Diabetes and Cognitive Decline in Older Adults: The Ginkgo Evaluation of Memory Study

BACKGROUND

Previous studies have shown that individuals with diabetes exhibit accelerated cognitive decline. However, methodological limitations have limited the quality of this evidence. Heterogeneity in study design, cognitive test administration, and methods of analysis of cognitive data have made it difficult to synthesize and translate findings to practice. We analyzed longitudinal data from the Ginkgo Evaluation of Memory Study to test our hypothesis that older adults with diabetes have greater test-specific and domain-specific cognitive declines compared to older adults without diabetes.

METHODS

Tests of memory, visuo-spatial construction, language, psychomotor speed, and executive function were administered. Test scores were standardized to z-scores and averaged to yield domain scores. Linear random effects models were used to compare baseline differences and changes over time in test and domain scores among individuals with and without diabetes.

RESULTS

Among the 3,069 adults, aged 72-96 years, 9.3% reported diabetes. Over a median follow-up of 6.1 years, participants with diabetes exhibited greater baseline differences in a test of executive function (trail making test, Part B) and greater declines in a test of language (phonemic verbal fluency). For the composite cognitive domain scores, participants with diabetes exhibited lower baseline executive function and global cognition domain scores, but no significant differences in the rate of decline.

CONCLUSIONS

Identifying cognitive domains most affected by diabetes can lead to targeted risk modification, possibly in the form of lifestyle interventions such as diet and physical activity, which we know to be beneficial for improving vascular risk factors, such as diabetes, and therefore may reduce the risk of executive dysfunction and possible dementia.

Is there a relationship between accelerometer-assessed physical activity and sedentary behavior and cognitive function in US Hispanic/Latino adults? The Hispanic Community Health Study/Study of Latinos (HCHS/SOL)

Normative changes in cognitive function are expected with increasing age. Research on the relationship between normative cognitive decline and moderate-to-vigorous physical activity (MVPA) and sedentary behavior (SED) needs further investigation in Hispanic/Latinos adults. We assessed the cross-sectional association between accelerometer assessed MVPA and SED with cognitive function in 7,478 adults aged 45-74years from the Hispanic Community Health Study/Study of Latinos. At baseline, cognitive tests included two executive function tests (Digit Symbol Substitution Test (DSST), a test of language (Word Fluency), and a test of memory (Spanish English Verbal Learning Test). Multiple regression models were used to examine associations of time spent in MVPA and SED with cognitive function by age groups, adjusted for age, education, sex, acculturation, and field center. Mean time spent in sedentary behaviors was 12.3h/day in females and 11.9 h/day in males (75% and 77% of accelerometer wear time, respectively). Higher SED, but not MVPA, was associated with lower DSST raw scores (β -0.03 with each 10-min increment in SED; P<0.05), indicating lower performance in executive function in all age groups. No associations were observed for MVPA and SED with tests of language or memory tests. Our findings suggest a distinct association of SED but not MVPA on executive functioning in middle-aged and older Latino adults. Longitudinal studies are needed to more conclusively determine causal links.

Cardiovascular Dysfunction and Frailty Among Older Adults in the Community: The ARIC Study

Background

The contribution of cardiovascular dysfunction to frailty in older adults is uncertain. This study aimed to define the relationship between frailty and cardiovascular structure and function, and determine whether these associations are independent of coexisting abnormalities in other organ systems.

Methods

We studied 3,991 older adults (mean age 75.6±5.0 years; 59% female) from the Atherosclerosis Risk in Communities (ARIC) Study in whom the following six organ systems were uniformly assessed: cardiac (by echocardiography), vascular (by ankle-brachial-index and pulse-wave-velocity), pulmonary (by spirometry), renal (by estimated glomerular filtration rate), hematologic (by hemoglobin), and adipose (by body mass index and bioimpedance). Frailty was defined by the presence of ≥3 of the following: low strength, low energy, slowed motor performance, low physical activity, or unintentional weight loss.

Results

Two hundred eleven (5.3%) participants were frail. In multivariable analyses adjusted for demographics, diabetes, hypertension, and measures of other organ system function, frailty was independently and additively associated with left ventricular hypertrophy (odds ratio [OR] = 1.72; 95% confidence interval [CI] = 1.30-2.40), reduced global longitudinal strain (reflecting systolic function; OR = 1.68; 95% CI = 1.16-2.44), and greater left atrial volume index (reflecting diastolic function; OR = 1.60; 95% CI = 1.13-2.27), which together demonstrated the greatest association with frailty (OR = 2.10; 95% CI = 1.57-2.82) of the systems studied. Lower magnitude associations were observed for vascular and pulmonary abnormalities, anemia, and impaired renal function. Cardiovascular abnormalities remained associated with frailty after excluding participants with prevalent cardiovascular disease.

Conclusions

Abnormalities of cardiac structure and function are independently associated with frailty, and together show the greatest association with frailty among the organ systems studied.

Hemoglobin A1c and Mortality in Older Adults With and Without Diabetes: Results From the National Health and Nutrition Examination Surveys (1988-2011)

OBJECTIVE

Hemoglobin A1c (HbA1c) level has been associated with increased mortality in middle-aged populations. The optimal intensity of glucose control in older adults with diabetes remains uncertain. We sought to estimate the risk of mortality by HbA1c levels among older adults with and without diabetes.

