Repeated Social Defeat Enhances CaCl2-Induced Abdominal Aortic Aneurysm Expansion by Inhibiting the Early Fibrotic Response via the MAPK-MKP-1 Pathway

Depression is an independent risk factor for cardiovascular disease and is significantly associated with the prevalence of abdominal aortic aneurysm (AAA). We investigated the effect of repeated social defeat (RSD) on AAA development. Eight-week-old male wild-type mice were exposed to RSD by being housed with larger CD-1 mice in a shared cage. They were subjected to vigorous physical contact. After the confirmation of depressive-like behavior, calcium chloride was applied to the infrarenal aorta of the mice. At one week, AAA development was comparable between the defeated and control mice, without any differences being observed in the accumulated macrophages or in the matrix metalloproteinase activity. At two weeks, the maximum diameter and circumference of the aneurysm were significantly increased in the defeated mice, and a significant decrease in periaortic fibrosis was also observed. Consistently, the phosphorylation of the extracellular signal-regulated kinase and the incorporation of 5-bromo-2'-deoxyuridine in the primarily cultured aortic vascular smooth muscle cells were significantly reduced in the defeated mice, which was accompanied by a substantial increase in mitogen-activated protein kinase phosphatase-1 (MKP-1). The MKP-1 mRNA and protein expression levels during AAA were much higher in the defeated mice than they were in the control mice. Our findings demonstrate that RSD enhances AAA development by suppressing periaortic fibrosis after an acute inflammatory response and imply novel mechanisms that are associated with depression-related AAA development.

Repeated Social Defeat Exaggerates Fibrin-Rich Clot Formation by Enhancing Neutrophil Extracellular Trap Formation via Platelet-Neutrophil Interactions

Depression is an independent risk factor for cardiovascular disease (CVD). We have previously shown that repeated social defeat (RSD) exaggerates atherosclerosis development by enhancing neutrophil extracellular trap (NET) formation. In this study, we investigated the impact of RSD on arterial thrombosis. Eight-week-old male wild-type mice (C57BL/6J) were exposed to RSD by housing with larger CD-1 mice in a shared home cage. They were subjected to vigorous physical contact daily for 10 consecutive days. After confirming depression-like behaviors, mice underwent FeCl3-induced carotid arterial injury and were analyzed after 3 h. Although the volume of thrombi was comparable between the two groups, fibrin(ogen)-positive areas were significantly increased in defeated mice, in which Ly-6G-positive cells were appreciably co-localized with Cit-H3-positive staining. Treatment with DNase I completely diminished exaggerated fibrin-rich clot formation in defeated mice. Flow cytometric analysis showed that neutrophil CD11b expression before FeCl3 application was significantly higher in defeated mice than in control mice. In vitro NET formation induced by activated platelets was significantly augmented in defeated mice, which was substantially inhibited by anti-CD11b antibody treatment. Our findings demonstrate that RSD enhances fibrin-rich clot formation after arterial injury by enhancing NET formation, suggesting that NET can be a new therapeutic target in depression-related CVD.

Maternal high-fat diet promotes calcified atherosclerotic plaque formation in adult offspring by enhancing transformation of vascular smooth muscle cells to osteochondrocytic-like phenotype

Background and objective

Maternal high-fat diet (HFD) has been shown to modulate vascular function and remodeling in adult offspring. Atherosclerotic vascular calcification is closely associated with the onset of cardiovascular event. We therefore investigated the impact of maternal HFD on calcification of atherogenic plaques.

