Early transcriptomic changes in peripheral blood 7 days after embryo transfer in dairy cattle

A common goal of the dairy industry is to shorten the calving interval to reap several benefits associated with improved fertility. Early pregnancy detection is crucial to shorten this interval, allowing for prompt re-insemination of cows that failed to conceive after the first service. Currently, the industry lacks a method to accurately predict pregnancy within the first 3 wk. The polypeptide cytokine IFN-tau (IFNT) is the primary signal for maternal recognition of pregnancy in ruminants. As IFNT is released from the early conceptus, it initiates a cascade of effects, including upregulation of IFN-stimulated genes (ISG). Expression of ISG can be detected in the peripheral blood. The present study aimed to characterize peripheral transcriptomic changes, including the ISG, as early as d 7 after embryo transfer. A total of 170 Holstein heifers received in vitro-produced embryos. Whole blood was collected from these heifers within 24 h of the embryo transfer (d 0), d 7, and d 14 after embryo transfer. The heifers were divided into 2 groups, pregnant and nonpregnant, based on pregnancy diagnosis on d 28 via ultrasound. Total RNA was extracted from the peripheral blood of pregnant and nonpregnant heifers, pooled and sequenced. Expression analysis on d 7 heifers resulted in 13 significantly differentially expressed genes mostly related to innate immunity. Differential expression analysis comparing pregnant heifers on d 0 to the same heifers on d 14 showed 51 significantly differentially expressed genes. Eight genes were further quantified through reverse-transcription quantitative real-time PCR for biological validation. On d 7 after embryo transfer, mRNA transcriptions of EDN1, CXCL3, CCL4, and IL1A were significantly upregulated in pregnant heifers (n = 14) compared with nonpregnant heifers (n = 14), with respective fold changes of 8.10, 18.12, 29.60, and 29.97. Although on d 14 after embryo transfer, mRNA transcriptions of ISG15, MX2, OASY1, and IFI6 were significantly upregulated in the blood of pregnant heifers (n = 14) compared with the same heifers on d 0, with respective fold changes of 5.09, 2.59, 3.89, and 3.08. These findings demonstrate that several immune-related genes and ISG are activated during the first 2 wk after embryo transfer, which may explain how the maternal immune system accommodates the allogenic conceptus. To further investigate the diagnostic potentials of these genes, future studies are warranted to analyze the specificity and sensitivity of these biomarkers to predict early pregnancy.

Effects of Radiation Doses on Clinical Recurrence in Patients with Biochemically Recurrent Prostate Cancer after Prostatectomy

PURPOSE/OBJECTIVE(S)

Salvage radiotherapy (SRT) to the prostate bed is the only curative treatment for patients with biochemical recurrence (BCR) after radical prostatectomy (RP). Although several systematic reviews indicated that a dose escalation in the range of 60-70 Gy improved biochemical control, the effects of radiation doses on clinical relapse after SRT remain unclear. Our aim was to investigate the relationship between radiation doses and clinical relapse-free survival (cRFS) after SRT.

MATERIALS/METHODS

We identified 295 eligible patients receiving SRT for biochemically recurrent prostate cancer after RP between 2005 and 2018 at 15 institutions. Sixteen patients (5%) received short-term (< 6 months) androgen deprivation therapy (ADT) following RP and/or concurrently with SRT. SRT was delivered to the prostate and seminal vesicle bed using photon beams at a median (range) dose of 66 Gy (61-85) in 1.8-3.0 Gy fractions. The primary outcome was cRFS. Clinical relapse was identified on radiological imaging and/or biopsy and included local recurrence, lymph node metastasis, and distant metastasis. In all analyses, doses were recalculated as an equivalent dose in 2-Gy fractions (EQD2) with α/β = 1.5 Gy. Clinical RFS between the EQD2 ≥ 66 Gy (n = 229) and EQD2 < 66 Gy (n = 66) groups were compared using the Log-rank test, followed by univariate and multivariate Cox regression analyses and a subgroup analysis.

RESULTS

The median follow-up duration was 73 months. Among patients with BCR (n = 119), 79 of 96 (82%) in the EQD2 ≥ 66 Gy group and 21 of 23 (91%) in the EQD2 < 66 Gy group received second salvage ADT (p = 0.36). Among all patients (n = 295), clinical relapse was identified in 22 (7%) patients after SRT. Six-year biochemical relapse-free survival (bRFS), cRFS, cancer-specific survival (CSS), and overall survival (OS) rates were 58%, 93%, 98%, and 94%, respectively. Six-year cRFS rates were 94% (95% confidence interval [CI], 90-97) in the EQD2 ≥ 66 Gy group and 87% (95% CI, 75-93) in the EQD2 < 66 Gy group (p = 0.020). The multivariate analysis revealed that EQD2 < 66 Gy, Gleason score ≥ 8, seminal vesicle involvement, and PSA at BCR ≥ 0.5 ng/ml correlated with clinical relapse (p = 0.0016, 0.014, 0.011, and 0.027, respectively). The subgroup analysis showed the consistent benefit of EQD2 ≥ 66 Gy in patients across most subgroups including PSA at BCR after RP, extracapsular extension, and age at SRT.

CONCLUSION

This large multi-institutional observational study demonstrated that a higher SRT dose (EQD2 ≥ 66 Gy) resulted in superior cRFS. The present result supports the dose recommendations in the 2023 National Comprehensive Cancer Network guidelines (64-72 Gy) even in terms of clinical relapse. Prospective trial is warranted to investigate an upper threshold for optimal SRT dose.

Corrigendum: Identification of novel canonical strigolactones produced by tomato

[This corrects the article DOI: 10.3389/fpls.2022.1064378.].

Identification of novel canonical strigolactones produced by tomato

Canonical strigolactones (SLs), such as orobanchol, consist of a tricyclic lactone ring (ABC-ring) connected to a methylbutenolide (D-ring). Tomato plants have been reported to produce not only orobanchol but also various canonical SLs related to the orobanchol structure, including orobanchyl acetate, 7-hydroxyorobanchol isomers, 7-oxoorobanchol, and solanacol. In addition to these, structurally unidentified SL-like compounds known as didehydroorobanchol isomers (DDHs), whose molecular mass is 2 Da smaller than that of orobanchol, have been found. Although the SL biosynthetic pathway in tomato is partially characterized, structural elucidation of DDHs is required for a better understanding of the entire biosynthetic pathway. In this study, three novel canonical SLs with the same molecular mass as DDHs were identified in tomato root exudates. The first was 6,7-didehydroorobanchol, while the other two were not in the DDH category. These two SLs were designated phelipanchol and epiphelipanchol because they induced the germination of Phelipanche ramosa, a noxious root parasitic weed of tomato. We also proposed a putative biosynthetic pathway incorporating these novel SLs from orobanchol to solanacol.