RESEARCH DESIGN AND METHODS

We analyzed data from adults aged ≥65 years (n = 7,333) from the Third National Health and Nutrition Examination Survey (NHANES III) (1998-1994) and Continuous NHANES (1999-2004) and their linked mortality data (through December 2011). Cox proportional hazards models were used to examine the relationship of HbA1c with the risk of all-cause and cause-specific (cardiovascular disease [CVD], cancer, and non-CVD/noncancer) mortality, separately for adults with diabetes and without diabetes.

RESULTS

Over a median follow-up of 8.9 years, 4,729 participants died (1,262 from CVD, 850 from cancer, and 2,617 from non-CVD/noncancer causes). Compared with those with diagnosed diabetes and an HbA1c <6.5%, the hazard ratio (HR) for all-cause mortality was significantly greater for adults with diabetes with an HbA1c >8.0%. HRs were 1.6 (95% CI 1.02, 2.6) and 1.8 (95% CI 1.3, 2.6) for HbA1c 8.0-8.9% and ≥9.0%, respectively (P for trend <0.001). Participants with undiagnosed diabetes and HbA1c >6.5% had a 1.3 (95% CI 1.03, 1.8) times greater risk of all-cause mortality compared with participants without diabetes and HbA1c 5.0-5.6%.

CONCLUSIONS

An HbA1c >8.0% was associated with increased risk of all-cause and cause-specific mortality in older adults with diabetes. Our results support the idea that better glycemic control is important for reducing mortality; however, in light of the conflicting evidence base, there is also a need for individualized glycemic targets for older adults with diabetes depending on their demographics, duration of diabetes, and existing comorbidities.

Operationalizing Frailty in the Atherosclerosis Risk in Communities Study Cohort

Background

Factors that may contribute to the development of frailty in late life have not been widely investigated. The Atherosclerosis Risk in Communities (ARIC) Study cohort presents an opportunity to examine relationships of midlife risk factors with frailty in late life. However, we first present findings on the validation of an established frailty phenotype in this predominantly biracial population of older adults.

Methods

Among 6,080 participants, we defined frailty based upon the Cardiovascular Health Study (CHS) criteria incorporating measures of weight loss, exhaustion, slow walking speed, low physical activity, and low grip strength. Criterion and predictive validity of the frailty phenotype were estimated from associations between frailty status and participants' physical and mental health status, physiologic markers, and incident clinical outcomes.

Results

A total of 393 (6.5%) participants were classified as frail and 50.4% pre-frail, similar to CHS (6.9% frail, 46.6% pre-frail). In age-adjusted analyses, frailty was concurrently associated with depressive symptoms, low self-rated health, low medication adherence, and clinical biomarker levels (ie, cholesterol, hemoglobin A1c, white blood cell count, C-reactive protein, and hemoglobin). During 1-year follow-up, frailty was associated with falls, low physical ability, fatigue, and mortality.

Conclusions

These findings support the validity of the CHS frailty phenotype in the ARIC Study cohort. Future studies in ARIC may elucidate early-life exposures that contribute to late-life frailty.

89 METHYLATION STATUS OF IGF2/H19 DMR3 REGION AFFECTS IN VITRO BLASTOCYST PRODUCTION IN GOAT (CAPRA HIRCUS)

Parthenogenesis has been observed in lower animals but no known instance has been reported in mammals because both maternal and paternal genomes are a fundamental prerequisite for embryogenesis. A major reason for developmental failure of uniparental zygotes is expression of certain genes in a parent-of-origin-specific manner, i.e. genomic imprinting of genes. Out of many imprinted genes identified so far, IGF2/H19 have been extensively studied and known to play an important role in fetal and placental development. Gene IGF2 is expressed by the paternal allele, H19 is transcribed from the maternal allele, and the reciprocal expression of both genes is regulated by the DMR3 region placed upstream of the H19 gene. In the present study we compared the methylation status of IGF2/H19 DMR in parthenogenetic activated (PA) and IVF goat (Capra hircus) blastocyst through bisulphite sequencing. For this, immature oocytes of usable quality were subjected to in vitro maturation and subsequently used for embryo production through parthenogenesis (n = 993) (by calcium ionophore and 6-DMAP activation) and IVF (n = 1096). It was found that embryo production rate at all the embryonic stages (2-cell, 4-cell, 8–16-cell, morula, and blastocyst) was significantly higher (P < 0.05) in parthenogenesis (74.66 ± 3.35%, 61.90 ± 2.73%, 47.83 ± 2.95%, 38.13 ± 5.28%, and 21.11 ± 2.51%, respectively) as compared with IVF (55.21 ± 2.02%, 38.12 ± 2.48%, 28.53 ± 1.67%, 21.57 ± 1.59%, and 8.23 ± 1.02%, respectively). When blastocysts (n = 6 each) were subjected to TUNEL, it was found that PA blastocyst showed significantly higher (P < 0.05) total cell number (217.83 ± 18.80 v. 159.67 ± 13.94) and significantly low (P < 0.05) apoptotic index (2.04 ± 0.25 v. 4.03 ± 0.29) as compared with IVF blastocysts. For the methylation pattern study, we analysed 17 CpG sites on the DMR3 region of the IGF2/H19 gene. Variable methylation pattern was observed within these CpG sites in different clones (n = 15) of PA and IVF blastocyst. The DMR3 region of the IGF2/H19 gene was significantly hypermethylated (P < 0.05) in PA blastocysts as compared with IVF blastocysts (80.39 ± 2.96, 32.55 ± 4.37, respectively), which suggests higher expression of IGF2 in parthenotes. The result suggests IGF2 might play different roles in different species; the same expression pattern of IGF2 is observed in ovine, but a contrary result is found in porcine species. Our results signify the hypermethylation of IGF2/H19 DMR3, which leads to higher expression of IGF2 to support embryonic development at the blastocyst stage. This work was supported by the NFBSFARA Project on Parthenogenetic Goat (CA-4002), New Delhi, India.