Methods and results

Eight-week-old female apo-E−/− mice (C57BL/6) were fed an HFD or a normal diet (ND) one week prior to mating, and the diet was continued throughout gestation and lactation. Offspring of both groups were fed a high-cholesterol diet (HCD) from 8 weeks of age. Ex vivo osteogenic activity of aortic root and aortic arch was analyzed using in vivo imaging system (IVIS) with OsteoSense 680. Sixteen-week-old male offspring of HFD-fed dams (O-HFD) showed a 1.4-fold increase in fluorescent intensity compared with those of ND-fed dams (O-ND) (p<0.05). Likewise, female O-HFD showed a significantly increased osteogenic activity in aortic arch (154%, p<0.05). Percentages of plaque area and oil red O-positive area were comparable between O-ND and O-HFD of both genders, suggesting that augmented osteogenic activity in O-HFD is not dependent on the plaque size. To investigate the underlying mechanism of augmented calcified plaque formation in O-HFD, vascular smooth muscle cells (VSMCs) of thoracic aorta form 8-week-old male offspring were primarily cultured and VSMCs calcification was induced by treatment with calcification media supplemented with phosphate (2.6 mM). Alizarin-red-positive area upon 10 days stimulation showed a 3.4-fold increase in VSMCs from O-HFD compared with that from O-ND (p<0.01). Consistently, western blotting analysis revealed that expression level of osteocalcin was significantly higher in O-HFD than O-ND, suggesting that osteochondrocytic transformation of VSMCs is augmented in O-HFD.

Conclusion

Our findings demonstrate that maternal HFD accelerates the development of atherogenic calcification independent of plaque size. In vitro transformation to osteochondrocytic-like cells is enhanced in VSMCs from offspring of HFD-fed dams. Inhibition of VSMCs skewing toward osteochondrocytic-like cells could be a potential therapeutic target for preventing the development of atherosclerotic vascular calcification.

Funding Acknowledgement

Type of funding source: None

Repeated social defeat exaggerates fibrin-rich clot formation in FeCl3-induced arterial thrombosis mouse model by enhancing NETs formation via modulation of neutrophil functional properties

Background and objective

Depression is an independent risk factor of cardiovascular disease (CVD). We have recently shown that repeated social defeat (RSD) precipitates depressive-like behaviors in apoE−/− mice and exaggerates atherosclerosis development by enhancing neutrophil extracellular traps (NETs) formation. Here, we investigated the impact of RSD on arterial thrombosis.

Methods and results

Eight-week-old male WT mice were exposed to RSD by housing with a larger CD-1 mouse in a shared home cage. They were subjected to vigorous physical contact daily for 10 consecutive days. Control mice were housed in the same gage without physical contact. After social interaction test to confirm depressive-like behaviors, defeated mice (19 of 31) and control mice (12 of 14) were underwent arterial injury at 10 wks of age. A filter paper saturated with 10% FeCl3 was applied on the adventitial surface of left carotid artery for 3 min and analyzed 3 hrs later. The volume of thrombi was comparable between the two groups. However, fibrinogen/fibrin-positive areas in immunofluorescent images significantly increased in defeated mice (27.8% vs. 48.8%, p<0.01). The number of Ly-6G-positive cells in thrombi was markedly higher in defeated mice (144/mm2 vs. 878/mm2, p<0.05). Further, Ly-6G-positive cells were almost accumulated at the inner surface of injured artery, which were co-localized with neutrophil elastase, Cit-H3, and CD41-positive staining. Treatment with DNase I completely diminished the exaggerated fibrin-rich clot formation in defeated mice to an extent similar to that in control mice (25.7% vs. 22.3%, p = ns), without affecting the volume of thrombi and accumulation of Ly-6G-positive cells. Given that platelet aggregations induced by ADP or collagen were comparable between the two groups, neutrophil functional properties primarily contribute to the exaggerated fibrin-rich clot formation in defeated mice. We then examined neutrophil subset and vulnerability to NETs formation. At 3 hrs after FeCl3 application, the numbers of immature neutrophils (Ly6Glo/+CXCR2-) were comparable between the two groups in both bone marrow (BM) and peripheral blood (PB). In contrast, the number of PB mature neutrophils (Ly6G+CXCR2+) was markedly higher in defeated mice than control mice (580±68 /μl vs. 1265±114, p<0.01). We next examined in vitro NETs formation upon PMA in BM mature neutrophils by FACS and nucleic acid staining. The percentage of double-positive cells (Cit-H3, MPO) was significantly higher in defeated mice (7.5% vs. 10.2%, p<0.05), as well as SYTOX green-positive cells expelling DNA fibers (8.1% vs. 11.8%, p<0.05).

