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Albuminuria is a hallmark of glomerular disease of various etiologies. It is not only a symptom of glomerular disease but also a cause leading to glomerulosclerosis, interstitial fibrosis, and eventually, a decline in kidney function. The molecular mechanism underlying albuminuria-induced kidney injury remains poorly defined. In our genetic model of nephrotic syndrome (NS), we have identified CHOP (C/EBP homologous protein)-TXNIP (thioredoxin-interacting protein) as critical molecular linkers between albuminuria-induced ER dysfunction and mitochondria dyshomeostasis. TXNIP is a ubiquitously expressed redox protein that binds to and inhibits antioxidant enzyme, cytosolic thioredoxin 1 (Trx1), and mitochondrial Trx2. However, very little is known about the regulation and function of TXNIP in NS. By utilizing Chop −/− and Txnip −/− mice as well as 68 Ga-Galuminox, our molecular imaging probe for detection of mitochondrial reactive oxygen species (ROS) in vivo, we demonstrate that CHOP up-regulation induced by albuminuria drives TXNIP shuttling from nucleus to mitochondria, where it is required for the induction of mitochondrial ROS. The increased ROS accumulation in mitochondria oxidizes Trx2, thus liberating TXNIP to associate with mitochondrial nod-like receptor protein 3 (NLRP3) to activate inflammasome, as well as releasing mitochondrial apoptosis signal-regulating kinase 1 (ASK1) to induce mitochondria-dependent apoptosis. Importantly, inhibition of TXNIP translocation and mitochondrial ROS overproduction by CHOP deletion suppresses NLRP3 inflammasome activation and p-ASK1–dependent mitochondria apoptosis in NS. Thus, targeting TXNIP represents a promising therapeutic strategy for the treatment of NS.

Calcium (Ca2+) homeostasis is a crucial determinant of cellular function and survival. Endoplasmic reticulum (ER) acts as the largest intracellular Ca2+ store that maintains Ca2+ homeostasis through the ER Ca2+ uptake pump, sarco/ER Ca2+ ATPase, ER Ca2+ release channels, inositol 1,4,5-trisphosphate receptor channel, ryanodine receptor, and Ca2+-binding proteins inside of the ER lumen. Alterations in ER homeostasis trigger ER Ca2+ depletion and ER stress, which have been associated with the development of a variety of diseases. In addition, recent studies have highlighted the role of ER Ca2+ imbalance caused by dysfunction of sarco/ER Ca2+ ATPase, ryanodine receptor, and inositol 1,4,5-trisphosphate receptor channel in various kidney diseases. Despite progress in the understanding of the importance of these ER Ca2+ channels, pumps, and binding proteins in the pathogenesis of kidney disease, treatment is still lacking. This mini-review is focused on: i) Ca2+ homeostasis in the ER, ii) ER Ca2+ dyshomeostasis and apoptosis, and iii) altered ER Ca2+ homeostasis in kidney disease, including podocytopathy, diabetic nephropathy, albuminuria, autosomal dominant polycystic kidney disease, and ischemia/reperfusion-induced acute kidney injury.

Emerging evidence has established primary nephrotic syndrome (NS), including focal segmental glomerulosclerosis (FSGS), as a primary podocytopathy. Despite the underlying importance of podocyte endoplasmic reticulum (ER) stress in the pathogenesis of NS, no treatment currently targets the podocyte ER. In our monogenic podocyte ER stress-induced NS/FSGS mouse model, the podocyte type 2 ryanodine receptor (RyR2)/calcium release channel on the ER was phosphorylated, resulting in ER calcium leak and cytosolic calcium elevation. The altered intracellular calcium homeostasis led to activation of calcium-dependent cytosolic protease calpain 2 and cleavage of its important downstream substrates, including the apoptotic molecule procaspase 12 and podocyte cytoskeletal protein talin 1. Importantly, a chemical compound, K201, can block RyR2-Ser2808 phosphorylation-mediated ER calcium depletion and podocyte injury in ER-stressed podocytes, as well as inhibit albuminuria in our NS model. In addition, we discovered that mesencephalic astrocyte-derived neurotrophic factor (MANF) can revert defective RyR2-induced ER calcium leak, a bioactivity for this ER stress-responsive protein. Thus, podocyte RyR2 remodeling contributes to ER stress-induced podocyte injury. K201 and MANF could be promising therapies for the treatment of podocyte ER stress-induced NS/FSGS.

The advent of next-generation sequencing (NGS) in recent years has led to a rapid discovery of novel or rare genetic variants in human kidney cell genes, which is transforming the risk assessment, diagnosis, and treatment of kidney disease. Mutations may lead to protein misfolding, disruption of protein trafficking, and endoplasmic reticulum (ER) retention. An imbalance between the load of misfolded proteins and the folding capacity of the ER causes ER stress and unfolded protein response. Mutations in nephrin (NPHS1), podocin (NPHS2), laminin β2 (LAMB2), and α-actinin-4 (ACTN4) have been shown to induce ER stress in HEK293 cells and podocytes in hereditary nephrotic syndromes; various founder mutations in collagen IV α chains (COL4A) have been demonstrated to activate podocyte ER stress in collagen IV nephropathies; and mutations in uromodulin (UMOD) have been reported to trigger tubular ER stress in autosomal dominant tubulointerstitial kidney disease. Meanwhile, ER resident protein SEC63 may modify disease severity in autosomal dominant polycystic kidney disease. These findings underscore the importance of ER stress in the pathogenesis of monogenic kidney disease. Recently, we have identified mesencephalic astrocyte-derived neurotrophic factor (MANF) and cysteine-rich with EGF-like domains 2 (CRELD2) as urinary ER stress biomarkers in ER stress-mediated kidney diseases.

