Timed-artificial insemination protocols for Bos indicus beef heifers: Evaluation of protocol length and variations in prostaglandin F2α treatments

The aim was to compare reproductive outcomes of Nelore heifers submitted to timed AI (TAI) protocols, with 7 or 9 d of permanence of the intravaginal progesterone (P4) device and different times of prostaglandin F2α (PGF) administration, for first (n = 935) and second (n = 530) services. On Day -24, heifers without corpus luteum (CL) underwent a protocol for induction of ovulation. On Day 0, heifers received a P4 device (0.5 g) and 1.5 mg estradiol (E2) benzoate. In order for the TAI to be carried out on the same day, these treatments were performed 2 d later on the heifers treated with the 7-d protocol. Additionally, heifers received 0.5 mg PGF at different times, resulting in four experimental groups: 9dP4-PGFd9 (n = 365); 9dP4-PGFd7 (n = 369); 9dP4-PGFd0&9 (n = 364); 7dP4-PGFd0&7 (n = 367). These nomenclatures indicate for how many d the P4 device was kept and the specific day on which PGF was given. At P4 removal, all heifers received 0.5 mg E2 cypionate and 200 IU eCG, and TAI was performed 2 d later. Effects were considered significant when P ≤ 0.05 (superscript letters a,b) whereas a tendency was assumed when 0.05 < P ≤ 0.10. Groups 9dP4-PGFd0&9 and 7dP4-PGFd0&7 had lower percentage of heifers with CL at P4 removal. The diameter (mm) of the dominant follicle (DF) was affected by treatment at P4 removal (9dP4-PGFd9: 11.3 ± 0.3b; 9dP4-PGFd7: 11.8 ± 0.2ab; 9dP4-PGFd0&9: 12.6 ± 0.2a; 7dP4-PGFd0&7: 10.8 ± 0.2c) and at TAI (9dP4-PGFd9: 12.7 ± 0.3ab; 9dP4-PGFd7: 13.2 ± 0.2a; 9dP4-PGFd0&9: 13.4 ± 0.2a; 7dP4-PGFd0&7: 12.4 ± 0.3b). Expression of estrus (%) was affected by treatment (9dP4-PGFd9: 89.6a; 9dP4-PGFd7: 93.5a; 9dP4-PGFd0&9: 88.2ab; 7dP4-PGFd0&7: 85.6b). There were no differences among treatments for P/AI on Day 40 (30-35 d post AI), final P/AI (between Day 70 and parturition) and pregnancy loss (between Day 40 and final P/AI). When the permanence of the P4 device was compared, regardless of PGF treatments, 9-d protocols resulted in greater DF diameter at P4 removal and at TAI, and greater expression of estrus (90.4 vs. 85.6%) than the 7-d protocol. Despite that, the 7-d protocol resulted in greater P/AI on Day 40 (55.3 vs. 49.1%). In addition, there was an interaction between protocol duration and body weight, in which heavier heifers (≥ 307 kg) had greater P/AI when treated with the 7-d protocol, in comparison to 9-d. In conclusion, longer TAI protocols (9 d of P4 device duration) resulted in greater DF diameter and expression of estrus. However, the shorter TAI protocol (7 d of P4 device duration) produced greater P/AI on Day 40, particularly in heavier heifers. Within 9-d protocols, the additional dose of PGF on Day 0 or the anticipation of the PGF to Day 7 did not influence fertility.

Comprehensive Analysis for Anti-Cancer Target-Indication Prioritization of Placental Growth Factor Inhibitor (PGF) by Use of Omics and Patient Survival Data

The expression of the placental growth factor (PGF) in cancer cells and the tumor microenvironment can contribute to the induction of angiogenesis, supporting cancer cell metabolism by ensuring an adequate blood supply. Angiogenesis is a key component of cancer metabolism as it facilitates the delivery of nutrients and oxygen to rapidly growing tumor cells. PGF is recognized as a novel target for anti-cancer treatment due to its ability to overcome resistance to existing angiogenesis inhibitors and its impact on the tumor microenvironment. We aimed to integrate bioinformatics evidence using various data sources and analytic tools for target-indication identification of the PGF target and prioritize the indication across various cancer types as an initial step of drug development. The data analysis included PGF gene function, molecular pathway, protein interaction, gene expression and mutation across cancer type, survival prognosis and tumor immune infiltration association with PGF. The overall evaluation was conducted given the totality of evidence, to target the PGF gene to treat the cancer where the PGF level was highly expressed in a certain tumor type with poor survival prognosis as well as possibly associated with poor tumor infiltration level. PGF showed a significant impact on overall survival in several cancers through univariate or multivariate survival analysis. The cancers considered as target diseases for PGF inhibitors, due to their potential effects on PGF, are adrenocortical carcinoma, kidney cancers, liver hepatocellular carcinoma, stomach adenocarcinoma, and uveal melanoma.