Conclusions

Our findings demonstrate for the first time that repeated social defeat enhances fibrin-rich clot formation after arterial injury by enhancing NETs formation via modulation of neutrophil functional properties, suggesting that NETosis could be a new therapeutic target in depression-related CVD development.

Funding Acknowledgement

Type of funding source: None

Maternal high-fat diet promotes the expansion of abdominal aortic aneurysm in adult offspring by enhancing osteoclast-like macrophage differentiation through down-regulation of IRF8 expression

Background and objective

Maternal high-fat diet (HFD) has been shown to modulate vascular function and remodeling in adult offspring. Here, we investigated the impact of maternal HFD on abdominal aortic aneurysm (AAA) formation.

Methods and results

Eight-week-old female wild-type mice (C57BL/6) were fed a HFD or normal diet (ND) one week prior to mating, and the diet was continued throughout gestation and lactation. In eight-week-old male offspring, AAA was induced with the application of 0.5 M calcium chloride (CaCl2) on the infrarenal aorta. Offspring of HFD-fed dams (O-HFD) showed a significant increase in maximum outer diameter of AAA at 1, 4 and 8 weeks after surgery compared with offspring of ND-fed dams (O-ND). The lengths of outer circumference assessed by histological analysis were increased in O-HFD (p<0.05). Likewise, female O-HFD showed a greater length of outer circumference than female O-ND (p<0.05). While the number of F4/80-positive cells at 1 wk after surgery was comparable in the O-HFD and O-ND, the percentage of MMP-9/F4/80 double-positive cells was significantly increased in O-HFD. Consistently, fluorescent image of abdominal aorta taken by IVIS at 1 wk after surgery revealed a 2-fold increase in MMP activity. Intriguingly, F4/80-positive cells in O-HFD showed a 2.5-fold increase in co-staining with tartrate-resistant acid phosphate (TRAP), typical marker of osteoclast-like macrophages which abundantly secrete proteases than classically activated macrophages, while the percentage of TNF-α/F4/80 double-positive cells was comparable in the two groups. Pharmacological inhibition of osteoclastogenesis by zoledronic acid (ZA) (100μg/kg) completely abolished the exaggerated AAA development in O-HFD to an extent similar to that in O-ND, while AAA development in O-ND mice did not change after ZA treatment. Furthermore, in vitro TNF-α-induced osteoclast differentiation of bone marrow-derived macrophages (BMDMs) showed a significantly higher number of TRAP-positive cells in O-HFD, accompanied by a significant increase in osteoclast-related genes expression. Western blotting analysis revealed that the expression of NFATc1, master regulator of osteoclastogenesis, was significantly higher in O-HFD than that in O-ND, and immunofluorescent imaging showed that nuclear translocation of NFATc1 upon TNF-α stimulation was significantly enhanced in O-HFD. We further examined the expression of IFN regulatory factor 8 (IRF8) which suppresses osteoclastogenesis by inhibiting the function and expression of NFATc1. IRF8 mRNA and nuclear protein expression levels were significantly lower in O-HFD than those in O-ND.

Conclusion

Our findings demonstrate that maternal HFD accelerates CaCl2-induced AAA expansion, accompanied by the exaggerated accumulation of osteoclast-like macrophages and augmented activity of MMPs. Inhibition of macrophages skewing toward osteoclast-like cells could be a potential therapeutic target for preventing AAA development.

Funding Acknowledgement

Type of funding source: None

Repeated social defeat exaggerates CaCl2-induced abdominal aortic aneurysm expansion by eliminating periaortic fibrosis in tissue repair phase: possible involvement of specific subtypes of macrophages

Background and objective

Depression is an independent risk factor of cardiovascular disease (CVD) and significantly associated with the prevalence of abdominal aortic aneurysm (AAA). We have recently shown that repeated social defeat (RSD) precipitates depressive-like behaviors in apoE−/− mice and exaggerates atherosclerosis development by enhancing leukocyte activation. Here, we investigated the impact of RSD on AAA formation.