Insulin signaling is essential for regulating glucose homeostasis. Numerous studies have demonstrated that reactive oxygen species (ROS) affect insulin signaling, and low ROS levels can act as a signal to regulate cellular function. Peroxiredoxins (Prxs) are highly abundant and widely expressed antioxidant enzymes. However, it is unclear whether antioxidant enzymes, such as Prx2, mediate insulin signaling. The aim of our study was to investigate the influence of Prx2 deficiency on insulin signaling. Our western blot results showed that Prx2 deficiency enhanced insulin signaling and increased oxidation of protein tyrosine phosphatase 1B (PTP1B) and phosphatase and tensin homologue (PTEN) in mouse embryonic fibroblasts (MEFs) treated with insulin. In addition, we assessed ROS levels with a Cytosol-HyPer H2O2 sensor. As a result, increased ROS levels and Akt activation were decreased by N-acetyl-cysteine (Nac), which acted as an antioxidant in Prx2-deficient MEFs. Body weight measurements and glucose tolerance test (GTT) revealed significant body weight reduction and increase in glucose clearance in Prx2-/- mice fed a high-fat diet. Interestingly, glucose transporter type 4 (GLUT4) was significantly higher in Prx2-/- mice than in wild-type mice according to western blotting results. Western blotting also revealed that Akt phosphorylation was higher in Prx2-/- MEFs and muscle tissue than in wild-type. Together, our findings indicate that increased ROS due to Prx2 deficiency promotes insulin sensitivity and glucose clearance in skeletal muscles by increasing protein tyrosine phosphatase (PTPs) oxidation. These results provide novel insights into the fundamental mechanisms of insulin signaling induced by Prx2 deficiency and suggest that ROS-based therapeutic strategies can be used to suppress insulin resistance.

Mesencephalic astrocyte-derived neurotrophic factor (MANF), a newly identified 18-kDa soluble protein, localizes to the luminal endoplasmic reticulum (ER), whose stress can stimulate MANF expression and secretion. In Drosophila and zebrafish, MANF regulates dopaminergic neuron development. In contrast, in mice, MANF deficiency leads to diabetes and activation of the unfolded protein response. Recent studies in rodent models have demonstrated that MANF mitigates diabetes, exerts neurotrophic function in neurodegenerative disease, protects cardiomyocytes and neurons in myocardial infarction and cerebral ischemia, respectively, and promotes immune cell phenotype switch from proinflammatory macrophages to prorepair anti-inflammatory macrophages. The cytoprotective mechanisms of MANF on ER stress are currently under active investigation. In addition, for the first time, we have discovered that MANF can potentially serve as a urinary ER stress biomarker in ER stress-mediated kidney disease. These studies have underscored the diagnostic and therapeutic importance of MANF in ER diseases.

Luteal regression is a natural and necessary event to regulate the reproductive process in all mammals. Prostaglandin F2α (PGF2α) is the main factor that causes functional and structural regression of the corpus luteum (CL). It is well known that PGF2α-mediated ROS generation is closely involved in luteal regression. Peroxiredoxin 2 (Prx2) as an antioxidant enzyme plays a protective role against oxidative stress-induced cell death. However, the effect of Prx2 on PGF2α-induced luteal regression has not been reported. Here, we investigated the role of Prx2 in functional and structural CL regression induced by PGF2α-mediated ROS using Prx2-deficient (-/-) mice. We found that PGF2α-induced ROS generation was significantly higher in Prx2-/- MEF cells compared with that in wild-type (WT) cells, which induced apoptosis by activating JNK-mediated apoptotic signaling pathway. Also, PGF2α treatment in the CL derived from Prx2-/- mice promoted the reduction of steroidogenic enzyme expression and the activation of JNK and caspase3. Compared to WT mice, serum progesterone levels and luteal expression of steroidogenic enzymes decreased more rapidly whereas JNK and caspase3 activations were significantly increased in Prx2-/- mice injected with PGF2α. However, the impaired steroidogenesis and PGF2α-induced JNK-dependent apoptosis were rescued by the addition of the antioxidant N-acetyl-L-cysteine (NAC). This is the first study to demonstrate that Prx2 deficiency ultimately accelerated the PGF2α-induced luteal regression through activation of the ROS-dependent JNK pathway. These findings suggest that Prx2 plays a crucial role in preventing accelerated luteal regression via inhibition of the ROS/JNK pathway.

XBP1 (X-box-binding protein 1) is activated in cancer and has a pivotal role in tumorigenesis and progression of human cancer. In particular, the XBP1 transcriptional regulatory network is well known to drive cancer development, but little is known about whether the stability of XBP1 is regulated and, if so, what controls the stability of XBP1. In the present study we show that PIN1 prolyl isomerase interacts with the active form of XBP1 (XBP1s) in a phosphorylation-dependent manner and promotes XBP1s-induced cell proliferation and transformation through the regulation of XBP1 stability. By contrast, depletion of Pin1 in cancer cells reduced XBP1s expression, which subsequently inhibits cell proliferation and transformation. Interestingly, XBP1s activates multiple oncogenic pathways including NF-κB (nuclear factor κB), AP1 (activator protein 1) and Myc, and down-regulates PIN1 transcription via a negative-feedback mechanism through p53 induction. Ultimately, reciprocal regulation of Pin1 and XBP1s is associated with the activation of oncogenic pathways, and the relationship of PIN1 and XBP1 may be an attractive target for novel therapy in cancers.

