, our results support the hypothesis that serum levels of leptin and ObR can be used as biomarkers of specific feline mammary carcinoma subtypes, and suggests the use of leptin antagonists as a therapeutic tool, reinforcing the utility of the cat as a cancer model.

Acute food deprivation and chronic food restriction differentially affect hypothalamic NPY mRNA expression

2003 ◽  
Vol 285 (5) ◽  
pp. R1030-R1036 ◽  
Author(s):  
Sheng Bi ◽  
Benjamin M. Robinson ◽  
Timothy H. Moran
Keyword(s):  
Gene Expression ◽  
Body Weight ◽  
Food Deprivation ◽  
Food Restriction ◽  
Leptin Receptor ◽  
Receptor Gene ◽  
Body Weight Loss ◽  
Receptor Expression ◽  
Mrna Levels ◽  
Chronic Food Restriction

Although acute food deprivation and chronic food restriction both result in body weight loss, they produce different metabolic states. To evaluate how these two treatments affect hypothalamic peptide systems involved in energy homeostasis, we compared patterns of hypothalamic neuropeptide Y (NPY), agouti-related protein (AgRP), proopiomelanocotin (POMC), and leptin receptor gene expression in acutely food-deprived and chronically food-restricted rats. Both acute food deprivation and chronic food restriction reduced body weight and circulating leptin levels and resulted in increased arcuate NPY and decreased arcuate POMC gene expression. Arcuate AgRP mRNA levels were only elevated in acutely deprived rats. NPY gene expression was increased in the compact subregion of the dorsomedial hypothalamus (DMH) in response to chronic food restriction, but not in response to acute food deprivation. Leptin receptor expression was not affected by either treatment. Double in situ hybridization histochemistry revealed that, in contrast to the situation in the arcuate nucleus, NPY and leptin receptor mRNA-expressing neurons were not colocalized in the DMH. Together, these data suggest that arcuate and DMH NPY gene expression are differentially regulated. DMH NPY-expressing neurons do not appear to be under the direct control of leptin signaling.

scholarly journals Effect of Qing’e Decoction on Leptin/Leptin Receptor and Bone Metabolism in Naturally Aging Rats

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Pan Sun ◽  
Yuanyuan Zhang ◽  
Zhenpu Wei ◽  
Zhiqiang Wang ◽  
Shiming Guo ◽  
...  
Keyword(s):  
Bone Metabolism ◽  
Bone Tissue ◽  
Bone Strength ◽  
Bone Quality ◽  
Leptin Receptor ◽  
Serum Levels ◽  
Mrna Levels ◽  
Aging Rats ◽  
Bone Aging ◽  
Age And Sex

Senile osteoporosis (SOP) is a common disease that has decreased bone strength as its main symptom. There is currently no medication that can treat SOP, and traditional Chinese medicine has advantages in slowing down bone aging. The present study aimed to observe the effects of Qing’e decoction on leptin, leptin receptor, sex hormone, and biochemical markers of bone metabolism in naturally aging rats and to explore its mechanism in regulating bone metabolism. The results revealed that, with the increase in age, the bone mineral density (BMD), bone strength, bone trabecula sparse, serum levels of leptin receptor (LEP-R), estradiol (E2), testosterone (T), core binding-factor α-1 (Cbfα-1), collagen-I (COL-I) and osteocalcin (OC), and the mRNA levels of leptin (LEP) and LEP-R in bone tissue decreased, while serum LEP levels increased in the female and male NS groups. The serum levels of LEP, LEP-R, E2, T, osteoprotegerin, Cbfα-1, COL-I, OC and bone alkaline phosphatase, and the mRNA levels of LEP and LEP-R in bone tissue in the female and male QED groups were higher than those in the same age and sex NS group, while the BMD, bone trabecular area percentage, maximum load, and maximum stress in the female and male QED groups were significantly higher than those in the same age and sex NS group. In conclusion, with the increase in age, the bone quality of naturally aging rats decreased gradually. Qing’e decoction can regulate the bone metabolism and increase the bone quality and delay bone aging, which may be achieved by increasing sex hormone, LEP, and LEP-R levels.

scholarly journals Increased Expression of the Leptin Gene in Adipose Tissue of Patients with Chronic Kidney Disease–The Possible Role of an Abnormal Serum Fatty Acid Profile

Metabolites ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 98
Author(s):  
Justyna Korczyńska ◽  
Aleksandra Czumaj ◽  
Michał Chmielewski ◽  
Maciej Śledziński ◽  
Adriana Mika ◽  
...  
Keyword(s):  
Gene Expression ◽  
Chronic Kidney Disease ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
Kidney Disease ◽  
Elevated Serum ◽  
Serum Levels ◽  
Mrna Levels ◽  
Serum Fatty Acid ◽  
Serum Leptin

