Accumulation of senescent cells in the adrenal gland induces hypersecretion of corticosterone via IL1β secretion

Aging progresses through the interaction of metabolic processes, including changes in the immune and endocrine systems. Glucocorticoids (GCs), which are regulated by the hypothalamic-pituitary-adrenal (HPA) axis, play an important role in regulating metabolism and immune responses. However, the age-related changes in the secretion mechanisms of GCs remain elusive. Here, we found that corticosterone (CORT) secretion follows a circadian rhythm in young mice, whereas it oversecreted throughout the day in aged mice >18 months old, resulting in the disappearance of diurnal variation. Furthermore, senescent cells progressively accumulated in the zF of the adrenal gland as mice aged beyond 18 months. This accumulation was accompanied by an increase in the number of Ad4BP/SF1 (SF1), a key transcription factor, strongly expressing cells (SF1-high positive: HP). Removal of senescent cells with senolytics, dasatinib, and quercetin resulted in the reduction of the number of SF1-HP cells and recovery of CORT diurnal oscillation in 24-month-old mice. Similarly, administration of a neutralizing antibody against IL1β, which was found to be strongly expressed in the adrenocortical cells of the zF, resulted in a marked decrease in SF1-HP cells and restoration of the CORT circadian rhythm. Our findings suggest that the disappearance of CORT diurnal oscillation is a characteristic of aging individuals and is caused by the secretion of IL1β, one of the SASPs, from senescent cells that accumulate in the zF of the adrenal cortex. These findings provide a novel insight into aging. Age-related hypersecretory GCs could be a potential therapeutic target for aging-related diseases.

Hypoxia induces downregulation of the tumor-suppressive sST2 in colorectal cancer cells via the HIF-nuclear IL-33-GATA3 pathway

As a decoy receptor, soluble ST2 (sST2) interferes with the function of the inflammatory cytokine interleukin (IL)-33. Decreased sST2 expression in colorectal cancer (CRC) cells promotes tumor growth via IL-33-mediated bioprocesses in the tumor microenvironment. In this study, we discovered that hypoxia reduced sST2 expression in CRC cells and explored the associated molecular mechanisms, including the expression of key regulators of ST2 gene transcription in hypoxic CRC cells. In addition, the effect of the recovery of sST2 expression in hypoxic tumor regions on malignant progression was investigated using mouse CRC cells engineered to express sST2 in response to hypoxia. Our results indicated that hypoxia-dependent increases in nuclear IL-33 interfered with the transactivation activity of GATA3 for ST2 gene transcription. Most importantly, hypoxia-responsive sST2 restoration in hypoxic tumor regions corrected the inflammatory microenvironment and suppressed tumor growth and lung metastasis. These results indicate that strategies targeting sST2 in hypoxic tumor regions could be effective for treating malignant CRC.

POS0336 PATTERNS OF LARGE-VESSEL LESIONS AND POOR TREATMENT OUTCOMES IN PATIENTS WITH LARGE-VESSEL GIANT CELL ARTERITIS

Background:

Giant cell arteritis (GCA) is characterized by cranial symptoms and large-vessel lesions (LVL) in the aorta or its branches. We retrospectively analyzed the Japanese patients newly diagnosed as GCA between 2007 and 2014, and subsequently treated with glucocorticoid (GC). The imaging studies revealed that LVLs were observed in approximately half of the GCA patients, and the LVLs were significantly associated with the increased probability of poor treatment outcomes (1).

Objectives:

The objective of this study is to evaluate whether the distribution of LVLs of GCA was associated with poor treatment response.

Methods:

In a retrospective, multi-centric, nationwide registry of GCA patients treated with GCs between 2007 and 2014, 68 newly-diagnosed GCA with LVLs by imaging were detected. All investigators were members of Japan Research Committee of the Ministry of Health, Labour, and Welfare for Intractable Vasculitis (JPVAS). Poor treatment outcomes (non-achievement of clinical remission by week 24 or relapse during 104 weeks) were primarily evaluated. Cumulative rates and median time to the first event were analyzed by the Kaplan-Meier method and the log-rank test. Associated factors with the outcomes were analyzed by using the Cox proportional hazard model.

Results:

The mean age was 70.5 years, and 70.6% were women. Twenty-seven (39.7%) of the 68 patients were diagnosed as having GCA by both positive temporal artery biopsy and positive imaging, and 41 (60.3%) by positive imaging. Aortic lesions were detected in 72.1% (group 2, n=49) of the 68 GCA patients with LVLs. Patients without aortic lesions were categorized into two phenotypes: large-vessel GCA with subclavian lesions (group 1, n=9) and atypical large-vessel GCA without subclavian lesions (group 3, n=10). Cranial lesions were observed in 66.7%, 55.1%, and 80.0% in the group 1, 2, and 3, respectively. The initial mean dose (SD) of prednisolone was 0.74 (0.26) mg/kg/day, and 20.6 % received methotrexate for remission induction therapy. Baseline dose of GCs and mean time to achievement of low-dose GCs (prednisolone ≤ 5 mg/day) was not significantly different among the three groups.

Overall, 35 (51.5%) of the 68 patients had the event of poor treatment outcomes. Eleven patients were not able to achieve clinical remission by week 24. Relapse after achievement of clinical remission was reported in total of 24 patients; 9 between week 0 and 24, 12 between week 24 and 52, 3 between week 52 and 104. The cumulative rate of events of poor treatment outcomes over the two years was 11.1% in patients with group 1, 55.3% in those with group 2, and 88.0% in those with group 3. Mean time to events was significantly different among the three groups. Multivariable analysis showed the risk of poor treatment outcomes was likely to decrease in the group 1 (hazard ratio 0.14 [95% CI 0.02-1.03], p=0.054), while it increased in the group 3 (hazard ratio 2.22 [95% CI 1.06-4.68], p=0.035).

Conclusion:

The distribution of LVLs were associated with poorer treatment outcomes. A half of the patients with aortic lesions had poor treatment outcomes while subclavian arteritis without aortic lesions had better clinical outcomes. Atypical large vessel-GCA without the aortic and subclavian artery involvement was the worst prognostic phenotype of LV-GCA. Extent of LVLs by imaging should be considered when determining the treatment strategy for GCA.

References:

[1]Sugihara T, et al. Arthritis Res Ther. 2020;22(1):72

Acknowledgements:

The authors would like to acknowledge Mitsuaki Isobe (Sakakibara Heart Institute), Yoshihiro Arimura (Kichijoji Asahi Hospital), and all the investigators in the Japan Research Committee of the Ministry of Health, Labour, and Welfare for Intractable Vasculitis (JPVAS). In addition to the authors, the following investigators and institutions participated in this study: Department of Internal Medicine, Juntendo University Koshigaya Hospital (Shigeto Kobayashi); Niigata Rheumatic Center (Satoshi Ito); Niigata Prefectural Shibata Hospital (Noriyuki Homma).