Isoliquritigenin (ISL) is an abundant dietary flavonoid with a chalcone structure, which is an important constituent in Glycyrrhizae Radix (GR). ISL exhibits anti-oxidant activity, and this activity has been shown to play a beneficial role in various health conditions. However, it is unclear whether the anti-oxidant activity of ISL affects insulin signaling pathway and lipid accumulation of adipocytes. We sought to investigate the effects and molecular mechanisms of ISL on insulin-stimulated adipogenesis in 3T3-L1 cells. We investigated whether ISL attenuates insulin-induced Reactive Oxygen Species (ROS) generation, and whether ISL inhibits the lipid accumulation and the expression of adipogenic-genes during the differentiation of 3T3-L1 cells. ISL blocked the ROS generation, suppressed the lipid accumulation and the expression of adipocyte-specific proteins, which are increased in response to insulin stimulation during adipocyte differentiation of 3T3-L1 cells. We also investigated whether the anti-oxidant capacity of ISL is involved in regulating the molecular events of insulin-signaling cascade in 3T3-L1 adipocytes. ISL restores PTP1B activity by inhibiting PTP1B oxidation and IR/PI3K/AKT phosphorylation during the early stages of insulin-induced adipogenesis. Our findings show that the anti-oxidant capacity of ISL attenuated insulin IR/PI3K/AKT signaling through inhibition of PTP1B oxidation, and ultimately attenuated insulin-induced adipocyte differentiation of 3T3-L1 cells.

Aims Leydig cells are characterized by their ability to produce testosterone. When the Leydig cells are unable to produce enough testosterone, spermatogenesis fails completely. Considering this, it is of great interest to investigate whether the expressions of steroidogenic enzymes are affected by testicular heat stress. This study aimed to demonstrate that heat induced ER-stress significantly influences steroidogenic enzyme expression and testosterone production in the Leydig cells. Main methods C57BL/6 mice were subjected to repetitive testicular heat-treatment at 42 °C for 15 min per day, and heat-treated mLTC-1 cells following hCG treatment for 1 h. The protein and RNA expressions were measured by Western blot, RT-PCR. The testosterone and progesterone levels were detected by EIA. The histological and pathological characteristics using hematoxylin and eosin (H&E) and antibody stains. Key findings The 3β-HSD expression was decreased by heat-stress and hCG treatment. While the GRP78/BiP and CHOP levels were increased by ER-stress inducers, those of the steroidogenic enzyme and progesterone were decreased. In contrast, an ER-stress inhibitor rescued the testosterone levels, even under heat-stress conditions. Moreover, the Leydig cells were randomly scattered, and severely damaged upon repetitive testicular heat-treatment. Additionally, immunohistochemical analyses revealed that cleaved caspase-3 was elevated in the testicular Leydig cells, and rescued by TUDCA. Thus, repetitive testicular heat-treatment in mice promotes excessive ER-stress, thereby leading to apoptosis of the Leydig cells and thus, decreased testosterone production. Significance Our findings help to provide an ER-stress mediate mechanistic explanation to the impairment of spermatogenesis upon elevation of the testicular temperature.

As retirement is widely considered as a major life change in older adults, the extensive research investigated the risk factors of well-being and vulnerability after retirement. As vulnerability is the outcome of complex interactions of multiple risks and lack of resources, the emergence, and evolvement of vulnerability will include multi-dimensional aspects, such as risk to poverty, health, social engagement, and depression. This study aims to explore patterns of multi-dimensional vulnerability of retirees, and examine the association between profiles of vulnerability and well-being. Our sample included 2,617 retirees who aged 65+ of Health and Retirement Study. Latent class analysis was utilized to identify the heterogeneous patterns of vulnerability, and then a series of OLS regression analyses were conducted to examine the relationship between patterns of vulnerability and well-being. Four vulnerability patterns were identified: Physical and psychological vulnerable (13%), Social vulnerable (35%), Low vulnerable (37%) and Material vulnerable (15%). The regression analysis showed that those who are in material vulnerable, social vulnerable, physical and psychological vulnerable groups had significantly lower well-being compared to those who are in low-vulnerable group after controlling for age, gender, education, and retirement voluntariness. In particular, physical and psychological vulnerability predicted the lower well-being than other types of vulnerability. Our study provides the empirical evidence that various patterns of vulnerability predicted different levels of well-being after retirement. This result expanded the current literature on retirement by suggesting the potential risk of the physical and psychological vulnerable group in postretirement. Implications for future research and services will be discussed.

Engagement in social and productive activities is beneficial for older adults. Little is known about the link between social engagement and the psychological well-being (depressive symptoms and life satisfaction) longitudinally, and how such relationship may differ by productive engagement. This study aims to identify the patterns of social engagement, examine the association between the patterns of social engagement and the trajectories of psychological well-being, and explore whether this association differs by work. Data came from three waves of Korean Longitudinal Study on Aging (2008–2012), with 3,132 respondents aged 65+ selected from the baseline. Latent class analysis identified three social engagement patterns. Latent growth curve modeling showed that social engagement patterns were associated with the initial and the slope of psychological well-being, with working group showed fewer declines in psychological well-being. Findings demonstrate the dynamics between different activity engagements to well-being but more studies are needed to understand this mechanism.

ICT has been recognized as a tool for facilitating older adults’ volunteering. Beneficial effect of engaging in volunteering on health and well-being is well-established. However, the concern low-income elders are often excluded from a chance of volunteering has been consistently raised. We investigated to what extent ICT confidence may influence volunteering level among older adults and if this associations differ across poverty levels. Data came from the 2012 Health and Retirement Study. The sample was restricted respondents between age of 60 to 84 who participated in a special survey of ICT (N=898). Volunteering was measured with four levels of intensity. ICT confidence was measured with a composite indicator of nine ICT ability and perception such as satisfaction, flexibility, and difficult. (alpha =0.99). Poverty status was measured with three Federal Poverty Level: Below 185%, 185%-300%, and Above 300%. An ordered logit regression was used to examine the association between ICT confidence and volunteering and if poverty status moderates the association. ICT confidence was significantly associated with higher volunteering ([OR] 1.02, p ≤ 0.001), and low-income group was significantly less likely to do volunteering compared to high-income group ([OR] 0.57, p ≤ 0.01). Interestingly, low-income older adults with higher level of ICT confidence were more likely to engage in volunteering ([OR] 1.03, p ≤ 0.05). We found that ICT confidence may facilitate older adults’ volunteering, and the role of ICT confidence may be more salient for low-income older adults. We provide empirical knowledge for the implementation of ICT training for low-income elders.

