Significance of plasma relaxin-2 levels in patients with primary hypertension and type 2 diabetes mellitus.

BACKGROUND: This study aimed to evaluate plasma relaxin­2 (RLN-2) levels in patients with arterial hypertension (AH) and their relationships with clinical and laboratory parameters. METHODS: The study involved 106 hypertensive patients, including 55 with type 2 diabetes mellitus (T2DM), and 30 control subjects. Plasma RLN-2 levels were measured using an enzyme-linked immunosorbent assay kit. RESULTS: RLN-2 levels were reduced in patients with AH compared to healthy volunteers (p < 0.001), and hypertensive patients with T2DM had lower RLN-2 levels than those without impaired glucose metabolism (p < 0.001). RLN­2 was negatively correlated with systolic blood pressure (SBP) (p < 0.001) and anthropometric parameters such as body mass index (BMI; p = 0.027), neck (p = 0.045) and waist (p = 0.003) circumferences, and waist-to-hip ratio (p = 0.011). RLN­2 also had inverse associations with uric acid levels (p = 0.019) and lipid profile parameters, particularly triglycerides (p < 0.001) and non-HDL-C/HDL­C (p < 0.001), and a positive relationship with HDL­C (p < 0.001). RLN­2 was negatively associated with glucose (p < 0.001), insulin (p = 0.043), HbA1c (p < 0.001), and HOMA-IR index (p < 0.001). Univariate binary logistic regression identified RLN­2 as a significant predictor of impaired glucose metabolism (p < 0.001). CONCLUSIONS: Decreased RLN-2 levels in patients with AH and T2DM and established relationships of RLN­2 with SBP and parameters of glucose metabolism and lipid profile suggest a diagnostic role of RLN­2 as a biomarker for AH with T2DM.

Endurance exercise improves avoidance learning and spatial memory, through changes in genes of GABA and relaxin-3, in rats.

Different exercise patterns, neurotransmitters, and some genes have numerous effects on learning and memory. This research aims to investigate the long-term effects of submaximal aerobic exercise on spatial memory (SM), passive avoidance learning (PAL), levels of serum relaxin-3, gamma-aminobutyric acid (GABA), RLN3 gene, and glutamic acid decarboxylase (GAD65/67 genes) in the brainstem of adult male Wistar rats. Fifty male Wistar rats were randomly divided into five groups: aerobic exercise groups, performed on a treadmill running (TR), for 5 weeks (Ex5, n = 10), 10 weeks (Ex10, n = 10), involuntary running wheel group for 5 weeks (IRW5, n = 10), sham (Sh, n = 10) and control (Co, n = 10). Consequently, SM, PAL, serum relaxin-3, GABA, and GAD65/67 and RLN3 genes were measured by ELISA and PCR. Ex5, Ex10 and IRW5 improved significantly SM (p ≤ 0.05), PAL (p ≤ 0.001) and decreased significantly relaxin-3 (p ≤ 0.001). RLN3 in the brain also decreased. However, it was not significant. GABA and GAD65/GAD67 increased significantly (p ≤ 0.05) in Ex5, Ex10 compared to Sh and Co. Aerobic exercise enhanced SM and PAL in Ex compared to Co and Sh. However, duration and type of exercise affected the level of enhancement. The serum relaxin-3 and RLN3 gene displayed reverse functions compared to GABA and GAD65/67 genes in Ex. Therefore, the changes of neurotransmitters in serum relaxin-3, GABA, and their genes: RLN3 and GAD65/67 respectively, influenced learning and memory meaningfully.

Relationships between reproductive hormones and maternal pregnancy physiology in women conceiving with or without in vitro fertilization.

