Human omentin-1 reduces vascular insulin resistance and hypertension in Otsuka Long-Evans Tokushima Fatty rats.

PURPOSE: Hypertension is one of the major risk factors for renal failure and cardiovascular diseases, and is caused by various abnormalities including the contractility of blood vessels. Otsuka Long-Evans Tokushima Fatty (OLETF) rats, which mimic human type 2 diabetes, are frequently used to study obesity-induced insulin resistance (IR) and hypertension. Human omentin-1 is one of the recently identified adipocytokines. We previously demonstrated that human omentin-1 not only caused vasodilation in rat isolated blood vessels, but also prevented inflammatory responses, a possible mechanism relating IR, in human vascular endothelial cells. Taken together, we hypothesized that human omentin-1 may reduce obesity-induced IR and hypertension in OLETF rats. METHODS: OLETF rats were intraperitoneally administered with human omentin-1 for 7 days. RESULTS: Human omentin-1 had no influence on overweight, hyperglycemia, urinary glucose extraction, hyperinsulinemia, and systemic IR in OLETF rats. Human omentin-1 decreased systolic blood pressure in OLETF rats. The measurement of isometric contraction revealed that human omentin-1 had no influence on the agonist-induced contractile and relaxant responses in isolated thoracic aorta from OLETF rats. However, the relaxant response mediated by human insulin was converted into the contractile response in thoracic aorta from OLETF rats, which was prevented by human omentin-1. The Western blotting revealed that human omentin-1 improved the decrease in endothelial nitric oxide synthase activation in isolated thoracic aorta from OLETF rats. CONCLUSION: In summary, we for the first time revealed that human omentin-1 partly reduces vascular IR and thereby inhibits hypertension in OLETF rats.

Evaluation of the efficacy of mitochondrial fission inhibitor (Mdivi-1) using non-alcoholic steatohepatitis (NASH) liver organoids.

Non-alcoholic steatohepatitis (NASH) is known to progress to cirrhosis and hepatocellular carcinoma in some patients. Although NASH is associated with abnormal mitochondrial function related to lipid metabolism, mechanisms for the development and effective treatments are still unclear. Therefore, new approaches to elucidate the pathophysiology are needed. In the previous study, we generated liver organoids from different stages of NASH model mice that could recapitulate the part of NASH pathology. In the present study, we investigated the relationship between mitochondrial function and NASH disease by comparing NASH liver organoids (NLO) and control liver organoids (CLO). Compared with CLO, mitochondrial and organoid morphology was abnormal in NLO, with increased expression of mitochondrial mitogen protein, DRP1, and mitochondria-derived reactive oxygen species (ROS) production. Treatment of NLO with a DPR1 inhibitor, Mdivi-1 resulted in the improvement of morphology and the decreased expression of fibrosis-related markers, Col1a1 and Acta2. In addition, treatment of NASH model mice with Mdivi-1 showed a decrease in fatty liver. Mdivi-1 treatment also prevented fibrosis and ROS production in the liver. These results indicate that NLO undergoes enhanced metabolism and abnormal mitochondrial morphology compared with CLO. It was also suggested that Mdivi-1 may be useful as a therapeutic agent to ameliorate NASH pathology.

Eukaryotic elongation factor 2 kinase inhibitor, A484954 induced diuresis via nitric oxide production in spontaneously hypertensive rats.

Eukaryotic elongation factor 2 (eEF2) kinase (eEF2K) is a protein kinase that inactivates eEF2, a protein that mediates a peptidyl-tRNA translocation during an elongation step of protein synthesis. We have previously shown that eEF2K was involved in pathogenesis of essential and pulmonary hypertension. A484954 (7-amino-1-cyclopropyl-3-ethyl-2,4-dioxo-1,2,3,4-tetrahydropyrido[2,3-d] pyrimidine-6-carboxamide), a selective eEF2K inhibitor, is a membrane permeable small molecule. We have previously shown that A484954 lowered blood pressure and induced diuretic effects in spontaneously hypertensive rats (SHR) due to an increase in renal blood flow. Here we aimed to reveal mechanisms underlying the diuretic effects of A484954 in SHR. A484954-induced diuresis and increase in urinary Na+ excretion were inhibited by N (G)-nitro-L-arginine methyl ester (L-NAME), a nitric oxide (NO) synthase inhibitor. A484954 increased mRNA expression of angiotensin type 2 receptor (AT2R) and nuclear factor-erythroid 2-related factor 2 (Nrf2). In summary, we for the first time revealed that A484954 induces diuresis in SHR at least partly via the activation of NO/Nrf2/AT2R pathway.