Constraints on Cosmic Strings Using Data from the Third Advanced LIGO-Virgo Observing Run

We search for gravitational-wave signals produced by cosmic strings in the Advanced LIGO and Virgo full O3 dataset. Search results are presented for gravitational waves produced by cosmic string loop features such as cusps, kinks, and, for the first time, kink-kink collisions. A template-based search for short-duration transient signals does not yield a detection. We also use the stochastic gravitational-wave background energy density upper limits derived from the O3 data to constrain the cosmic string tension Gμ as a function of the number of kinks, or the number of cusps, for two cosmic string loop distribution models. Additionally, we develop and test a third model that interpolates between these two models. Our results improve upon the previous LIGO-Virgo constraints on Gμ by 1 to 2 orders of magnitude depending on the model that is tested. In particular, for the one-loop distribution model, we set the most competitive constraints to date: Gμ≲4×10^{-15}. In the case of cosmic strings formed at the end of inflation in the context of grand unified theories, these results challenge simple inflationary models.

Constraints on Cosmic Strings Using Data from the Third Advanced LIGO-Virgo Observing Run

We search for gravitational-wave signals produced by cosmic strings in the Advanced LIGO and Virgo full O3 dataset. Search results are presented for gravitational waves produced by cosmic string loop features such as cusps, kinks, and, for the first time, kink-kink collisions. A template-based search for short-duration transient signals does not yield a detection. We also use the stochastic gravitational-wave background energy density upper limits derived from the O3 data to constrain the cosmic string tension Gμ as a function of the number of kinks, or the number of cusps, for two cosmic string loop distribution models. Additionally, we develop and test a third model that interpolates between these two models. Our results improve upon the previous LIGO-Virgo constraints on Gμ by 1 to 2 orders of magnitude depending on the model that is tested. In particular, for the one-loop distribution model, we set the most competitive constraints to date: Gμ≲4×10^{-15}. In the case of cosmic strings formed at the end of inflation in the context of grand unified theories, these results challenge simple inflationary models.

Postpartal resumption of ovarian activity in dairy cows: Implications for herbage-based feeding systems in Switzerland

INTRODUCTION

Milk production in Switzerland is mainly based on herbage feeding with little input of concentrates. The present study investigated the effects of a solely herbage-based diet with (C) and without concentrate (nC) supplementation on luteal activity, milk production and metabolic status in 23 multiparous Holstein dairy cows with early or delayed resumption of ovarian cyclicity post partum (pp). Cows were retrospectively assigned either to a group with early (until d 25 pp, EOV) or delayed resumption of ovarian activity (> d 30 pp, DOV), resulting in four subgroups depending on concentrate feeding: DOV-C, DOV-nC, EOV-C, EOV-nC. Milk progesterone (P4) concentration was measured every 3 d, and different metabolites were analyzed in weekly blood samples. Resumption of ovarian activity was detected between d 19 and 25 pp in EOV, and between d 30 and 60 pp in DOV. In DOV-C, resumption of cyclicity tended to start earlier (38.3 ± 1.7 d pp) compared to DOV-nC (45.2 ± 6.3 d pp; P = 0.10). Independent of grouping, the ovarian activity occurred later in cows with greater plasma β-hydroxybutyrate (BHB) concentrations (P  1 ng/mL did not differ between groups (P > 0.05), but milk P4 peaks during the experiment were higher in EOV compared to DOV (P .

The relationship between sucrose intake in coffee or tea, and root or coronal caries in an elderly Japanese population

OBJECTIVES

Few studies have examined the effect of sucrose intake in coffee or tea (SCT) on dental caries, especially root caries, in elderly people. The purpose of the present study was to examine the associations between SCT and the prevalence of root or coronal caries in community-dwelling elderly Japanese.

METHODS

Participants were 370 elders aged 75 years from a larger cohort study of elders in Niigata City, Japan. Dietary habits during the preceding month were assessed with a validated brief self-administered diet history questionnaire (BDHQ). The caries examination was conducted using mirror and ball-pointed periodontal probes under artificial light. Poisson regression analysis was performed to analyze the prevalence-rate ratios (PRRs) between SCT and the root or coronal caries. The number of root or coronal caries was selected as the dependent variable for the analysis. Then, SCT (tertiles labeled low, medium and high) and other 4 variables were selected as independent variables.

RESULTS

The PRRs between the number of root caries lesions and SCT were signifi cantly higher in the second (medium intake, 1.38, p ⟨ 0.001) and third tertiles (high intake, 2.07, p ⟨ 0.001). Similar tendencies were seen for the number of coronal caries lesions (PRRs in the second and third tertiles 1.74 and 2.46, respectively, both p ⟨ 0.001).

CONCLUSION

A significant positive relationship was observed between sucrose in coffee and tea and the number of coronal or root caries lesions in community-dwelling elderly Japanese.

Prospects for observing and localizing gravitational-wave transients with Advanced LIGO, Advanced Virgo and KAGRA

We present our current best estimate of the plausible observing scenarios for the Advanced LIGO, Advanced Virgo and KAGRA gravitational-wave detectors over the next several years, with the intention of providing information to facilitate planning for multi-messenger astronomy with gravitational waves. We estimate the sensitivity of the network to transient gravitational-wave signals for the third (O3), fourth (O4) and fifth observing (O5) runs, including the planned upgrades of the Advanced LIGO and Advanced Virgo detectors. We study the capability of the network to determine the sky location of the source for gravitational-wave signals from the inspiral of binary systems of compact objects, that is binary neutron star, neutron star-black hole, and binary black hole systems. The ability to localize the sources is given as a sky-area probability, luminosity distance, and comoving volume. The median sky localization area (90% credible region) is expected to be a few hundreds of square degrees for all types of binary systems during O3 with the Advanced LIGO and Virgo (HLV) network. The median sky localization area will improve to a few tens of square degrees during O4 with the Advanced LIGO, Virgo, and KAGRA (HLVK) network. During O3, the median localization volume (90% credible region) is expected to be on the order of 10 5 , 10 6 , 10 7 Mpc 3 for binary neutron star, neutron star-black hole, and binary black hole systems, respectively. The localization volume in O4 is expected to be about a factor two smaller than in O3. We predict a detection count of 1 - 1 + 12 ( 10 - 10 + 52 ) for binary neutron star mergers, of 0 - 0 + 19 ( 1 - 1 + 91 ) for neutron star-black hole mergers, and 17 - 11 + 22 ( 79 - 44 + 89 ) for binary black hole mergers in a one-calendar-year observing run of the HLV network during O3 (HLVK network during O4). We evaluate sensitivity and localization expectations for unmodeled signal searches, including the search for intermediate mass black hole binary mergers.