34 PRODUCTION OF TRANSGENIC CLONED BUFFALO EMBRYOS CONTAINING OVEREXPRESSED STEAROYL Co-A DESATURASE GENE FOLLOWING EFFICIENT TRANSFECTION

Stearoyl-CoA desaturase (SCD) is a rate-limiting enzyme that catalyses the synthesis of monounsaturated fatty acids and polyunsaturated fatty acids from saturated fatty acids, which are components of triglycerides, wax esters, cholesteryl esters, and membrane phospholipids. Alterations in phospholipid composition have been implicated in a variety of diseases including obesity and the associated metabolic syndrome. SCD also magnifies the conjugated linoleic acid (CLA) content in milk; CLA is a natural fat element, having reputed therapeutic health values including anti-carcinogenic properties. In light of this fact, this study was designed to amplify the levels of SCD at the gene level. In order to achieve the enhanced expression of SCD gene, combination of techniques were used. The somatic cells (fetal fibroblast) culture were established from ear pinnae obtained from bovine fetus procured from the abattoir and were cultured in basal medium, comprising DMEM with 10% fetal bovine serum, 1X NEAA and 1X PS antibiotics. These isolated cultured cells were transfected with a gene construct carrying buSCD gene (pAcGFPN1-buSCD) as BLGP-buSCD-BLG3′UTR-CMVP-EGFP-SV40. The buffalo fetal fibroblast cells were transfected using 3 methods: Nucleofection, Fugene and Lipofection. The successful transfection, as confirmed by PCR and Southern hybridisation, proved Nucleofection to be more efficient in transfecting cells among the techniques used, which were further maintained and selected by Geneticin (G418). These selected transfected cells were then used for nuclear transfer. Somatic cell nuclear transfer (SCNT) has provided an efficient pathway for the production of transgenic animals. Buffalo cumulus–oocyte complexes (COCs) were collected from ovaries collected from abattoir and matured in TCM-199 supplemented with 10% FBS, 5 µg mL−1 FSH, and 1 µg mL−1 β-oestradiol for 21 h in CO2 incubator at 5% CO2 in air and 38.5°C temperature with >95% relative humidity. After 21 h, these COCs were denuded and subjected to zona removal. These zona-free oocytes were manually enucleated using microsurgical blades and 2 enucleated oocytes were fused with a transgenic cell using electro cell manipulator. Further, these reconstructed embryos were activated using calcium ionophore and cultured in IVC media thereafter for 8 days. The developmental competence rate as recorded on Day 8 was 53.26 ± 1.73%, 69.87 ± 6.24%, 62.99 ± 7.15%, 42.71 ± 5.05% and 28.00 ± 3.33% for 2-cell, 4-cell, 8–16 cell, morula, and blastocyst, respectively. When observed under fluorescence microscope, the embryos showed successful expression of GFP, which can be further used for animal production or further research analysis. In conclusion, amplified SCD at gene level will result in a boost to the dairy sector as well ameliorating human health due to its crucial role in anti-cancer, anti-diabetic, reduced cardio-vascular disease, and improved immune responses.

90 OVIDUCTAL EPITHELIAL CELLS Co-CULTURE PROMOTES GOAT (CAPRA HIRCUS) IN VITRO PARTHENOGENETIC EMBRYO DEVELOPMENT

Co-culture of pre-implantation embryos with oviducal epithelial cells mimics the in vivo conditions, thus, playing a crucial role in embryo metabolism and gene expression and finally supporting embryonic developmental competence in several ways. Hence, the objective of the present study was to evaluate the effect of goat oviducal epithelial cells (GOEC) co-culture on goat parthenogenetic embryonic development, quality, and relative mRNA abundance of genes related to developmental competence and oxidative stress. The GOEC were obtained from goat oviducts by squeezing and thorough washing with TCM-199 + 10% fetal bovine serum. Goat cumulus–oocyte complexes were collected from slaughterhouse ovaries and matured in TCM-199 + 10% fetal bovine serum supplemented with 5 μg mL−1 of FSH, 10 μg mL−1 of LH, and 1 μg mL−1 of β-oestradiol for 27 h in CO2 incubator with 5% CO2 and at 38.5°C with >95% RH. In vitro matured cumulus–oocyte complexes were denuded and activated with 5 μM calcium ionophore and 2 mM 6-DMAP. Following activation, embryos were co-cultured with and without GOEC (control) in mCR2aa media. The blastocyst development rate was significantly (P < 0.05) higher (23.00 ± 1.15% v. 17.33 ± 1.45%) in the media cultured with GOEC than in control. The total cell number of blastocysts (n = 4) was also found to be significantly more (167.25 ± 17.51 v. 110.25 ± 12.02) than that of control (P < 0.05). However, the apoptotic index (3.76 ± 0.23% v. 7.97 ± 1.99%) was not significantly different in both groups. Further, RNA was isolated from both groups (20 each) of blastocysts on Day 8, and cDNA was prepared. Analysis by qPCR revealed that the relative mRNA abundance of development related genes, i.e. VEGF, BMP4, and CCNB1, showed significantly high (P < 0.05) expression, whereas the expression of CRABP1 was significantly low (P < 0.05) in GOEC co-culture than control. Oxidative stress related genes GPX-1 and SOD2 had comparable expression in both the culture systems, whereas a nonsignificant (P < 0.05) increase in expression of PRDX1 was observed in GOEC co-culture group. In conclusion, co-culture of embryos with GOEC in the simple culture media like mCR2aa helps in improving developmental competence and quality of parthenogenetic embryos. This work was supported by the NFBSFARA Project on Parthenogenetic Goat (CA-4002), New Delhi, India.