Disclosure of Interests:

takahiko sugihara Speakers bureau: TS has received honoraria from Abbvie Japan Co., Ltd., AsahiKASEI Co., Ltd., Astellas Pharma Inc., Ayumi Pharmaceutical, Bristol Myers Squibb K.K., Chugai Pharmaceutical Co., Ltd., Eli Lilly Japan K.K., Mitsubishi-Tanabe Pharma Co., Ono Pharmaceutical, Pfizer Japan Inc., Takeda Pharmaceutical Co. Ltd., and UCB Japan Co. Ltd., Grant/research support from: TS has received research grants from AsahiKASEI Co., Ltd., Daiichi Sankyo., and Ono Pharmaceutical., Haruhito A. Uchida Grant/research support from: HAU belongs to the Department of Chronic Kidney

Disease and Cardiovascular Disease which is endowed by Chugai Pharmaceutical, MSD, Boehringer Ingelheim, and Kawanishi Holdings., Hajime Yoshifuji Speakers bureau: HY has received lecture fees from Chugai Pharmaceutical Co., Ltd. and Nihon Medi-Physics Co., Ltd., Yasuhiro Maejima Speakers bureau: YM have received honoraria from Chugai Pharmaceutical Co., Ltd.., Taio Naniwa Speakers bureau: TN has received lecture fees from Chugai Pharmaceutical Co., Ltd.., Grant/research support from: TN has received research grants from Chugai Pharmaceutical Co., Ltd.., Yasuhiro Katsumata Speakers bureau: YK has received honoraria from Chugai Pharmaceutical Co., Ltd., Glaxo-Smithkline K.K., Sanofi K.K., Pfizer Japan Inc., and Asahi Kasei Pharma Corp., Takahiro Okazaki Grant/research support from: TO has received research grants from Chugai Pharmaceutical Co., Ltd., Eisai Pharmaceutical., and Actelion, Jun Ishizaki: None declared, Yohko Murakawa Speakers bureau: YM has received honoraria from Abbvie, Astellas, Ayumi Pharmaceutical, Bristol Myers Squibb, Chugai Pharmaceutical, Eisai Pharmaceutical, Janssen Pharmaceutical, Kissei Pharmaceutical, Nippon Kayaku, Pfizer Pharmaceutical, Takeda Pharmaceutical, UCB Pharmaceutical, Grant/research support from: YM has received research grant support from Asahi Kasei Pharma, AbbVie Japan, Chugai Pharmaceutical, Daiichi Sankyo, Eisai Pharmaceutical, Mitsubishi Tanabe Pharma, Nippon Kayaku, Gilead Sciences Inc, Janssen Pharmaceutical, and Teijin Pharma., Noriyoshi Ogawa: None declared, Hiroaki Dobashi: None declared, Tetsuya Horita: None declared, Yoshiya Tanaka Speakers bureau: YT has received consulting fees, speaking fees, and/or honoraria from Daiichi-Sankyo, Astellas, Pfizer, Mitsubishi-Tanabe, Bristol-Myers, Chugai, YL Biologics, Eli Lilly, Sanofi, Janssen, UCB, Grant/research support from: YT has received research grants from Mitsubishi-Tanabe, Takeda, Bristol-Myers, Chugai, Astellas, Abbvie, MSD, Daiichi-Sankyo, Pfizer, Kyowa- Kirin, Eisai, Ono., Shunsuke Furuta: None declared, Tsutomu Takeuchi Speakers bureau: TT has served on speakers’ fees for AbbVie, Bristol-Myers Squibb, Chugai, Mitsubishi Tanabe, Pfizer, Astellas, Daiichi Sankyo, Eisai, Sanofi, Teijin, Takeda, and Novartis., Consultant of: TT has received consulting fees from Astra Zeneca, Eli Lilly, Novartis, Mitsubishi Tanabe, AbbVie, Nippon Kayaku, Janssen, Astellas, Taiho, Chugai, Taisho Toyama, GlaxoSmithKline, and UCB., Grant/research support from: TT has received research grants from Astellas, Chugai, Daiichi Sankyo, Takeda, AbbVie, Asahi Kasei, Mitsubishi Tanabe, Pfizer, Eisai, AYUMI, Nippon Kayaku, and Novartis., Yoshinori Komagata Speakers bureau: YK has received speakers’ fees from Bristol-Myers Squibb, Eli Lilly, Janssen, Novartis, Daiichi Sankyo, AbbVie, Nippon Shinyaku, Towa., Consultant of: YK has received consulting fees from Chugai, Kyowa Hakko Kirin, Asahi Kasei, UCB, Yoshikazu Nakaoka Speakers bureau: YN has received lecture fees from Astellas, Takeda, Daiichi Sankyo, Actelion, and Japan Blood Products Organization (JB)., Consultant of: YN has received consulting fees and/or lecture fees from AbbVie and Chugai, Grant/research support from: YN has received research grants from Chugai and Bayer Yakuhin, Ltd, masayoshi harigai Speakers bureau: MH has received speaker’s fee from AbbVie Japan GK, Ayumi Pharmaceutical Co., Boehringer Ingelheim Japan, Inc.,Bristol Myers Squibb Co., Ltd., Chugai Pharmaceutical Co., Ltd., Eisai Co., Ltd., Eli Lilly Japan K.K., GlaxoSmithKline K.K., Kissei Pharmaceutical Co., Ltd., Pfizer Japan Inc., Takeda Pharmaceutical Co., Ltd., and Teijin Pharma Ltd., Consultant of: MH is a consultant for AbbVie, Boehringer-ingelheim, Bristol Myers Squibb Co., Kissei Pharmaceutical Co.,Ltd. and Teijin Pharma., Grant/research support from: MH has received research grants from AbbVie Japan GK, Asahi Kasei Corp., Astellas Pharma Inc., Ayumi Pharmaceutical Co., Bristol Myers Squibb Co., Ltd., Chugai Pharmaceutical Co., Daiichi-Sankyo, Inc.,Eisai Co., Ltd., Kissei Pharmaceutical Co., Ltd., Mitsubishi Tanabe Pharma Co., Nippon Kayaku Co., Ltd., Sekiui Medical, Shionogi & Co., Ltd., Taisho Pharmaceutical Co., Ltd., Takeda Pharmaceutical Co., Ltd., and Teijin Pharma Ltd.

Left atrial strain and outcome in heart failure with preserved ejection fraction

Funding Acknowledgements

Type of funding sources: None.