P4704The efficacy of intravascular ultrasound for patients with peripheral artery diseases presenting aorto-iliac artery disease

Background

The use of intravascular ultrasound (IVUS) promotes better clinical outcomes for intervention in complex lesions. However, the data demonstrating whether use of IVUS improves primary patency following stenting for aorto-iliac lesions in patients with peripheral artery disease (PAD) are limited.

Purpose

The purpose of the current study was to investigate the impact of IVUS use on primary patency 12 months after stent implantation for aorto-iliac lesions.

Methods

We analyzed a clinical database of the OMOTENASHI registry (Observational prospective Multicenter registry study on Outcomes of peripheral arTErial disease patieNts treated by AngioplaSty tHerapy in aortoIliac artery), registering symptomatic PAD patients (Rutherford category 2, 3, or 4) undergoing endovascular therapy for aorto-iliac lesions between January 2014 and April 2016 in Japan. The current study analyzed 803 patients who underwent self-expandable stent implantation at 61 centers with the institutional volume known. The primary endpoint was 12-month restenosis, defined as ≥50% stenosis on computed tomography or angiography, or a peak systolic velocity ratio ≥2.5 on duplex ultrasound. When treatment strategies, endovascular procedures and clinical outcomes were compared between the patients treated with IVUS use and those treated without IVUS use, the propensity score matching was performed to minimize the inter-group difference in baseline characteristics.

Results

A total of 545 patients (67.9%) underwent IVUS-supported stent implantation. Patients treated with IVUS use had a lower prevalence of regular dialysis, whereas they had a higher prevalence of TASC II class D and chronic total occlusion. In patients treated with IVUS use, carbon dioxide contrast agent were more often used, and 0.035-inch guidewire was less frequently selected. Implanted stents in these patients were longer and smaller in diameter. The propensity score matching extracted 138 pairs, with no remarkable intergroup difference in baseline characteristics. Procedure time ≤1 hour was less frequent in patients treated with IVUS use; their radiation time was longer. Endovascular strategies, as well as postoperative medication were not significantly different between patients with and without IVUS use. The 12-month restenosis risk was not significantly different between patients with and without IVUS use (10.2% [6.9 to 14.9%] versus 10.3% [5.4 to 18.6%], P=0.99).

Conclusion

IVUS use in aorto-iliac stenting for patients with PAD was not associated with primary patency at 12 months.

Acknowledgement/Funding

None

P713Short term treatment of a low dose erythropoietin improves vascular function in a rat model of insulin resistance

Background/Introduction

Erythropoietin (EPO) exerts haematopoiesis-independent cardiovascular and renal protective effects by binding to EPO receptors expressed in hearts, arteries, and kidneys. We have reported that EPO inhibits vascular and renal injury in rat models of hypertension and type 1 diabetes. Recent studies report that EPO improves glucose tolerance in insulin resistant animals.

Purpose

This study investigated whether EPO would inhibit vascular and renal dysfunction in the setting of insulin resistance.

Methods

Rats were treated with sucrose (12% in drinking water) for 10 weeks to induce insulin resistance. EPO (3 times/week, s.c) was administered at the dose of 150U/kg for 10 weeks from the beginning (group A) or at the dose of 75U/kg for the last 4 weeks (group B) of sucrose treatment. Blood pressure was measured every second week by the tail-cuff method. HOMA-IR, haematocrit, and urinary protein excretion were measured. Using isolated aortas, acetylcholine-induced vasorelaxation under phenylephrine-induced pre-contraction was examined. Aortic sections were stained with haematoxylin-eosin.

Results

Both groups A and B showed higher haematocrit levels compared with the control and sucrose alone-treated groups. Sucrose treatment increased HOMA-IR (7.7±2.0 vs. 24±4.5, p<0.05), which was attenuated in groups A (3.6±0.9) and B (9.7±4.0). EPO treatment (150U/kg) had no effects on blood pressure for the first 4 weeks but caused time-dependent increases in blood pressure from the 6th week. Increased proteinuria and impaired aortic vasorelaxation in sucrose-treated rats were exacerbated by EPO (150U/kg) maybe because of hypertension (Control 122±2mmHg, Sucrose 125±2mmHg, group A 148±5mmHg), one of the major side effects of EPO. According to these results, we treated a half dose of EPO only for the last 4 weeks (group B). A lower dose of EPO treatment for a shorter period did not increase proteinuria (Control 15±2mg/day, Sucrose 25±3mg/day, group B 24±3mg/day) despite a mild increase in blood pressure (132±2mmHg). Impaired endothelium-dependent vasodilation and aortic thickening in the aorta of sucrose alone-treated rats were attenuated by lower and shorter EPO treatment (group B).

Conclusions

EPO inhibited insulin resistance and vascular injury in sucrose-induced insulin resistant rats. Further investigation into the mechanisms of tissue protective effects of EPO, especially focusing on the effects on insulin signalling in not only hepatic and muscle cell but also vascular and renal cells, will be needed.

Prospects for observing and localizing gravitational-wave transients with Advanced LIGO, Advanced Virgo and KAGRA

We present possible observing scenarios for the Advanced LIGO, Advanced Virgo and KAGRA gravitational-wave detectors over the next decade, with the intention of providing information to the astronomy community to facilitate planning for multi-messenger astronomy with gravitational waves. We estimate the sensitivity of the network to transient gravitational-wave signals, and study the capability of the network to determine the sky location of the source. We report our findings for gravitational-wave transients, with particular focus on gravitational-wave signals from the inspiral of binary neutron star systems, which are the most promising targets for multi-messenger astronomy. The ability to localize the sources of the detected signals depends on the geographical distribution of the detectors and their relative sensitivity, and [Formula: see text] credible regions can be as large as thousands of square degrees when only two sensitive detectors are operational. Determining the sky position of a significant fraction of detected signals to areas of 5-[Formula: see text] requires at least three detectors of sensitivity within a factor of [Formula: see text] of each other and with a broad frequency bandwidth. When all detectors, including KAGRA and the third LIGO detector in India, reach design sensitivity, a significant fraction of gravitational-wave signals will be localized to a few square degrees by gravitational-wave observations alone.

