Gene related to Aging, Obesity, and Myocardial InfarctionFragile X Syndrome, Hirschsprung Disease, Hearing Impairment

MAY SOE THU

5836362 MTMT/M

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Outline

Aging and related genes

Obesity and related genes

Myocardial Infarction and related genes

Fragile X syndrome

Hirschsprung disease

Hearing Impairment

Update Article

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AgingThe process during which structural and functional changes accumulate in an organism as a result of the passage of time

Deterioration results in a high susceptibility to environmental challenges, leading to age-associated pathologies that ultimately cause death

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GenAge Model Organisms of Aging-Related Genes

mouse (Mus musculus)

fruit fly (Drosophila melanogaster)

roundworm (Caenorhabditis elegans)

baker's yeast (Saccharomyces cerevisiae)

http://genomics.senescence.info/genes/ 4

http://www.nature.com/nrg/journal/v6/n11/box/nrg1706_BX1.html

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Gene related with Human Aging

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3295054/pdf/ad-2-3-186.pdf 6

LMNAA protein encoded by LMNA gene

Encodes both lamin A and C, two components of the lamina, a layer of the inner nuclear membrane that may interact with chromatin

Involved in nuclear stability, chromatin structure and gene expression

http://www.premierexhibitions.com/exhibitions

Progeria

Mutation Hutchinson-Gilford progeria syndrome, Emery-Dreifuss muscular dystrophy, familial partial lipodystrophy, limb girdle muscular dystrophy, dilated cardiomyopathy, etc.

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WRNAn enzyme encoded by WRN gene

A member of the RecQ Helicase family

Also known as Werner syndrome ATP-dependent helicase or DNA helicase or RecQ-like type 3

An only RecQ Helicase that contains 3' to 5' exonuclease activity

Important in repairing of double stranded breaks, non-homologous end joining, and base excision repair

Essential in telomere maintenance and replication, especially the replication of the G-rich sequences

Werner Syndrome

http://depts.washington.edu/monnatws/projects.php 8

ERCC8A protein encoded by ERCC gene

Involved in transcription and maybe in DNA repair

Mutation Hereditary Cockayne syndrome

CS cell : abnormally sensitive to ultraviolet radiation

defective in the repair of transcriptionally active genes

https://www.emaze.com 9https://ghr.nlm.nih.gov/gene/ERCC8

ObesityA condition in which excess fat accumulates in the body

It can have an adverse effect on health

Obesity : BMI > 30 kg/m2

10http://drpaulwizman.com/about-obesity/obesity

Obesity Trends Among U.S. Adults, 2014

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http://www.ijem.in/text.asp?2014/18/7/17/145049 12

Obesity related Genes

Odd Ratio

http://www.nature.com/nrg/journal/v10/n7/fig_tab/nrg2594_F2.html 13

FTO geneFat mass and obesity associated protein (alpha-ketoglutarate-dependent dioxygenase)

Chromosome 16

http://www.cnschronicle.com/2013/12/ 14

CTNNBL1 geneBeta-catenin-like protein 1

On chromosome 20q11.2

A protein involved in Wnt/β-catenin signaling pathway which is a central pathway in adipogenesis

Biological process – Apoptosis, Gene expression, mRNA splicing, somatic diversification of immunoglobulins

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Myocardial InfarctionAlso called ‘Heart Attack’

Irreversible necrosis of heart muscle secondary to prolonged ischaemia.

Due to an imbalance in oxygen supply and demand, which is most often caused by plaque rupture with thrombus formation in a coronary vessel, resulting in an acute reduction of blood supply to a portion of the myocardium

16http://ereidmiller.com/myocardial-infarction-symptoms

Differentiation between MI types 1 and 2 according to the condition of the coronary arteries

17http://www.nature.com/nrcardio/journal

MI related Genes

Fig: Common genetic variations in genes involved in LDL-cholesterol metabolism that have an effect on the risk of myocardial infarction

Jeanette Erdmann, et al. Genetic cause of Myocardial Infarction, Dtsch Arztebl Int 2010; 107(40): 694–9 18

MI related Genes

Jeanette Erdmann, et al. Genetic cause of Myocardial Infarction, Dtsch Arztebl Int 2010; 107(40): 694–9 19