Background

Left atrial (LA) function is impaired in heart failure with preserved ejection fraction (HFpEF). However, the association between LA longitudinal strain and heart failure (HF) events in patients with HFpEF is still unknown. We evaluated whether LA strain measurements would be useful to predict hospitalizations for worsening HF in this study.

Methods

This study included 121 patients (Male 73, Female 48) with HFpEF who had echocardiogram at our institute (Age = 76 ± 14y, Left ventricular ejection fraction; LVEF = 63 ± 8%). Patients with atrial fibrillation were excluded. LA longitudinal strain was measured by speckle-tracking echocardiography, using TOMTEC imaging system. The endpoints were hospitalizations for worsening HF.

Results

During follow-up period of 319 ± 269 days, 33 patients (27%) experienced hospitalizations for worsening HF. LA strain was markedly lower in patients with HF events at 11.3 ± 5.6, whereas LA strain was higher at 20.3 ± 10.1 in patients without HF events. Kaplan-Meier analysis demonstrated a significant separation of survival curves stratified by median value of LA strain (Figure).

Conclusions

LA dysfunction in HFpEF is associated with a higher risk of HF hospitalization, and LA strain measurements would be useful to predict HF events.

Abstract Figure

Pulmonary arterial wave reflection as a novel estimate of pulmonary vascular resistance

Funding Acknowledgements

Type of funding sources: Public hospital(s). Main funding source(s): International Medical Research and Development Fund

Background

Measuring pulmonary vascular resistance (PVR) is essential for diagnosing pulmonary hypertension. PVR can be estimated from a simple ratio of tricuspid regurgitation velocity (TRV) to time-velocity integral of flow through right ventricular outflow tract (RVOT) (Abbas equation), but this relationship has been shown to be unreliable in patients with high PVR. Once PVR is elevated, there is an increased pressure wave reflected from the peripheral of pulmonary artery (PA). We tested the hypothesis that assessing PA wave reflection could be an alternative method for estimating PVR.

Methods

This study recruited 83 patients (69 ± 14 years old, 44 men), including 41 patients with left-sided heart disease, 23 patients with pulmonary arterial hypertension and 19 patients with chronic thromboembolic pulmonary hypertension. PA wave reflection was assessed by separating PA pressure waveform derived from a Doppler tracing of TRV into forward and backward pressure (Pf and Pb), using a velocity profile at RVOT. This separation was based on the concept of wave intensity. PVR was estimated using Abbas equation. Pb and PVR by Abbas equation were compared for the correlations with direct measurement of PVR by right heart catheterisation within 48 hours after echocardiography.

Results

Figure A illustrates Pb and Pf waveforms obtained from a patient with chronic thromboembolic pulmonary hypertension. Pb increased from mid systole and formed a late peak of PA pressure waveform. Pb correlated strongly with PVR by catheter (figure B), whereas PVR by Abbas equation underestimated PVR especially when PVR was high, resulting in a moderate correlation (figure C). Receiver-operator characteristic curves showed a higher accuracy of Pb for identifying PVR > 3WU as well as 6WU, compared with PVR by Abbas equation (figure D and E).

Conclusions

This novel echocardiographic method for assessing PA wave reflection helps diagnose the severity of pulmonary hypertension.

Abstract Figure.

25(OH)D3 stimulates the expression of vitamin D target genes in renal tubular cells when Cyp27b1 is abrogated

Recently, it was reported that 25(OH)D₃ (25D3) has physiological bioactivity in certain tissues derived from Cyp27b1 knockout mice. To investigate the function of 25D3 in the kidney as an informational crossroad of various calciotropic substances, we employed the CRISPR-Cas9 system to knock out Cyp27b1 in the mouse renal distal tubular mDCT cell line. Unlike the previously reported mice in which Cyp27b1 was targeted systemically, Cyp27b1 knockout mDCT cells did not produce any measurable 1α,25(OH)₂D₃ (1,25D3) after 25D3 administration. As was seen with treatment of Cyp27b1 knockout mDCT cells with ≥10^-8 M of 1,25D3, the administration of 10^-7 M of 25D3 translocated the vitamin D₃ receptor (VDR) into the nucleus and promoted the expression of the representative 1,25D3-responsive gene Cyp24a1. The exhaustive target gene profiles of 25D3 were similar to those of 1,25D3. Subsequently, we confirmed that 25D3 induced the expression of the calcium reabsorption-related gene calbindin-D9K, in a way similar to 1,25D3. We also found that 1,25D3 and 25D3 induced the expression of the megalin gene. A chromatin immunoprecipitation assay identified two vitamin D response elements in the upstream region of the megalin gene that seemed to contribute to its expression. Together, we surmise that the ability of 25D3 to stimulate VDR target genes may provide a novel perspective for its role in certain tissues.

Imaging of local structures affecting electrical transport properties of large graphene sheets by lock-in thermography

The distribution of defects and dislocations in graphene layers has become a very important concern with regard to the electrical and electronic transport properties of device applications. Although several experiments have shown the influence of defects on the electrical properties of graphene, these studies were limited to measuring microscopic areas because of their long measurement times. Here, we successfully imaged various local defects in a large area of chemical vapor deposition graphene within a reasonable amount of time by using lock-in thermography (LIT). The differences in electrical resistance caused by the micrometer-scale defects, such as cracks and wrinkles, and atomic-scale domain boundaries were apparent as nonuniform Joule heating on polycrystalline and epitaxially grown graphene. The present results indicate that LIT can serve as a fast and effective method of evaluating the quality and uniformity of large graphene films for device applications.

DNA damage response induced by Etoposide promotes steroidogenesis via GADD45A in cultured adrenal cells

Glucocorticoid production is regulated by adrenocorticotropic hormone (ACTH) via the cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) pathway in the adrenal cortex, but the changes in steroidogenesis associated with aging are unknown. In this study, we show that cell-autonomous steroidogenesis is induced by non-ACTH- mediated genotoxic stress in human adrenocortical H295R cells. Low-dose etoposide (EP) was used to induce DNA damage as a genotoxic stress, leading to cellular senescence. We found that steroidogenesis was promoted in cells stained with γH2AX, a marker of DNA damaged cells. Among stress-associated and p53-inducible genes, the expression of GADD45A and steroidogenesis-related genes was significantly upregulated. Immunofluorescence analysis revealed that GADD45A accumulated in the nuclei. Metabolite assay using cultured media showed that EP-treated cells were induced to produce and secrete considerable amounts of glucocorticoid. Knockdown of GADD45A using small interfering RNA markedly inhibited the EP-induced upregulation of steroidogenesis-related gene expression, and glucocorticoid production. A p38MAPK inhibitor, but not a PKA inhibitor, suppressed EP-stimulated steroidogenesis. These results suggest that DNA damage itself promotes steroidogenesis via one or more unprecedented non-ACTH-mediated pathway. Specifically, GADD45A plays a crucial role in the steroidogenic processes triggered by EP-stimulated genotoxic stress. Our study sheds new light on an alternate mechanism of steroidogenesis in the adrenal cortex.