Local immune system in oviduct physiology and pathophysiology: attack or tolerance?

The local immune system in the oviduct has a unique ability to deal with pathogens, allogeneic spermatozoa, and the semi-allogeneic embryo. To achieve this, it seems likely that the oviduct possesses an efficient and strictly controlled immune system that maintains optimal conditions for fertilization and early embryo development. The presence of a proper sperm and/or embryo-oviduct interaction begs the question of whether the local immune system in the oviduct exerts beneficial or deleterious effects on sperm and early embryo; support or attack?. A series of studies has revealed that bovine oviduct epithelial cells (BOECs) are influenced by preovulatory levels of Estradiol-17β, progesterone, and LH to maintain an immunologic homeostasis in bovine oviduct, via inhibition of proinflammatory responses that are detrimental to allogenic sperm. Under pathologic conditions, the mucosal immune system initiates the inflammatory response to the infection; the bacterial lipopolysaccharide (LPS) at low concentrations induces a proinflammatory response with increased expression of TLR-4, PTGS2, IL-1β, NFκB1, and TNFα, resulting in tissue damage. At higher concentrations, however, LPS induces a set of anti-inflammatory genes (TLR-2, IL-4, IL-10, and PTGES) that may initiate a tissue repair. This response of BOECs is accompanied by the secretion of acute phase protein, suggesting that BOECs react to LPS with a typical acute proinflammatory response. Under physiological conditions, polymorphonuclear neutrophils (PMN) are existent in the oviductal fluid during preovulatory period in the bovine. Interestingly, the bovine oviduct downregulates sperm phagocytosis by PMN via prostaglandin E2 (PGE2) action. In addition, the angiotensin-endothelin-PGE2 system controlling oviduct contraction may fine-tune the PMN phagocytic behavior to sperm in the oviduct. Importantly, a physiological range of PGE2 supplies anti-inflammatory balance in BOEC. Our recent results show that the sperm binding to BOECs further shift the local immunity toward anti-inflammatory conditions with upregulation of IL-10, TGFβ, and PGE2. In addition, this local environment leads PMN to express anti-inflammatory cytokines. In conclusion, the oviduct displays mucosal immunity that maintains an anti-inflammatory environment under physiological conditions that supports the sperm. Under pathologic condition, however, the oviduct supplies the innate immunity that may attack the sperm. Moreover, the oviduct-sperm interaction further suppresses the innate immune cells and strengthens the anti-inflammatory balance in the oviduct. Therefore, the oviduct immunity ensures sperm viability before fertilization.

Polymorphism in promoter region of growth hormone receptor is associated with potential production capacity of insulin-like growth factor-1 in pre-pubertal Holstein heifers

Insulin-like growth factor-1 (IGF-1) is one of the important factors for growth, milk production and reproductive functions and mainly released from the liver in response to growth hormone (GH) via GH receptor (GHR) in cattle. Recently, some single nucleotide polymorphisms (SNPs) were identified in the bovine GHR gene. Some GHR-SNPs were shown to be related to plasma IGF-1 concentration in cattle. Hence, the capacity to IGF-1 production in the liver might be affected by GHR-SNP and associated with performance in the future. This study examined whether GHR-SNP is associated with IGF-1 production in the liver of pre-pubertal heifers. In 71 Holstein calves, blood samples for genomic DNA extraction were obtained immediately after birth. To genotype the GHR-SNPs in the promoter region, polymerase chain reaction (PCR) products were digested with restriction enzyme NsiI (cutting sites: AA, AG and GG). All heifers at 4 months of age were intramuscularly injected with 0.4 mg oestradiol benzoate. Blood samples were obtained from the jugular vein just before (0 h) and 24 h after injection. The number of AA, AG and GG at the NsiI site was 0, 17 and 54 respectively. In AG and GG, plasma GH concentrations were higher pre-injection than 24 h post-injection (p < 0.01). Moreover, plasma GH concentrations in AG post-injection were higher than in GG (p < 0.05). In contrast, the GG genotype exhibited higher plasma IGF-1 concentrations in pre-injection than post-injection (p < 0.01), although oestradiol did not change IGF-1 concentration in the AG genotype. We conclude that the GG polymorphism in the promoter region of GHR is associated with a higher potential capacity of IGF-1 production in the liver of cattle.

Short communication: Urea induces T helper 2 (Th2) type environment at transcriptional level and prostaglandin E2 secretion in bovine oviduct epithelial cells in culture

Excess dietary protein intake in early lactation dairy cows resulting in blood urea nitrogen of greater than 19 to 20mg/dL is associated with decreased fertility. Little is known about the local interference of urea in the normal immunological environment of the oviduct that provides optimal conditions for early reproductive events. A bovine oviduct epithelial cell (BOEC) culture was used to determine how urea influences immune environment. The BOEC monolayer was supplemented with low (20mg/dL) and high (40mg/dL) concentrations of urea together with ovarian steroids, estradiol (1ng/mL) and progesterone (1ng/mL), and LH (10ng/mL) at concentrations observed during the preovulatory period. The urea values used in this study were equivalent to 9.3 and 18.7mg/dL of blood urea nitrogen, which are typically common in lactating dairy cows with low or high protein intake, respectively. Stimulation of BOEC with 40mg/dL of urea induced gene expression of IL10 and IL4, epithelial-derived T helper type 2-driving (anti-inflammatory) cytokines as well as mPGES-1 expression and prostaglandin E2 (PGE2) secretion. However, urea concentrations of both 20 and 40mg/dL failed to alter the expression of IL1B and TNFA, Th1-driving cytokines, and the gene expression of TLR4. However, a concentration of 40mg/dL of urea stimulated α 1-acid glycoprotein expression, an acute phase protein. Data from this in vitro study suggest that urea, at least in part, contributes to influence the expression of some immune-related genes toward T helper type 2 type and prostaglandin E2 secretion, leading to disruption in local environment for fertilization and early embryonic development.