We evaluated maternal pregnancy adaptations and their relationships with circulating hormones in women who conceived with or without in vitro fertilization (IVF). Pregnancies were grouped by corpus luteum (CL) number: 1 CL with physiological plasma relaxin concentration (PRLN; spontaneous pregnancies); 0 CL without circulating RLN (programmed cycles); >1 CL with elevated PRLN (ovarian stimulation). Major findings were that declines in plasma osmolality (Posm) and plasma sodium concentration ([Formula: see text]) were comparable in the 1 CL and 0 CL cohorts, correlated with plasma estradiol and progesterone concentrations but not PRLN; gestational declines in plasma uric acid (UA) concentration (PUA) were attenuated after IVF, especially programmed cycles, partly because of subdued increases of renal UA clearance; and PRLN and cardiac output (CO) were inversely correlated when plasma estradiol concentration was below ∼2.5 ng/mL but positively correlated above ∼2.5 ng/mL. Unexpectedly, PRLN and plasma sFLT1 (PsFLT1) were directly correlated. Although PsFLT1 and CO were not significantly associated, CO was positively correlated with plasma placental growth factor (PLGF) concentration after the first trimester, particularly in women who conceived with 0 CL. Major conclusions are that 1) circulating RLN was unnecessary for gestational falls in Posm and [Formula: see text]; 2) PRLN and CO were inversely correlated during early gestation, suggesting that PRLN in the lower range may have contributed to systemic vasodilation, whereas at higher PRLN RLN influence became self-limiting; 3) evidence for cooperativity between RLN and estradiol on gestational changes in CO was observed; and 4) after the first trimester in women who conceived without a CL, plasma PLGF concentration was associated with recovery of CO, which was impaired during the first trimester in this cohort.

The Relationship between Serum Relaxin Concentrations and Knee Valgus.

Female athletes are at an elevated risk for tearing their anterior cruciate ligament, compared to their male counterparts. Though injury screening clinical tests and neuromuscular training programs have been widely implemented, injury rates remain high among female athletes. The purpose of this study was to examine the relationship between serum relaxin concentrations and knee valgus during three clinical tests (single leg squat, drop vertical jump, and single leg crossover dropdown). Twenty-two female athletes volunteered. Participants were scheduled for collection during the mid-luteal phase, when serum relaxin concentrations are known to be measurable. Blood samples were collected, and serum relaxin concentrations were quantified. Kinematic data were collected while participants performed the three clinical tests. Regression analyses revealed statistically significant relationships between serum relaxin concentrations and knee valgus throughout all tests. These findings suggest that serum relaxin concentrations and knee valgus are not independent of each other and more holistic approaches may be necessary to truly map out the risk for injury and ultimately reduce the rate of anterior cruciate ligament injuries. Thus, concluding that knee valgus, a highly utilized modifiable biomechanical risk factor, and relaxin, a hormone that has been associated with anterior cruciate ligament injury in female athletes, are related to each other.

Serum relaxin level predicts recurrence of atrial fibrillation after radiofrequency catheter ablation.

Relaxin, an emerging biomarker in heart failure, is involved in fibrosis and inflammation. The value of relaxin in predicting recurrence of atrial fibrillation (AF) after radiofrequency catheter ablation (RFCA) is unknown and the subject of this study. We prospectively enrolled 248 consecutive patients with AF (paroxysmal in 127 and persistent in 121) who underwent RFCA at our center after measurement of circulating levels of relaxin by ELISA. Kaplan-Meier analysis with log-rank test and multivariate analysis were used to assess the association between pre-RFCA relaxin levels and post-RFCA AF recurrence at 18 months follow-up. At mean 16.3 ± 3.8 months post-RFCA, 195 (78.6%) patients maintained sinus rhythm, and their pre-RFCA relaxin level was lower than that in patients with AF recurrence (P < 0.001). From lowest to highest pre-RFCA relaxin level tertiles (T1; 82.10-< 234.36; T2; 234.36-< 342.26; and T3; 342.26-740.63 ng/L), AF recurrence rate increased significantly (8.5%, 20.5% and 34.9%, respectively; Kaplan-Meier analysis with log-rank test, χ2 = 18.44, P < 0.001). Using a cutoff of 285.4 ng/L, pre-RFCA relaxin level predicted AF recurrence during follow-up with sensitivity of 77.4% and specificity of 55.9% (area under the receiver operating characteristic curve = 0.71). On multivariate Cox proportional hazard model, relaxin level by tertile (T2, hazard ratio 2.678; 95% confidence interval 1.110-6.460; P = 0.028, and T3, hazard ratio 4.745; 95% confidence interval 2.075-10.854; P < 0.001, respectively compared with the T1) was the independent factor predicting recurrence. Elevated pre-RFCA relaxin level is associated with post-RFCA AF recurrence. A simple measurement of relaxin level therefore might help identify patients at high risk of AF recurrence after RFCA.Clinical Trial Registration chictr.org.cn identifier: ChiCTR-OOC-15006130.