Autocrine role of senescent cardiac fibroblasts-derived extracellular vesicles.

Cellular senescence is a highly stable state associated with cell cycle arrest, that is elicited in response to various stresses. The accumulation of senescent cells in tissues drives age-related diseases. Recent studies have shown that the cellular senescence enhances an extracellular vesicles (EV) secretion. EV are lipid-bilayer-capsuled particles released by various cells mediating cell-to-cell communication. It was recently reported that EV secreted by the senescent cells had several functions such as cancer cell proliferation and immune cell activation. In the present study, we investigated whether senescent cardiac fibroblasts-derived EV play an autocrine/paracrine role in the heart cells. Neonatal rat cardiac fibroblasts (NRCFs) were treated with doxorubicin (DOX) to induce cellular senescence. EV were isolated from NRCFs culture media. The vehicle-treated NRCFs-derived EV (D0-EV, 72 hr) increased a living cell number in NRCFs, which was attenuated by DOX (1,000 nM)-treated NRCFs-derived EV (D103-EV, 72 hr). While D0-EV did not affect protein concentration in NRCFs, D103-EV decreased it. Furthermore, D103-EV significantly increased a ratio of microtubule-associated protein 1 light chain 3 (LC3)-II to LC3-I in NRCFs, indicating an induction of autophagy. In addition, D103-EV increased phosphorylation of adenosine monophosphate-activated kinase (AMPK) α in NRCFs. In neonatal rat cardiomyocytes, however, NRCFs-derived EV (72 hr) had no effect on the living cell number, protein concentration, and ratio of LC3-II to LC3-I. In conclusion, we for the first time revealed that DOX-induced senescent NRCFs-derived EV induce autophagy in NRCFs perhaps partly through the activation of AMPKα.

Derivation of a new model of lung adenocarcinoma using canine lung cancer organoids for translational research in pulmonary medicine.

Canine primary lung cancer (cPLC) is a rare malignant tumor in dogs, and exhibits poor prognosis. Effective therapeutic drugs against cPLC have not been established yet. Also, cPLC resembles human lung cancer in histopathological characteristics and gene expression profiles and thus could be an important research model for this disease. Three-dimensional organoid culture is known to recapitulate the tissue dynamics in vivo. We, therefore, tried to generate cPLC organoids (cPLCO) for analyzing the profiles of cPLC. After samples from cPLC and the corresponding normal lung tissue were collected, cPLCO were successfully generated, which recapitulated the tissue architecture of cPLC, expressed lung adenocarcinoma marker (TTF1), and exhibited tumorigenesis in vivo. The sensitivity of cPLCO to anti-cancer drugs was different among strains. RNA-sequencing analysis showed significantly upregulated 11 genes in cPLCO compared with canine normal lung organoids (cNLO). Moreover, cPLCO were enriched with the MEK-signaling pathway compared with cNLO. The MEK inhibitor, trametinib decreased the viability of several strains of cPLCO and inhibited the growth of cPLC xenografts. Collectively, our established cPLCO model might be a useful tool for identifying novel biomarkers for cPLC and a new research model for dog and human lung cancer.

Anti-cancer activity of Chaga mushroom (Inonotus obliquus) against dog bladder cancer organoids.