An Excess of CYP24A1, Lack of CaSR, and a Novel lncRNA Near the PTH Gene Characterize an Ectopic PTH-Producing Tumor

Thus far, only 23 cases of the ectopic production of parathyroid hormone (PTH) have been reported. We have characterized the genome-wide transcription profile of an ectopic PTH-producing tumor originating from a retroperitoneal histiocytoma. We found that the calcium-sensing receptor (CaSR) was barely expressed in the tumor. Lack of CaSR, a crucial braking apparatus in the presence of both intraparathyroid and, probably, serendipitous PTH expression, might contribute strongly to the establishment and maintenance of the ectopic transcriptional activation of the PTH gene in nonparathyroid cells. Along with candidate drivers with a crucial frameshift mutation or copy number variation at specific chromosomal areas obtained from whole exome sequencing, we identified robust tumor-specific cytochrome P450 family 24 subfamily A member 1 (CYP24A1) overproduction, which was not observed in other non–PTH-expressing retroperitoneal histiocytoma and parathyroid adenoma samples. We then found a 2.5-kb noncoding RNA in the PTH 3′-downstream region that was exclusively present in the parathyroid adenoma and our tumor. Such a co-occurrence might act as another driver of ectopic PTH-producing tumorigenesis; both might release the control of PTH gene expression by shutting down the other branches of the safety system (e.g., CaSR and the vitamin D3–vitamin D receptor axis).

Prolonged Negative Pressure Wound Therapy Followed by Split-Thickness Skin Graft Placement for Wide Dehiscence of Clamshell Incision After Bilateral Lung Transplantation: A Case Report

Clamshell incision is a standard approach for bilateral lung transplantation, providing a good operative field; however, once wide dehiscence occurs, its management is sometimes difficult because of intense immunosuppression and malnutrition of the recipient. A 22-year-old man with idiopathic pulmonary arterial hypertension underwent cadaveric bilateral lung transplantation through a clamshell incision using standard cardiopulmonary bypass. He developed wound dehiscence on postoperative day (POD) 20 that resulted in exposure of the bilateral fifth ribs and open pneumothorax. Considering the extreme malnutrition and emaciation of the recipient, we avoided initial closure of the dehiscence. After the debridement of necrotic tissue, negative pressure wound therapy was initiated on POD 25 and was continued for approximately 6 months with trafermin spray application. Eventually, the wound, including the fifth ribs, was completely covered with granulation tissue except for the wire tying the sternum. On POD 217, the patient underwent removal of the sternal wire followed by split-thickness skin grafting. His wound was successfully closed and he was discharged without activity limitation on POD 265.

Characterization of SPATA5-related encephalopathy in early childhood

Mutations in SPATA5 have recently been shown to result in a phenotype of microcephaly, intellectual disability, seizures, and hearing loss in childhood. Our aim in this report is to delineate the SPATA5 syndrome as a clinical entity, including the facial appearance, neurophysiological, and neuroimaging findings. Using whole-exome sequencing and Sanger sequencing, we identified three children with SPATA5 mutations from two families. Two siblings carried compound heterozygous mutations, c.989_991del (p.Thr330del) and c.2130_2133del (p.Glu711Profs*21), and the third child had c.967T>A (p.Phe323Ile) and c.2146G>C (p.Ala716Pro) mutations. The three patients manifested microcephaly, psychomotor retardation, hypotonus or hypertonus, and bilateral hearing loss from early infancy. Common facies were a depressed nasal bridge/ridge, broad eyebrows, and retrognathia. Epileptic spasms or tonic seizures emerged at 6-12 months of age. Interictal electroencephalography showed multifocal spikes and bursts of asynchronous diffuse spike-wave complexes. Augmented amplitudes of visually evoked potentials were detected in two patients. Magnetic resonance imaging revealed hypomyelination, thin corpus callosum, and progressive cerebral atrophy. Blood copper levels were also elevated or close to the upper normal levels in these children. Clinical delineation of the SPATA5-related encephalopathy should improve diagnosis, facilitating further clinical and molecular investigation.

Ceramide limits phosphatidylinositol-3-kinase C2β-controlled cell motility in ovarian cancer: potential of ceramide as a metastasis-suppressor lipid

Targeting cell motility, which is required for dissemination and metastasis, has therapeutic potential for ovarian cancer metastasis, and regulatory mechanisms of cell motility need to be uncovered for developing novel therapeutics. Invasive ovarian cancer cells spontaneously formed protrusions, such as lamellipodia, which are required for generating locomotive force in cell motility. Short interfering RNA screening identified class II phosphatidylinositol 3-kinase C2β (PI3KC2β) as the predominant isoform of PI3K involved in lamellipodia formation of ovarian cancer cells. The bioactive sphingolipid ceramide has emerged as an antitumorigenic lipid, and treatment with short-chain C6-ceramide decreased the number of ovarian cancer cells with PI3KC2β-driven lamellipodia. Pharmacological analysis demonstrated that long-chain ceramide regenerated from C6-ceramide through the salvage/recycling pathway, at least in part, mediated the action of C6-ceramide. Mechanistically, ceramide was revealed to interact with the PIK-catalytic domain of PI3KC2β and affect its compartmentalization, thereby suppressing PI3KC2β activation and its driven cell motility. Ceramide treatment also suppressed cell motility promoted by epithelial growth factor, which is a prometastatic factor. To examine the role of ceramide in ovarian cancer metastasis, ceramide liposomes were employed and confirmed to suppress cell motility in vitro. Ceramide liposomes had an inhibitory effect on peritoneal metastasis in a murine xenograft model of human ovarian cancer. Metastasis of PI3KC2β knocked-down cells was insensitive to treatment with ceramide liposomes, suggesting specific involvement of ceramide interaction with PI3KC2β in metastasis suppression. Our study identified ceramide as a bioactive lipid that limits PI3KC2β-governed cell motility, and ceramide is proposed to serve as a metastasis-suppressor lipid in ovarian cancer. These findings could be translated into developing ceramide-based therapy for metastatic diseases.

Vascular Wall Imaging of Unruptured Cerebral Aneurysms with a Hybrid of Opposite-Contrast MR Angiography

BACKGROUND AND PURPOSE

Inflammation and degeneration of the intracranial saccular aneurysm wall play a major role in aneurysm formation, development and subsequent rupture. The aim of this study was to characterize the walls of unruptured intracranial aneurysms by using a hybrid of opposite-contrast MRA at 3T.