Reactive oxygen species (ROS) produced in biological reactions have been shown to contribute to ovarian aging. Peroxiredoxin 2 (Prx2) is an antioxidant enzyme that protects cells by scavenging ROS; however, its effect on age-related, oxidative stress-associated ovarian failure has not been reported. Here, we investigated its role in age-related ovarian dysfunction and 4-vinylcyclohexene diepoxide (VCD)-induced premature ovarian failure using Prx2-deficient mice. Compared to those in wildtype (WT) mice, serum levels of anti-Mullerian hormone, 17β-estradiol, and progesterone and numbers of follicles and corpora lutea were significantly lower in 18-month-old Prx2-/- mice. Moreover, levels of Bax, cytochrome c, cleaved caspase-3, and phosphorylated JNK proteins were higher and numbers of apoptotic (terminal deoxynucleotidyl transferase dUTP nick end labeling-positive) cells were considerably greater in 18-month-old Prx2-/- ovaries than WT ovaries. Furthermore, the effects of the ovarian toxicant VCD in significantly enhancing ROS levels and apoptosis through activation of JNK-mediated apoptotic signaling were more pronounced in Prx2-/- than WT mouse embryonic fibroblasts. Expression of the steroidogenic proteins StAR, CYP11A1, and 3β-HSD and serum levels of 17β-estradiol and progesterone were also reduced to a greater extent in Prx2-/- mice than WT mice after VCD injection. This reduced steroidogenesis was rescued by addition of the Prx mimic ebselen or JNK inhibitor SP600125. This constitutes the first report that Prx2 deficiency leads to acceleration of age-related or VCD-induced ovarian failure by activation of the ROS-induced JNK pathway. These findings suggest that Prx2 plays an important role in preventing accelerated ovarian failure by inhibiting ROS-induced JNK activation.

Elevated levels of reactive oxygen species (ROS) are a hallmark of obesity. Peroxiredoxin 5 (Prx5), which is a cysteine-dependent peroxidase enzyme, has an intensive ROS scavenging activity because it is located in the cytosol and mitochondria. Therefore, we focused on the role of Prx5 in regulating mitochondrial ROS and adipogenesis. We demonstrated that Prx5 expression was upregulated during adipogenesis and Prx5 overexpression suppressed adipogenesis by regulating cytosolic and mitochondrial ROS generation. Silencing Prx5 promoted preadipocytes to differentiate into adipocytes accumulating lipids by activating adipogenic protein expression. Prx5-deletion mice fed on a high-fat diet (HFD) exhibited significant increase in body weight, enormous fat pads, and adipocyte hypertrophy in comparison to wild type mice. Prx5 deletion also remarkably induced adipogenesis-related gene expression in white adipose tissue. These phenotypic changes in Prx5-deletion mice were accompanied with lipid metabolic disorders, such as excessive lipid accumulation in the liver, severe hepatic steatosis, and high levels of triglyceride in the serum. These results demonstrated that Prx5 deletion increased the susceptibility to HFD-induced obesity and several of its associated metabolic disorders. In conclusion, we suggest that Prx5 inhibits adipogenesis by modulating ROS generation and adipogenic gene expression, implying that Prx5 may serve as a potential strategy to prevent and treat obesity.

Although statin is one of the most widely used drugs worldwide, the association between statin use and hepatocellular carcinoma (HCC) risk remains controversial. This study aims to investigate the association between statin use and risk of HCC in a large scale population-based prospective cohort. We selected participants aged >40 years in 2002 whose health examination data were available from the Korean National Health Insurance Service-National Sample Cohort (NHIS-NSC) database. We collected statin exposure data and medical information of the population in the database over 5 years (2002–2006), and followed up eligible participants for HCC development over the next 7 years (2007–2013). We used Cox proportional hazard regression models to calculate the hazard ratios of statin use and HCC risk, after adjusting for sex, age, incoming status, disability, body mass index, smoking status, alcohol consumption, physical activity, comorbidity, underlying liver disease, and medication use. Overall, 443,239 participants were included in the analysis, including 3,147 cases of HCC during the observation period. The adjusted hazard ratio for HCC in statin users was 0.66 (95% confidence interval [CI], 0.56–0.77), indicating a 34% risk reduction in a dose-response manner (P for trend < 0.001). Sensitivity analysis showed a reduced risk of HCC in statin users in all subgroups, in terms of age and sex, as well as a stronger risk reduction in patients with underlying liver disease. In conclusion, statin use is associated with a reduced risk of HCC in a dose-response manner.

ER stress has emerged as a signaling platform underlying the pathogenesis of various kidney diseases. Thus, there is an urgent need to develop ER stress biomarkers in the incipient stages of ER stress-mediated kidney disease, when a kidney biopsy is not yet clinically indicated, for early therapeutic intervention. Cysteine-rich with EGF-like domains 2 (CRELD2) is a newly identified protein that is induced and secreted under ER stress. For the first time to our knowledge, we demonstrate that CRELD2 can serve as a sensitive urinary biomarker for detecting ER stress in podocytes or renal tubular cells in murine models of podocyte ER stress-induced nephrotic syndrome and tunicamycin- or ischemia-reperfusion-induced acute kidney injury (AKI), respectively. Most importantly, urinary CRELD2 elevation occurs in patients with autosomal dominant tubulointerstitial kidney disease caused by UMOD mutations, a prototypical tubular ER stress disease. In addition, in pediatric patients undergoing cardiac surgery, detectable urine levels of CRELD2 within postoperative 6 hours strongly associate with severe AKI after surgery. In conclusion, our study has identified CRELD2 as a potentially novel urinary ER stress biomarker with potential utility in early diagnosis, risk stratification, treatment response monitoring, and directing of ER-targeted therapies in selected patient subgroups in the emerging era of precision nephrology.