Despite its disadvantages, chemotherapy is still commonly used for the treatment of bladder cancer (BC). Developing natural supplements that can target cancer stem cells (CSCs) which cause drug resistance and distant metastasis is necessary. Chaga mushrooms are popular to have several health-promoting and anti-cancer potentials. Organoid culture can recapitulate tumor heterogeneity, epithelial environment, and genetic and molecular imprints of the original tissues. In the previous study, we generated dog bladder cancer organoids (DBCO) as a novel experimental model of muscle-invasive BCO. Therefore, the present study aimed to examine the anti-tumor potentials of Chaga mushroom extract (Chaga) against DBCO. Four strains of DBCO were used in the present study. Treatment with Chaga inhibited the cell viability of DBCO in a concentration-dependent way. Treatment of DBCO with Chaga has significantly arrested its cell cycle and induced apoptosis. Expression of bladder CSC markers, CD44, C-MYC, SOX2, and YAP1, declined in the Chaga-treated DBCO. Also, Chaga inhibited the phosphorylation of ERK in DBCO. Expression of downstream signals of ERK, C-MYC, and Cyclins (Cyclin-A2, Cyclin-D1, Cyclin-E1, and CDK4) was also inhibited by Chaga in DBCO. Interestingly, the combinational treatment of DBCO with Chaga and anti-cancer drugs, vinblastine, mitoxantrone, or carboplatin, showed a potentiating activity. In vivo, Chaga administration decreased tumor growth and weight of DBCO-derived xenograft in mice with the induction of necrotic lesions. In conclusion, Chaga diminished the cell viability of DBCO by inhibiting proliferation-related signals and stemness conditions as well as by arresting the cell cycle. Collectively, these data suggest the value of Chaga as a promising natural supplement that could potentiate the effect of adjuvant chemotherapy, lower its adverse effects, and thus, limit the recurrence and metastasis of BC.

Establishment of an experimental model of canine malignant mesothelioma organoid culture using a three-dimensional culture method.

Canine malignant mesothelioma (cMM) is a rare and drug-resistant malignant tumor. Due to few patients and experimental models, there have not been enough studies to demonstrate the pathogenesis of the disease and novel effective treatment for cMM. Since cMM resembles human MM (hMM) in histopathological characteristics, it is also considered a promising research model of hMM. Compared with conventional 2-dimensional (2D) culture methods, 3-dimensional (3D) organoid culture can recapitulate the properties of original tumor tissues. However, cMM organoids have never been developed. In the present study, we for the first time generated cMM organoids using the pleural effusion samples. Organoids from individual MM dogs were successfully generated. They exhibited the characteristics of MM and expressed mesothelial cell markers, such as WT-1 and mesothelin. The sensitivity to anti-cancer drugs was different in each strain of cMM organoids. RNA sequencing analysis showed cell adhesion molecule pathways were specifically upregulated in cMM organoids compared with their corresponding 2D cultured cells. Among these genes, the expression level of E-cadherin was drastically higher in the organoids than that in the 2D cells. In conclusion, our established cMM organoids might become a new experimental tool to provide new insights into canine and human MM therapy.

Human Omentin-1 Administration Ameliorates Hypertensive Complications without Affecting Hypertension in Spontaneously Hypertensive Rats.

Hypertension is one of the major risk factors for cardiovascular diseases and is caused by various abnormalities including the contractility of blood vessels. Spontaneously hypertensive rats (SHR), whose systemic blood pressure increases with aging, are a frequently used animal model for investigating essential hypertension and related complications in humans due to the damage of several organs. Human omentin-1 is an adipocytokine consisting of 313 amino acids. Serum omentin-1 levels decreased in hypertensive patients compared with normotensive controls. Furthermore, omentin-1 knockout mice showed elevated blood pressure and impaired endothelial vasodilation. Taken together, we hypothesized that adipocytokine, human omentin-1 may improve the hypertension and its complications including heart and renal failure in the aged SHR (65-68-weeks-old). SHR were subcutaneously administered with human omentin-1 (18 µg/kg/day, 2 weeks). Human omentin-1 had no effect on body weight, heart rate, and systolic blood pressure in SHR. The measurement of isometric contraction revealed that human omentin-1 had no influence on the enhanced vasocontractile or impaired vasodilator responses in the isolated thoracic aorta from SHR. On the other hand, human omentin-1 tended to improve left ventricular diastolic failure and renal failure in SHR. In summary, human omentin-1 tended to improve hypertensive complications (heart and renal failure), while it had no influence on the severe hypertension in the aged SHR. The further study of human omentin-1 may lead to the development of therapeutic agents for hypertensive complications.