The subset of patients with acute heart failure able to secrete relaxin-2 at pregnancy concentrations could have a longer survival: a pilot study.

OBJECTIVE: To investigate how many patients with acute heart failure (AHF) hypersecrete relaxin-2 concentrations similar to those of pregnant women and determine their long-term outcome. METHODS: In consecutive AHF patients relaxin-2 was quantified by ELISA sandwich method. Patients were divided into pregnancy-like group (PLG, relaxin-2 ≥ 500 pg/mL) and control group (CG, relaxin-2 < 500 pg/mL). The primary outcome was all-cause death during follow-up. Secondary endpoints were prolonged hospitalisation (>10 days), combined endpoint (death, rehospitalisation, ED revisit) 30 days after discharge, and 30-day, one-year and three-year death rates. RESULTS: We included 814 patients [81 (SD = 9) years; 53.0% women] followed during 1.9 (SD 2.8) years; 517 (63.5%) died. Twenty patients (2.5%) formed the PLG (median relaxin-2 = 1459 pg/mL; IQR = 1722) and 794 the CG (median = 26; IQR = 44). There was no interaction with variables included on adjustment (age, sex, ischaemic cardiomyopathy, NT-proBNP, glycaemia, and sodium). PLG patients did not have better short-term secondary endpoints, but did show a significantly lower three-year mortality [ORadjusted = 0.17 (0.05-0.5), p = 0.003]. CONCLUSIONS: The small proportion of AHF patients achieving relaxin-2 concentrations similar to those observed in pregnancy may survive longer.

Serum relaxin and cervical length for prediction of spontaneous preterm birth in second-trimester symptomatic women.

OBJECTIVE: To investigate whether serum relaxin level is associated with preterm birth in symptomatic women, either as a standalone test or in the context of a combined model of serum relaxin and cervical length (CL). METHODS: This was a case-control study of women with a singleton pregnancy who presented between 24 + 0 and 26 + 6 weeks' gestation with threatened preterm labor and intact membranes. CL, full blood count, C-reactive protein level and maternal demographics were recorded at presentation, and blood samples were taken for relaxin measurement. Parameters were compared between women who delivered preterm (before 37 weeks) (n = 46) and those delivering at term (n = 66). Logistic regression with receiver-operating characteristics (ROC) curve analysis was used to assess significant predictors for birth before 37 and before 34 weeks. RESULTS: Women delivering before 37 weeks had higher mean serum relaxin levels and lower mean CL than those delivering at term (P < 0.0001). Relaxin alone had 63% (95% CI, 49-75%) sensitivity for birth before 37 weeks and 61% (95% CI, 47-74%) for birth before 34 weeks, at a 10% false-positive rate (FPR). Serum relaxin levels did not correlate with CL; a combined model of the two predictors had an area under the ROC curve of 0.895 (95%CI, 0.835-0.954) for the prediction of birth before 37 weeks and 0.869 (95% CI, 0.802-0.937) for birth before 34 weeks (n = 44). Serum relaxin > 1010 pg/mL had 58% sensitivity for prediction of preterm birth in women with a CL > 15 mm, at a 10% FPR. CONCLUSIONS: High serum relaxin level is associated with an increased risk of preterm birth in second-trimester symptomatic women with intact membranes. A combination of serum relaxin and CL increases predictive accuracy for preterm birth. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Associations between serum relaxin 2, aneurysm formation/size and severity of atherosclerosis: a preliminary prospective analysis.