Methods and results

Eight-week-old male WT mice were exposed to RSD by housing with a larger CD-1 mouse in a shared home cage. They were subjected to vigorous physical contact daily for 10 consecutive days. Control mice were housed in the same gage without physical contact. After social interaction test to confirm depressive-like behaviors, defeated mice (28 of 48) and control mice (31 of 36) underwent application of 0.5 M calcium chloride (CaCl2) on the infrarenal aorta to induce AAA. At 1 week after application, maximum diameter and circumference of external elastic membrane were comparable between the two groups. The number of F-4/80, MMP-9, and TNF-α-positive cells in immunofluorescent images were also comparable. Further, in vitro bone marrow derived macrophages stimulation by LPS did not show any difference in mRNA expression levels of inflammatory cytokines, suggesting no discernable difference in acute inflammatory response between the two groups. In contrast, at 2 weeks after application, at the time point when MMP-9 and TNF-α-positive cells were scarcely observed, maximum diameter and circumference of external elastic membrane were significantly increased in defeated mice (0.72 mm vs. 0.90 mm, 1.59 mm vs. 2.00 mm, respectively, Control vs. Defeat, p<0.01). Intriguingly, periaortic fibrotic area in aneurysmal portion was markedly decreased in defeated mice (12.5×103 μm2 vs. 3.7×103 μm2, Control vs. Defeat, p<0.01). Consistently, accumulation of α-SMA-positive cells in adventitia of aneurysmal portion was much less in defeated mice than control mice (876 cells/mm2 vs. 319 cells/mm2, Control vs. Defeat, p<0.05), whereas those in tunica media of non-aneurysmal portion did not show any difference between the two groups. We next focused on the segregated nucleus-containing atypical monocyte (SatM), specific subtypes of monocytes/macrophages that are involved in fibrosis in injured tissues during the healing phase. We could observe SatM fraction in AAA tissue of control mice using flow cytometry. We also found that mRNA expression level of C/EBPβ, an essential regulator for SatM differentiation, was markedly decreased by 76% in BM cells of defeated mice compared with control mice (p<0.05).

Conclusions

Our findings demonstrate for the first time that RSD enhances AAA expansion by eliminating periaortic fibrosis in tissue repair phase, suggesting that the impaired resolution of acute inflammation after CaCl2 application contributes, at least in part, to the augmented expansion of AAA in defeated mice.

Funding Acknowledgement

Type of funding source: None

Social Stress Increases Vulnerability to High-Fat Diet-Induced Insulin Resistance by Enhancing Neutrophil Elastase Activity in Adipose Tissue

Social stress (SS) has been linked to the development of cardiovascular disease (CVD), which is closely associated with insulin resistance (IR); however, the causal effect of SS on IR remains unclear. The 8-week-old male C57BL/6 mice were exposed to SS by housing with a larger CD-1 mouse in a shared home cage without physical contact for 10 consecutive days followed by high-fat diet (HFD) feeding. Control mice were housed in the same cage without a CD-1 mouse. After 6 weeks of HFD, insulin sensitivity was significantly impaired in stressed mice. While the percentage of classically activated macrophages in epididymal white adipose tissue (eWAT) was equivalent between the two groups, the percentage of lymphocyte antigen 6 complex locus G6D (Ly-6G)/neutrophil elastase (NE)-double positive cells markedly increased in stressed mice, accompanied by augmented NE activity assessed by ex vivo eWAT fluorescent imaging. Treatment with an NE inhibitor completely abrogated the insulin sensitivity impairment of stressed mice. In vitro NE release upon stimulation with a formyl peptide receptor 1 agonist was significantly higher in bone marrow neutrophils of stressed mice. Our findings show that SS-exposed mice are susceptible to the development of HFD-induced IR accompanied by augmented NE activity. Modulation of neutrophil function may represent a potential therapeutic target for SS-associated IR.