Effects of a Soluble Guanylate Cyclase Stimulator Riociguat on Contractility of Isolated Pulmonary Artery and Hemodynamics of U46619-Induced Pulmonary Hypertension in Dogs.

Soluble guanylate cyclase (sGC) stimulator riociguat is a relatively novel therapeutic agent for pulmonary hypertension (PH) in human medicine. Riociguat induces endothelium-independent pulmonary artery (PA) relaxation by directly activating the sGC-cyclic guanosine-3',5'-monophosphate (cGMP) pathway in muscle cells. Although riociguat may be effective in the treatment of dogs with refractory PH, basic studies on its clinical application in veterinary medicine are lacking. The present study aimed to explore the effects of riociguat on the contractility of an isolated canine PA and the hemodynamics of dogs with acute PH. In an isolated endothelium-denuded canine PA, the effects of riociguat on endothelin (ET)-1-induced contraction and cGMP levels were investigated using the Magnus method and ELISA, respectively. The effect of riociguat on the hemodynamics of the thromboxane A2 analog U46619-induced PH model dog was examined by invasive catheterization. Riociguat increased cGMP levels and reduced ET-1-induced contraction of the isolated PA. Riociguat inhibited the U46619-induced elevation of PA pressure and pulmonary vascular resistance and increased cardiac output, but it had no effect on basal systemic blood pressure. These results demonstrate for the first time that riociguat can inhibit the elevation of PA pressure through PA relaxation via an endothelium-independent increase in cGMP in dogs with PH.

Chemerin fragments show different effects on systemic blood pressure dependent on carboxyl-terminal cleavage site.

Chemerin is an adipocytokine whose concentration in blood correlates positively with blood pressure (BP). We have recently revealed that acute intracerebroventricular (i.c.v.) injection of chemerin-9, an active fragment of human chemerin, increased systemic BP in normal Wistar rats, suggesting that chemerin is involved in the central nervous control of peripheral BP. After secreted as an inactive form as prochemerin, a mature form of active chemerin is produced through the cleavage of its carboxyl (C)-terminus by proteases. Although the activity of cleaved products of chemerin has been examined in vitro, in vivo effects remained to be elusive. In order to explore them, we performed acute i.c.v. injection of mouse chemerin-9 (mChemerin-9; 148F-156S), mouse chemerin-8 (mChemerin-8; 148F-155F), and mouse chemerin-7 (mChemerin-7; 148F-154A) into Wistar rats, and examined the effects on systemic BP. After chemerin fragment (1-30 nmol/head, i.c.v.) was cumulatively administered, systemic BP was measured by a cannulation method under an isoflurane anesthesia. mChemerin-9 but not mChemerin-8 and -7 induced a pressor response, which was concentration-dependent. In conclusion, we for the first time demonstrated that mChemerin-9 that corresponds to the C-terminal nine amino acids of active mouse chemerin156S increased systemic BP in rats, and also that chemerin fragments showed different effects on systemic BP dependent on how their C-terminus was cleaved.

Establishment of a direct 2.5D organoid culture model using companion animal cancer tissues.

Like humans, cancer affects companion animals with similar genetic risks and incident rates. To improve treatment strategies for pet cancers, new research models are necessary. Patient-derived 3D organoid culture models are valuable and ensure the development of new effective therapies. In the previous study, we established a 3D organoid-derived 2.5D organoid culture model that recapitulated some characteristics of their parental 3D organoids. In the present study, we aimed to generate a 2.5D organoid culture model directly from cancer-diseased dogs and cats using special 2.5D media. The primary cultured cells in 2.5D media (direct 2.5D organoids) showed better attachment, growth, marker expression, and faster proliferation speed than those cultured in normal Dulbecco's Modified Eagle Medium media. The direct 2.5D organoids showed expression of each specific marker to their original cancer tissues and exhibited tumorigenesis in vivo. Moreover, the direct 2.5D organoids exhibited concentration-dependent responses to anti-cancer drugs, and different sensitivity profiles were shown among the strains. Our data suggest that the direct 2.5D organoid culture model might become a useful tool beyond 2D cell lines to study cancer biology in companion animals and could provide new platforms for screening the anti-cancer drugs.