Long non-coding RNA ARAP1-AS1 contributes to cell proliferation and migration in clear cell renal cell carcinoma via the miR-361-3p/placental growth factor axis

Clear cell renal cell carcinoma (ccRCC) is an aggressive malignancy with a poor prognosis. Therefore, investigating the molecular mechanism of ccRCC is important for ccRCC treatment. Here, we aimed to explore the effect of the long non-coding RNA ARAP1-AS1/miR-361-3p/PGF axis on ccRCC. The expression of lncRNA ARAP1-AS1, miR-361-3p, and placental growth factor (PGF) in ccRCC cells was verified by real-time quantitative PCR (RT-qPCR). The influence of the ARAP1-AS1/miR-361-3p/PGF axis on ccRCC cells was identified using the Cell Counting Kit-8 (CCK-8) assay, colony formation assay, flow cytometry, and wound healing assay. The interaction between ARAP1-AS1, miR-361-3p, and PGF was confirmed by bioinformatics analysis and luciferase assay. The results showed that the levels of ARAP1-AS1 and PGF increased in ccRCC cells, while miR-361-3p expression decreased. Cell functional experiments showed that cell proliferation and migration were inhibited by silencing ARAP1-AS1 or PGF, while miR-361-3p inhibitor or PGF overexpression could relieve the inhibitory effect of silencing ARAP1-AS1 on ccRCC cells. Moreover, ARAP1-AS1 sponges miR-361-3p to increase PGF expression. In conclusion, our study revealed that ARAP1-AS1 enhanced the malignancy of ccRCC cells by regulating the miR-361-3p/PGF axis.

MiR-212-3p promotes proliferation and migration of trophoblast in fetal growth restriction by targeting placental growth factor

The purpose of this study was to evaluate the function and possible mechanism of miR-212-3p in fetal growth restriction (FGR) and to demonstrate the relationship between miR-212-3p and placental growth factor (PGF). First, we used qRT-PCR to detect the expression of miR-212-3p and PGF in placental tissues of normal delivery (HC group) and FGR, as well as in human trophoblast cell HTR-8/Svneo. The results revealed that miR-212-3p expression was significantly upregulated and PGF was significantly downregulated in placental tissue in the FGR group compared with the HC group. In addition, interference with miR-212-3p expression increased the proliferation, invasion, and migration of HTR-8/SVneo cells and decreased apoptosis of cells. Meanwhile, Western blot results showed that miR-212-3p expression downregulation promoted the phosphorylated protein expression of Phosphoinositide 3-kinase (PI3K) and protein kinase B (AKT), which in turn activated the PI3K/AKT signaling pathway. And the results of dual luciferase reporter further showed that miR-212-3p could target PGF, and the expression of both was negatively correlated in FGR group tissues. In addition, downregulation of miR-212-3p expression reversed the inhibitory effect of PGF downregulation on HTR-8/SVneo cells. In conclusion, miR-212-3p can target and inhibit the PGF expression and regulate the PI3K/AKT signaling pathway to regulate trophoblast cell invasion, migration, proliferation and cell apoptosis. This provides a potential biomarker for the development of FGR.

Mechanobiology-informed regenerative medicine: Dose-controlled release of placental growth factor from a functionalized collagen-based scaffold promotes angiogenesis and accelerates bone defect healing

Leveraging the differential response of genes to mechanical loading may allow for the identification of novel therapeutics and we have recently established placental growth factor (PGF) as a mechanically augmented gene which promotes angiogenesis at higher doses and osteogenesis at lower doses. Herein, we sought to execute a mechanobiology-informed approach to regenerative medicine by designing a functionalized scaffold for the dose-controlled delivery of PGF which we hypothesized would be capable of promoting regeneration of critically-sized bone defects. Alginate microparticles and collagen/hydroxyapatite scaffolds were shown to be effective PGF-delivery platforms, as demonstrated by their capacity to promote angiogenesis in vitro. A PGF release profile consisting of an initial burst release to promote angiogenesis followed by a lower sustained release to promote osteogenesis was achieved by incorporating PGF-loaded microparticles into a collagen/hydroxyapatite scaffold already containing directly incorporated PGF. Although this PGF-functionalized scaffold demonstrated only a modest increase in osteogenic capacity in vitro, robust bone regeneration was observed after implantation into rat calvarial defects, indicating that the dose-dependent effect of PGF can be harnessed as an alternative to multi-drug systems for the delivery of both pro-angiogenic and pro-osteogenic cues. This mechanobiology-informed approach provides a framework for strategies aimed at identifying and evaluating novel scaffold-based systems for regenerative applications.

Overcoming graft failure after haploidentical transplantation: Is this a possibility?

Allogeneic hematopoietic stem cell transplantation (allo-HSCT), including haploidentical HSCT (haplo-HSCT), is a potentially curative treatment for several hematologic disorders. However, the occurrence of poor graft function (PGF) can lead to mortality. Advances in the use of novel conditioning regimens and strategies to improve engraftment while reducing PGF, are expected to improve outcomes. This review has examined recent evidence that will provide insights into reducing graft failure in haplo-HSCT.

Placental expression of angiogenesis-related genes and their receptors in IUGR pregnancies: correlation with fetoplacental and maternal parameters