Lipopolysaccharide enhances apoptosis of corpus luteum in isolated perfused bovine ovaries in vitro

Lipopolysaccharide (LPS), the endotoxin of Gram-negative bacteria, has detrimental effects on the structure and function of bovine corpus luteum (CL)in vivo. The objective was to investigate whether these effects were mediated directly by LPS orviaLPS-induced release of PGF2α. Bovine ovaries with a mid-cycle CL were collected immediately after slaughter and isolated perfused for 240 min. After 60 min of equilibration, LPS (0.5 μg/ml) was added to the medium of five ovaries, whereas an additional six ovaries were not treated with LPS (control). After 210 min of perfusion, all ovaries were treated with 500 iu of hCG. In the effluent perfusate, concentrations of progesterone (P4) and PGF2αwere measured every 10 and 30 min, respectively. Punch biopsies of the CL were collected every 60 min and used for RT-qPCR to evaluate mRNA expression of receptors for LPS (TLR2,-4) and LH (LHCGR); the cytokineTNFA; steroidogenic (STAR,HSD3B), angiogenic (VEGFA121,FGF2), and vasoactive (EDN1) factors; and factors of prostaglandin synthesis (PGES,PGFS,PTGFR) and apoptosis (CASP3,-8,-9). Treatment with LPS abolished the hCG-induced increase in P4(P≤0.05); however, there was a tendency (P=0.10) for increased release of PGF2αat 70 min after LPS challenge. Furthermore, mRNA abundance ofTLR2,TNFA,CASP3,CASP8,PGES,PGFS, andVEGFA121increased (P≤0.05) after LPS treatment, whereas all other factors remained unchanged (P>0.05). In conclusion, reduced P4responsiveness to hCG in LPS-treated ovariesin vitrowas not due to reduced steroidogenesis, but was attributed to enhanced apoptosis. However, an impact of luteal PGF2αcould not be excluded.

Comparison between 5-day aprepitant and single-dose fosaprepitant meglumine for preventing nausea and vomiting induced by cisplatin-based chemotherapy

Purpose

We aimed to compare the preventive effect of 5-day administration of aprepitant with single administration of fosaprepitant meglumine against nausea and vomiting symptoms due to highly emetogenic chemotherapy regimens comprising cisplatin (CDDP).

Methods

Subjects were inpatients who underwent chemotherapy for gastric cancer, esophageal cancer, lung cancer, or head and neck cancer with a regimen comprising 60 mg/m² or higher dose of CDDP. In this randomised, open-label, controlled study, the subjects were assigned to a group given aprepitant for 5 days or a group given a single administration of fosaprepitant meglumine. The nausea and vomiting symptoms that emerged within 7 days after the first CDDP administration were investigated with a questionnaire form; the results were compared between the two groups. Risk factors affecting nausea and vomiting symptoms were also investigated.

Results

Of the 101 patients enrolled, 93 patients were included (48 in the 5-day aprepitant group and 45 in the single fosaprepitant meglumine group). No significant intergroup differences in the complete response rate or the complete control rate were found over the entire period. The nausea score tended to increase from day 3 in both groups, but no significant intergroup difference was observed. Furthermore, the investigation of risk factors affecting moderate or severe nausea symptoms indicated that the fosaprepitant meglumine administration was not a risk factor.

Conclusions

Single administration of fosaprepitant meglumine was not inferior to 5-day administration of aprepitant for preventing acute and delayed nausea and vomiting symptoms occurring after administration of CDDP (60 mg/m² or higher).

Smad9 is a new type of transcriptional regulator in bone morphogenetic protein signaling

Smad1, Smad5 and Smad9 (also known as Smad8) are activated by phosphorylation by bone morphogenetic protein (BMP)-bound type I receptor kinases. We examined the role of Smad1, Smad5, and Smad9 by creating constitutively active forms (Smad(DVD)). Transcriptional activity of Smad9(DVD) was lower than that of Smad1(DVD) or Smad5(DVD), even though all three Smad(DVD)s associated with Smad4 and bound to the target DNA. The linker region of Smad9 was sufficient to reduce transcriptional activity. Smad9 expression was increased by the activation of BMP signaling, similar to that of inhibitory Smads (I-Smads), and Smad9 reduced BMP activity. In contrast to I-Smads, however, Smad9 did not inhibit the type I receptor kinase and suppressed the constitutively active Smad1(DVD). Smad9 formed complexes with Smad1 and bound to DNA but suppressed the transcription of the target gene. Taken together, our findings suggest that Smad9 is a new type of transcriptional regulator in BMP signaling.

CELL BIOLOGY SYMPOSIUM: perspectives: possible roles of polymorphonuclear neutrophils in angiogenesis and lymphangiogenesis in the corpus luteum during development and early pregnancy in ruminants

The establishment of pregnancy requires well-balanced regulation of the endocrine and immune systems and involves interactions among the conceptus, oviduct-uterus, and corpus luteum (CL). In particular, a rapid increase in plasma progesterone during the first week after ovulation is critical for the growth of the conceptus and successful pregnancy in cattle. Events involved in maternal recognition of pregnancy (MRP) may commence within 1 wk from AI, when interferon-stimulated gene expression in circulating polymorphonuclear neutrophils (PMN) increases in pregnant cows. To regulate optimal endocrine conditions within this time, the CL must develop rapidly, with active angiogenesis and lymphangiogenesis. The major angiogenic factors, vascular endothelial growth factor and fibroblast growth factor 2, contribute to the development of the CL but may also act as chemoattractants for PMN. Indeed, the number of PMN is greatest in the new CL, where PMN together with IL-8 induce active angiogenesis and lymphangiogenesis. During MRP, the conceptus secretes interferon tau (IFNT), which prevents CL regression by inhibiting luteolytic release of PGF2α from uterine endometrium. In addition, IFNT and PGE2 reach the CL and may contribute to desensitizing the CL to the luteolytic effects of PGF2α. In the bovine CL, lymphangiogenesis, stimulated by IFNT, may occur during MRP, and thus a shift of local immunity might occur at this timing. The aforementioned evidence supports the possible involvement of PMN in the establishment of pregnancy via CL regulation. Further investigation could expand our understanding of the communication between zygotes, PMN, and reproductive organs during early pregnancy. This should provide new insight into the contribution of neutrophils to CL function and immune tolerance during early pregnancy in ruminants.

A naturally occurring α(s1)-casein-derived peptide in bovine milk inhibits apoptosis of granulosa cells induced by serum-free conditions

Several naturally occurring peptides in bovine milk were characterized by tandem mass spectrometry and Edman degradation. Chromatograms of peptide fractions (passed through an ultra-filtration membrane, nominal molecular weight limit 3000) prepared from colostrum (collected immediately after parturition) and transitional milk (collected 5 days postpartum) showed that they were almost identical. In total, six peptides, α(s1)-CN (f16-23) (RPKHPIKH), α(s1)-CN (f16-24) (RPKHPIKHQ), α(s1)-CN (f17-25) (PKHPIKHQG), α(s1)-CN (f46-52) (VFGKEKV), α(s1)-CN (f94-105) (HIQKEDVPSER), and β-CN (f121-128) (HKEMPFPK), were identified. One of the major peptides, the N-terminal fragment of αs1 -casein, varied structurally during early lactation: α(s1)-CN (f17-25) (PKHPIKHQG) and α(s1)-CN (f16-23) (RPKHPIKH)/α(s1)-CN (f16-24) (RPKHPIKHQ) were found in colostrum and transitional milk, respectively. A chemically synthesized peptide, α(s1)-CN (f16-23) (RPKHPIKH), inhibited apoptosis of bovine granulosa cells induced by serum-free conditions in a dose-dependent manner, in consequence of caspase-3 and caspase-9 suppressions. The physiological function of the peptide remains unclear, but it may have potential use as pharmaceutical agent and as an anti-apoptotic agent in cell culture medium.