Establishment of an experimental model of normal dog bladder organoid using a three-dimensional culture method.

Dog bladder cancer (BC) is mostly muscle-invasive (MI) with poor prognosis, and its pathogenesis is close to human MIBC. Three-dimensional (3D) organoid culture ensures novel knowledge on cancer diseases including BC. Recently, we have established dog BC organoids (BCO) using their urine samples. BCO recapitulated the epithelial structures, characteristics, and drug sensitivity of BC-diseased dogs. However, organoids from dog normal bladder epithelium are not established yet. Therefore, the present study aimed to establish dog normal bladder organoids (NBO) for further understanding the pathogenesis of dog BC and human MIBC. The established NBO underwent various analyzes including cell marker expressions, histopathological structures, cancer-related gene expression patterns, and drug sensitivity. NBO could be produced non-invasively with a continuous culturing and recapitulated the structures and characteristics of the dog's normal bladder mucosal tissues. Different drug sensitivities were observed in each NBO. The analysis of RNA sequencing revealed that several novel genes were changed in NBO compared with BCO. NBO showed a higher expression of p53 and E-cadherin, but a lower expression of MDM2 and Twist1 compared with BCO. These results suggest that NBO could be a promising experimental 3D model for studying the developmental mechanisms of dog BC and human MIBC.

Eukaryotic elongation factor 2 kinase inhibitor, A484954 inhibits perivascular sympathetic nerve stimulation-induced vasoconstriction in isolated renal artery.

Eukaryotic elongation factor 2 (eEF2) kinase (eEF2K) repressively regulates protein translation through phosphorylating eEF2. We previously showed that expression and activity of eEF2K are increased in isolated mesenteric arteries from spontaneously hypertensive rats (SHR) contributing to development of essential hypertension. Furthermore, we have recently shown that 7-Amino-1-cyclopropyl-3-ethyl-1,2,3,4-tetrahydro-2,4-dioxopyrido[2,3-d]pyrimidine-6-carboxamide (A484954), a selective eEF2K inhibitor, induces endothelium-dependent relaxation in isolated mesenteric arteries from SHR inducing an antihypertensive effect. In order to test the hypothesis that inhibition of eEF2K activity induces vasodilatation by suppressing sympathetic nerve activity, we examined the effects of A484954 on perivascular sympathetic nerve stimulation-induced contraction in isolated renal artery from normotensive and hypertensive rats. Electrodes were placed near the isolated renal arteries that were applied with transmural nerve stimulation (TNS). Then, contraction of the arteries was isometrically measured. A484954 inhibited TNS-induced contraction. The A484954-mediated inhibition of TNS-induced contraction was significantly prevented by NG-nitro-L-arginine methyl ester. In SHR isolated renal artery, TNS-induced contraction was enhanced compared with normotensive Wistar rats. Furthermore, A484954-mediated inhibition of TNS-induced contraction in SHR was enhanced compared with Wistar rats. In conclusion, this study demonstrates for the first time that A484954 inhibits perivascular sympathetic nerve stimulation-induced vasoconstriction at least in part perhaps through nitric oxide (NO) release from NO-operating nerve.

Cardiovascular Characteristics of Zucker Fatty Diabetes Mellitus Rats, an Animal Model for Obesity and Type 2 Diabetes.