33 BUFFALO (BUBALUS BUBALIS) EMBRYOS PRODUCED BY HAND-MADE CLONING AND IN VITRO FERTILIZATION DIFFER IN THEIR GLOBAL TRANSCRIPTOME PROFILE

Although the blastocyst rate obtained with nuclear transferred (NT) embryos is higher than that obtained following in vitro fertilization (IVF) in buffalo, the live birth rate of NT embryos is <2% across different farm animal species compared with a birth rate >40% obtained with IVF embryos. This is believed to be due primarily to incomplete or incorrect nuclear reprogramming of the donor somatic cell by the oocyte, which results in aberrant embryonic gene expression. We compared the global transcriptome profile of buffalo blastocysts produced by hand-made cloning (HMC) and IVF using next-generation sequencing (NGS) for discovering transcripts that are differentially expressed between the 2 types of embryos. NT blastocysts were produced using fibroblast donor cells obtained from ear skin of a buffalo bull. The semen of the same bull was used for producing genetically half-identical IVF blastocysts. Total RNA was isolated from 3 pools of Day 8 NT and IVF blastocysts, with each pool containing 40 blastocysts. Complementary DNA library was prepared and subjected to NGS on Illumina HiSEqn 2000 (Illumina Inc., San Diego, CA, USA). The reads generated were aligned to Bos taurus reference genome, UMD 3.1. Differential expression analysis between the 2 blastocysts types at a minimum of 2-fold change revealed that 5557 transcripts were differentially expressed, of which 584 were unique to NT blastocysts, 709 were unique to IVF blastocysts, and 4264 were expressed in both types of blastocysts. Among these transcripts, at a significance level of P < 0.05, 331 transcripts were differentially expressed between the 2 blastocyst types, of which 19 were unique, 188 were down-regulated, and 143 were up-regulated in NT blastocysts. One-way ANOVA with Benjamini and Hochberg false discovery rate (FDR) correction was applied to determine the statistically significant differentially expressed transcripts. Nine of the differentially expressed transcripts (at minimal 2-fold change, P < 0.05), from different functional classes (RELN, NDRG1, SULT1A1, MAP1LC3A, MTHFD1L, PCBD1, PPA2, MGST1 and PRPH) were subjected to quantitative real-time PCR analysis for validation of NGS data. Gene expression level of RELN, NDRG1, SULT1A1, MAP1LC3A, PPA2, MGST1, and PRPH was found to be up-regulated while that of MTHFD1L and PCBD1 was down-regulated (P < 0.05) in NT embryos compared with IVF embryos. This pattern and the magnitude of relative gene expression level were found to be similar to that observed in NGS. These results indicate that the gene expression profile of NT embryos is very different from that of their IVF counterparts. Further analysis of these differentially expressed transcripts can help in identification of gene functional classes and pathways that are affected by the inefficient reprogramming of donor nuclei in NT embryos. Normalizing the expression of some of the differentially expressed genes may help in improving the cloning efficiency.

Association of Central Arterial Stiffness and Pressure Pulsatility with Mild Cognitive Impairment and Dementia: The Atherosclerosis Risk in Communities Study-Neurocognitive Study (ARIC-NCS)

BACKGROUND

The association of central arterial stiffness and pressure pulsatility with mild cognitive impairment (MCI) and dementia is not well characterized in the population-based setting.

OBJECTIVE

The aim of this study was to quantify the cross-sectional association of arterial stiffness and pressure pulsatility with MCI and dementia among 4,461 older white and black adults from the population-based Atherosclerosis Risk in Communities Study-Neurocognitive Study.

METHODS

We used race-stratified multinomial logistic regression to evaluate associations of percentile cut points of carotid-femoral pulse wave velocity, central systolic blood pressure, central pulse pressure, and pulse pressure amplification with MCI and dementia versus no cognitive impairment.

RESULTS

Among whites, those with carotid-femoral pulse wave velocity or central systolic blood pressure ≥75th percentile had a higher prevalence of MCI compared to participants <75th percentile (conditional odds ratio (OR); 95% confidence interval (CI): 1.27 (1.02, 1.56) and 1.28 (1.04, 1.57), respectively) and those with central pulse pressure ≥75th percentile had a higher prevalence of MCI (OR 1.27 (95% CI: 1.03, 1.58)) and dementia (OR 1.76 (95% CI: 1.06, 2.92) compared to participants <75th percentile. Also among whites, those with pulse pressure amplification ≤25th percentile had a higher prevalence of dementia compared to participants >25th percentile (OR 1.65; (95% CI: 1.01, 2.70). Weaker associations were seen among black participants.