Department of Reproductive Medicine, University of California, San Diego, 9500 Gilman Drives, La Jolla, California 92093, USAReceived July 17, 2014/Revised August 11, 2014/Accepted August 11, 2014This study analyzed whether human chorionic gonadotropin (hCG) induces ER stress via the IRE/XBP1 pathway in mouse Leydig tumor (mLTC-1) cells. In a previous study, we demonstrated that the unfolding protein response (UPR) plays an important role in the expression of steroidogenic enzymes by modulating the ATF6 pathway, as well as ER stress-mediated apoptosis in hCG-stimu-lated Leydig cells. Although UPR signaling has been reported to regulate the IRE1/XBP1 pathway, it is not known whether hCG-induced ER stress in Leydig cells can activate the pathway. To inves-tigate the activation of the IRE1/XBP1 pathway in mLTC-1 cells after hCG treatment, we performed a Western blot analysis to detect the phospho-IRE1 protein and an RT-PCR analysis to validate splic-ing of XBP1 mRNA. We used ER stress-activated indicator (ERAI) constructs for monitoring the activ-ity of IRE1 and then analyzed by fluorescence microscopy and flow cytometry. The expression levels of the phospho-IRE1 protein markedly increased in response to the hCG treatment. In the mLTC-1 cells transfected with an F-XBP1-venus/F-XBP1△DBD-venus construct, the hCG treatment led to the appearance of green fluorescent cells and detectable fluorescence in the nucleus and cytosol, respectively. In addition, splicing of XBP1 mRNA significantly increased after the hCG treatment. Taken together, these results indicate that hCG-induced ER stress leads to activation of the IRE1/XBP pathway in Leydig cells. Keywords

Aims We examined whether the three unfolded protein response (UPR) signaling pathways, which are activated in response to endoplasmic reticulum (ER)-stress, are involved in progesterone production in the luteal cells of the corpus luteum (CL) during the mouse estrous cycle. Main methods The luteal phase of C57BL/6 female mice (8 weeks old) was divided into two stages: the functional stage (16, 24, and 48 h) and the regression stage (72 and 96 h). Western blotting and reverse transcription (RT)-PCR were performed to analyze UPR protein/gene expression levels in each stage. We investigated whether ER stress affects the progesterone production by using Tm (0.5 μg/g BW) or TUDCA (0.5 μg/g BW) through intra-peritoneal injection. Key findings Our results indicate that expressions of Grp78/Bip, p-eIF2α/ATF4, p50ATF6, and p-IRE1/sXBP1 induced by UPR activation were predominantly maintained in functional and early regression stages of the CL. Furthermore, the expression of p-JNK, CHOP, and cleaved caspase3 as ER-stress mediated apoptotic factors increased during the regression stage. Cleaved caspase3 levels increased in the late-regression stage after p-JNK and CHOP expression in the early-regression stage. Additionally, although progesterone secretion and levels of steroidogenic enzymes decreased following intra-peritoneal injection of Tunicamycin, an ER stress inducer, the expression of Grp78/Bip, p50ATF6, and CHOP dramatically increased. Significance These results suggest that the UPR signaling pathways activated in response to ER stress may play important roles in the regulation of the CL function. Furthermore, our findings enhance the understanding of the basic mechanisms affecting the CL life span.

The corpus luteum (CL) is a transient endocrine organ. Development, maintenance, and regression of CL are effectively controlled by dynamic changes in gene expression. However, it is unknown what types of gene are affected during the CL life span of the estrous cycle in bovine. Here, we determined whether unfolded protein response (UPR) signaling via eIF2α/ATF4/GADD34, p90ATF6/p50ATF6, and IRE1/XBP1, which is a cellular stress response associated with the endoplasmic reticulum (ER), is involved in the bovine CL life span. Our results indicated that expression of Grp78/Bip, the master UPR regulator, was increased during the maintenance stage and rapidly decreased at the regression stage. Additionally, UPR signaling pathways genes were found to be involved in luteal phase progression during the estrous cycle. Our findings suggested that Grp78/Bip, ATF6, and XBP1 act as ER chaperones for initiating CL development and maintaining the CL. In addition, we investigated whether ER stress-mediated apoptosis is occurred through three UPR signaling pathways in CL regression stage. Interestingly, pIRE1 and CHOP were found to be involved in both the adaptive response and ER stress-mediated apoptosis. During the CL regression stage, increased expression of pJNK and CHOP, two components of ER stress-mediated apoptotic cascades, occurred before increased level of cleaved caspase 3 were observed. The present investigation was performed to identify a functional link between UPR signaling and CL life span during the bovine estrous cycle. Taken together, results from this study demonstrated that UPR protein/gene expression levels were different at various stages of the bovine CL life span. Variations in the expression of these protein/genes may play important roles in luteal stage progression during the estrous cycle.