Objectives: Aberrations in placental vascular development compromising fetal supply of oxygen and essential nutrients can be a significant contributor to intrauterine growth restriction (IUGR). The development of placental vascular tree is under the influence of two families of growth factors, namely the vascular endothelial growth factor (VEGF) family and angiopoietin/TEK family. In this study, we have examined the expression of angiogenesis-related growth factors, mainly VEGF family and angiopoietin-TEK (endothelial-specific receptor tyrosine kinase) family genes in placentae from IUGR pregnancies uncomplicated by preeclampsia (PE) compared to normal pregnancies.Methods: Placentae from normotensive IUGR (n = 42) and appropriate for gestational age (AGA) pregnancies (n = 47) were collected and examined histologically. Clinical parameters were obtained from the medical records. Real-time quantitative PCR was performed to assess placental transcript abundance of VEGF, PGF, FLT1, ANGPT1, ANGPT2, and TEK normalized to a panel of reference genes. Associations of placental transcript abundance of the genes with maternal, placental, and neonatal parameters were tested.Results: Placental transcript abundance for VEGF (relative expression 10.81 versus 12.98, p < .001), PGF (12.14 versus 13.8, p < .001) and ANGPT2 (3.67 versus 9.55, p = .002) were significantly lower in IUGR placentae compared to AGA. The transcript level of VEGF showed significant negative correlation with birth weight (r = -0.419, p = .006), placental weight (r = -0.318, p = .040), placental length (r = -0.389, p = .011) and breadth (r = -0.308, p = .047) only in the IUGR group. Presence of histopathological features of hypoxia correlated with significantly higher transcript levels of PGF in IUGR placentae (12.6 versus 10.9, p = .046).Conclusion: The low levels of VEGF transcripts may be responsible for the impaired angiogenesis in IUGR placentae. The significance of higher relative expression of PGF in the presence of chronic hypoxia needs to be explored.

Genetic polymorphisms of PGF and TNFAIP2 genes related to cervical cancer risk among Uygur females from China

Background

PGF and TNFAIP2 are important angiogenic factors, which were abnormal expression in cervical cancer (CC). However, there is currently no report investigating the relationship of PGF and TNFAIP2 gene polymorphisms to CC risk.

Methods

We conducted a case-control study of 342 CC patients and 498 cancer-free controls in a Chinese Uygur female population. Three SNPs (PGF rs8019391, PGF rs2268615, and TNFAIP2 rs710100) were selected and genotyped to assess the possible association of PGF and TNFAIP2 polymorphisms with CC susceptibility. Logistic regression analysis adjusted by age was used.

Results

PGF rs2268615 (OR = 1.39, 95% CI = 1.04–1.86, p = 0.024) and TNFAIP2 rs710100 (OR = 1.44, 95% CI =1.07–1.95, p = 0.018) polymorphisms were associated with the increased risk of CC. Moreover, T allele of PGF rs8019391 was highly represented in patients with stage III–IV compared with stage I-II (OR = 2.17, p = 4.58 × 10^− 4). MDR analysis revealed a positive interaction between the SNPs.

Conclusion

Our data indicated that PGF rs2268615, and TNFAIP2 rs710100 polymorphisms might be risk factors for CC susceptibility, which contributed to the increased risk of CC.

Trial registration

Not applicable.

Supplementary information

Supplementary information accompanies this paper at 10.1186/s12881-020-01144-5.

Poor graft function after T cell-depleted allogeneic hematopoietic stem cell transplant

PGF implies persistent cytopenia in the presence of predominant donor chimerism. We examined contributors to PGF in 104 HCT recipients who survived ≥100 days without relapse or major complications. Surrogate parameters for PGF were: Hg <10 g/dl, RBC transfusion dependence, platelet count <20 × 10⁹/L or ANC < 0.5 × 10⁹/L. All patients received T cell depletion with alemtuzumab or ATG. The 2-year OS and PFS probabilities were 66%, 95%CI (56 - 75%) and 51%, 95%CI (41-60%) respectively. Fifty-four patients (52%) met one or more PGF criteria. There was significant association between major ABO incompatibility and platelet <20 × 109/L (OR = 4.7, 95%CI 1.05-21.26, p = .043), acute GVHD and Hg <10 g/dl (OR 3.7, 95%CI 1.4-9.6, p = .005) and CMV viremia and ANC < 0.5 × 10⁹/L (OR 3.0, 95% CI 1.0, 8.7, p = .043). NRM was significantly higher in the PGF group compared to patients with adequate graft function (45.5% vs 16.7%, p = .014).

The orphan nuclear receptor NUR77 promotes trophoblast invasion at early pregnancy through paracrine placental growth factor

NR4A1 (NUR77) is an orphan nuclear receptor that has been implicated in both cell survival and apoptosis. However, the role of NUR77 in trophoblast function during early placenta development has not been fully elucidated. In this study, we showed that NUR77 expression was significantly lower in the villi of the recurrent miscarriage (RM) group compared to that in the healthy controls (HCs) group. We used immunohistochemistry and found that NUR77 was highly expressed in human placental villi during early pregnancy, especially in syncytiotrophoblast (STB), and was expressed at a much lower level in STB from the RM group than in those from HC group. Western blotting data further confirmed that NUR77 was highly expressed in primary human term placental STB and the FSK-induced BeWo cell line. Moreover, antibody array screening and ELISA revealed that NUR77 promoted significant placental growth factor (PGF) expression during trophoblast fusion. Ectopic overexpression and knockdown experiments demonstrated that PGF was a novel downstream target of NUR77, and serum PGF expression correlated positively with trophoblast NUR77 mRNA levels in HCs and RM patients. Importantly, bioinformatics analysis identified two NUR77 binding sites in the PGF promoter region, and chromatin immunoprecipitation (ChIP) coupled with Western blotting analysis further verified that NUR77 bound directly to the PGF promoter region and promoted PGF expression. Furthermore, in a BeWo/HTR-8 co-culture system, FSK-induced BeWo-secreted PGF promoted HTR-8 cell migration and invasion, and an anti-PGF antibody reversed this effect. Collectively, these results indicated that NUR77 may play a key role in regulating trophoblast invasion at early pregnancy. KEY MESSAGES: NUR77 expression was significantly decreased in the syncytiotrophoblast of the recurrent miscarriage group compared to that in the healthy control group. NUR77 promoted PGF expression during trophoblast fusion. ChIP and western blotting experiments verified that NUR77 bound directly to the PGF promoter region and activated PGF expression in trophoblast. Trophoblast-derived PGF promoted HTR-8 cell migration and invasion in a cell co-culture system.