CONCLUSION

Higher arterial stiffness and pulsatility were associated with MCI and dementia in white participants. Longitudinal characterization of the observed associations is warranted to assess whether arterial stiffness and pressure pulsatility predict MCI and dementia among older adults.

151 EFFECT OF ASCORBIC ACID ON OXIDATIVE STRESS AND ITS THERMOPROTECTANT ROLE ON IN VITRO EMBRYONIC DEVELOPMENT OF BUFFALO (BUBALUS BUBALIS) EMBRYOS

The most important factors that lead to stress in farm animals are oxidative and thermal stress, leading to reduced reproductive efficiency. Oxidative stress leads to an increase in proportion of reactive oxygen species, whereas heat stress affects the physiology of animals, which lowers the conception rates of dairy cattle. In vitro culture systems have been enhanced by manipulating media with various supplements such as vitamins, growth factors, and antioxidants that have overcome these problems. Ascorbic acid has been shown to play an antioxidant role in many species such as sheep, goat, and pigs. Keeping this in mind, this study was conducted to investigate the effect of supplementation of in vitro-matured (IVM) and/or in vitro-cultured (IVC) media with ascorbic acid and evaluate its antioxidant role in in vitro development of buffalo embryos. Immature oocytes were collected from visible surface follicles (2 to 8 mm in diameter) in slaughterhouse buffalo ovaries and subjected to IVM, IVF, and IVC in a humidified CO2 incubator at 38.5°C. Ascorbic acid was supplemented to IVM [TCM-199 + 10% featl bovine serum (FBS) + 1 µg mL−1 oestradiol-17β + 5 µg mL−1 pFSH + 0.81 mM sodium pyruvate + 0.68 mM l-glutamine + 50 µg mL−1 gentamicin sulfate] at 50 or 100 µM or IVC (mCR2aa + 0.6% BSA + 10% FBS+ 50 µg mL−1 gentamicin sulfate) at 50 µM or both IVM and IVC media at 50 µM. Oocytes without ascorbic acid were treated as the control group. Cleavage and blastocyst rate was improved when 50 µM (66.67 ± 2.27; 16.67 ± 1.26%) ascorbic acid was supplemented to IVM medium but no significant difference (P < 0.05) was observed at 100 µM (54.04 ± 2.20; 6.16 ± 0.37%) as compared with the control (62.77 ± 2.71; 10.67 ± 0.24%), respectively. When 50 µM ascorbic acid was supplemented in IVM, IVC, or both media, though cleavage rate (66.67 ± 2.27; 69.09 ± 3.22; 66.67 ± 2.23%) was similar in 3 groups, a significant increase was observed in blastocyst rate (16.67 ± 1.26; 20.18 ± 0.86; 28.57 ± 0.37%) when both media were supplemented, respectively. To evaluate the thermoprotectant effect, 4 groups were taken: group 1 without and group 2 with ascorbic acid supplementation, oocytes were given heat treatment at 39.5°C initially for 12 h during IVM; group 3 without and group 4 with ascorbic acid supplementation, oocytes were given heat treatment at 40.5°C initially for 12 h during IVM. No significant difference in developmental rate was observed at elevated temperature of 39.5°C or 40.5°C as compared with the control. Relative mRNA abundance of heat stress-related genes, HSP 70.1 and HSP 70.2, was nonsignificantly higher in oocytes matured at 39.5°C or 40.5°C after supplementation with ascorbic acid as compared to control. Relative mRNA abundance of BAX decreased at 50 µM and increased at 100 µM ascorbic acid compared with control, whereas BID showed similar results between control and treatment. Regarding anti-apoptotic gene expression, significantly higher expression was observed in MCL1 for 50 µM and lower for 100 µM ascorbic acid, and a similar nonsignificant trend was observed for BCL-XL. Developmental genes GDF9 and BMP15 showed a nonsignificant increase in 50 µM, and a nonsignificant decrease in the 100 µM supplemented group as compared with the control. Oxidative stress-related genes SOD and GPX showed a nonsignificant decrease in treated groups as compared to control. From above results, it was concluded that ascorbic acid had an anti-oxidant as well as thermoprotectant role in developmental competence that increased the potential for generation of large domestic animal in vitro embryos for research and applied technologies such as cloning and transgenesis.