Zucker fatty diabetes mellitus (ZFDM) rats harboring the missense mutation (fa) in a leptin receptor gene have been recently established as a novel animal model of obesity and type 2 diabetes (T2D). Here, we explored changes in cardiovascular dynamics including blood pressure and heart rate (HR) associated with the progression of obesity and T2D, as well as pathological changes in adipose tissue and kidney. There was no significant difference in systolic blood pressure (SBP) in ZFDM-Leprfa/fa (Homo) compared with ZFDM-Leprfa/+ (Hetero) rats, while HR and plasma adrenaline in Homo were significantly lower than Hetero. The mRNA expression of monocyte chemotactic protein-1 in perirenal white adipose tissue (WAT) from Homo was significantly higher than Hetero. Interscapular brown adipose tissue (BAT) in Homo was degenerated and whitened. The plasma blood urea nitrogen in Homo was significantly higher than Hetero. In summary, we demonstrated for the first time that HR and plasma adrenaline concentration but not SBP in Homo decrease with obesity and T2D. In addition, inflammation occurs in WAT from Homo, while whitening occurs in BAT. Further, renal function is impaired in Homo. In the future, ZFDM rats will be useful for investigating metabolic changes associated with the progression of obesity and T2D.

Eukaryotic elongation factor 2 kinase inhibitor, A484954 induces diuretic effect via renal vasorelaxation in spontaneously hypertensive rats.

Eukaryotic elongation factor 2 (eEF2) kinase (eEF2K), alternatively known as calmodulin-dependent protein kinase III, inhibits protein translation via phosphorylating its sole substrate, eEF2. We previously demonstrated that expression and activity of eEF2K change in mesenteric artery from spontaneously hypertensive rats (SHR) with aging and that eEF2K is involved in pathogenesis of essential hypertension. In addition, we have recently revealed that acute intravenous injection with A484954, a selective eEF2K inhibitor, lowers blood pressure specifically in SHR partly via inducing vasorelaxation. In this study, we examined whether A484954 induces diuretic effect. After male SHR and normotensive Wistar Kyoto rats (WKY) were given a single intraperitoneal injection of A484954 (2.5 mg/kg, 0.5-9 h), urine was collected using metabolic cage. Contraction of isolated renal arteries form SHR was isometrically measured. While A484954 did not induce diuretic effect in WKY, it increased urine output, water intake, and urinary sodium excretion in SHR. A484954 (10 µM) induced vasorelaxation in isolated renal arteries, which was inhibited by a ß-adrenergic receptor antagonist, propranolol. It was confirmed that A484954 increased renal blood flow in SHR as measured by renal ultrasonography. In summary, it was for the first time revealed that A484954 induces diuretic effect in SHR at least partly via renal vasorelaxation through ß-adrenergic receptor.

Chemokine-like Receptor 1 in Brain of Spontaneously Hypertensive Rats Mediates Systemic Hypertension.

Adipocytokine chemerin is a biologically active molecule secreted from adipose tissue. Chemerin elicits a variety of functions via chemokine-like receptor 1 (CMKLR1). The cardiovascular center in brain that regulates blood pressure (BP) is involved in pathophysiology of systemic hypertension. Thus, we explored the roles of brain chemerin/CMKLR1 on regulation of BP in spontaneously hypertensive rats (SHR). For this aim, we examined effects of intracerebroventricular (i.c.v.) injection of CMKLR1 small interfering (si)RNA on both systemic BP as measured by tail cuff system and protein expression in paraventricular nucleus (PVN) of SHR as determined by Western blotting. We also examined both central and peripheral protein expression of chemerin by Western blotting. Systolic BP of SHR but not normotensive Wistar Kyoto rats (WKY) was decreased by CMKLR1 siRNA. The decrease of BP by CMKLR1 siRNA persisted for 3 days. Protein expression of CMKLR1 in PVN of SHR tended to be increased compared with WKY, which was suppressed by CMKLR1 siRNA. Protein expression of chemerin in brain, peripheral plasma, and adipose tissue was not different between WKY and SHR. In summary, we for the first time revealed that the increased protein expression of CMKLR1 in PVN is at least partly responsible for systemic hypertension in SHR.