The decreased lncRNA ZEB2-AS1 in pre-eclampsia controls the trophoblastic cell line HTR-8/SVneo's invasive and migratory abilities via the miR-149/PGF axis

Pre-eclampsia (PE) is a pregnancy disease that causes maternal death and threatens the health of newborns. Accumulating evidence has revealed the essential roles of long noncoding RNAs (lncRNAs) in the progression of PE. The present investigation determined lncRNA ZEB2 antisense RNA 1 (ZEB2-AS1) expression in PE and looked into the potential role of ZEB2-AS1 in modulating trophoblastic cell functions. Quantitative real-time polymerase chain reaction evaluated gene expression. Western blot analyzed the placental growth factor (PGF) protein level. Cell counting kit-8 and Transwell invasion assays assessed the proliferative and invasive abilities of placental trophoblast cells, respectively. Wound healing assay determined cell migratory potentials. Dual-luciferase reporter assay assessed the targeting relationship among ZEB2-AS1, miR-149, and PGF. Downregulation of lncRNA ZEB2-AS1 was detected in placentas from patients with PE when compared with those from normal pregnancies. Moreover, ZEB2-AS1 upregulation markedly promoted proliferative, migratory, and invasive potentials in HTR-8/SVneo cells, while knockdown of ZEB2-AS1 had the opposite effects. The effects on HTR-8/SVneo cells mediated by ZEB2-AS1 was correlated with the miR-149/PGF axis. These findings indicate that ZEB2-AS1 contributes to PE progression by affecting cell proliferative and invasive capacities via the miR-149/PGF axis in HTR-8/SVneo cells. In sum, we identified that ZEB2-AS1 was a novel aberrantly expressed lncRNA in the placentas of PE patients and lncRNA ZEB2-AS1 modulated trophoblastic cell line HTR-8/SVneo's proliferative and invasive potentials via targeting the miR-149/PGF axis.

Placental Growth Factor and Endothelial Cell-Specific Molecule 1 Levels in Discordant and Concordant Twins and Their Effects on Fetal Growth

OBJECTIVE

We explored whether fetal twin growth was related to the levels of placental growth factor (PGF) and endothelial cell-specific molecule 1 (ESM-1) and sought correlations between cord blood PGF and ESM1 levels and birth weight discordance.

METHODS

This was a prospective study. We evaluated 79 pairs of twins, thus 158 infants. Twenty-nine (37%) twins were naturally conceived; the remaining 50 (63%) resulted from assisted reproduction.

RESULTS

Nine (11%) sets of twins were monochorionic. Eighteen of the 79 twin sets (22%) were discordant. We found a positive correlation between PGF and ESM-1 levels (r = 0.51, p = 0.001) and between discordance and PGF level (r = 0.430, p = 0.001).

CONCLUSION

The growth discordance may not be attributable to the different PGF levels, but the difference in PGF level may be a consequence.

Biology of preeclampsia: Combined actions of angiogenic factors, their receptors and placental proteins

Although massive efforts have been undertaken to elucidate the etiology of the pregnancy syndrome preeclampsia, its developmental origin remains a mystery. Most efforts of the last decade have focused on biomarkers to predict and/or diagnose preeclampsia, including the anti-angiogenic factor sFlt-1 (soluble fms-like tyrosin kinase-1), the angiogenic factor PGF (placental growth factor) and PP13 (placental protein 13). The origins of these marker proteins are still under debate, and so far their actions have only been describe separate from each other. This study will focus on the origins and actions of all three markers during pregnancy and outside pregnancy and will describe a scenario where all three markers act synergistically to rescue the mother from the deleterious effects of the debris that is released from the placenta during preeclampsia. This more holistic approach may open new avenues to think about maternal-fetal interactions and putative therapies.

An updated view on the origin and use of angiogenic biomarkers for preeclampsia

Introduction: The last decade has seen massive efforts towards the identification and the potential use of predictive biomarkers for the pregnancy pathology preeclampsia. The angiogenic factors sFlt-1 and placental growth factor (PGF) have been in focus and have been massively supported. Areas covered: This review describes preeclampsia and intra-uterine growth restriction (IUGR), focusing on sFlt-1 and PGF, their sources during and outside pregnancy and the application of these markers in diseases outside pregnancy. Finally, the specificity of the angiogenic markers for preeclampsia is discussed. Expert commentary: The admixture of the two independent syndromes preeclampsia and IUGR has not helped in identifying the etiologies of either. Rather, it has made the search for new markers and pathways much more complicated as has the constriction on the angiogenic markers. The current markers sFlt-1 and PGF have a clear value once an adverse outcome is diagnosed but are not specific for preeclampsia. Also, they are mostly derived from the maternal vascular system rather than the placenta and are already in use as markers outside pregnancy. A new holistic approach using disease maps and interoperable workflows based on topic-related big data will help in broadening our understanding of the etiology of preeclampsia and hence, develop new markers and therapies.