32 NEXT-GENERATION SEQUENCING DISCLOSES DIFFERENCES IN microRNA EXPRESSION PROFILES OF BUFFALO (BUBALUS BUBALIS) EMBRYOS PRODUCED BY HAND-MADE CLONING AND IN VITRO FERTILIZATION

Mammalian embryo development is a complex process with a series of critical events taking place at every stage of development. It is an established fact that the birth rate of animals produced by nuclear transfer (NT) is far less (<2%) than that of IVF embryos (40%) after successful embryo transfers in different farm animal species. Micro(mi)RNAs are small non-coding RNAs of 17 to 25 nucleotides that alter the function of their target genes by either degrading them or inhibiting their expression. MiRNAs play a vital role during mammalian embryo development and may be adding to the extremely low birth rate and abnormalities in cloned animals. The present study was done with an objective of comparing the miRNA expression profiles of pre-implantation buffalo blastocysts produced by handmade cloning (HMC) and IVF. We hypothesised that there may be differences in the profiles of miRNAs expressed between the 2 groups that contribute to higher success rate in IVF group compared with HMC. Next-generation sequencing (NGS) was done to generate and compare the miRNA profiles and further discern the differentially expressed miRNAs between the 2 groups of blastocysts. For this study, NT blastocysts were produced using fibroblast donor cells isolated from ear skin of a buffalo bull. To produce genetically half-identical IVF blastocysts, the semen of the same bull was used. The oocytes used for generation of both HMC and IVF blastocysts were aspirated from buffalo ovaries obtained from abattoir. Total RNA was isolated from HMC and IVF blastocysts in 4 pools of each group. Each pool consisted of 40 blastocysts. A MiRNA cDNA library was prepared which was then subjected to NGS on Illumina HiSEqn 2000 (Illumina Inc., San Diego, CA, USA). Bos taurus genome was taken as reference to align the reads generated. The data from NGS was validated by RT-qPCR, taking 10 miRNAs (mir-15a, mir-23a, mir-128, mir-130a, mir-133a, mir-194, mir-196b, mir-200b, mir-431 and mir-451). The results positively validated the NGS data. Differential expression analysis of miRNAs between the 2 types of blastocysts revealed that the number of differentially expressed miRNAs with fold change of ≥ 2.0 were 74, with 52 miRNAs up-regulated in HMC and 22 miRNAs up-regulated in IVF. At significance level of P < 0.2, there were 2 miRNAs (mir-202 and mir-133a) that were uniquely expressed in IVF blastocysts and 8 miRNAs (mir-219, mir-451, mir-497, mir-33a, mir-2448, mir-592, mir-187, and mir-502a) that were uniquely expressed in HMC blastocysts. According to the gene ontology analysis, mir-202 is involved in negative regulation of apoptosis and positive regulator of cell growth, whereas mir-133a is involved in generating immunity. Absence of mir-202 and mir-133a expression from HMC blastocysts may be contributing to high apoptosis and other abnormalities in them compared with IVF counterparts. The NGS results indicate that the miRNA profiles of HMC and IVF blastocysts show huge differences. Further analysis of these differentially expressed miRNAs may open the door to miRNA therapies for treating the HMC blastocysts by regulating the expression of critical miRNAs in HMC blastocysts, thereby improving the success rate of cloning.

198 SUCCESSFUL TRANSPLANTATION OF BUFFALO (Bubalus bubalis) GERM CELLS TO HOMOLOGOUS RECIPIENTS

Transplantation of isolated germ cells from a fertile donor male into the seminiferous tubules of infertile recipients can result in donor germ cells-derived sperm production. This technique has the potential to be used as an alternative strategy for producing transgenic livestock with higher efficiency and less time and capital requirement than the current methods. The objective of the present study was to investigate whether the homologous transplantation of isolated buffalo germ cells could result in colonization of recipient testes. Germ cells were isolated from prepubertal buffalo testes (4–6 months of age) by using double enzymatic digestion method and filtration through 80- and 60-µm nylon mesh filters. Further enrichment was achieved by differential plating on Datura stramonium agglutinin lectin-coated dishes and after that Percoll density gradient centrifugation as descrived by van Pelt et al. (1996) with minor modifications. A discontinuous density gradient was prepared with 60, 50, 40, 36, 34, 32, 30, 28, and 20% Percoll in a 15-mL centrifuge tube. The enriched germ cells were then labelled with red fluorescent linker dye PKH26 (Sigma, St. Louis, MO, USA) as per the manufacturer’s instructions, and ~10 million cells/testis were transferred into the rete testis of 3 recipients (16–18 months of age) under ultrasonographic guidance. After 45 days, testes were surgically removed and samples were prepared for analysis of labelled cells via wet mount of seminiferous tubules and individual cells isolation. When wet mount specimen were observed under a fluorescence microscope, PKH26-positive cells were identified on the seminiferous tubule basement membrane in all 3 recipients, which indicated that these cells had successfully migrated from the tubule lumen and were likely to be donor germ cells. In freshly isolated cells, clumps of PKH26-positive cells were observed, which indicated either cell division or extensive local colonization of specific areas of the seminiferous tubules. In conclusion, we report successful homologous transplantation of germ cells in prepubertal buffalo testes. Further studies will investigate functionality of transferred testicular cells.