MATERIALS AND METHODS

Fourteen consecutive patients with 17 unruptured intracranial aneurysms who initially underwent clipping surgery were prospectively evaluated. All aneurysms were scanned preoperatively by using a hybrid of opposite-contrast MRA in 3T high-resolution MR imaging. We classified intraoperative findings of atherosclerotic plaques in the aneurysms into 3 grades: grade A (major plaques), grade B (minor plaques), and grade C (no plaques). The contrast ratio of the high-intensity area was also measured relative to the background low-intensity area inside the carotid artery.

RESULTS

Findings from preoperative plaque imaging of the aneurysm corresponded to the intraoperative findings in 15 of 16 aneurysms (excluding 1 that was impossible to visualize in its entirety due to anatomic reasons). Overall sensitivity and specificity of the hybrid of opposite-contrast MRA were 88.9% and 100%, respectively. During the operation, 4 aneurysms were classified as grade A; 5, as grade B; and 7, as grade C. The means of the contrast ratio for grades A, B, and C were 0.72 ± 0.03, 0.34 ± 0.30, and -0.02 ± 0.09, respectively.

CONCLUSIONS

The hybrid of opposite-contrast MRA can detect visible atherosclerotic plaques in the unruptured aneurysm wall, and the contrast ratio in intracranial aneurysms correlated with their presence and extent. A study including a larger series is needed to validate the diagnostic potential of this imaging technique.

Wild-type and specific mutant androgen receptor mediates transcription via 17β-estradiol in sex hormone-sensitive cancer cells

We previously encountered regulatory processes wherein dihydrotestosterone (DHT) exerted its inhibitory effect on parathyroid hormone‐related protein (PTHrP) gene repression through the estrogen receptor (ER)α, but not the androgen receptor (AR), in breast cancer MCF‐7 cells. Here, we investigated whether such aberrant ligand‐nuclear receptor (NR) interaction is present in prostate cancer LNCaP cells. First, we confirmed that LNCaP cells expressed large amounts of AR at negligible levels of ERα/β or progesterone receptor. Both suppression of PTHrP and activation of prostate‐specific antigen genes were observed after independent administration of 17β‐estradiol (E2), DHT, or R5020. Consistent with the notion that the LNCaP AR lost its ligand specificity due to a mutation (Thr‐Ala877), experiments with siRNA targeting the respective NR revealed that the AR monopolized the role of the mediator of shared hormone‐dependent regulation, which was invariably associated with nuclear translocation of this mutant AR. Microarray analysis of gene regulation by DHT, E2, or R5020 disclosed that more than half of the genes downstream of the AR (Thr‐Ala877) overlapped in the LNCaP cells. Of particular interest, we realized that the AR (wild‐type [wt]) and AR (Thr‐Ala877) were equally responsible for the E2‐AR interactions. Fluorescence microscopy experiments demonstrated that both EGFP‐AR (wt) and EGFP‐AR (Thr‐Ala877) were exclusively localized within the nucleus after E2 or DHT treatment. Furthermore, reporter assays revealed that some other cancer cells exhibited aberrant E2‐AR (wt) signaling similar to that in the LNCaP cells. We herein postulate the presence of entangled interactions between wt AR and E2 in certain hormone‐sensitive cancer cells. J. Cell. Physiol. 230: 1594–1606, 2015. © 2014 The Authors. Journal of Cellular Physiology Published by Wiley Periodicals, Inc.

Marked cortisol production by intracrine ACTH in GIP-treated cultured adrenal cells in which the GIP receptor was exogenously introduced

The ectopic expression of the glucose-dependent insulinotropic polypeptide receptor (GIPR) in the human adrenal gland causes significant hypercortisolemia after ingestion of each meal and leads to Cushing’s syndrome, implying that human GIPR activation is capable of robustly activating adrenal glucocorticoid secretion. In this study, we transiently transfected the human GIPR expression vector into cultured human adrenocortical carcinoma cells (H295R) and treated them with GIP to examine the direct link between GIPR activation and steroidogenesis. Using quantitative RT-PCR assay, we examined gene expression of steroidogenic related proteins, and carried out immunofluorescence analysis to prove that forced GIPR overexpression directly promotes production of steroidogenic enzymes CYP17A1 and CYP21A2 at the single cell level. Immunofluorescence showed that the transfection efficiency of the GIPR gene in H295R cells was approximately 5%, and GIP stimulation enhanced CYP21A2 and CYP17A1 expression in GIPR-introduced H295R cells (H295R-GIPR). Interestingly, these steroidogenic enzymes were also expressed in the GIPR (–) cells adjacent to the GIPR (+) cells. The mRNA levels of a cholesterol transport protein required for all steroidogenesis, StAR, and steroidogenic enzymes, HSD3β2, CYP11A1, CYP21A2, and CYP17A1 increased 1.2-2.1-fold in GIP-stimulated H295R-GIPR cells. These changes were reflected in the culture medium in which 1.5-fold increase in the cortisol concentration was confirmed. Furthermore, the levels of adenocorticotropic hormone (ACTH) receptor and ACTH precursor proopiomelanocortin (POMC) mRNA were upregulated 2- and 1.5-fold, respectively. Immunofluorescence showed that ACTH expression was detected in GIP-stimulated H295R-GIPR cells. An ACTH-receptor antagonist significantly inhibited steroidogenic gene expression and cortisol production. Immunostaining for both CYP17A1 and CYP21A2 was attenuated in cells treated with ACTH receptor antagonists as well as with POMC siRNA. These results demonstrated that GIPR activation promoted production and release of ACTH, and that steroidogenesis is activated by endogenously secreted ACTH following GIP administration, at least in part, in H295R cells.

Phosphorylation of Smad2/3 at the specific linker threonine residue indicates slow-cycling esophageal stem-like cells before re-entry to the cell cycle

The stem cell compartment in the esophageal epithelium is possibly located in the basal layer. We have identified significant expression of Smad2/3, phosphorylated at specific linker threonine residues (pSmad2/3L-Thr), in the epithelial cells of murine stomach and intestine, and have suggested that these cells are epithelial stem cells. In this study, we explore whether pSmad2/3L-Thr could serve as a biomarker for esophageal stem cells. We examined esophageal tissues from normal C57BL/6 mice and those with esophagitis. Double immunofluorescent staining of pSmad2/3L-Thr with Ki67, CDK4, p63, or CK14 was performed. After immunofluorescent staining, we stained the same sections with hematoxylin-eosin and observed these cells under a light microscope. We used the 5-bromo-2-deoxyuridine (BrdU) labeling assay to examine label retention of pSmad2/3L-Thr immunostaining-positive cells. We collected specimens 5, 10, 15 and 20 days after repeated BrdU administrations and observed double immunofluorescent staining of pSmad2/3L-Thr with BrdU. In the esophagus, pSmad2/3L-Thr immunostaining-positive cells were detected in the basal layer. These cells were detected between Ki67 immunostaining-positive cells, but they were not co-localized with Ki67. pSmad2/3L-Thr immunostaining-positive cells showed co-localization with CDK4, p63, and CK14. Under a light microscope, pSmad2/3L-Thr immunostaining-positive cells indicated undifferentiated morphological features. Until 20 days follow-up period, pSmad2/3L-Thr immunostaining-positive cells were co-localized with BrdU. pSmad2/3L-Thr immunostaining-positive cells significantly increased in the regeneration phase of esophagitis mucosae, as compared with control mice (esophagitis vs.