Establishment of Intestinal Organoid from Rousettus leschenaultii and the Susceptibility to Bat-Associated Viruses, SARS-CoV-2 and Pteropine Orthoreovirus.

Various pathogens, such as Ebola virus, Marburg virus, Nipah virus, Hendra virus, Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV), Middle East Respiratory Syndrome Coronavirus (MERS-CoV), and SARS-CoV-2, are threatening human health worldwide. The natural hosts of these pathogens are thought to be bats. The rousette bat, a megabat, is thought to be a natural reservoir of filoviruses, including Ebola and Marburg viruses. Additionally, the rousette bat showed a transient infection in the experimental inoculation of SARS-CoV-2. In the current study, we established and characterized intestinal organoids from Leschenault's rousette, Rousettus leschenaultii. The established organoids successfully recapitulated the characteristics of intestinal epithelial structure and morphology, and the appropriate supplements necessary for long-term stable culture were identified. The organoid showed susceptibility to Pteropine orthoreovirus (PRV) but not to SARS-CoV-2 in experimental inoculation. This is the first report of the establishment of an expandable organoid culture system of the rousette bat intestinal organoid and its sensitivity to bat-associated viruses, PRV and SARS-CoV-2. This organoid is a useful tool for the elucidation of tolerance mechanisms of the emerging rousette bat-associated viruses such as Ebola and Marburg virus.

Evaluation of the Safety and Feasibility of Apheresis in Dogs: For Application in Metastatic Cancer Research.

In patients with solid tumors, circulating tumor cells (CTCs) spread in their blood and function as a seed for metastases. However, the study of CTCs has been limited by their rarity, low frequency, and heterogeneity. The efficient collection of CTCs will contribute to further research of metastatic cancers. Apheresis is a process in which the whole blood of an individual is passed through a machine that isolates a particular constituent and returns the remainder to the circulation. In the present study, we investigated the safety and feasibility of apheresis to separate peripheral blood monocytes (PBMCs), whose density is closely similar to that of CTCs, and to capture intravenously administered human breast cancer cells, MCF7s, from the dogs. No life-threatening events were observed in dogs during the apheresis process. The changes in the hemogram were transient and recovered gradually within a few days after apheresis. During apheresis, 50 mL of PBMCs could be collected from each dog. Notably, a thrombus was formed along the circuit wall during apheresis, which decreased the blood collection pressure. MCF7 cells were successfully captured by the apheresis machine. The captured cells were regrown in vitro and characterized compared with the original cells. In conclusion, apheresis could be safely performed in dogs to isolate CTCs with precautions to maintain hemodynamic stability.

Chemerin-9 stimulates migration in rat cardiac fibroblasts in vitro.

Since chemerin is an adipocytokine whose concentration in blood increases in the subjects with various cardiac diseases, chemerin may be involved in pathogenesis of cardiac diseases. In the present study, we examined the effects of chemerin-9, an active fragment of chemerin, on functions of cardiac fibroblasts, which are involved in pathophysiology of cardiac diseases. Primary cardiac fibroblasts were enzymatically isolated from adult male Wistar rats. Migration of cardiac fibroblasts was measured by a Boyden chamber assay and a scratch assay. Phosphorylation of Akt and extracellular signal-regulated kinase (ERK) was measured by Western blotting. Reactive oxygen species (ROS) production was measured by 2',7'-dichlorodihydrofluoresein staining. Chemerin-9 significantly stimulated migration in cardiac fibroblasts. Chemerin-9 significantly stimulated phosphorylation of Akt and ERK as well as ROS production. An Akt pathway inhibitor, LY294002, an ERK pathway inhibitor, PD98059, an antagonist of chemokine-like receptor 1 (CMKLR1), 2-(α-Napththoyl) ethyltrimethylammonium iodide, or an antioxidant, N-acetyl-L-cysteine prevented the migration induced by chemerin-9. In summary, we for the first time revealed that chemerin-9 stimulates migration perhaps through the ROS-dependent activation of Akt and ERK via CMKLR1 in cardiac fibroblasts. It is proposed that chemerin plays a role in the pathogenesis of cardiac diseases.