Serum relaxin 2 (RL2) is a pleiotropic hormone that acts on various organs and systems, particularly the cardiovascular system. Although RL2 seems to upregulate the synthesis of nitric monoxide (NO) and matrix metalloproteinase (MMP)-2 and -9, current literature on its role in atherosclerosis and aneurysm formation is scarce. The aim of this study was to investigate the levels of serum RL2 in patients with an arterial aneurysm as well as in atherosclerotic patients, and correlate them with the severity of their related vascular disease. A total of 53 subjects were enrolled in this study: 37 patients were scheduled to undergo surgery: 21 patients for different forms of atherosclerotic disease (ATH), 16 patients for an arterial aneurysm (AA), 6 patients for undergoing temporal artery biopsy (TAB), and 10 healthy blood donors (HBD) served as the control groups. RL2 was measured using enzymelinked immunosorbent assay. RL2 was significantly higher in AA patients compared to ATH (P<0.01), TAB (P<0.001) and HBD (P<0.01). No significant difference was found between the ATH and TAB groups (P>0.05). In addition, ATH and AA patients were further subdivided based on the severity of their disease. Serum RL2 was progressively increased in patients with arterial aneurysms, showing a positive relationship with the size of the aneurysmatic dilatation. By contrast, the RL2 level was inversely related to the severity of the atherosclerotic disease. Studies with a larger cohort incorporating a consistent study population are warranted to verify our results and shed light on the mechanistic background of these processes.

Longitudinal profiles of relaxin and progestagens during pregnancy, pregnancy loss and false pregnancy in the killer whale (Orcinus orca).

The circulating pattern of immunoreactive relaxin and progestagens based on monthly and gestational stage (early, mid, late) profiles were determined during pregnancies that resulted in live calves (LIVE, n = 30), stillbirths (STILLB, n = 3), abortions (ABORT, n = 5) and presumptive false pregnancies (FALSE, n = 8), and during the follicular (n = 34) and luteal phase (n = 58). Monthly LIVE relaxin concentrations steadily increased during gestation, but values did not significantly exceed those of the luteal phase until 9 months prior to parturition, peaking during the final month at 2356 ng/ml. Relaxin surged (P < 0.05) during the final week of gestation (36,397 ng/ml), undergoing a 3 and 9-fold increase compared with concentrations in the preceding two weeks, respectively. Monthly relaxin production did not differ among each reproductive state with the exception of months-13-16 where concentrations were higher (P < 0.001) for STILLB than LIVE. Relaxin concentration was reduced (P < 0.0001) by 849% in placental versus maternal serum collected within 1 day of labor. Mid- and late-pregnancy progestagen concentrations were lower for FALSE (P < 0.001) compared with STILLB and LIVE. Late pregnancy progestagen concentrations were reduced for FALSE (P < 0.05) and ABORT (P < 0.02) compared with LIVE and STILLB. Monthly progestagen production in ABORT tended to be lower than LIVE across a range of gestational months (Months 2, 7, 8, 11) but this difference only became significant during months 14 and 15. Results indicate that relaxin is primarily produced by the CL during pregnancy, and that concentrations could not be used to differentiate from non-pregnant females until the final 6 months of gestation. In addition, as would be expected from a primarily CL product, relaxin cannot be used to detect abnormal pregnancies. Conversely, progestagens, which are produced by both the placenta and CL can be used to differentiate FALSE from normal pregnancy and may be useful indicators of fetal health in the killer whale.

Serum relaxin-3 hormone relationship to male delayed puberty.

Puberty is the transitional period between childhood and adulthood, a process encompassing morphological, physiological and behavioural development to attain full reproductive capability. This study aimed to assess serum relaxin-3 hormone relationship with male delayed puberty. Sixty males were investigated as two equal groups: males with delayed puberty and healthy matched males as controls. They were subjected to history taking, clinical examination and estimation of serum FSH, LH, testosterone, relaxin-3 hormonal levels. The results showed that the secondary sexual characters in the patients group were at Tanner stages 1-2 and in the healthy controls at Tanner stages 3-5. The mean BMI in the patients group was significantly increased, whereas the mean levels of the span, testicular volume, serum LH, FSH, testosterone as well as relaxin-3 hormonal levels were significantly decreased compared with the healthy controls. Serum relaxin-3 levels showed significant positive correlation with the age, testis volume, span, Tanner stages, serum testosterone, FSH, LH hormones. In addition, serum relaxin-3 levels showed significant negative correlation with BMI. It is concluded that serum level of relaxin-3 hormone is an important mediator in the pathophysiological process of normal puberty being significantly decreased in males with delayed puberty.