Maternal high-fat diet exaggerates diet-induced insulin resistance in adult offspring by enhancing inflammasome activation through noncanonical pathway of caspase-11

Objective

Maternal high-fat diet (HFD) has been shown to promote the development of insulin resistance (IR) in adult offspring; however, the underlying mechanisms remain unclear.

Methods

Eight-week-old female wild-type mice (C57BL/6) were fed either an HFD or a normal diet (ND), one week prior to mating, and the diet was continued throughout gestation and lactation. Eight-week-old male offspring of both groups were fed an HFD for 8 weeks.

Results

Offspring of HFD-fed dams (O-HFD) exhibited significantly impaired insulin sensitivity compared with the offspring of ND-fed dams (O-ND). The adipocyte size of the eWAT increased significantly in O-HFD and was accompanied by abundant crown-like structures (CLSs), as well as a higher concentration of interleukin 1β (IL-1β) in the eWAT. Treatment with an inflammasome inhibitor, MCC950, completely abrogated the enhanced IR in O-HFD. However, ex vivo caspase-1 activity in eWAT revealed no difference between the two groups. In contrast, noncanonical inflammasome activation of caspase-11 was significantly augmented in O-HFD compared with O-ND, suggesting that membrane pore formation, but not cleavage of pro-IL-1β by caspase-1, is augmented in O-HFD. To examine the membrane pore formation, we performed metabolic activation of bone marrow-derived macrophages (BMDMs). The percentage of pore formation assessed by ethidium bromide staining was significantly higher in BMDMs of O-HFD, accompanied by an enhanced active caspase-11 expression. Consistently, the concentration of IL-1β in culture supernatants was significantly higher in the BMDMs from O-HFD than those from O-ND.

Conclusions

These findings demonstrate that maternal HFD exaggerates diet-induced IR in adult offspring by enhancing noncanonical caspase-11-mediated inflammasome activation.

•

Maternal HFD increases the vulnerability to HFD-induced IR in adult offspring.

•

Maternal HFD augments inflammasome activation in eWAT in adult offspring.

•

Treatment with an inflammasome inhibitor abrogates IR in offspring of HFD-fed dam.

•

Maternal HFD augments the noncanonical inflammasome activation pathway of caspase-11.

•

Maternal HFD augments IL-1β release from BMDMs by enhancing membrane pore formation.

P732Maternal high-fat diet promotes the expansion of abdominal aortic aneurysm in adult offspring by enhancing osteoclast-like macrophage differentiation

Background and objective

Maternal high-fat diet (HFD) has been shown to modulate vascular function and remodeling in adult offspring. Here, we investigated the impact of maternal HFD on abdominal aortic aneurysm (AAA) formation.

Methods and results

Eight-week-old female wild-type mice (C57BL/6) were fed a HFD or normal diet (ND) one week prior to mating and received during pregnancy and lactation. In eight-week-old offspring of both genders, AAA was induced with the application of 0.5M calcium chloride (CaCl2) on the infrarenal aorta. Male offspring of HFD-fed dams (O-HFD) showed a significant increase in maximum outer diameter of AAA at 1, 4 and 8 weeks after surgery compared with offspring of ND-fed dams (O-ND) (P<0.05). The lengths of outer circumference assessed by histological analysis were increased in O-HFD (P<0.05). Likewise, female O-HFD showed a greater length of outer circumference than female O-ND (P<0.05). While the number of F4/80-positive cells at 1 wk after surgery was comparable between the male O-HFD and O-ND, the percentage of MMP-9/F4/80 double-positive cells was significantly increased in male O-HFD. Consistently, fluorescent image of abdominal aorta taken by IVIS at 1 wk after surgery revealed a 2-fold increase in MMP activity (P<0.01). Intriguingly, F4/80-positive cells in male O-HFD showed a 2.5-fold increase in co-staining with tartrate-resistant acid phosphate (TRAP), typical marker of osteoclast-like macrophages which abundantly secrete proteases than classically activated macrophages (M1), while the percentage of TNF-α/F4/80 double-positive cells was comparable between the 2 groups. Pharmacological inhibition of osteoclastogenesis by zoledronic acid (ZA) (100μg/kg) completely abolished the exaggerated AAA development in male O-HFD to a similar extent of that in male O-ND, while AAA development in male O-ND mice did not change even after ZA treatment. Furthermore, in vitro TNF-α-induced osteoclast differentiation of bone marrow-derived macrophages (BMDMs) showed a significantly higher number of TRAP-positive cells, accompanied by increased calcitonin receptor mRNA expression. Western blotting analysis showed that protein expression level of NFATc1, master regulator of osteoclastogenesis, was significantly higher in BMDM of O-HFD than O-ND.