Chronic kidney disease (CKD) is associated with an increased level of leptin and an abnormal fatty acid (FA) profile in the serum. However, there are no data on the associations between them, and the reason for increased serum levels in patients with CKD is not well elucidated. Recently, we found that a CKD-related abnormal FA profile caused significant changes in the expression of genes involved in lipid metabolism in hepatocytes. The aim of this study was to examine whether leptin gene expression in subcutaneous adipose tissue (SAT) of patients with CKD may contribute to increased serum levels of this adipokine and whether the abnormal serum FA profile observed in CKD patients has an impact on leptin gene expression in adipocytes. The FA profile was measured in serum samples from patients with CKD and controls by GC–MS. The relative mRNA levels of leptin were measured in SAT by Real-Time PCR. Moreover, the effect of the CKD-related abnormal FA profile on leptin gene expression was studied in in vitro cultured 3T3-L1 adipocytes. Patients with CKD had higher concentrations of serum leptin than controls and higher expression level of the leptin gene in SAT. They also had increased serum monounsaturated FAs and decreased polyunsaturated FAs. The incubation of adipocytes with FAs isolated from CKD patients resulted in an increase of the levels of leptin mRNA. Increased leptin gene expression in SAT may contribute to elevated concentrations of these adipokine in patients with CKD. CKD-related alterations of the FA profile may contribute to elevated serum leptin concentrations in patients with CKD by increasing the gene expression of this adipokine in SAT.

scholarly journals Thrombopoietin in Patients With Congenital Thrombocytopenia and Absent Radii: Elevated Serum Levels, Normal Receptor Expression, But Defective Reactivity to Thrombopoietin

Blood ◽  
1997 ◽  
Vol 90 (2) ◽  
pp. 612-619 ◽  
Author(s):  
Matthias Ballmaier ◽  
Harald Schulze ◽  
Gabriele Strauβ ◽  
Klara Cherkaoui ◽  
Nicole Wittner ◽  
...  
Keyword(s):  
Elevated Serum ◽  
Signal Transduction Pathway ◽  
Adenosine Diphosphate ◽  
Serum Levels ◽  
Receptor Expression ◽  
Healthy Controls ◽  
Transduction Pathway ◽  
Platelet Response ◽  
Tar Syndrome

Abstract The pathophysiology of thrombocytopenia in the syndrome of thrombocytopenia with absent radii (TAR) is not yet understood. We examined thrombopoietin (TPO) serum levels and the in vitro reactivity of platelets to TPO in five patients affected with TAR syndrome. We found elevated TPO serum levels in all patients tested, excluding a TPO production defect as cause for thrombocytopenia in TAR syndrome. In addition, we found similar expression of the TPO receptor c-Mpl on the surface of platelets from TAR patients (5 of 5) and a similar molecular weight of the receptor as compared with healthy controls (4 of 4). Platelet response to adenosine diphosphate or thrombin receptor agonist peptide SFLLRN (TRAP) was normal in TAR patients. However, in contrast to results with healthy controls we could show absence of in vitro reactivity of platelets from TAR patients to recombinant TPO as measured by testing TPO synergism to adenine diphosphate and TRAP in platelet activation. TPO induced tyrosine phosphorylation of platelet proteins was completely absent (3 of 4) or markedly decreased (1 of 4). Our results indicate that defective megakaryocytopoiesis/thrombocytopoiesis in TAR syndrome is not caused by a defect in TPO production but a lack of response to TPO in the signal transduction pathway of c-Mpl.

scholarly journals Region-Specific Leptin Resistance within the Hypothalamus of Diet-Induced Obese Mice

Endocrinology ◽  
2004 ◽  
Vol 145 (11) ◽  
pp. 4880-4889 ◽  
Author(s):  
Heike Münzberg ◽  
Jeffrey S. Flier ◽  
Christian Bjørbæk
Keyword(s):  
High Fat Diet ◽  
Leptin Receptor ◽  
Elevated Serum ◽  
Brain Regions ◽  
Leptin Resistance ◽  
Hypothalamic Nucleus ◽  
Cytokine Signaling ◽  
Mrna Levels ◽  
High Fat ◽  
Suppressor Of Cytokine Signaling

Abstract Leptin resistance in diet-induced obese (DIO) mice is characterized by elevated serum leptin and a decreased response to exogenous leptin and is caused by unknown defects in the central nervous system. Leptin normally acts on several brain nuclei, but a detailed description of leptin resistance within individual brain regions has not been reported. We first mapped leptin-responsive cells in brains from DIO mice using phospho-signal transducer and activator of transcription (P-STAT3) immunohistochemistry. After 16 wk of high-fat-diet feeding, leptin-activated P-STAT3 staining within the arcuate nucleus (ARC) was dramatically decreased. In contrast, other hypothalamic and extrahypothalamic nuclei remained leptin sensitive. Reduced leptin-induced P-STAT3 in the ARC could also be detected after 4 wk and as early as 6 d of a high-fat diet. To examine potential mechanisms for leptin-resistant STAT3 activation in the ARC of DIO mice, we measured mRNA levels of candidate signaling molecules in the leptin receptor-STAT3 pathway. We found that the level of suppressor of cytokine signaling 3 (SOCS-3), an inhibitor of leptin signaling, is specifically increased in the ARC of DIO mice. The study suggests that the ARC is selectively leptin resistant in DIO mice and that this may be caused by elevated suppressor of cytokine signaling 3 in this hypothalamic nucleus. Defects in leptin action in the ARC may play a role in the pathogenesis of leptin-resistant obesity.