Application of mycotoxin adsorbent to cattle feed contaminated with zearalenone: urinary zearalenone excretion and association with anti-Müllerian hormone

This study investigated (1) protective effects of a commercially available mycotoxin adsorbent (MA) and (2) endocrine effects of in vivo exposure to zearalenone (ZEA) in cattle. The sample included a Japanese Black female cattle herd (MYT herd) that displayed persistently high urinary ZEA concentrations. A second herd (NM herd) was used as a control. Three groups from each herd were assessed: MX (n=6; MA mixed with concentrate), TD (n=6; MA applied as topdressing with the concentrate), and a positive control (n=6; no MA application). Urine and blood samples were collected at the start of MA supplementation (day 0), on the final day of supplementation (day 16), and on the final day of the sampling period (day 58 for MYT herd and day 50 for NM herd). Urinary ZEA concentrations (pg/mg of creatinine) were measured by ELISA and liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Haematological and serum biochemical analyses were performed to monitor hepatic, renal, nutritional, and mineral intake statuses. Ovulation status was assessed by progesterone (P4) and antral follicle population by anti-Müllerian hormone (AMH) levels. The urinary concentrations of ZEA and its metabolites in the MX and TD groups were significantly lower (P<0.05) at day 16 compared with the control group, as measured by LC-MS/MS. The valid ratio of AMH-positive (≯0.08 ng/ml) cattle was significantly higher in the NM herd than in the MYT herd without affecting the P4-positive (≯3 ng/ml) ratio, suggesting different populations of antral follicles. Significant differences were also observed between the MX and the control in aspartate aminotransferase and γ-glutamyltransferase at day 58, suggesting preventive effects of MA supplementation. Our field trial indicated that MA supplementation of a ZEA-contaminated diet has beneficial effects in reducing ZEA absorption from the intestine of cattle, maintaining endocrine homeostasis and reversing hepatic effects.

Jasmonic acid and salicylic acid activate a common defense system in rice

Jasmonic acid (JA) and salicylic acid (SA) play important roles in plant defense systems. JA and SA signaling pathways interact antagonistically in dicotyledonous plants, but, the status of crosstalk between JA and SA signaling is unknown in monocots. Our rice microarray analysis showed that more than half of the genes upregulated by the SA analog BTH are also upregulated by JA, suggesting that a major portion of the SA-upregulated genes are regulated by JA-dependent signaling in rice. A common defense system that is activated by both JA and SA is thus proposed which plays an important role in pathogen defense responses in rice.

Involvement of OsJAZ8 in jasmonate-induced resistance to bacterial blight in rice

The plant hormone jasmonic acid (JA) has a crucial role in both host immunity and development in plants. Here, we report the importance of JA signaling in the defense system of rice. Exogenous application of JA conferred resistance to bacterial blight caused by Xanthomonas oryzae pv. oryzae (Xoo) in rice. Expression of OsJAZ8, a rice jasmonate ZIM-domain protein, was highly up-regulated by JA. OsJAZ8 interacted with a putative OsCOI1, which is a component of the SCF(COI1) E3 ubiquitin ligase complex, in a coronatine-dependent manner. OsJAZ8 also formed heterodimers with other OsJAZ proteins but did not form homodimer. JA treatment caused OsJAZ8 degradation and this degradation was dependent on the 26S proteasome pathway. Furthermore, the JA-dependent OsJAZ8 degradation was mediated by the Jas domain. Transgenic rice plants overexpressing OsJAZ8ΔC, which lacks the Jas domain, exhibited a JA-insensitive phenotype. A large-scale analysis using a rice DNA microarray revealed that overexpression of OsJAZ8ΔC altered the expression of JA-responsive genes, including defense-related genes, in rice. Furthermore, OsJAZ8ΔC negatively regulated the JA-induced resistance to Xoo in rice. On the basis of these data, we conclude that JA plays an important role in resistance to Xoo, and OsJAZ8 acts as a repressor of JA signaling in rice.

Expression of prostaglandin F2α (PGF2α) receptor and its isoforms in the bovine corpus luteum during the estrous cycle and PGF2α-induced luteolysis

Prostaglandin F2α (PGF2α) induces luteolysis via a specific receptor, PTGFR. Although PTGFR mRNA expression in the bovine corpus luteum (CL) has been studied previously, changes in PTGFR protein and its localization are not fully understood during the life span of the CL. In addition to full-length PTGFR, several types of PTGFR isoforms, such as PTGFRα (type I) and PTGFRζ (type II), were reported in the bovine CL, suggesting isoform-specific luteal action. Full-length PTGFR mRNA in the bovine CL increased from the early to the mid-luteal phase and decreased during luteolysis, whereas PTGFR protein remained stable. PTGFR protein was localized to both luteal and endothelial cells and was expressed similarly during the life span of the CL. Like full-length PTGFR mRNA, PTGFRα and PTGFRζ mRNA also increased from the early to mid-luteal phases, and mRNA of PTGFRζ, but not PTGFRα, decreased in the regressing CL. During PGF2α-induced luteolysis, the mRNAs of full-length PTGFR, PTGFR,α and PTGFRζ decreased rapidly (from 5 or 15 min after PGF2α injection), but PTGFR protein decreased only 12 h later. Silencing full-length PTGFR using small interfering RNA prevented PGF2α-stimulated cyclooxygenase-2 (PTGS2) mRNA induction. By contrast, PGF2α could stimulate vascular endothelial growth factor A (VEGFA) mRNA even when full-length PTGFR was knocked down, thus suggesting that PGF2α may stimulate PTGS2 via full-length PTGFR, whereas VEGFA is stimulated via other PTGFR isoforms. Collectively, PTGFR protein was expressed continually in the bovine CL during the estrous cycle, implying that PGF2α could function throughout this period. Additionally, the bovine CL expresses different PTGFR isoforms, and thus PGF2α may have different effects when acting via full-length PTGFR or via PTGFR isoforms.