Over-activation of microglia cells in the brain contributes to neurodegenerative processes promoted by the production of various neurotoxic factors including pro-inflammatory cytokines and nitric oxide. Recently, accumulating evidence has suggested that mitochondrial dynamics are an important constituent of cellular quality control and function. However, the role of mitochondrial dynamics in microglial activation is still largely unknown. In this study, we determined whether mitochondrial dynamics are associated with the production of pro-inflammatory mediators in lipopolysaccharide (LPS)-stimulated immortalization of murine microglial cells (BV-2) by a v-raf/v-myc carrying retrovirus (J2). Excessive mitochondrial fission was observed in lentivirus-transfected BV-2 cells stably expressing DsRed2-mito following LPS stimulation. Furthermore, mitochondrial localization of dynamin-related protein 1 (Drp1) (a key regulator of mitochondrial fission) was increased and accompanied by de-phosphorylation of Ser637 in Drp1. Interestingly, inhibition of LPS-induced mitochondrial fission and reactive oxygen species (ROS) generation by Mdivi-1 and Drp1 knock-down attenuated the production of pro-inflammatory mediators via reduced nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and mitogen-activated protein kinase (MAPK) signaling. Our results demonstrated for the first time that mitochondrial fission regulates mitochondrial ROS production in activated microglial cells and influences the expression of pro-inflammatory mediators through the activation of NF-κB and MAPK. We therefore suggest that mitochondrial dynamics may be essential for understanding pro-inflammatory mediator expression in activated microglial cells. This could represent a new therapeutic approach for preventing neurodegenerative diseases.

Volunteering and caregiving are both considered as productive activities in old age, but little is known about the influence of caregiving on volunteering. According to role extension hypothesis, caregiving may facilitate volunteering, whereas caregiving may decrease the chances of volunteering if role overload hypothesis is adapted. The present study investigates whether types of caregiving (i.e., no caregiving, spousal caregiving only, grandchildren caregiving only, and caregiving for both) are associated with levels of volunteering (i.e., no, mid (1-190hrs/yr), and high (190+hrs/yr) levels), and whether this association differs across gender. Data came from seven waves of Health and Retirement Study (2000–2012), and sample was restricted to those who participated in 3+ consecutive waves (n=2,727; observation=68,794). Longitudinal multinomial regression analyses showed that women caregivers were more likely to do high-level volunteering, but men were not. These findings partially support role extension hypotheses. Future research is encouraged to identify reasons why such differences exist.

As one of the major domains of productive engagement, this symposium focuses on work. The research papers use diverse designs and data sources across the U.S. to explore the intersectionality of work and caregiving, as well as characteristics of self-employment. The first paper focuses on the work-caregiving conflict among employed daughters caring for older parents in a sample of 89 intergenerational family caregivers. The findings show preparedness for caregiving and perceived stress were significant predictors of work strain. The second paper examines the relationship between employment benefits and retirement savings among both male and female care-giver employees (ages 50–57 in 2014) using the 1979 National Longitudinal Survey of Youth (NLSY79) (1994–2014). Findings suggest those with more paid vacation days and access to flexible work hours have higher retirement savings. The third paper examines the effect of a Paid Family Leave program in California (CA-PFL) on employment among older female caregivers with data from multiple years (2000‒2014) of the Current Population Survey (CPS). Results show a significant increase in the likelihood of working and decrease in the likelihood of being not employed for those covered by paid family leave. The final paper documents the characteristics of self-employed older adults using the Health and Retirement Study (HRS). Results indicate age, being male, volunteering, risk tolerance, and reporting better health, earnings and wealth were positively associated with self-employment. These studies identify barriers and facilitators in employment and self-employment, and suggest how public programs, organizational and policy level supports enhance productive engagement in work

Concerning about the negative impact of chemical pesticides on human health and the environment has been leading to dramatic increase of research in natural product-based pesticides. An antagonistic bacterium Streptomyces sp. S-1110 was isolated from apple farm soil. The culture filtrate of the strain showed growth inhibition effects to apple pathogenic fungi, Botryosphaeria dothidea, Colletotrichum gloeosporioides and Rhizoctonia solani . The unidentified antibiotic substances from the strain kept antagonistic activity either after heat treatment at 121 ℃ for 1 h or pH treatment at range of pH 3 - pH 12 for 24 h. The substances also prevented apple fruit from spoiling by inoculated two pathogenic molds, B. dothidea and C. gloeosporioides . These results suggested that the isolated strain would be useful as a biocontrol agent to control apple spoiling occurred from mold.Key Words: Antagonistic bacteria, Biocontrol agent, Botryosphaeria dothidea, Colletotrichum gloeosporioides, Rhizoctonia solani

Superovulation induced by exogenous gonadotropin treatment (PMSG/hCG) increases the number of available oocytes in humans and animals. However, Superovulatory PMSG/hCG treatment is known to affect maternal environment, and these effects may result from PMSG/hCG treatment-induced oxidative stress. 2-Cys peroxiredoxins (2-Cys Prxs) act as antioxidant enzymes that protect cells from oxidative stress induced by various exogenous stimuli. Therefore, the objective of this study was to test the hypothesis that repeated PMSG/hCG treatment induces 2-Cys Prx expression and overoxidation in the reproductive tracts of female mice. Immunohistochemistry and western blotting analyses further demonstrated that, after PMSG/hCG treatment, the protein expression levels of 2-Cys Prxs increased most significantly in the ovaries, while that of Prx1 was most affected by PMSG/hCG stimulation in all tissues of the female reproductive tract. Repeated PMSG/hCG treatment eventually leads to 2-Cys Prxs overoxidation in all reproductive organs of female mice, and the abundance of the 2-Cys Prxs-SO2/3 proteins reported here supports the hypothesis that repeated superovulation induces strong oxidative stress and damage to the female reproductive tract. Our data suggest that excessive oxidative stress caused by repeated PMSG/hCG stimulation increases 2-Cys Prxs expression and overoxidation in the female reproductive organs. Intracellular 2-Cys Prx therefore plays an important role in maintaining the reproductive organ environment of female mice upon exogenous gonadotropin treatment.