The involvement of NR4A1 and NR4A2 in the regulation of the luteal function in rats

The nuclear receptor 4A (NR4A) members play important roles in cellular proliferation, differentiation and apoptosis. The current study first evaluate the expression of ovarian NR4A1 during different luteal stages in rats. Immature rats aged 28 days were treated with sequential Pregnant mare serum gonadotropin (PMSG) (D -2) / human chorionic gonadotropin (hCG) (D 0) to induce pseudopregnancy. Serum progesterone (P₄) and ovarian expression of NR4A1 were detected by RIA and WB, respectively, at follicle stage (D 0), early (D 2), middle (D 7) and late (D 14 and D 20) luteal stages. To confirm the role of NR4A1 during the luteal regression, rats were treated with prostaglandin F_2α analog (PGF) for 0-8 h on D 7 to detect the expressions of NR4A1 and NR4A2. RIA result showed that serum P₄ reached highest level on D 7 and then declined. WB results showed that there were two types of NR4A1 (NR4A1-L and NR4A1-S) expressed in the ovary. The ovarian NR4A1-L decreased at the late luteal stage (D 20). However, the NR4A1-S increased at the late luteal stage (D 14). After PGF treatment on D 7, the expression of NR4A1-S increased which peaked at 0.5-1 h and then declined; while NR4A1-L expression did not change within 8 h. Real-time PCR results showed that the ovarian NR4A1 mRNA increased within 0.5 h, maintained high at 1 h and then declined. The NR4A2 mRNA expression exhibited a similar pattern to that of NR4A1 mRNA, though its abundance was not as high as NR4A1. IHC results revealed that NR4A1-L was expressed mainly in the cytoplasm of luteal steroidogenic cells, faintly expressed in the follicle theca cells, oocytes and the pericytes; while NR4A2 was primarily localized in the cytoplasm of luteal steroidogenic cells. In conclusion, all these results demonstrate that NR4A2 as well as NR4A1 might be involved in the luteal development and luteolysis in rats.

New insights into the regulation of placental growth factor gene expression by the transcription factors GCM1 and DLX3 in human placenta

Expression of placental growth factor (PGF) is closely associated with placental perfusion in early pregnancy. PGF is primarily expressed in placental trophoblasts, and its expression decreases in preeclampsia, associated with placental hypoxia. The transcription factors glial cells missing 1 (GCM1) and metal-regulatory transcription factor 1 (MTF1) have been implicated in the regulation of PGF gene expression through regulatory elements upstream and downstream of the PGF transcription start site, respectively. Here, we clarified the mechanism underlying placenta-specific PGF expression. We demonstrate that GCM1 up-regulates PGF expression through three downstream GCM1-binding sites (GBSs) but not a previously reported upstream GBS. Interestingly, we also found that these downstream GBSs also harbor metal-response elements for MTF1. Surprisingly, however, we observed that MTF1 is unlikely to regulate PGF expression in the placenta because knockdown or overexpression of GCM1, but not MTF1, dramatically decreased PGF expression or reversed the suppression of PGF expression under hypoxia, respectively. We also demonstrate that another transcription factor, Distal-less homeobox 3 (DLX3), interacts with the DNA-binding domain and the first transactivation domain of GCM1 and that this interaction inhibits GCM1-mediated PGF expression. Moreover, the GCM1-DLX3 interaction interfered with CREB-binding protein-mediated GCM1 acetylation and activation. In summary, we have identified several GBSs in the PGF promoter that are highly responsive to GCM1, have demonstrated that MTF1 does not significantly regulate PGF expression in placental cells, and provide evidence that DLX3 inhibits GCM1-mediated PGF expression. Our findings revise the mechanism for GCM1- and DLX3-mediated regulation of PGF gene expression.

Expression patterns of claudin-5 and its related signals during luteal regression in pseudopregnant rats: The enhanced effect of additional PGF treatment

To study the expression patterns of claudin-5 and its related signals during luteal regression in rats, a sequential PMSG/hCG treatment paradigm was used to obtain a single, well-defined generation of corpus luteum (CL). A total of 35 rats were treated with one PGF or two PGF at an interval of 24 h from day 7 of pseudopregnancy to induce CL regression. Serum and ovaries were collected at 0, 2, 4, 8 or 24 h after one PGF injection (1 PGF), 2 or 24 h after two PGF injections (2 PGF). The serum progesterone level was detected by RIA; the ovarian expression of claudin-5, the phosphorylations of STAT3 (p-STAT3), Akt (p-Akt), ERK1/2 (p-ERK) and p38 MAPK (p-p38) were detected by western blot, real-time PCR and IHC. Results showed that serum progesterone (P₄) decreased after PGF treatment. Claudin-5 mRNA decreased at 4 h and 8 h after 1 PGF and 2 h after 2 PGF, and claudin-5 protein decreased at 4 h after 1 PGF. p-STAT3 increased at 4 h after 1 PGF and 2 h after 2 PGF. p-ERK increased at 2 h after 2 PGF. The level of p-Akt decreased at 4 h after 1 PGF. PGF treatment did not alter the phosphorylation of p38 MAPK at any time points in this study. IHC results revealed that claudin-5 was expressed in the nuclei and cytoplasm of steroidogenic cells and in the vessels, while PGF induced-p-STAT3 was expressed uniformly in the cytoplasm of luteal steroidogenic cells. In conclusion, PGF treatment decreased the expression of claudin-5 and the additional PGF treatment enhanced the decrease in claudin-5 mRNA expression and the increases in ERK1/2 and STAT3 phosphorylation in the corpus luteum of pseudopregnant rats, which will contribute new information to the further study of molecular mechanism of luteal regression.