Conclusion

Our findings demonstrate that maternal HFD accelerates CaCl2-induced AAA expansion, accompanied by the exaggerated accumulation of osteoclast-like macrophages and augmented activity of MMPs. Inhibition of macrophages skewing toward osteoclast-like cells could be a potential therapeutic target for preventing AAA development.

P740Repeated social defeat exaggerates fibrin-rich clot formation in FeCl3-induced arterial thrombosis mice model by enhancing NETs formation

Background and objective

Depression is an independent risk factor of cardiovascular disease (CVD). We have recently shown that repeated social defeat (RSD) precipitates depressive-like behaviorsin apoE−/− mice and exaggerates atherosclerosis development by enhancing neutrophil extracellular traps (NETs) formation (BBRC 2018; 500:490). Here, we investigated the impact of RSD on arterial thrombosis.

Methods and results

Eight-week-old male WT mice were exposed to RSDby housing with a larger CD-1 mouse in a shared home cage. They were subjected to vigorous physical contact daily for 10 consecutive days. Control mice were housed in the same gage without physical contact. After social interaction testto confirm depressive-like behaviors, defeated mice (19 of 31) and control mice (12 of 14) were underwent arterial injury at 10 wks of age. A filter paper saturated with 10% FeCl3was applied on the adventitial surface of left carotid artery for 3 min and analyzed 3 hrs later. The volume of thrombi calculated by summing8–15 frozen cross-sectional images, each separated by 200 μm, was comparable between the 2 groups. However, fibrinogen/fibrin-positive areas in immunofluorescent images were significantly increased in defeated mice (27.8% vs. 48.8%, Control vs. Defeat, P<0.01).The numberof Ly-6G-positive cells in thrombi was markedly higher in defeated mice (144/mm2 vs. 878/mm2, Control vs. Defeat, P<0.05). Further, Ly-6G-positive cells were almost accumulated at the inner surface of injured artery, which were co-localized with neutrophil elastase, Cit-H3, and CD41-positive staining. Treatment with DNase Icompletely diminished the exaggerated fibrin-rich clot formation in defeated miceto a similar extent of control mice (25.7% vs. 22.3%, Control vs. Defeat, P= NS), while the volume of thrombi and number of Ly-6G-positive cells in thrombi were comparable between the 2 groups even afterDNase I treatment. Platelet aggregations induced by ADP or collagen were comparable between the 2 groups, suggesting that NETs formation primarily contributes to the exaggerated fibrin-rich clot formation in defeated mice.

Conclusions

Our findings demonstrate for the first time that repeated social defeat enhances fibrin-rich clot formation after arterial injury by enhancing NETs formation, suggesting that NETosis could be a new therapeutic target in depression-related CVD development.

5220Maternal high-fat diet exaggerates the development of diet-induced insulin resistance in adult offspring by enhancing pyroptosis through augmented gasdermin D-mediated pore formation

Background

Maternal high-fat diet (HFD) has been shown to promote the development of insulin resistance (IR) in adult offspring; however, the underlying mechanisms remain unclear.