Decreased Serum Relaxin-2 Is Correlated with Impaired Islet ß-Cell Function in Patients with Unstable Angina and Abnormal Glucose Metabolism.

Circulating relaxin (RLX) is altered in patients with diabetes mellitus (DM) or cardiovascular diseases. This study was designed to evaluate the changes of RLX in patients with unstable angina (UA) complicated with various categories of abnormal glucose metabolism.Patients who confirmed UA by angiographic and clinical standard were grouped according to the glucose metabolism status with oral glucose tolerance test (OGTT) and medical history categorized as normal, prediabetes, newly diagnosed type 2 DM (T2DM), and previously diagnosed T2DM. Serum RLX-2 was measured and islet ß-cell function was evaluated. The severity of the coronary arterial lesions was evaluated with Syntax Scores.Serum RLX-2 was significantly higher in UA patients with prediabetes (median [quartiles]: 9.87 [7.48, 32.58] pg/mL) and newly diagnosed T2DM (18.36 [9.52, 48.08] pg/mL), compared with those with normal glucose tolerance (6.24 [4.02, 7.27] pg/mL, both P < 0.05). Interestingly, UA patients with previously diagnosed T2DM exhibited lower RLX-2 levels (4.17 [3.23, 5.72] pg/mL) compared with those with normal glucose tolerance (P < 0.05). Subsequent analyses indicated that serum RLX-2 was positively associated with parameters of islet ß-cell function, C-peptide, and fasting insulin levels; however, it was negatively associated with the levels of fasting glucose, 2-hour postprandial blood glucose, HbA1c, and insulin sensitivity, suggesting a potential protective role of RLX-2 during abnormal glucose metabolism in UA patients. Serum RLX-2 was not correlated with the Syntax Scores in these patients.Serum RLX-2 is a potential marker for UA patients with early glucose metabolism abnormality, and increased RLX-2 level was correlated with preserved islet ß-cell function.

A validated UPLC-MS/MS method coupled with protein precipitation and ion exchange solid phase extraction for the quantitation of porcine relaxin B29 in dog plasma and its application to a pharmacokinetic study.

Porcine relaxin is a 6 kDa peptide hormone of pregnancy with important physiological and pharmacological effects. It contains a number of analogs of which porcine relaxin B29 is one of the most important. To support the development of porcine relaxin B29 as a new drug, we established an UPLC-MS/MS method for its quantitation in dog plasma. Sample preparation by protein precipitation and ion exchange solid phase extraction was followed by UPLC on an XBridge™ BEH300 C18 column at 40 °C in a run time of only 5.5 min. Detection was performed on a Qtrap 6500 mass spectrometer using ESI in the positive ion mode with MRM of the transitions at m/z 831.7 [M+7H]7+ â†’ 505.4 and m/z 1162.4 [M+5H]5+ â†’ 226 for pRLX B29 and internal standard (recombinant human insulin), respectively. The method was linear over the concentration range 30-2000 ng/mL with no matrix effects. Intra- and inter-day precisions were < 15% with accuracies in the range 98.8-100.6%. The method was successfully applied to a pharmacokinetic study in beagle dogs after administration of a 0.15 mg/kg intravenous dose. Graphical abstract Sample preparation and detection procedure.

Relaxin as a hormonal aid to evaluate pregnancy and pregnancy loss in bottlenose dolphins (Tursiops truncatus).