The accumulation of iron in neurons has been proposed to contribute to the pathology of numerous neurodegenerative diseases, such as Alzheimer's disease and Parkinson's disease. However, insufficient research has been conducted on the precise mechanism underlying iron toxicity in neurons. In this study, we investigated mitochondrial dynamics in hippocampal HT-22 neurons exposed to ferric ammonium citrate (FAC) as a model of iron overload and neurodegeneration. Incubation with 150 μM FAC for 48 h resulted in decreased cell viability and apoptotic death in HT-22 cells. The FAC-induced iron overload triggered mitochondrial fragmentation, which was accompanied by Drp1(Ser637) dephosphorylation. Iron chelation with deferoxamine prevented the FAC-induced mitochondrial fragmentation and apoptotic cell death by inhibiting Drp1(Ser637) dephosphorylation. In addition, a S637D mutation of Drp1, which resulted in a phosphorylation-mimetic form of Drp1 at Ser637, protected against the FAC-induced mitochondrial fragmentation and neuronal apoptosis. FK506 and cyclosporine A, inhibitors of calcineurin activation, determined that calcineurin was associated with the iron-induced changes in mitochondrial morphology and the phosphorylation levels of Drp1. These results indicate that the FAC-induced dephosphorylation of Drp1-dependent mitochondrial fragmentation was rescued by the inhibition of calcineurin activation. Therefore, these findings suggest that calcineurin-mediated phosphorylation of Drp1(Ser637) acts as a key regulator of neuronal cell loss by modulating mitochondrial dynamics in iron-induced toxicity. These results may contribute to the development of novel therapies for treatment of neurodegenerative disorders related to iron toxicity.

The purposes of this study were to investigate the relationship between anthropometric data of foot and other body sizes. to categorize the foot shape of elementary school boys and to find out determinant factors related the foot that enable us to deduce the foot shape and size for the design of more comfortable shoes. Subjects of this study were 249 elementary school boys of age ranged from 6 to 11 residing Seoul and lncheon area. Anthropometric sizes were measured with the direct measurement method using Martin scales and the indirect measurement method using digital photos. Pearson`s correlation, factor analysis. cluster analysis. analysis of variance, post-hoc test, and cross tabs were performed for statistical analysis of the data by SPSS program. From the investigation on the relationship between foot-related items and body items, most items of foot measure were significantly related to body size items. However, angle of the foot did not related to other body sizes although other height items and mass items of the foot did have relationships with other body sizes. Results of ANOVA indicated there were significant differences in foot-related items except for items of foot angle and all body anthropometric items by subjects` age. This implicates big toe angle, little toe angle and foot ratio factors are required in sizing shoes besides foot length. On the basis of cluster analysis using factor scores. three different foot shapes were categorized. Type 1 was large and wide foot, Type 2 was small and narrow foot with large toe angle. and Type 3 was medium foot with no deformity on big toe. These three groups show significant differences in almost all measurement items. However, Rorher index and foot angle didn`t show any significant differences among groups. This implicates the foot shape can be a determinant of shoe size.

Liquid ammonia treatment of the textile fabric has been studied before now in order to improve the softness of cotton fabric with regard to shape stability finish. Furthermore, we are studying now on an application of ammonia-gas treatment to textile finishing instead of liquid ammonia treatment. In this study, two kinds of silk fabrics were treated with ammonia-gas under atmospheric (0.098 MPa) and at pressures of 2, 4, and 6 kgf/cm 2 which correspond to 0.196, 0.392 and 0.588 MPa respectively. After the treatment, shearing and bending hysteresis curves were measured with a KES evaluation system, and then shearing and bending modulus G, B, and the hysteresis width 2HG, 2HG5 and 2HB were obtained. Each parameter decreased obviously by the treatment, especially at a pressured condition. Therefore, it is clear that the ammonia-gas treatment is effective to improve the soft hand of the silk fabric.

Merino wool fiber and fabric were treated with ammonia-gas varying the condition, and the fiber was dyed with two acid dyes, C.I. Acid Red 13 and C.I. Acid Blue 83. Apparent dyeing rate, equilibrium dye uptake and dyeing transition temperature were measured. The dyeing rate and equilibrium dye uptake of the treated wool increased with both acid dyes. Also, dyeing transition temperature for both acid dyes decreased by the treatments. Therefore, it seems that acid dyes penetrate by the intercellular diffusion through the interscale Cell Membrane Complex (CMC) of wool. Furthermore, shearing and bending modulus G, B decreased a little by the treatment. The treatment is not always defective to improve the soft hand of the wool fabric.

Cotton and regenerated cellulose fiber lyocell were treated with liquid ammonia (NH3), and subsequently processed with dry heat, high temperature (HT) steam at atmospheric pressure and high pressure (HP) steam at 0.22 MPa and hot water at various temperatures. The effects of the processing on crystal modification, crystallinity, moisture regain, water absorption, and dyeing property was investigated. The diffraction intensity of cellulose IIII crystallite of the cotton fiber decreased with increasing a temperature of the hot water, while cellulose I crystallite increased by the treatment. On the other hand, dry heat treatment was not effective for the modification of cellulose IIII crystallite generated at the NH3 treatment. Change of the crystallite phase by the HT and HP steamings occurred less than that of the hot water and more than dry heat. Furthermore, an intensity of the cellulose IIIII crystallite of the NH3 treated lyocell took place no change not only with subsequent hot water but also with dry heat processing. Moisture regain, water absorption, and equilibrium dye uptake of the cotton were decreased by subsequent hot water processing, whereas thoseof the lyocell were almost unchanged.