Approach and results

Eight-week-old female wild-type mice (C57BL/6) were fed a HFD or normal diet (ND) one week prior to mating, and received during pregnancy and lactation. Eight-week-old male offspring of both groups were fed a HFD for 8 weeks. Offspring of HFD-fed dams (O-HFD) showed significantly enhanced IR compared with offspring of ND-fed dams (O-ND). There was no difference in body weight, epidydimal white adipose tissue (eWAT) weight, and cumulative caloric intake between the 2 groups. However, eWAT adipocyte size was significantly increased in O-HFD, accompanied by the abundant crown-like structures. Flow cytometric analysis revealed an increased percentage of M1, but not M2, macrophages. Serum and eWAT concentrations of IL-1β, but not TNF-α, were significantly higher in O-HFD than O-ND (3.7-fold and 2.0-fold, respectively, P<0.05). Treatment with NLRP3 inflammasome inhibitor MCC950 completely abrogated the enhanced IR in O-HFD to a similar extent of that in O-ND, although IR was modestly, but not significantly, ameliorated in O-ND even after MCC950 treatment. Consistent with in vivo findings, in vitro polarization of bone marrow-derived macrophages (BMDMs) did not show any difference in TNF-α mRNA expression after conventional stimulation. In contrast, palmitate acid (PA)-mediated metabolic activation of BMDMs following LPS priming showed a significantly higher concentration of IL-1β in culture supernatants from O-HFD (45%, P<0.05). However, protein expression levels of NLRP-3, ASC, and procaspase-1 after LPS priming were equivalent between the 2 groups. Consistently, intracellular flow cytometric analysis of caspase-1 activity after PA activation did not show any difference, which was compatible with the finding that ex vivo caspase-1 activity of eWAT assessed by fluorescent image of IVIS revealed no difference between the 2 groups. To further examine the mechanism of augmented IL-1β release in BMDM of O-HFD, we examined the cleavage of caspase substrate gasdermin D (GSDMD) and subsequent pore formation. Protein and gene expression levels of GSDM-D after LPS priming were significantly higher in O-HFD (50% and 381%, respectively, P<0.05). At 2 hrs after PA stimulation following LPS priming, cleaved GSDM-D was significantly increased in O-HFD (80%, P<0.01). Consistently, percentage of pore formation assessed by ethidium bromide staining was significantly higher in O-HFD (60%, P<0.05), while LDH release could not be observed.

Conclusions

Our findings demonstrate that maternal HFD exaggerates diet-induced insulin resistance in adult offspring by enhancing pyroptosis through augmented GSDM-D-mediated pore formation.

Augmented neutrophil extracellular traps formation promotes atherosclerosis development in socially defeated apoE-/- mice

Depression is an independent risk factor of cardiovascular disease (CVD); however, the causal association remains undefined. We exposed mice to repeated social defeat (RSD) to precipitate depressive-like behaviors, and investigated the effects on atherosclerosis. Eight-week-old male apoE^-/- mice were exposed to RSD by housing with a larger CD-1 mouse in a shared home cage. They were subjected to vigorous physical contact daily for 10 consecutive days and fed a high-cholesterol diet (HCD) for 6 weeks. The social interaction ratio and immobility time showed dramatic social avoidance before and after HCD feeding. Defeated mice showed higher increase in atherosclerotic lesion areas in the aortic root and entire aorta than control mice. Mean blood pressure and lipid profile were equivalent in both groups. While Ly-6G- and Mac3-positive areas in the aortic root were comparable between the groups, citrullinated histone H3 (Cit-H3)- and myeloperoxidase (MPO)-positive areas, markers of neutrophil extracellular traps (NETs), were significantly increased in the defeated mice. Treatment with DNase I completely diminished the exaggerated atherosclerosis. The proportion of peripheral blood polymorphonuclear myeloid-derived suppressor cells (PMN-MDSC), but not of inflammatory monocytes, was markedly increased. Moreover, in vitro NETs formation from bone marrow (BM) PMN-MDSC was markedly augmented, accompanied by higher expression of Nox2 gene and reactive oxygen species. Our findings demonstrate that exposure to RSD promotes atherosclerosis by augmenting NETs formation within the plaque. This provides new insight into the underlying mechanism of depression-related CVD.