This study was conducted to critically evaluate weekly and monthly circulating concentrations of immunoreactive relaxin throughout pregnancies that resulted in live births, stillbirths, and abortions in aquarium-based bottlenose dolphins. A relaxin RIA was used to analyze serum collected during 74 pregnancies involving 41 dolphins and 8 estrous cycles as well as 8 non-pregnant dolphins. Pregnancies resulted in live births (n=60), stillbirths (n=7), or abortions (n=7). Relative to parturition (Month 0), monthly changes (P<0.0001) in relaxin was indicated by relatively low concentrations during early pregnancy (Months -12 to -9) which subsequently increased (P<0.05) during mid- (Months -8 to -5) to late (Months -4 to -1) pregnancy; relaxin was highest (P<0.05) at the time of parturition. Post-parturition (Month 1), concentrations decreased (P<0.05). During the first 4weeks post-ovulation, relaxin concentrations were not different between pregnant and non-pregnant dolphins (status-by-week interaction, P=0.59). Status-by-month interaction (P<0.0002) involving different pregnancy outcomes was due, impart, to an increase in relaxin during early pregnancy (P<0.05) that was comparable among dolphins with live births, stillbirths, and abortions except concentrations were lower (P<0.05; 52%) at mid-pregnancy in association with pregnancy loss. Thereafter, concentrations increased (P<0.05) during late pregnancy in dolphins with stillbirths but not in dolphins with abortions. In conclusion, this study provided new information on the pregnancy-specific nature of relaxin, critical evaluation of the fundamental characteristics of relaxin during pregnancy and pregnancy loss, and clarification on the strengths and limitations of relaxin as a diagnostic aid to determine pregnancy status and assess maternal-fetal health in bottlenose dolphins.

Evidence of altered brain regulatory gene expression in tobacco-exposed fetuses.

AIM: We sought to determine the association between prenatal smoking status and expression of fetal brain regulatory genes. METHODS: At delivery, we collected information from parturient women on prenatal smoking habits and analyzed salivary cotinine levels. We obtained neonatal umbilical cord blood and extracted total RNA. We then employed the quantitative polymerase chain reaction (QPCR) analyses and the comparative CT method to calculate the relative gene expression of selected fetal brain regulatory genes responsible for (1) brain growth (brain-derived neutrotrophic factor, BDNF), (2) myelination (proteolipidic protein 1, PLP1 and myelin basic protein, MBP), and (3) neuronal migration and cell-cell interactions during fetal brain development or RLN. The χ2-test, analysis of variance (ANOVA), and the Grubb test were used to evaluate the relationship between prenatal smoking status and relative gene expression levels. Further analysis using bootstrapping was performed to assess the precision of our estimates. RESULTS: Of the 39 maternal-infant dyads included in this study, 25.6% were non-smokers, 43.6% were passive smokers and 30.8% were active smokers. The results showed down-regulation of the selected fetal brain regulatory genes among active smokers. CONCLUSIONS: These findings represent preliminary evidence in humans that intrauterine tobacco exposure impacts fetal brain programming. Future studies are warranted to examine whether our findings represent potential mechanisms through which adverse childhood/adult-onset cognitive and behavioral outcomes that have been previously linked to intrauterine exposure occur.

Oral contraceptive therapy reduces serum relaxin-2 in elite female athletes.

AIM: Recent investigations have demonstrated that athletes with high relaxin-2 levels have a high risk of anterior cruciate ligament injuries, while athletes taking oral contraceptives (OC) have low relaxin-2 levels. It has not yet been clarified whether taking OC reduces relaxin-2 levels. The purpose of this study was to investigate changes in relaxin-2 levels in athletes taking OC. METHODS: Levels of relaxin-2, estradiol, progesterone, luteinizing hormone and follicle-stimulating hormone were measured in serum samples (n = 183) from 106 elite female athletes. Five athletes with serum relaxin-2 concentrations > 6 pg/mL during the luteal phase were recruited to assess the effect of OC therapy. RESULTS: Serum relaxin-2 concentrations were significantly higher during the luteal phase (n = 57) than in the follicular phase (n = 72), or in athletes on OC therapy (n = 10) (P < 0.001, P < 0.001 and P < 0.05, respectively). In the luteal phase, 36.8% (21/57) of the athletes had relaxin levels > 6 pg/mL. In 23 athletes, serum relaxin-2 concentrations were measured during both the follicular and luteal phases, revealing that relaxin-2 levels were significantly higher in the luteal phase compared with the follicular phase. In 5 out of 23 athletes, serum relaxin-2 concentrations were > 6 pg/mL in the luteal phase and during the second cycle of OC therapy, relaxin-2 concentrations decreased dramatically to below the detection limit (0.26 pg/mL). CONCLUSIONS: High serum relaxin-2 concentrations were only detected during the luteal phase. In athletes with high relaxin-2 concentrations during the luteal phase, OC therapy decreased serum relaxin-2 levels.