Influence Of Angiogenic Mediators And Bone Remodelling In Paget´s Disease Of Bone

Paget´s disease of bone (PDB) is characterized by increased bone resorption followed by an excessive compensatory bone formation, with an abnormal bone structure with altered mechanical properties. Pagetic bone also has a higher vascularization and marrow fibrosis. Despite of pagetic bone being a highly vascularized tissue, there are no studies on the plasma levels of angiogenic mediators in the different states of the disease; moreover, the effect of PDB treatment on plasma levels of these angiogenic mediators is not very well known. The aim of this study was to analyse plasma levels of cytokines implicated in the increased bone turnover (OPG, RANKL, sclerostin) and hypervascularization (VEGF, PGF, ENG) observed in PDB and their evolution and response to zoledronic acid treatment in 70 PDB patients, 29 with an active disease measured by plasma alkaline phosphatase (ALP). Plasma ALP concentration was higher in active PDB than in inactive PDB patients, whereas there were no differences in OPG, RANKL, sclerostin, VEGF, PGF and ENG plasma levels between active and inactive PDB patients. ALP decreased at 3 and 12 months after zoledronic acid treatment. RANKL levels were reduced and sclerostin levels were increased after 12 months of treatment. PGF levels were lower 12 months after zoledronic acid treatment, whereas there were no differences in plasma VEGF and ENG after zoledronic acid treatment. Summarizing, zoledronic acid treatment is associated to decreases in plasma levels of ALP, RANKL, sclerostin and P1GF in active PDB patients. This treatment may reduce bone turnover and might reduce the pathological vascularisation typical of pagetic bone.

Levosimendan, a new therapeutic approach to prevent delayed cerebral vasospasm after subarachnoid hemorrhage?

BACKGROUND

Under physiological cerebral conditions, levosimendan, a calcium-channel sensitizer, has a dose-dependent antagonistic effect on prostaglandin F2alpha (PGF)-induced vasoconstriction. This circumstance could be used in antagonizing delayed cerebral vasospasm (dCVS), one of the main complications after subarachnoid hemorrhage (SAH), leading to delayed cerebral ischemia and ischemic neurological deficits. Data already exist that identified neuroprotective effects of levosimendan in a traumatic brain injury model and additionally, it has been proven that this compound prevents narrowing of the basilar artery (BA) luminal area after SAH in an in vitro rabbit model. Takotsubo cardiomyopathy, a severe ventricular dysfunction, is also a well-known complication after SAH, associated with pulmonary edema and prolonged intubation.

METHODS

The polypeptide endothelin-1 (ET-1) plays a key role in the development of dCVS after SAH. Therefore, the aim of the present investigation was to detect functional interactions between the calcium-sensitizing and the ET-1-dependent vasoconstriction after experimental-induced SAH; interactions between levosimendan and a substrate-specific vasorelaxation in the BA were also examined. It was reviewed whether levosimendan has a beneficial influence on endothelin(A) and/or endothelin(B₁) receptors (ET-(A) and ET-(B₁) receptors) in cerebral vessels after SAH. We also examined whether this drug could have antagonistic effects on a PGF-induced vasoconstriction.

RESULTS

Under treatment with levosimendan after SAH, the endothelin system seems to be affected. The ET-1-induced contraction is decreased, not significantly. In addition, we detected changes in the nitric oxide-cyclic guanosine monophosphate (NO-cGMP) pathway. Preincubation with levosimendan causes a modulatory effect on the ET-(B₁) receptor-dependent vasorelaxation. It induces an upregulation of the NO-cGMP pathway with a significantly increased relaxation. Even after PGF-induced precontraction a dose-dependent relaxation was registered, which was significantly higher (E_max) and earlier (pD₂) compared to the concentration-effect curve without levosimendan.

CONCLUSIONS

After experimental-induced dCVS, levosimendan seems to restore the well-known impaired function of the vasorelaxant ET-(B₁) receptor. Levosimendan also reversed the PGF-induced contraction dose-dependently. Both of these mechanisms could be used for antagonizing dCVS in patients suffering SAH. Levosimendan could even be used additionally in treating patients developing takotsubo cardiomyopathy.

Fertility after two doses of PGF2α concurrently or at 6-hour interval on the day of CIDR removal in 5-day CO-Synch progesterone-based synchronization protocols in beef heifers