CONTROL

6.889 ± 0.676/cm vs. 4.293 ± 0.659/cm; P < 0.001). We have identified significant expression of pSmad2/3L-Thr in the specific epithelial cells of murine esophagi. We suggest that these cells are slow-cycling epithelial stem-like cells before re-entry to the cell cycle.

Serum choline plasmalogens, particularly those with oleic acid in sn-2, are associated with proatherogenic state

Serum plasmalogens (Pls) (1-O-alk-1'-enyl-2-acyl glycerophospholipids) are of particular interest for studies on metabolic disorders associated with oxidative stress and chronic inflammation. Serum levels of Pls are known to correlate positively with HDL-cholesterol (HDL-C); however, few studies have examined serum Pls molecular species in association with pathophysiological conditions and their clinical significance. To clarify these, we determined serum levels of individual ether glycerophospholipids in Japanese asymptomatic cohorts (n = 428; 362 male and 66 female subjects) by LC/MS/MS, and examined their correlations with clinical parameters. We found that the proportion of choline Pls (PlsCho) among total serum phospholipids was significantly lower in the male group over 40 years old and was associated with multiple risk parameters more strongly than HDL-C. The abundance of serum PlsCho with oleic acid (18:1) in sn-2 exhibited the strongest positive correlation with serum concentrations of adiponectin and HDL-C, while being inversely associated with waist circumference and the serum levels of TG and small dense LDL-cholesterol. The characterization of serum ether glycerophospholipids verified the specificity of PlsCho, particularly the ones with 18:1 in sn-2, as a sensitive biomarker for the atherogenic state.

Histone acetyltransferase Hbo1 destabilizes estrogen receptor α by ubiquitination and modulates proliferation of breast cancers

The estrogen receptor (ER) is a key molecule for growth of breast cancers. It has been a successful target for treatment of breast cancers. Elucidation of the ER expression mechanism is of importance for designing therapeutics for ER-positive breast cancers. However, the detailed mechanism of ER stability is still unclear. Here, we report that histone acetyltransferase Hbo1 promotes destabilization of estrogen receptor α (ERα) in breast cancers through lysine 48-linked ubiquitination. The acetyltransferase activity of Hbo1 is linked to its activity for ERα ubiquitination. Depletion of Hbo1 and anti-estrogen treatment displayed a potent growth suppression of breast cancer cell line. Hbo1 modulated transcription by ERα. Mutually exclusive expression of Hbo1 and ERα was observed in roughly half of the human breast tumors examined in the present study. Modulation of ER stability by Hbo1 in breast cancers may provide a novel therapeutic possibility.

Ordered and disordered packing of coronene molecules in carbon nanotubes

Monte Carlo simulations of coronene molecules in single-walled carbon nanotubes (SWCNTs) and dicoronylene molecules in SWCNTs are performed. Depending on the diameter D of the encapsulating SWCNT, regimes favoring the formation of ordered, one-dimensional (1D) stacks of tilted molecules (D ≤ 1.7 nm for coronene@SWCNT, 1.5 nm ≤ D ≤ 1.7 nm for dicoronylene@SWCNT) and regimes with disordered molecular arrangements and increased translational mobilities enabling the thermally induced polymerization of neighboring molecules resulting in the formation of graphene nanoribbons (GNRs) are observed. The results show that the diameter of the encapsulating nanotube is a crucial parameter for the controlled synthesis of either highly ordered 1D structures or GNR precursors.

Tysnd1 deficiency in mice interferes with the peroxisomal localization of PTS2 enzymes, causing lipid metabolic abnormalities and male infertility

Peroxisomes are subcellular organelles involved in lipid metabolic processes, including those of very-long-chain fatty acids and branched-chain fatty acids, among others. Peroxisome matrix proteins are synthesized in the cytoplasm. Targeting signals (PTS or peroxisomal targeting signal) at the C-terminus (PTS1) or N-terminus (PTS2) of peroxisomal matrix proteins mediate their import into the organelle. In the case of PTS2-containing proteins, the PTS2 signal is cleaved from the protein when transported into peroxisomes. The functional mechanism of PTS2 processing, however, is poorly understood. Previously we identified Tysnd1 (Trypsin domain containing 1) and biochemically characterized it as a peroxisomal cysteine endopeptidase that directly processes PTS2-containing prethiolase Acaa1 and PTS1-containing Acox1, Hsd17b4, and ScpX. The latter three enzymes are crucial components of the very-long-chain fatty acids β-oxidation pathway. To clarify the in vivo functions and physiological role of Tysnd1, we analyzed the phenotype of Tysnd1^−/− mice. Male Tysnd1^−/− mice are infertile, and the epididymal sperms lack the acrosomal cap. These phenotypic features are most likely the result of changes in the molecular species composition of choline and ethanolamine plasmalogens. Tysnd1^−/− mice also developed liver dysfunctions when the phytanic acid precursor phytol was orally administered. Phyh and Agps are known PTS2-containing proteins, but were identified as novel Tysnd1 substrates. Loss of Tysnd1 interferes with the peroxisomal localization of Acaa1, Phyh, and Agps, which might cause the mild Zellweger syndrome spectrum-resembling phenotypes. Our data established that peroxisomal processing protease Tysnd1 is necessary to mediate the physiological functions of PTS2-containing substrates.

Peroxisomes are subcellular organelles that are present in almost all eukaryotic cells. The syllables “per-oxi” reflect the oxidative functions of these single-membrane-bound organelles in various metabolic processes, including those of very-long-chain fatty acids and branched-chain fatty acids. In an earlier study we identified a protease named Tysnd1 that is specifically located in the peroxisomes and processes the enzymes catalyzing the peroxisomal β-oxidation of very-long-chain fatty acids. In this study, we identified two novel Tysnd1 substrates, Agps and Phyh, which are involved in plasmalogen synthesis and phytanic acid metabolism, respectively. To further investigate the in vivo function of Tysnd1, we analyzed Tysnd1 knock-out mice. Mice that lack Tysnd1 showed reduced peroxisomal β-oxidation activity and an altered plasmalogen composition, as well as an abnormal phytanic acid metabolism. Male infertility is one of the major phenotypic manifestations of Tysnd1 deficiency. Our data support the idea that Tysnd1 affects the localization and activity of some of its substrates inside peroxisomes. Altogether, our Tysnd1-deficient mouse model expands the current peroxisome biology knowledge with regard to the molecular pathogenic mechanisms that may be relevant to some patients with Zellweger syndrome spectrum disorders.