PCSK9 & LDLR

http://eurheartj.oxfordjournals.org/content/early/2013/08/15/eurheartj.eht273 20

ApoB & ApoEApoB - on chromosome 2

- primary apolipoprotein of chylomicrons, VLDL, IDL, and LDL particles

ApoE - on chromosome 19 with apolipoprotein C1 & C2

- an important regulator of cholesterol, fatty acid, and glucose homeostasis

Higher ApoB Higher LDL Plagues

Defects in ApoE Impaired transport HLP

HLP : Hyperlipoproteinaemia

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Fragile X SyndromeA genetic condition that causes a range of developmental problems including intellectual disabilities and cognitive impairment

Caused by mutations in the FMR1 gene, which is located on the X chromosome and whose locus at Xq27.3

Males > Females

Occurrence : approximately 1 in 4000 (M), 1 in 8000 (F)

Physical Characteristics : Protruding ears, Long face, Flat feet,

Soft skin, High-arched palate, etc.

Behavioral Characteristics : Stereotypic movements, Social anxiety.

http://amessageofmeanfrommeghan.com/ 22

FMR1 Gene

Bagni C, Tassone F, Neri G, Hagerman R. Fragile X syndrome: causes, diagnosis, mechanisms, and therapeutics. The Journal of clinical investigation. 2012;122(12):4314-22.23

Hirschsprung DiseaseDisorder that arise as a consequence of defective neural crest cell development (Neurocristopathies)

Characterized by a congenital absence of neurons in a portion of intestinal tract usually distal colon

Occurrence: 1 in 5000 births

http://flipper.diff.org/apprulesitems/items/6712 24

Genes related to Hirschsprung Disease

Butler Tjaden NE, Trainor PA. The developmental etiology and pathogenesis of Hirschsprung disease. 2013;162(1):1-15. 25

RET and GDNF gene

http://www.nature.com/nrn/journal/v3/n5/fig_tab/nrn812_F1.html

ENCC proliferation & survival, apoptosis, migration and differentiation

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Hearing ImpairmentA partial or total inability to hear

Not the same with deafness; no hearing

May occur in one or both ears

In children, it can affect the ability to learn language

In adults, it can cause work-related difficulties

http://www.ncbi.nlm.nih.gov/books/NBK1434/ 27

Genetic Association of Hearing Impairment

DFNA: Non-syndromic deafness, autosomal dominant

DFNB: Non-syndromic deafness, autosomal recessive

DFNX: Non-syndromic deafness, X-linked

http://www.cmsact.org/uploads/4/6/7/5/4675465 28

http://www.ncbi.nlm.nih.gov/books/NBK1434/ 29

GJB2 Gap Junction Beta-2 protein which is encoded by GJB2 gene

Also known as connexin26 (Cx26)

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GJB2Non-syndromic

DeafnessMutationHinders gap junction

construction

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Obesity

It is characterized by an increase in adipose tissue mass and excess lipid

deposition, and is associated with enlarged adipocytes

Endogenous and exogenous factors such as various stressors, aging, and low

physical activity lead to obesity and may change patterns of gene expression

However the factors responsible for these differences in obesity pathogenesis

between males and females are largely unknown

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Hypothesis

1) To study the expression of the obesity-related genes in young male and

female mice

2) To compare the expression in older males and females fed either a STD of a

high fat diet (HFD) for 35 weeks

3) To compare the expression of these genes and glucose metabolic activity

between males and females

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Gene Selection

At least 400 genes associated with obesity

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35 genesLipid & Glucose

Metabolism

Receptors for insulin signaling

in WAT

Materials and Methods

Statistical Analysis

RNA isolation and RT-PCR

Intraperitoneal glucose tolerance test

Animal Treatment

Animals

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Animal Group

8-week-old MiceMice

129/SvCPJ mice

STD 35 wks(343kcal/100g, crude fat 3.8%)

HFD 35 wks(508kcal/100g, crude fat 32%)

N = 7 Males + 9 Females

N = 7 Males + 9 Females

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Animal Treatment

8-wk-old Mice 43-wk-old Mice

Fasting 6 hr

Organs and Blood

White Adipose Tissue (WAT) Ovaries Testes Kidney Post. Belly Lining

Plasma level Glucose Insulin Leptin Adiponectin

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Intraperitoneal glucose tolerance test (IPGTT)8-wk-old Mice

(N = 4 Each sex)21-24-wk-old Mice

(N = 4 Each sex & diet)