Diagnostic and prognostic significance of the alternatively spliced ACTN4 variant in high-grade neuroendocrine pulmonary tumours

BACKGROUND

High-grade neuroendocrine tumours (HGNTs) of the lung manifest a wide spectrum of clinical behaviour, but no method for predicting their outcome has been established.

MATERIALS AND METHODS

We newly established a monoclonal antibody specifically recognizing the product of the alternatively spliced ACTN4 transcript (namely, variant actinin-4), and used it to examine the expression of variant actinin-4 immunohistochemically in a total of 609 surgical specimens of various histological subtypes of lung cancer.

RESULTS

Variant actinin-4 was expressed in 55% (96/176) of HGNTs, but in only 0.8% (3/378) of non-neuroendocrine (NE) lung cancers. The expression of variant actinin-4 was significantly associated with poorer overall survival in HGNT patients (P=0.00021, log-rank test). Multivariate analysis using the Cox proportional hazards model showed that the expression of variant actinin-4 was the most significant independent negative predictor of survival in HGNT patients (hazard ratio (HR), 2.15; P=0.00113) after the presence of lymph node metastasis (HR, 2.25; P=0.00023).

CONCLUSIONS

The expression of variant actinin-4 is an independent prognostic factor for patients with HGNTs. This protein has a high affinity for filamentous actin polymers and likely promotes aggressive behaviour of cancer cells. The present clinical findings clearly support this notion.

Vascular and immune regulation of corpus luteum development, maintenance, and regression in the cow

The bovine corpus luteum (CL) is a unique, transient organ with well-coordinated mechanisms by which its development, maintenance, and regression are effectively controlled. Angiogenic factors, such as vascular endothelial growth factor A and basic fibroblast growth factor, play an essential role in promoting progesterone secretion, cell proliferation, and angiogenesis. These processes are critically regulated, through both angiogenic and immune systems, by the specific immune cells, including macrophages, eosinophils, and neutrophils, that are recruited into the developing CL. The bovine luteolytic cascade appears to be similar to that of general acute inflammation in terms of time-dependent infiltration by immune cells (neutrophils, macrophages, and T lymphocytes) and drastic changes in vascular tonus and blood flow, which are regulated by luteal nitric oxide and the vasoconstrictive factors endothelin-1 and angiotensin II. Over the period of maternal recognition of pregnancy, the maternal immune system should be well controlled to accept the semiallograft fetus. The information on the presence of the developing embryo in the genital tract is suggested to be transmitted to the ovary by both the endocrine system and the circulating immune cells. In the bovine CL, the lymphatic system, but not the blood vascular system, is reconstituted during early pregnancy, and interferon tau from the embryo could trigger this novel phenomenon. Collectively, the angiogenic and vasoactive factors produced by luteal cells and the time-dependently recruited immune cells within the CL and their interactions appear to play critical roles in regulating luteal functions throughout the life span of the CL.

Escherichia coli lipopolysaccharide administration transiently suppresses luteal structure and function in diestrous cows

The objective was to characterize the effects of Escherichia coli lipopolysaccharide (LPS) endotoxin (given i.v.) on luteal structure and function. Seven nonlactating German Holstein cows, 5.1 ± 0.8 years old (mean ± s.e.m.), were given 10  ml saline on day 10 (ovulation=day 1) of a control estrous cycle. On day 10 of a subsequent cycle, they were given 0.5 μg/kg LPS. Luteal size decreased (from 5.2 to 3.8 cm², P≤0.05) within 24 h after LPS treatment and remained smaller throughout the remainder of the cycle. Luteal blood flow decreased by 34% (P≤0.05) within 3 h after LPS and remained lower for 72 h. Plasma progesterone (P₄) concentrations increased (P≤0.05) within the first 3 h after LPS but subsequently declined. Following LPS treatment, plasma prostaglandin (PG) F metabolites concentrations were approximately tenfold higher in LPS-treated compared with control cows (9.2 vs 0.8 ng/ml, P≤0.05) within 30 min, whereas plasma PGE concentrations were nearly double (P≤0.05) at 1 h after LPS. At 12 h after treatment, levels of mRNA encoding Caspase-3 in biopsies of the corpus luteum (CL) were increased (P≤0.05), whereas those encoding StAR were decreased (P≤0.05) in cattle given LPS vs saline. The CASP3 protein was localized in the cytoplasm and/or nuclei of luteal cells, whereas StAR was detected in the cytosol of luteal cells. In the estrous cycle following treatment with either saline or LPS, there were no significant differences between groups on luteal size, plasma P₄ concentrations, or gene expression. In conclusion, LPS treatment of diestrus cows transiently suppressed both the structure and function of the CL.

Regulation of corpus luteum development and maintenance: specific roles of angiogenesis and action of prostaglandin F2alpha

Development of the corpus luteum (CL) in ruminants occurs in a rapid and time-dependent manner within 1 week after ovulation, with morphologic and biochemical changes in the cells of the theca interna and granulosa cells of the preovulatory follicle. These changes involve luteinisation of steroidogenic cells and angiogenesis to establish normal luteal function (progesterone secretion). The CL is composed of a large number of vascular endothelial cells, large and small steroidogenic luteal cells, smooth muscle cells, pericytes, fibrocytes and immune cells, indicating that the CL is a heterogeneous tissue. Moreover, the CL produces and secretes growth factors (fibroblast growth factor, vascular endothelial growth factor and insulin-like growth factor), vasoactive factors (nitric oxide, angiotensin II and endothelin-1), steroids (progesterone is important for its own production), oxytocin and prostaglandins (PGF2alpha and PGE2) to regulate luteal formation and development. Clearly, the main function of the CL is to produce progesterone, which is a prerequisite for survival of the embryo, implantation and maintenance of pregnancy. Inadequate luteinisation and angiogenesis during the early luteal phase results in poor progesterone secretion and causes compromised embryo development and reduced fertility. Secretion of adequate amounts of progesterone during luteal development requires "precise luteinisation" of theca and granulosa cells to form luteal cells, neovascularization, and the establishment of a blood supply (angiogenesis). PGF2alpha in the developing CL acts as a local regulator to enhance progesterone secretion directly and indirectly by stimulating angiogenic factors, VEGF and FGF2. The preceding role of PGF2alpha may explain why the developing CL does not acquire luteolytic capacity until several days following ovulation. The balance between luteotrophic and luteolytic factors as well as stimulation and inhibition of angiogenic factors during luteal formation, development and maintenance can have a profound effect on the fate of the CL.