Monochorial diamniotic dizygotic twins in a German Shepherd Dog: A case report.

CASE REPORT: A 6.5-year-old clinically healthy German Shepherd Dog with regular oestrous cycles of 6 months was presented for pregnancy diagnosis on day 38 after ovulation (p.ov.). Ultrasonography revealed three individual placental sites in progressed resorption and two vital adequately developed foetuses sharing a joint placenta. On days 41 and 48 p.ov., sonographic signs indicated normal development of both foetuses, but on day 52 p.ov., both foetuses were found to be dead. A caesarean section was performed the same day. Examination of the removed uterus confirmed the diagnosis of a "twin" pregnancy with two foetuses sharing the same placental site but separate amniotic membranes. One foetus showed generalized oedema (anasarca). Bacterial culture of swabs taken from inside the placental cavity was negative. At histological examination of the uterus, no signs of inflammation were found. Serum relaxin concentrations (day 38, 41, 48 and 52. p.ov.) were consistent with those of bitches with normal pregnancies. Cytogenetic analysis of the two foetuses revealed dizygotic twins, one male and one female according to SRY-PCR. By genotyping 17 high-polymorphic canine microsatellites, it could be demonstrated that the two foetuses developed from two different oocytes.

Diagnostic and predictive biomarkers for pre-eclampsia in patients with established hypertension and chronic kidney disease.

Women with chronic kidney disease (CKD) and chronic hypertension (CHT) frequently develop superimposed pre-eclampsia, but distinction from pre-existing disease is challenging. Plasma placental growth factor (PlGF), B-type natriuretic peptide (BNP), neutrophil gelatinase-associated lipocalin (NGAL), and serum relaxin concentrations were quantified in a longitudinal prospective cohort of 121 women with CKD: 44 with chronic hypertension, and 79 healthy controls. Biomarker concentrations were compared with 32 women with pre-eclampsia without pre-existing disease. Test performance was evaluated for diagnosis of superimposed pre-eclampsia requiring delivery within 14 days of sampling. PlGF was evaluated as a promising marker in a validation cohort of women with suspected pre-eclampsia (29 with CKD; 94 with chronic hypertension; 29 with superimposed pre-eclampsia requiring delivery within 14 days) and compared with women without pre-existing disease (290 with no pre-eclampsia and 176 with pre-eclampsia requiring delivery within 14 days). From 20 and up to 42 weeks of gestation, lower maternal PlGF concentrations had high diagnostic accuracy for superimposed pre-eclampsia requiring delivery within 14 days (receiver operator characteristic 0.85) and confirmed in the validation cohort. The other plasma and serum biomarkers were not discriminatory. Thus, plasma PlGF concentrations could potentially help guide clinical decision making regarding admission and delivery for superimposed pre-eclampsia.

A single adenovirus-mediated relaxin delivery attenuates established liver fibrosis in rats.

BACKGROUND: Liver fibrosis is characterized by an excess accumulation and repressed degradation of extracellular matrix. Although methods of alleviating already established liver fibrosis have scarcely been reported, continuous relaxin (RLX) infusion has demonstrated some promising results. In the present study, we investigated whether a single adenoviral delivery of RLX would attenuate established liver fibrosis in rats. METHODS: Rats were given thioacetamide (TAA) for 8 weeks and infected once with either RLX-expressing adenovirus (TAA + RLX) or control virus (TAA + Vector) via the tail vein. They were sacrificed either 3 days or 3 weeks after adenovirus infection. RESULTS: Morphometric analysis of picrosirius red stained area demonstrated that the TAA + RLX group had significantly decreased fibrosis at week 3 when liver fibrosis of the TAA + Vector group remained unchanged. Although the liver and serum RLX levels were elevated on day 3 and reversed by week 3, expression of RLX receptor (Rxfp1; relaxin-like family peptide receptor-1) in TAA + RLX rats was sustained and elevated. The production of tissue cyclic adenosine monophosphate, which is a second messenger of activated Rxfp1, was still enhanced in the TAA + RLX group by week 3. Expression of lysyl oxidase homolog 2, which contributes to collagen cross-linking and is up-regulated by TAA treatment, was significantly decreased by week 3 in the TAA + RLX group. Expression of tissue inhibitor of metalloprotiase-2 was alleviated in the TAA + RLX group at week 3, whereas that of TAA + Vector rats was still elevated. CONCLUSIONS: A single adenoviral delivery of RLX in the liver attenuated established hepatic fibrosis by suppressing collagen cross-linking and enhancing collagen degradation.