209 PRODUCTION OF BUFFALO (BUBALUS BUBALIS) EMBRYOS CONTAINING HUMAN LYSOZYME GENE

Lysozyme is a ubiquitous enzyme found in all major taxa of living organisms with a diverse role in human and animal health. It plays an important role as a nonspecific immune factor and anti-inflammatory factor and is a part of the innate immune system. Research on the expression of recombinant human lysozyme is, thus, potentially valuable to the dairy industry. Therefore, the present study was carried out to observe the developmental competence and quality of cloned embryos containing the human lysozyme gene. Primary fetal fibroblast cells were obtained from a slaughterhouse-derived fetus. The initial passage cells were transfected with pAchLYZ vector containing human lysozyme gene and green fluorescence protein (GFP) via nucleofection, lipofectamine, and FuGene (Roche Diagnostics, Indianapolis, IN, USA). Transfected cells were selected by adding G418 (400–800 µg µL−1), which selectively killed the nontransfected cells in culture. The presence of hLYZ gene in transfected cells was confirmed by PCR amplification of this gene. For cloned embryo production, reconstructs were formed with 2 enucleated demi oocyte fused with 1 donor cell of hLYZ transfected cells or nontransfected fibroblast cells. Gene expression in the resulting embryos was assessed for apoptosis (BID, BAX, and BCL-XL) and development- (G6PD, IGF1R, and FGF) and pluripotency-related (OCT4, SOX2, and NANOG) genes. The transfection efficiency of the cells by nucleofection methods was the highest and toxicity to the cells was minimum as compared with chemical methods. Transfected cells expressed GFP within 48 to 72 h of transfection. When these cells were passaged the intensity of GFP expression was reduced and the reduced level was maintained in subsequent passages. A total of 114 and 60 reconstructed embryos were produced using transfected and nontransfected cells, respectively. When transfected cells were used, the cleavage, 4 cell, 8 to 16 cell, morula, and blastocyst rate was 62.01 ± 4.78, 43.54 ± 3.93, 27.69 ± 4.44, 24.55 ± 5.12, and 22.87 ± 5.39%, respectively, whereas rates were 73.34 ± 2.36, 68.34 ± 4.82, 59.89 ± 2.39, 46.44 ± 2.64, and 36.36 ± 2.53% for nontransfected cells, respectively. The cleavage rate had no significant (P < 0.05, Student’s t-test) difference in both type of donor cells but all other stages [i.e. 4 cell, 8 to 16 cell, morula, and blastocyst rate was significantly (P < 0.05) lower with transfected cells]. Most of the transgenic cloned embryos expressed GFP and integrated with hLYZ gene. We found that proapoptotic gene (BID and BAX) expression did not differ, whereas BCL-XL expression was significantly low (P < 0.05) in transgenic embryos. The development- (G6PD, IGF1R, and FGF) and pluripotency-related (OCT4, SOX2, and NANOG) gene expression was significantly (P < 0.05) lower in transgenic embryos. In conclusion, transgenic cloned embryo successfully developed up to the blastocyst stage in the preliminary study for producing genetically modified animal with human milk components having antimicrobial activity, which would be potentially valuable for human as well as animal health.

208 PRODUCTION OF TRANSGENIC CLONED BUFFALO (BUBALUS BUBALIS) EMBRYOS CONTAINING HUMAN INSULIN GENE THROUGH HAND-GUIDED CLONING

Diabetes is a growing disease worldwide and has emerged as a major healthcare problem in India. Insulin is an essential medicine for the treatment of diabetes. Large dairy animals, such as buffaloes and cows, may be used as bioreactors for cost-effective production of human insulin. The present study was aimed to produce transgenic buffalo embryos containing the human insulin gene through hand-guided cloning for production of transgenic animals. Buffalo female fetal fibroblast cells at passage number 3 were transfected using mammary gland- specific expression vector containing the human insulin gene under buffalo β-lactoglobulin promoter by nucleofection method and cultured with G418 drug for 3 weeks to obtain positive transgenic cell clones. Transgene integration into buffalo female fetal fibroblast genome was confirmed by PCR and Southern blotting. Nontransfected and transgene integrated cells were used as nuclear donors to produce embryos by the hand-guided cloning technique. The developmental competence and quality of embryos as judged by total cell number and TUNEL assay were compared among transgenic and nontransgenic (control) embryos. The blastocyst rate was lower (P < 0.05) for transgenic embryos than that of nontransgenic cloned embryos (35.97 ± 2.16 v. 45.80 ± 4.11, respectively). The apoptotic index was found to be lower (P < 0.05) for control blastocysts than that for transgenic blastocysts. However, the total cell number was similar (P < 0.05) among transgenic and control cloned blastocysts. Thus, transgenic cells, and subsequently transgenic embryos containing the human insulin gene, were successfully produced and transferred in recipients. In the future, these may be used for production of transgenic buffalo expressing human insulin in its milk and thus can be further utilised in large-scale production of human insulin.

Smoking Behaviors and Arterial Stiffness Measured by Pulse Wave Velocity in Older Adults: The Atherosclerosis Risk in Communities (ARIC) Study

BACKGROUND

Though smoking is strongly associated with peripheral vascular disease and arteriosclerosis, smoking's association with arterial stiffness has been inconsistent and mostly limited to a single arterial segment. We examined the relationship between smoking behaviors with arterial stiffness in multiple arterial segments among community dwelling older adults.

METHODS

The cross-sectional relationship between smoking behavior with carotid-femoral (cfPWV) and femoral-ankle pulse wave velocity (faPWV) was examined in 5,002 men and women, separately, of the Atherosclerosis Risk in Communities (ARIC) cohort study. Brachial-ankle PWV was also assessed and presented in Supplementary Material. Heckman selection models were used to control for selective attrition and death in the ARIC cohort.

RESULTS

In women, faPWV was lower in current smokers compared to never smokers (-66.0cm/s; 95% confidence interval (95% CI): -94.6, -37.4), and was 1.0cm/s lower (95% CI: -1.8, -0.2) for every additional year a woman smoked, after adjustment for confounders. Among women, cfPWV was not associated with smoking status or cigarette pack-years. Additionally, no associations of smoking status and cigarette pack-years with PWV were observed among men. Years since smoking cessation was not associated with PWV in either gender.