Mercerization is one of the most common wet processing of cotton materials to improve the dyeing property. On the other hand, it is known that the treatment brings about a stiff hand. So, hot mercerization is expected to improve the soft hand. Scoured and bleached cotton fiber and fabric were mercerized for 5 min at a temperature of 20°C to 100°C with 20% sodium hydroxide aqueous solution. The X-ray diffraction, apparent dyeing rate and equilibrium dye uptake were measured. Although crystallite of the cotton fiber was transformed from cellulose I to cellulose III with a decreasing of the mercerizing temperature, especially by the treatment under 60°C, the diffraction pattern of the cotton fabric as fiber assembly was not changed to cellulose III.Apparent dyeing rate of the fiber increased with a decrease of the mercerizing temperature, whereas an increase of the rate of the fabric was considerably small compared with that of the fiber. Also, there was no difference among the mercerizing temperature. Therefore, it seems that mercerization of the fiber proceeds easily and transformed from cellulose I to cellulose III, while mercerization of the fabric as fiber assembly is difficult to penetrate sodium hydroxide like a fiber, because of the tight structure of the fiber assembly. Therefore, is clear that mercerization of the fabric is quitely different with that of the fiber. Hot mercerization is not always effective to decrease the KES parameters in shearing and bending behaviors.

The testes of most mammals are sensitive to temperature. To survive and adapt under conditions that promote endoplasmic reticulum (ER) stress such as heat shock, cells have a self-protective mechanism against ER stress that has been termed the “Unfolded Protein Response” (UPR). However, the cellular and molecular events underlying spermatogenesis with testicular hyperthermia involved in the UPR signaling pathway under ER stress remain poorly understood. In the present study, we verified that UPR signaling via phospho-eIF2α/ATF4/GADD34, p90ATF6, and phospho-IRE1α/XBP-1 is activated with testicular hyperthermia (43 °C, 15 min/day) and induced ER stress-mediated apoptosis associated with CHOP, phospho-JNK, and caspase-3 after repetitive periods of hyperthermia. Levels of phospho-eIF2α protein of mouse spermatocytes in the testis were rapidly increased by one cycle of testicular hyperthermia. ATF4/GADD34 and p90ATF6 expression gradually increased and decreased, respectively, with repetitive cycles of hyperthermia. Spliced XBP1 mRNA as a marker of IRE1 activity was increased after one, three cycles of hyperthermia and decreased by five cycles of hyperthermia. Although the levels of anti-apoptotic phospho-JNK (p54) were gradually decreased after three cycles of hyperthermia, CHOP expression was rapidly increased. After five cycles of testicular hyperthermia, the levels of cleaved caspase-3 and TUNEL-positive apoptotic spermatocytes cells were significantly increased. Our data demonstrated that testicular hyperthermia induces UPR signaling and repetitive cycles of hyperthermia lead to apoptosis of spermatocytes in mouse testis. These results suggest a link between the UPR signaling pathway and testicular hyperthermia.

Endoplasmic reticulum (ER) stress generally occurs in secretory cell types. It has been reported that Leydig cells, which produce testosterone in response to human chorionic gonadotropin (hCG), express key steroidogenic enzymes for the regulation of testosterone synthesis. In this study, we analyzed whether hCG induces ER stress via three unfolded protein response (UPR) pathways in mouse Leydig tumor (mLTC-1) cells and the testis. Treatment with hCG induced ER stress in mLTC-1 cells via the ATF6, IRE1a/XBP1, and eIF2α/GADD34/ATF4 UPR pathways, and transient expression of 50 kDa protein activating transcription factor 6 (p50ATF6) reduced the expression level of steroidogenic 3β-hydroxysteroid dehydrogenase △5-△4-isomerase (3β-HSD) enzyme. In an in vivo model, high-level hCG treatment induced expression of p50ATF6 while that of steroidogenic enzymes, especially 3β-HSD, 17α-hydroxylase/C17–20 lyase (CYP17), and 17β-hydrozysteroid dehydrogenase (17β-HSD), was reduced. Expression levels of steroidogenic enzymes were restored by the ER stress inhibitor tauroursodeoxycholic acid (TUDCA). Furthermore, lentivirus-mediated transient expression of p50ATF6 reduced the expression level of 3β-HSD in the testis. Protein expression levels of phospho-JNK, CHOP, and cleaved caspases-12 and -3 as markers of ER stress-mediated apoptosis markedly increased in response to high-level hCG treatment in mLTC-1 cells and the testis. Based on transmission electron microscopy and H&E staining of the testis, it was shown that abnormal ER morphology and destruction of testicular histology induced by high-level hCG treatment were reversed by the addition of TUDCA. These findings suggest that hCG-induced ER stress plays important roles in steroidogenic enzyme expression via modulation of the ATF6 pathway as well as ER stress-mediated apoptosis in Leydig cells.

Liquid ammonia treated cotton fiber and fabric were mercerized with 20% sodium hydroxide (NaOH) aqueous solution for 5 min at 20°C to 100°C. X-ray diffraction patterns of the cottons were measured with a Rigaku Denki III DMAX. The NH3-treated cotton fiber showed almost Cellulose III crystallite pattern. After mercerization, the crystallite phase transformed to Cellulose IIIII and a little Cellulose IIII. On the other hand, though NH3-treated cotton fabric was changed partially to Cellulose IIIII, untreated Cellulose I crystallite was remained not a little. The obtained Cellulose IIII crystallite of the fabric was completely returned to Cellulose IIII by mercerization regardless of the temperature, Cellulose IIIII crystallite was not observed despite of a decreasing of the mercerizing temperature. Therefore, it seems that mercerization of the fiber and fabric is considerably different. Apparent dyeing rate of the NH3-treated cotton fiber and fabric with C.I. Direct Blue 1 was increased by the hot mercerizing. The rate of the fiber was increased with a decrease of the mercerizing temperature, whereas that of the fabric was no difference among the temperature.

A new of vibration transducer, a DFMT (differential floating mass type) is introduced for use in an MEI (middle ear implant) system. The DFMT transducer is not influenced by external noise magnetic flux and has a very high vibration efficiency because its two magnets, which are glued back to back with the same poles facing, are located in the coil.