Characterization of 5-hydroxytryptamine-induced contraction and acetylcholine-induced relaxation in isolated chicken basilar artery

The aim of the present study was to clarify the responsiveness of the chicken basilar artery to 5-hydroxytryptamine (5-HT) and acetylcholine (ACh) and to characterize the related receptor subtypes in vitro. Basilar arteries were obtained from freshly slaughtered broiler chickens. The 5-HT induced concentration-dependent contraction of the arteries. The concentration-response curves for 5-HT were shifted 30-fold to the right by methiothepin (a 5-HT(1) and 5-HT(2) receptor antagonist) and 3-fold to the right by ketanserin (a 5-HT(2) receptor antagonist). In the presence of ketanserin, the concentration-response curve for 5-HT was shifted 10-fold to the right by methiothepin. The pA(2) value for methiothepin was 8.26. The ACh induced concentration-dependent relaxation under conditions of precontraction by 5-HT. The concentration-response curve for ACh was shifted to the right by atropine [a nonselective muscarinic (M) receptor antagonist] and hexahydro-sila-difenidol hydrochloride, a p-fluoroanalog (pFHHSiD, an M(3) receptor antagonist), but not by pirenzepine (an M(1) receptor antagonist) or methoctramine (an M(2) receptor antagonist). The pA(2) value for pFHHSiD was 7.55. Nω-Nitro-l-arginine (a nitric oxide synthase inhibitor) inhibited ACh-induced relaxation by approximately 50%. These results suggest that 5-HT induces contraction via activation of 5-HT(1) and 5-HT(2) receptors and that ACh induces relaxation via activation of the M(3) receptor. The 5-HT(1) receptor might play a dominant role in 5-HT-induced contraction. One of the factors involved in ACh-induced relaxation is probably nitric oxide released from endothelial cells.

FOXG1 mutations in Japanese patients with the congenital variant of Rett syndrome

Rett syndrome (RTT) is a severe neurodevelopmental disorder characterized by microcephaly, psychomotor regression, seizures and stereotypical hand movements. Recently, deletions and inactivating mutations in FOXG1, encoding a brain-specific transcription factor that is critical for forebrain development, have been found to be associated with the congenital variant of RTT. Here we report the clinical features and molecular characteristics of two cases of the congenital variant of RTT. We conducted mutation screenings of FOXG1 in a cohort of 15 Japanese patients with a clinical diagnosis of atypical RTT but without MECP2 and CDKL5 mutations. Two unrelated female patients had heterozygous mutations (c.256dupC, p.Gln86ProfsX35 and c.689G>A, pArg230His). Both showed neurological symptoms from the neonatal period, including hypotonia, irritability and severe microcephaly. Further, their psychomotor development was severely impaired, as indicated by their inability to sit unaided or acquire speech sounds, and they had a hyperkinetic movement disorder, because both displayed hand stereotypies and jerky movements of the upper limbs. Brain magnetic resonance imaging scans revealed delayed myelination with hypoplasia of the corpus callosum and frontal lobe. These cases confirm the involvement of FOXG1 in the molecular etiology of the congenital variant of RTT and show the characteristic features of FOXG1-related disorder.

Craniospinal irradiation using helical tomotherapy: evaluation of acute toxicity and dose distribution

The purpose of this study was to evaluate acute toxicity of craniospinal irradiation (CSI) using helical tomotherapy (HT) and compare its dose distribution with that of conventional linac-based plans. Twelve patients with various brain tumors were treated with HT-CSI. Median patient age was 14 years (range: 4-37 years). Median CSI dose was 30.6 Gy in 18 fractions (range: 23.4-40 Gy in 13-25 fractions). Toxicities were assessed according to the Common Terminology Criteria for Adverse Events version 4.0. Before CSI, 11 patients (92%) received neoadjuvant chemotherapy, so acute toxicity was evaluated by comparing patient status before and after CSI. HT-CSI plans were compared with linac-based CSI plans made using Pinnacle(3) planning system in 9 patients. All patients completed planned CSI without interruption. Grade 3 or higher toxicities were leukopenia seen in 11 patients (92%), anorexia in 6 (50%), anemia in 5 (42%), and thrombopenia in 5 (42%). Administration of granulocyte colony-stimulating factor, platelet transfusion and total parenteral nutrition were required in 8 (67%), 5 (42%) and 5 (42%) patients, respectively. HT plans were superior to linac-based plans in terms of homogeneity and conformality in planning target volume (PTV). For most organs at risk (OARs), volumes receiving more than 10 Gy (V10 Gy) or 20 Gy (V20 Gy) were lower in HT plans. However, HT plans significantly increased mean doses to the lung, kidneys and liver, and V5 Gy of 6 OARs including the lung. Despite intensive neoadjuvant chemotherapy, acute toxicity of HT-CSI was acceptable. HT provided better dose distribution in PTV than conventional linac. In most OARs, smaller volumes received >10-20 Gy in HT plans, although larger volumes received 5-10 Gy.

Effect of β-carotene supply during close-up dry period on the onset of first postpartum luteal activity in dairy cows

The aim of this study was to examine the effect of β-carotene supply during the close-up dry period on the onset of first postpartum luteal activity in dairy cows. Twelve cows were supplied with 2000 mg of β-carotene (20 g Rovimix(®) β-Carotene containing 10% β-carotene; DSM Nutrition Japan K.K., Tokyo, Japan) by oral administration daily from day 21 before expected calving date to parturition. Fourteen cows (control) did not receive β-carotene supplementation. Blood samples were obtained on days 21, 14 and 7 before expected calving date and on days 1, 7, 14, 21 postpartum. When the plasma progesterone concentration exceeded 1 ng/ml by day 21 postpartum, luteal activity was assumed to have been initiated. The result showed that serum β-carotene concentrations in the β-carotene cows were higher than in the control cows during the experimental period (p < 0.01). The number of cows with the onset of luteal activity by day 21 postpartum was 9/12 in the β-carotene cows and 4/14 in the control cows (p < 0.05). Retinol, certain metabolic parameters and metabolic hormones concentrations did not differ between β-carotene and control cows. In addition, serum retinol concentration in β-carotene cows without luteal activity was lower than in β-carotene cows with luteal activity (p < 0.05), and serum gamma-glutamyl transpeptidase concentration in β-carotene cows with luteal activity (p < 0.05) and control cows without luteal activity (p < 0.01) was higher than in control cows with luteal activity. In conclusion, β-carotene supply during the close-up dry period may support the onset of luteal activity during early lactation in dairy cows.