Primary polydipsia, but not accumulated ceramide, causes lethal renal damage in saposin D-deficient mice

Saposin D-deficient (Sap-D(-/-)) mice develop polydipsia/polyuria and die prematurely due to renal failure with robust hydronephrosis. Such symptoms emerged when they were around 3 mo of age. To investigate the pathogenesis of their water mishandling, we attempted to limit water supply and followed sequential changes of physiological and biochemical parameters. We also analyzed renal histological changes at several time points. At 3 mo old just before water restriction challenge was started, their baseline arginine vasopressin level was comparable to the wild-type (WT) level. Twenty-four-hour water deprivation and desamino d-arginine vasopressin administration improved polydipsia and polyuria to certain degrees. However, creatinine concentrations in Sap-D(-/-) mice were significantly higher than those in WT mice, suggesting that some renal impairment already emerged in the affected mice at this age. Renal histological analyses revealed that renal tubules and collecting ducts were expanded after 3 mo old. After 6 mo old, vacuolar formation was observed, many inflammatory cells migrated around the ducts, and epithelial monolayer cells of tubular origin were replaced by plentiful cysts of various sizes. At 10∼12 mo old, severe cystic deformity appeared. On the other hand, 8-mo-long water restriction started at 4 mo old dramatically improved tubular damage and restored once-dampened amount of tubular aquaporin2 protein to the WT level. Furthermore, 10-mo-long water restriction ameliorated their renal function. Remarkably, by continuing water restriction thereafter, overall survival period became comparable with that of the WT. Together, polyuria, devastating renal tubular lesions, and renal failure were ameliorated by the mere 10-mo-long water restriction, which would trigger lethal dehydration if the disease were to be caused by any processes other than primary polydipsia. Our study demonstrates that long-term water restriction surely improved renal histopathological changes leading to prevention of premature death in Sap-D(-/-) mice.

Intraoperative colonoscopy facilitates safe dissection of the rectal pouch in a case of male imperforate anus

INTRODUCTION

In an imperforate anus, colostography often fails to identify recto-urethral fistula (RUF). Thus, surgeons must always assume an RUF is present, despite colostography findings, and dissect the distal rectal pouch (RP) with caution. We report the usefulness of intraoperative colonoscopy (IOC) for excluding RUF and, thus, facilitating safe dissection of the RP.

METHODS

We used IOC in six cases of imperforate anus. All had right transverse colostomy initially after birth. Distal colostography excluded RUF in five cases and was inconclusive in one. Laparoscopy was used to free the RP carefully from the bladder neck in all cases. Near the prostate, a 4-mm fine, flexible colonoscope was inserted into the RP through the anterior rectal wall to observe the laparoscopic dissection of the RP, which was attached closely to the prostate/bulbar urethra intraluminally to prevent injury to the urethra. The mucosa of the distal end of the RP was mucosectomized or diathermied, and the colon was pulled-through. Mean age at surgery was 11 months.

RESULTS

IOC excluded RUF under direct vision in all cases, which enabled the dissection of the RP to be monitored and to proceed smoothly. At follow-up (mean: 31 months), all cases were well.

CONCLUSIONS

IOC can be used to exclude RUF and facilitate safe dissection of the RP in imperforate anus.

Degradation of p21Cip1 through anaphase-promoting complex/cyclosome and its activator Cdc20 (APC/CCdc20) ubiquitin ligase complex-mediated ubiquitylation is inhibited by cyclin-dependent kinase 2 in cardiomyocytes

Cyclin-dependent kinase inhibitor p21Cip1 plays a crucial role in regulating cell cycle arrest and differentiation. It is known that p21Cip1 increases during terminal differentiation of cardiomyocytes, but its expression control and biological roles are not fully understood. Here, we show that the p21Cip1 protein is stabilized in cardiomyocytes after mitogenic stimulation, due to its increased CDK2 binding and inhibition of ubiquitylation. The APC/CCdc20 complex is shown to be an E3 ligase mediating ubiquitylation of p21Cip1 at the N terminus. CDK2, but not CDC2, suppressed the interaction of p21Cip1 with Cdc20, thereby leading to inhibition of anaphase-promoting complex/cyclosome and its activator Cdc20 (APC/CCdc20)-mediated p21Cip1 ubiquitylation. It was further demonstrated that p21Cip1 accumulation caused G2 arrest of cardiomyocytes that were forced to re-enter the cell cycle. Taken together, these data show that the stability of the p21Cip1 protein is actively regulated in terminally differentiated cardiomyocytes and plays a role in inhibiting their uncontrolled cell cycle progression. Our study provides a novel insight on the control of p21Cip1 by ubiquitin-mediated degradation and its implication in cell cycle arrest in terminal differentiation.

Improvement and validation of 125I-high-performance liquid chromatography method for determination of total human serum choline and ethanolamine plasmalogens

Background

Serum plasmalogens (Pls) have gained interest in several clinical symptoms such as metabolic syndrome/atherosclerosis or Alzheimer's disease possibly because of their antioxidant properties. We have developed a highly sensitive and simple method to determine plasmenylcholine (PlsCho; choline plasmalogen) and plasmenylethanolamine (PlsEtn; ethanolamine plasmalogen) separately, using a radioactive iodine and high-performance liquid chromatography (125I-HPLC method). The present study reports the improvement and validation of 125I-HPLC method by introducing a quantitative standard (QS) and online detection with a flow γ-counter.

Methods

1-Alkenyl 2,3-cyclic glycerophosphate was prepared as QS from l- α-lyso plasmenylcholine by enzymatic treatment with phospholipase D. Online detection with a flow γ-counter was investigated to be available to quantify Pls. The method validation was carried out in terms of selectivity, sensitivity, linearity, precision, accuracy and recovery.

Results

Linearity was established over the concentration range 5–300 μmol/L for Pls and QS with regression coefficients >0.99. The accuracy and reliability were satisfactory. The method has been applied to the determination of human serum Pls from healthy subjects and the elderly with dementia or artery stenoses.

Conclusions

The improved 125I-HPLC method is useful as an autoanalytical system for a routine diagnostic test of human serum Pls.

Appendiceal stump closure in children with complicated appendicitis: a prospective analysis of endoloops versus endostaples

INTRODUCTION

Laparoscopic appendectomy (LA) can be performed safely and effectively using endoloops (EL) or endostaples (ES). We compared EL and ES for stump closure during LA for complicated appendicitis in children.