scholarly journals Comparative Evaluation of Four Potent Neospora caninum Diagnostic Antigens Using Immunochromatographic Assay for Detection of Specific Antibody in Cattle

2021 ◽  
Vol 9 (10) ◽  
pp. 2133
Author(s):  
Ragab Fereig ◽  
Hanan Abdelbaky ◽  
Yoshifumi Nishikawa
Keyword(s):  
Current Knowledge ◽  
Neospora Caninum ◽  
Control Strategies ◽  
Acute Infection ◽  
High Sensitivity ◽  
Protozoan Parasite ◽  
Dense Granule ◽  
Caninum Infection ◽  
Kappa Value ◽  
Intracellular Protozoan Parasite

Neospora caninum is an intracellular protozoan parasite responsible for numerous abortion outbreaks and neonatal abnormalities in cattle. Rapid and accurate diagnosis is critical for N. caninum control owing to the lack of vaccine or drug-based control strategies. Herein, we evaluated the performance of four frequently used antigens in the diagnosis of N. caninum infection using immunochromatographic tests (ICTs) as a rapid, affordable, and field applicable tool. These antigens included recombinant proteins of N. caninum surface antigen 1 (NcSAG1), dense granule proteins 7 (NcGRA7) and 6 (NcGRA6), in addition to native Neospora lysate antigen (NLA). Our study revealed the utility of all antigen-based ICTs for detection of specific antibodies to N. caninum. However, the NcSAG1-based ICT was the best for detection of all control N. caninum-infected mouse or cattle sera, while NcGRA7 and NcGRA6-based ICTs exhibited specific ability to detect samples from acute and sub-acute infection in mice and cattle, respectively. Analyses of the NcSAG1-based ICT against enzyme-linked immunosorbent assays (ELISAs) of the same antigen revealed its efficiency in detection of field cattle samples as observed in high sensitivity (84.2%), specificity (93.5%), agreement (90%), and kappa value (0.78). The current knowledge provides an efficient platform for N. caninum control through on-site diagnosis of infected cattle.

Stage-specific expression of NcSAG4 as a marker of chronic Neospora caninum infection in a mouse model

Parasitology ◽  
2009 ◽  
Vol 136 (7) ◽  
pp. 757-764 ◽  
Author(s):  
A. AGUADO-MARTÍNEZ ◽  
L. M. ORTEGA-MORA ◽  
G. ÁLVAREZ-GARCÍA ◽  
S. RODRÍGUEZ-MARCO ◽  
V. RISCO-CASTILLO ◽  
...  
Keyword(s):  
Chronic Infection ◽  
Messenger Rna ◽  
Neospora Caninum ◽  
Expression Patterns ◽  
Chronic Phase ◽  
Chemotherapeutic Agents ◽  
Specific Gene ◽  
Mrna Levels ◽  
Caninum Infection ◽  
The Brain

SUMMARYNeospora caninum infection persists throughout the life of its intermediate host due to the conversion of tachyzoites to slowly dividing bradyzoites that encyst in the brain. This event results in persistent N. caninum infection in bovine herds and partially explains the poor efficacy of many chemotherapeutic agents and vaccine formulations. Thus, there is a need for greater understanding of the tachyzoite-to-bradyzoite conversion mechanisms. Here we studied for the first time the transcription kinetics of the N. caninum bradyzoite-specific gene NcSAG4 in brain samples from chronically infected mice by means of real-time RT-PCR. NcSAG4-messenger RNA (mRNA) levels increased significantly during the chronic phase but followed 2 different expression patterns depending on the isolate used for murine inoculation. NcSAG4-mRNA levels in brains from Nc-1-inoculated mice peaked during late chronic infection (on day 64 post-infection, p.i.), whereas those from Nc-Liv-inoculated mice peaked earlier during the chronic infection (on day 32 p.i.). This difference could be a reflection of the different abilities of these isolates to replicate and form cysts in parasitized brains. These results are consistent with our observations of anti-rNcSAG4 antibody production; low levels were present at seroconversion and slowly increased during the chronic phase. In contrast, NcSAG1 transcription levels, which mark the tachyzoite stage, were maintained without variation in both groups of mice. This suggests the presence of a significant amount of tachyzoites or intermediate zoites expressing NcSAG1 in the brain, even during the late chronic infection.

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