Timed artificial insemination protocols in beef cattle are designed to synchronize ovulation in a greater proportion of females while simultaneously achieving acceptable pregnancy rates and a concise calving season. Protocols achieving such goals reduce time and labor associated with estrus detection and make advanced reproductive technologies implementable for beef producers. The objective of the study was to determine the effect of three different PGF2α (PGF) dosage schemes on artificial insemination (AI) pregnancy rates in beef heifers. We hypothesized that two doses of PGF administered concurrently at the time of controlled internal drug release (CIDR) removal would attain similar pregnancy rates compared with two doses given 6-hours apart-one at CIDR removal and the next 6 hours later in the 5-day CO-Synch progesterone-based synchronization protocol. Angus heifers (n = 875) at six locations in Washington, Idaho, and Oregon states were included in this study. Heifers within locations were assigned a body condition score (BCS). All heifers received a CIDR (1.38 g of progesterone) and 100 μg IM of GnRH on Day 0. The CIDRs were removed on Day 5, heifers were randomly allocated to one of three protocol groups: 1PGF (n = 291), received 25 mg IM of dinoprost (PGF); 2CO-PGF (n = 291), received 50 mg IM of dinoprost at CIDR removal, 2PGF (n = 293), received 25 mg IM of dinoprost at CIDR removal, and an additional 25 mg IM of dinoprost 6 hours later. Each heifer was given GnRH (100 μg, IM) and artificially inseminated at 56 hours after CIDR removal. Heifers were examined for pregnancy status between 50 and 70 days after AI to determine time of conception. A mixed-model procedure (PROC GLIMMIX of SAS) was used to evaluate the effect of treatments (1PGF, 2CO-PGF, and 2PGF) on AI pregnancy rates. Models included were treatments, BCS categories (≤5 and >5), and treatment by BCS category interaction. Location (state), handling facilities, handlers, inseminators, and AI sires were included as a random effect in the model. The 2PGF group had greater AI pregnancy rate of 63.6% (185/291), compared with the 2CO-PGF group at 51.9% (151/291) and 1PGF group at 54.9% (161/293; P < 0.001). An AI pregnancy rate of 50% (104/208) was observed for heifers with BCS less than or equal to 5 versus 58.9% (393/667) for heifers with BCS greater than 5 (P < 0.05). Location did not influence the AI pregnancy rate (P > 0.1). In conclusion, beef heifers received two 25-mg doses of PGF at 6-hour interval on Day 5 at CIDR insert removal in a 5-day CO-Synch + CIDR synchronization protocols achieved greater pregnancy compared with heifers received 50 mg of PGF concurrently at CIDR removal.

Placental growth factor deficiency is associated with impaired cerebral vascular development in mice

STUDY HYPOTHESIS

Placental growth factor (PGF) is expressed in the developing mouse brain and contributes to vascularization and vessel patterning.

STUDY FINDING

PGF is dynamically expressed in fetal mouse brain, particularly forebrain, and is essential for normal cerebrovascular development.

WHAT IS KNOWN ALREADY

PGF rises in maternal plasma over normal human and mouse pregnancy but is low in many women with the acute onset hypertensive syndrome, pre-eclampsia (PE). Little is known about the expression of PGF in the fetus during PE. Pgf  (-/-) mice appear normal but recently cerebral vascular defects were documented in adult Pgf  (-/-) mice.

STUDY DESIGN, SAMPLES/MATERIALS, METHODS

Here, temporal-spatial expression of PGF is mapped in normal fetal mouse brains and cerebral vasculature development is compared between normal and congenic Pgf  (-/-) fetuses to assess the actions of PGF during cerebrovascular development. Pgf/PGF, Vegfa/VEGF, Vegf receptor (Vegfr)1 and Vegfr2 expression were examined in the brains of embryonic day (E)12.5, 14.5, 16.5 and 18.5 C57BL/6 (B6) mice using quantitative PCR and immunohistochemistry. The cerebral vasculature was compared between Pgf  (-/-) and B6 embryonic and adult brains using whole mount techniques. Vulnerability to cerebral ischemia was investigated using a left common carotid ligation assay.

MAIN RESULTS AND THE ROLE OF CHANCE

Pgf/PGF and Vegfr1 are highly expressed in E12.5-14.5 forebrain relative to VEGF and Vegfr2. Vegfa/VEGF is relatively more abundant in hindbrain (HB). PGF and VEGF expression were similar in midbrain. Delayed HB vascularization was seen at E10.5 and 11.5 in Pgf  (-/-) brains. At E14.5, Pgf  (-/-) circle of Willis showed unilateral hypoplasia and fewer collateral vessels, defects that persisted post-natally. Functionally, adult Pgf  (-/-) mice experienced cerebral ischemia after left common carotid arterial occlusion while B6 mice did not.

LIMITATIONS, REASONS FOR CAUTION

Since Pgf  (-/-) mice were used, consequences of complete absence of maternal and fetal PGF were defined. Therefore, the effects of maternal versus fetal PGF deficiency on cerebrovascular development cannot be separated. However, as PGF was strongly expressed in the developing brain at all timepoints, we suggest that local PGF has a more important role than distant maternal or placental sources. Full PGF loss is not expected in PE pregnancies, predicting that the effects of PGF deficiency identified in this model will be more severe than any effects in PE-offspring.

WIDER IMPLICATIONS OF THE FINDINGS

These studies provoke the question of whether PGF expression is decreased and cerebral vascular maldevelopment occurs in fetuses who experience a preeclamptic gestation. These individuals have already been reported to have elevated risk for stroke and cognitive impairments.

LARGE SCALE DATA

N/A.

STUDY FUNDING AND COMPETING INTERESTS

This work was supported by awards from the Natural Sciences and Engineering Research Council, the Canada Research Chairs Program and the Canadian Foundation for Innovation to B.A.C. and by training awards from the Universidade Federal de Pernambuco and Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq), Brazil to R.L.L.; Queen's University to V.R.K. and the Canadian Institutes of Health Research to M.T.R. The work of P.C. is supported by the Belgian Science Policy BELSPO-IUAP7/03, Structural funding by the Flemish Government-Methusalem funding, and the Flemish Science Fund-FWO grants. There were no competing interests.