METHODS

All LA for complicated appendicitis performed between July 2005 and August 2009 were assessed prospectively. EL were used in 37 procedures and ES in 31. Apart from choice of technique which was the personal preference of the attending surgeon, all patients were managed according to the same intraoperative and postoperative protocols.

RESULTS

There was no significant difference between mean age at operation; gender ratio; mean preoperative and postoperative white blood cell; mean preoperative and postoperative white blood cell C-reactive protein; histopathology; mean operating time (EL: 71 minutes; ES: 64 minutes); mean hospitalization (EL: 5.3 days; ES: 5.1 days); febrile period (EL: 2.1 days; ES: 1.9 days); white blood cell normalization (EL: 2.6 days; ES: 2.4 days); and intravenous antibiotic usage (EL: 3.8 days; ES: 3.7 days). There were no intraoperative complications or ICU admissions in either group, but two EL cases required conversion to open surgery (P=NS). Incidences of intra-abdominal abscess (EL: n=1 or 2.7%; ES: n=1 or 3.2%), transient ileus (EL: n=2 or 5.4%; ES: n=2 or 6.4%), small bowel obstruction (EL: n=0; ES: n=0), and wound infection (EL: n=1 or 2.7%; ES: n=1 or 3.2 %) were not significantly different. Rate of rehospitalization for EL was 2.7% (n=1; colitis), and for ES, it was 3.2% (n=1; intra-abdominal abscess) (P=NS). Mean cost for EL was US$890, and for ES, it was US$1300.

CONCLUSION

This is the first prospective study comparing EL and ES during LA for complicated appendicitis in children. ES is more expensive, but there was no significant difference in morbidity for this technique, particularly with regard to incidence of postoperative intra-abdominal abscess.

Perioperative outcomes for elective open abdominal aortic aneurysm repair since the adoption of endovascular grafting procedures

OBJECTIVES

The objective of this study was to evaluate and compare our perioperative outcomes for open abdominal aortic aneurysm (AAA) between the pre-endovascular aneurysm repair (pre-EVAR) and EVAR eras and to analyse whether the AAA that was excluded from EVAR could affect the perioperative outcome.

MATERIALS AND METHODS

The Kurume University Hospital vascular registry was reviewed to identify all patients undergoing an elective open AAA repair from January 2004 through November 2006 (pre-EVAR era, n = 99) and from December 2006 through June 2010 (EVAR era, n = 125). The early clinical outcomes between the two groups were compared.

RESULTS

In the EVAR era, the proportion of EVAR in all elective AAA repairs was 43.4%. The EVAR era had a significantly higher proportion of very elderly patients over 80 years of age (23.2% vs. 11.1%, P = 0.0391). The morbidity rates were similar between the two groups (22.3% vs. 24,8%) and the mortality rate was 0% for both.

CONCLUSION

Despite the increased complexity of OAR in the EVAR era, we believe that OAR remains a valid procedure for AAA repair.

Negative regulation of parathyroid hormone-related protein expression by steroid hormones

Elevated parathyroid hormone-related protein (PTHrP) is responsible for humoral hypercalcemia of malignancy (HHM), which is of clinical significance in treatment of terminal patients with malignancies. Steroid hormones were known to cause suppression of PTHrP expression. However, detailed studies linking multiple steroid hormones to PTHrP expression are lacking. Here we studied PTHrP expression in response to steroid hormones in four cell lines with excessive PTHrP production. Our study established that steroid hormones negatively regulate PTHrP expression. Vitamin D receptor, estrogen receptor α, glucocorticoid receptor, and progesterone receptor, were required for repression of PTHrP expression by the cognate ligands. A notable exception was the androgen receptor, which was dispensable for suppression of PTHrP expression in androgen-treated cells. We propose a pathway(s) involving nuclear receptors to suppress PTHrP expression.

21 THE INJECTION OF CORTISOL TO UTERUS INCREASES THE IMPLANTATION RATE AND LITTER SIZE IN PIG ARTIFICIAL INSEMINATION USING CYROPRESERVED SPERMATOZOA

Cryopreserved boar spermatozoa are not routinely available to swine artificial insemination (AI) because conception and farrowing rates, along with litter size, have remained low. We have reported the positive roles of seminal plasma in frozen–thawed sperm functions (Okazaki et al. 2009 Theriogenology 71, 491–498). Moreover, the injection of seminal plasma to uterus with frozen–thawed spermatozoa significantly increased the implantation rate. Thus, the factors in seminal plasma act not only on sperm but also on uterus to induce successful fertilization and implantation in pig AI using cryopreserved spermatozoa. To test this hypothesis, we identified the factors in seminal plasma and then developed novel pig AI method using cryopreserved spermatozoa. The sperm-rich fraction was collected weekly from each boar using the gloved-hand technique. The seminal plasma was removed just after collection by centrifuge and then was frozen as described in our previous study (Okazaki et al. 2009 Theriogenology 71, 491–498). When the frozen–thawed sperm was incubated with Fluo-3/AM to determine the level of intercellular Ca2+, the level of Ca2+ was increased in a time-dependent manner, and spontaneous capacitation that was judged by tyrosine phosphorylation of sperm protein by Western blotting (Shimada et al. 2008 Development 135, 2001–2011), was also induced in post-thawed sperm. The addition of EGTA to thawing solution significantly suppressed the Ca2+-induced capacitation. Moreover, the treatment increased fertilization rate in in vitro fertilization and in vivo in artificial insemination as similar as those in sperm with seminal plasma. The same number of blastocyst was collected from uterus by AI using post-thawed sperm with EGTA. However, the pregnancy rate remained low, and the number of leukocytes in the uterus was increased. In the next experiment, we examined in seminal plasma, the level of cortisol that has been known to play an important role in controlling immune function. The results showed that cortisol (1.0 ng mL–1) was detected in seminal plasma. When the sows of natural oestrus were twice artificial inseminated with or without cortisol, the injection of cortisol (5 μg/50 mL) to uterus with sperm significantly decreased the number of leukocytes in the uterus or endometrium at 24 to 36 h after AI. The low number of leukocytes in the uterus was similar to that in uterus injected fresh semen. The cortisol injection significantly increased the implantation rate and litter size of sows as compared to AI without cortisol (implantation rate; 83% v. 51%, litter size; 10.6 v. 7.3). From these results, we concluded that the injection of cortisol with frozen–thawed spermatozoa by EGTA-containing solution was a novel method of pig AI using cryopreserved spermatozoa. This work was supported by the Programme for Promotion of Basic and Applied Researches for Innovations in Bio-oriented Industry, and JST-Grant (No. 12-068 and No. 12-104).