Intraperitoneal inoculation of Glucose (2g/10ml/kg)

Collecting Blood samples at 0, 15, 30, 60, 120, 180 min

Area Under Curve (AUC) & Half-life (t1/2)

Fasting 12 hr

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Reverse Transcription-Polymerase Chain Reaction

RNA Extraction

RT reaction

Primer sets and PCR conditions

Electrophoresis

Densitometry

Normalized with internal control

genes, 36b4

Density ratios of the products For comparison

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Fundamental parameters of 8-wk-old mice

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Comparison of parameters of 43-week-old male & female mice

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Comparison of parameters of 43-week-old male & female mice

STD for 35 weeks did not induce obesity in both mice

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HFD Markedly increase in body weight, weight gain, perigonadal, perirenal, subcutaneous WAT

mRNA Expression in Perigonadal WAT

8 week-old mice 43 week-old mice

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8 week-old mice 43 week-old mice

mRNA Expression in Perigonadal WAT

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8 week-old mice 43 week-old mice

mRNA Expression in Perigonadal WAT

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8 week-old mice 43 week-old mice

mRNA Expression in Perigonadal WAT

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The expression level of 6 genes (Acaca, Fasn, Slc2a1, Slc2a4, Adipoq, Nampt) were higher in WAT of 43-week-old female mice than in male mice

Females have a greater ability to metabolize glucose in WAT regardless of diet

The expression level of 2 genes (Acaca, & Fasn) were higher in WAT of 8-week-old female mice than in male mice but the other gene expressions are similar.

Glucose Metabolism Capacity

Glucose metabolism capacity is marginally greater in females than in males

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IPTGG for 21-24 week-old 129/Sv mice after 12 h fasting

oSTD-fed female mice

●STD-fed male mice

□HFD-fed female mice

∎HFD-fed male mice

Half-life Longer in males

Glucose absorption and metabolism were faster in female mice fed a STD

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Plasma Adiponectin

Plasma adiponectin – Higher in female than males at 8-week old & after 35 weeks

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Lep mRNA and plasma leptin levels

Expression levels of Lep mRNA and plasma leptin levels were upregulated in HFD-fed mice

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Lep mRNA and plasma leptin levels

Expression levels of Lep mRNA and plasma leptin levels were upregulated in HFD-fed mice

Lipid accumulation might mediate this up-regulation in HFD

Levels of plasma glucose, insulin, & adiponectin remain unchanged despite the consumption of a HFD for 35 weeks

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Discussion (1)Expression levels of four genes (Slc2a1, Slc2a4, Adipoq, Nampt) were greater in the WAT of 43-week-old female mice

So females might have a greater ability to metabolize glucose in WAT regardless of diet fat content

Expression levels of two genes (Acaca & Fasn) were higher in females than males at both 8 weeks and 43 weeks

So it may be associated with sex, but not aging

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In IPGTTs, the value of half-life was not significantly different between males and females at 8 weeks but it was lower in females than males fed a STD

It suggests that the capacity to metabolize glucose may change with age in a sex-dependent manner

Consuming a HFD for 35 weeks significantly increased AUC in male and female mice compared with mice fed with STD, and AUC & t1/2 was greater in males

It demonstrate that a HFD may decrease the ability of glucose metabolism

Discussion (2)

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Conclusion

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Sex and aging may cause diet-independent differences in gene expression levels in female and male mice

Higher expression of these genes in females could contribute to higher metabolic activity and resistance to obesity

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References1. S. Rodríguez-Rodero et al. Aging Genetics and Aging. Gene and Aging. June 2011; Vol.2, Number 3; 186-195.

2. Andrew J. Walley et al. The genetic contribution to non-syndromic human obesity. Nature Reviews Genetics. July 2009; Vol.10, 431-442.

3. Jeanette Erdmann, et al. Genetic cause of Myocardial Infarction, Dtsch Arztebl Int. 2010;107(40): 694–9.

4. Bagni C, Tassone F, Neri G, Hagerman R. Fragile X syndrome: causes, diagnosis, mechanisms, and therapeutics. The Journal of clinical investigation. 2012;122(12):4314-22.

5. Butler Tjaden NE, Trainor PA. The developmental etiology and pathogenesis of Hirschsprung disease. Translational research : the journal of laboratory and clinical medicine. 2013;162(1):1-15.

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