CONCLUSION

Both smoking status and cumulative smoking exposure were associated with lower peripheral arterial stiffness among women, but not among men. We did not observe an association between central arterial stiffness and smoking status in either gender. The profound and well-documented adverse effects of cigarette smoking on the vasculature may not include a sustained stiffening of the arteries measured at older age.

Multiple imputation of cognitive performance as a repeatedly measured outcome

Longitudinal studies of cognitive performance are sensitive to dropout, as participants experiencing cognitive deficits are less likely to attend study visits, which may bias estimated associations between exposures of interest and cognitive decline. Multiple imputation is a powerful tool for handling missing data, however its use for missing cognitive outcome measures in longitudinal analyses remains limited. We use multiple imputation by chained equations (MICE) to impute cognitive performance scores of participants who did not attend the 2011-2013 exam of the Atherosclerosis Risk in Communities Study. We examined the validity of imputed scores using observed and simulated data under varying assumptions. We examined differences in the estimated association between diabetes at baseline and 20-year cognitive decline with and without imputed values. Lastly, we discuss how different analytic methods (mixed models and models fit using generalized estimate equations) and choice of for whom to impute result in different estimands. Validation using observed data showed MICE produced unbiased imputations. Simulations showed a substantial reduction in the bias of the 20-year association between diabetes and cognitive decline comparing MICE (3-4 % bias) to analyses of available data only (16-23 % bias) in a construct where missingness was strongly informative but realistic. Associations between diabetes and 20-year cognitive decline were substantially stronger with MICE than in available-case analyses. Our study suggests when informative data are available for non-examined participants, MICE can be an effective tool for imputing cognitive performance and improving assessment of cognitive decline, though careful thought should be given to target imputation population and analytic model chosen, as they may yield different estimands.

Prediabetes and Diabetes Are Associated With Arterial Stiffness in Older Adults: The ARIC Study

BACKGROUND

To determine whether prediabetes and diabetes in older adults are associated with arterial stiffness measured in central and peripheral arteries and to examine characteristics that modify these associations.

METHODS

Cohort members attending the 5th exam (2011-2013) of the Atherosclerosis Risk in Communities (ARIC) study had pulse wave velocity (PWV) measures performed at the carotid-femoral (cfPWV), brachial-ankle (baPWV), and femoral-ankle (faPWV) segments. Fasting glucose ≥126mg/dl, glycated hemoglobin (HbA1c) ≥6.5%, or currently taking diabetes medication defined diabetes. Fasting glucose 100-125mg/dl or HbA1c 5.7%-6.4% among those without diabetes defined prediabetes. Cross-sectional associations were modeled using multivariable linear regression.

RESULTS

Among 4,279 eligible participants with cfPWV measures (mean age 75 years), 22% were African-American, 25.5% had diabetes, and 54.7% had prediabetes. Compared to those with normal glucose, cfPWV was 95.8cm/s higher (stiffer) on average for those with diabetes (for reference: being 1 year older was associated with 14.4cm/s higher cfPWV). Similar findings were seen for diabetes and baPWV, although attenuated. Interestingly, faPWV was 17.6cm/s lower for those with diabetes compared to normal glucose. There was a significant positive association between baPWV and prediabetes. Among those with diabetes, cfPWV was higher for those with albuminuria, reduced kidney function, duration of diabetes ≥10 years, and elevated HbA1c (HbA1c ≥7).

CONCLUSION

Among older adults, diabetes is associated with higher central arterial stiffness and lower peripheral arterial stiffness, and prediabetes is associated with higher baPWV. Cross-sectionally, the magnitude of the effect of diabetes on central stiffness is equivalent to 6 years of arterial aging.

Social support and cognition in a community-based cohort: the Atherosclerosis Risk in Communities (ARIC) study

OBJECTIVE

social support has demonstrated cross-sectional associations with greater cognitive function and a protective effect against cognitive decline in older adults, but exploration of its temporal role in cognitive ageing from mid-life to older adulthood has been limited. We aimed to quantify the associations of social support, assessed at mid-life, with cognitive function in mid-life and with cognitive decline into late life among African Americans and Caucasians.

METHODS

data from the community-based, prospective Atherosclerosis Risk in Communities (ARIC) cohort of 15,792 biracial participants were examined for baseline and longitudinal associations of mid-life social support with global cognition at mid-life and with 20-year change in global cognition, respectively, stratified by race. Interactions with sociodemographic and cardiometabolic covariates were additionally explored within each race group. Social support was ascertained using two metrics: interpersonal support and social network.

RESULTS

interpersonal support was directly associated with greater global cognition at baseline in both race groups. Social network was directly associated with greater global cognition at baseline among Caucasians and African American females, but it was not significantly associated with global cognition in African American males. Neither mid-life social support measure was associated with 20-year change in global cognition.

CONCLUSIONS

higher levels of social support were moderately associated with greater multi-dimensional cognitive function at mid-life, but mid-life social support was not associated with temporal change in global cognitive function over 20 years into late life. Prospective studies with time-dependent measures of social support and cognition are needed to better understand the role of social engagement in ageing-related cognitive functioning.