Nephrotoxicity of concomitant use of tacrolimus and teicoplanin in allogeneic hematopoietic stem cell transplant recipients

Both tacrolimus and glycopeptide antibiotics are known to be nephrotoxic, and are often concomitantly given after hematopoietic stem cell transplantation (HSCT) or solid organ transplantation. The aim of this study is to evaluate the nephrotoxicity of concomitant use of tacrolimus and glycopeptide antibiotics in HSCT recipients. We retrospectively evaluated 67 patients who received intravenous tacrolimus and teicoplanin concomitantly for >4 days after allogeneic HSCT for hematologic diseases. Therapeutic drug monitoring (TDM) was performed in all patients for both tacrolimus and teicoplanin. The median age of the patients was 48 years (range: 16-62), and the median duration of the co-administration of tacrolimus and teicoplanin was 11 days (range: 4-40). The mean serum creatinine (sCr) level tended to be elevated after the co-administration (from 0.69 ± 0.26 to 0.75 ± 0.30 mg/dL; P = 0.08); however, a 2-fold or greater increase in sCr was observed only in 2 (3.0%) patients. Increased sCr was reversible, and no patient required hemodialysis. These results suggest that the incidence of clinically significant nephrotoxicity can be minimized if the TDM of each drug is properly applied.

Sjögren syndrome presenting with encephalopathy mimicking Creutzfeldt-Jakob disease

A 61-year-old man developed subacute progressive dementia, general fatigue, a tonic-clonic seizure, and a decreased level of consciousness. He had a past history of chronic hepatitis type C and was diagnosed as having hepatic encephalopathy due to hyperammonemia. His level of consciousness did not improve even though the serum ammonia level improved. In addition, he had repeated general myoclonic seizures. Head MRI (diffusion-weighted imaging) showed high signal intensities in the right thalamus and the cerebral cortices in the frontal, temporal and parietal lobes (predominantly on the right side). An electroencephalogram (EEG) showed periodic lateralized epileptic discharges (PLEDs). Cerebrospinal fluid analysis revealed high total tau protein and 14-3-3 protein levels. This case was diagnosed as Creutzfeldt-Jakob disease (CJD) based on these clinical data. However, the patient gradually improved without specific treatment. The differential diagnosis was reconsidered, and an increased erythrocyte sedimentation rate and positive serum anti-SS-A and anti-SS-B antibodies were noted. A diagnosis of Sjögren syndrome (SjS) was finally made based on a biopsy of a minor salivary gland showing infiltration of lymphocytes around the gland ducts. Steroid therapy (prednisolone 40mg/day orally) was given, and his clinical condition improved. The lesions on the head MRI decreased, and the EEG findings normalized. This case suggests that SjS has a wide spectrum, including neurological disorders, and that SjS should be considered in the differential diagnosis of CJD.

A multimicroelectrode system composed of independent glass micropipettes with an eccentric tip structure for simultaneous intracellular recording

A glass multimicroelectrode system for simultaneous intracellular recordings is described in which four pieces of micropipettes with rectangular cross section are arranged in a square compartment. Each tip position is shifted from the central axis of the electrode stem toward the crest line of its corner. Such micropipettes are mechanically bundled to one another so that the horizontal spacing among tips can be made shorter than the electrode diameter and components are independently penetrable. This paper offers techniques for fabricating such an eccentric micropipette. Finally, an example of simultaneous recordings of intracellular membrane potentials in the carp retina is demonstrated. This paper provides a technique which would allow researchers to record from three or four neurons simultaneously.

Synthesis of amino acyl adenylates using the tert-butoxycarbonyl protecting group

Alayl, [ 14c]-alanyl, phenylalanyl, and methionyl adenylates have been synthesized in high yields and relatively good purities. Elemental analysis 1H nmr and ir spectra have been utilized for the characterization of these extremely labile compounds. The present synthesis, which uses readily available N-tert-butoxycarbonyl amino acids, is compared with previous methods.