Protection from Cigarette Smoke-Induced Lung Dysfunction and Damage by H2 Relaxin (Serelaxin).

Cigarette smoke (CS) is the major etiologic factor of chronic obstructive pulmonary disease (COPD), which is characterized by airway remodeling, lung inflammation and fibrosis, emphysema, and respiratory failure. The current therapies can improve COPD management but cannot arrest its progression and reduce mortality. Hence, there is a major interest in identifying molecules susceptible of development into new drugs to prevent or reduce CS-induced lung injury. Serelaxin (RLX), or recombinant human relaxin-2, is a promising candidate because of its anti-inflammatory and antifibrotic properties highlighted in lung disease models. Here, we used a guinea pig model of CS-induced lung inflammation, and remodeling reproducing some of the hallmarks of COPD. Animals exposed chronically to CS (8 weeks) were treated with vehicle or RLX, delivered by osmotic pumps (1 or 10 µg/day) or aerosol (10 µg/ml/day) during CS treatment. Controls were nonsmoking animals. RLX maintained airway compliance to a control-like pattern, likely because of its capability to counteract lung inflammation and bronchial remodeling. In fact, treatment of CS-exposed animals with RLX reduced the inflammatory recruitment of leukocytes, accompanied by a significant reduction of the release of proinflammatory cytokines (tumor necrosis factor α and interleukin-1ß). Moreover, RLX was able to counteract the adverse bronchial remodeling and emphysema induced by CS exposure by reducing goblet cell hyperplasia, smooth muscle thickening, and fibrosis. Of note, RLX delivered by aerosol has shown a comparable efficacy to systemic administration in reducing CS-induced lung dysfunction and damage. In conclusion, RLX emerges as a new molecule to counteract CS-induced inflammatory lung diseases.

Relaxin in Obstructive Sleep Apnea: Relationship with Blood Pressure and Inflammatory Mediators.

BACKGROUND: Obstructive sleep apnea (OSA) is associated with nocturnal intermittent hypoxia, which may be responsible for increased circulating levels of vascular endothelial growth factor (VEGF) and inflammatory mediators, such as metalloproteinases (MMPs), and which contributes to the pathogenesis of systemic hypertension. Why some OSA patients remain normotensive is poorly understood. Relaxin-2, a pregnancy hormone, may sometimes circulate in men and could increase in hypoxic conditions. It exerts a vasodilatory activity and can modulate the release of molecules, such as MMPs and VEGF. OBJECTIVES: The objective of this study was to explore if circulating relaxin-2 in male OSA subjects may be related to OSA severity, to circulating levels of MMPs, of their inhibitors (tissue inhibitors of metalloproteinases; TIMPs), and of VEGF, and if it may protect from hypertension. PATIENTS AND METHODS: Fifty untreated male subjects with suspected OSA were recruited. After nocturnal polysomnography, a morning venous blood sample was withdrawn. Then, 24-hour ambulatory blood pressure (BP) monitoring was performed. RESULTS: The respiratory disturbance index in the sample was 30.4 [interquartile range (IQR) 15.6-55.2]. Relaxin-2 was detectable in 20 subjects. These subjects did not differ in OSA severity or diurnal and nocturnal BP from subjects with undetectable relaxin-2, but they showed lower TIMP-1 (126.8 ± 29.1 vs. 156.9 ± 41.7 pg/ml, respectively; p = 0.007) and a marginally higher MMP-9/TIMP-1 molar ratio [0.58 (IQR 0.23-1.35) vs. 0.25 (IQR 0.15-0.56); p = 0.052]. CONCLUSIONS: Relaxin-2 in male subjects was not related to OSA severity, but it was associated with lower TIMP-1. As it was often undetectable, even when BP values were normal, it is unlikely that it plays a role as a major factor protecting from hypertension in OSA.