Prostaglandin F2α induces expression of activating transcription factor 3 (ATF3) and activates MAPK signaling in the rat corpus luteum

The current study was conducted to evaluate the expression of ATF3, in association with the activation of mitogen-activated protein kinases (MAPK) during prostaglandin F2α analog (PGF)-induced luteal regression in rats. A sequential PMSG/hCG treatment paradigm was used to obtain a single, well-defined generation of corpora lutea (CL) in rats. Rats were treated with PGF for 0-4h on day 7 of pseudopregnancy. Results showed that serum progesterone (P4) concentrations declined in a time dependent manner. Western blot results revealed that ATF3 increased within 2h post-PGF injection. Phosphorylated ERK1/2 (p-ERK) and JNK (p-JNK) increased within 30min and then were gradually reduced in response to PGF. In contrast, the levels of phosphorylated p38 MAPK (p-p38) were not significantly altered. The immunostaining density for p-ERK decreased from the periphery to the center of the corpus luteum following treatment with PGF, while ATF3 was expressed uniformly in the nuclei of luteal steroidogenic cells. These results indicated that treatment with PGF in vivo could induce increases in MAPK phosphorylation, especially in p-ERK, which might be correlated with the increases in ATF3 expression and the decline in P4 concentrations. To our knowledge, this is the first study to provide evidence for temporal relationships between MAPK activation and ATF3 expression during PGF-induced luteal regression in the rat.

Phylogenetic analysis and positive-selection site detecting of vascular endothelial growth factor family in vertebrates

Vascular endothelial growth factor (VEGF), known to play an important role in vascular homeostasis, vascular integrity and angiogenesis, is little known about the evolutionary relationship of its five members especially the role of gene duplication and natural selection in the evolution of the VEGF family. In this study, seventy-five full-length cDNA sequences from 33 vertebrate species were extracted from the NCBI's GenBank, UniProt protein database and the Ensembl database. By phylogenetic analyses, we investigated the origin, conservation, and evolution of the VEGFs. Five VEGF family members in vertebrates might be formed by gene duplication. The inferred evolutionary transitions that separate members which belong to different gene clusters correlated with changes in functional properties. Selection analysis and protein structure analysis were combined to explain the relationship of the site-specific evolution in the vertebrate VEGF family. Eleven positive selection sites, one transmembrane region and the active sites were detected in this process.

Targeting tumor micro-environment for design and development of novel anti-angiogenic agents arresting tumor growth. Prog Biophys Mol Biol. 2013;113:333-354. [PMID: 24139944 DOI: 10.1016/j.pbiomolbio.2013.10.001]

Angiogenesis: a process of generation of new blood vessels has been proved to be necessary for sustained tumor growth and cancer progression. Inhibiting angiogenesis pathway has long been remained a significant hope for the development of novel, effective and target orientated antitumor agents arresting the tumor proliferation and metastasis. The process of neoangiogenesis as a biological process is regulated by several pro- and anti-angiogenic factors, especially vascular endothelial growth factor, fibroblast growth factor, epidermal growth factor, hypoxia inducible factor 1 and transforming growth factor. Every endothelial cell destined for vessel formation is equipped with receptors for these angiogenic peptides. Moreover, numerous other angiogenic cytokines such as platelet derived growth factor (PGDF), placenta growth factor (PGF), nerve growth factor (NGF), stem-cell factor (SCF), and interleukins-2, 4, 6 etc. These molecular players performs critical role in regulating the angiogenic switch. Couple of decade's research in molecular aspects of tumor biology has unraveled numerous structural and functional mysteries of these angiogenic peptides. In present article, a detailed update on the functional and structural peculiarities of the various angiogenic peptides is described focusing on structural opportunities made available that has potential to be used to modulate function of these angiogenic peptides in developing therapeutic agents targeting neoplastic angiogenesis. The data may be useful in the mainstream of developing novel anticancer agents targeting tumor angiogenesis. We also discuss major therapeutic agents that are currently used in angiogenesis associated therapies as well as those are subject of active research or are in clinical trials.

Donor and surgical risk factors for primary graft failure following Descemet's stripping automated endothelial keratoplasty in Asian eyes

Background

Descemet’s stripping automated endothelial keratoplasty (DSAEK) has been shown to have superior refractive and visual results compared with penetrating keratoplasty, but higher rates of primary graft failure (PGF). This paper presents donor and surgical risk factors for PGF in DSAEK cases in Asian eyes.

Design

Retrospective case-control study.

Participants

All consecutive patients who underwent DSAEK at a tertiary referral teaching hospital from March 2006–December 2008.

Methods

Donor details analyzed were: age of donor, cause of donor death, death to harvesting time, donor storage time, distribution distance of tissue, preoperative endothelial cell count. Surgical factors analyzed were: donor diameter, donor thickness, and method of donor insertion. These risk factors in cases of PGF were compared with patients with successful DSAEK as the control group.

Main outcome measure

PGF.

Results

A total of 124 DSAEK procedures were performed. Six DSAEK procedures (five eyes of five patients; one eye with two failures) resulted in PGF (4.8%). Significant risk factors were found for PGF to include graft insertion using a folding technique (odds ratio [OR], 34.03; 95% confidence interval [CI], 3.75–314.32; P = 0.0017) and a small donor diameter (OR, 39.94; 95% CI, 2.18–732.17; P = 0.013).

Conclusion

The results of this study suggest that in Asian eyes with shallow anterior chambers, surgical trauma relating to the technique of donor insertion, and the use of a small donor are major risk factors for PGF following DSAEK.