Animal Models for Human Diseases

Y. Henry Sun 孫以瀚Institute of Molecular Biology

Academia Sinica中研院分生所

Animal models of human diseases

•Closely mimic the human disease

•Study pathogenic mechanisms

•Identify disease markers and drug targets

•Screen for drugs for prevention and therapy

常用模式生物

線蟲 (nematode Caenorhabditis elegans) http://elegans.swmed.edu/

果蠅 (fruit fly Drosophila melanogaster) http://flybase.org/

斑馬魚 (zebrafish Danio rerio) http://zfin.org

小鼠 (mouse Mus musculus)

（狗） (Canis lupus familiaris)

•Experimental advantages

•Genetically homogeneous

Mutation

Transgenic

Disease model

Animal model of diseases have defined cause(s)

簡化、模擬、參考

衛生署公佈 98 年十大主要死因（占總死亡人數的 75.4% ）

惡性腫瘤 28.1%心臟疾病 10.6%腦血管疾病 7.3% 肺炎 5.9%糖尿病 5.8%事故傷害 5.2%慢性下呼吸道疾病 3.5%慢性肝病及肝硬化 3.5%自殺 2.9%腎炎、腎徵候群及腎性病變 2.8%

Cancer, Obesity, Neurodegeneration

Cardiovascular diseases, Hair

shar-pei = salvador (sav)沙皮

癌症 : 細胞分裂失控

沙皮

Identifying tumor suppressors in genetic mosaics: the Drosophila lats gene encodes a putative protein kinase

Development 121, 1053-1063 (1995)許田

The Hippo pathway

Pan (2010) Dev Cell 19:491-505

Science 302:1227- 1231 (2003)

細胞遷移 (migration)

Montell (2003) Nature Revi Mol Cell Biol 4, 13-24

•離鄉背井•殺出血路•定居

Drosophila border cell migration

•食慾的控制 ( 瘦體素 leptin ）•熱量的吸收、運用、儲存•脂肪細胞的發育、數目

obWT

Obesity

2010 Albert Lasker award

Douglas Coleman Jeffrey M. Friedman

For the discovery of leptin, a hormone that regulates appetite and body weight—a breakthrough that opened obesity research to molecular exploration.

Coleman (2010) Nature Med. 16:1097-1099

ob lacks a blood-borne satiety factor (leptin)

db overproduce a blood-borne satiety factor, but un-responsive(defect in leptin receptor)(feedback regulation)

Effects of parabiosis of obese with diabetes and normal miceColeman (1973) Diabetologia 9:294-8

Farooqi and O’Rahilly (2006) Endocr. Rev. 27:710-718

Therapy by leptin

Body fat distribution

不患「多」而患不均

Masuzaki et al. (2001) Science 294:2166 -2170

Nature Genetics 24:66-70 (2000)

Spinal muscular atrophy (SMA) is an autosomal recessive diseasecharacterized by degeneration of the anterior horn cells of the spinal cord, leading to muscular paralysis with muscular atrophy. No effective treatment of this disorder is presently available.

Histological analysis of SMA-like mice

PNAS 98: 9808-9813 (2001)

Assay based on ratio of Exon 7 splice isoforms

=> Screen/test of drugs in in vitro system: more efficient

=> Test on animal model (in vivo)

HDAC inhibitor

Neurobiology of Disease (2006) 24:286–295

Human Molecular Genetics (2007)16: 499–514

Molecular mechanism

=> Rational search for drug target

Therapeutic approaches in SMA

Completed or ongoing clinical trials in SMA

Summer (2006) NeuroRx 3:235-245

Neurodegeneration due to loss-of-function mutations in fly

Lessing & Bonini (2009) Nature Rev Gent 10:359-370

WT

mutant

WT mutant

Observing neurodegeneration in Drosophila

Transgenic models of neurodegeneration

Studying genetic interactions

Screen for modifier mutations (additional genes with functional interaction)

Sang & Jackson (2005) NeuroRx 2:438-446

果蠅的酒測

Wolf & Heberlein (03) J Neurobiol. 54:161-78

對酒精的耐受性成癮（酒精、藥物）

心臟血管的發育、疾病 （斑馬魚）

心臟血管發育

血液流動心臟跳動

透明，可看活體

A novel mouse model of cerebral cavernous malformations based on the twohit mutation hypothesis recapitulates the human disease

McDonald et al, HMG Advance Access published October 11, 2010

Cerebral cavernous malformations (CCMs) are vascular lesions of the central nervous system appearing as multicavernous, blood-filled capillaries, leading to headache, seizure and hemorrhagic stroke. CCM occurs either sporadically or as an autosomal dominant disorder caused by germline mutation of one of three genes: CCM1/KRIT1, CCM2/MGC4607, and CCM3/PDCD10. Surgically-resected human CCM lesions have provided molecular and immunohistochemical evidence for a two-hit (germline plus somatic) mutation mechanism. In contrast to the equivalent human genotype, mice heterozygous for a Ccm1- or Ccm2-null allele do not develop CCM lesions. Based on the two-hit hypothesis, we attempted to improve the penetrance of the model by crossing Ccm1 and Ccm2 heterozygotes into a mismatch repairdeficient Msh2-/- background. Ccm1+/-Msh2-/- mice exhibit CCM lesions with high penetrance as shown by MRI and histology. … The late-stage CCM lesions displayed many of the characteristics of human CCM lesions, including hemosiderin deposits, immune cell infiltration, increased endothelial cell proliferation, and increased Rho kinase activity. … The CCM1 mouse model provides an in vivo tool to investigate CCM pathogenesis and new therapies.

腦海綿狀血管瘤

狗與人類疾病

•A single species

•Many highly inbred breeds (>1000)

•Selected for certain traits

•Other traits also fixed (~ 350 human disease)

致心律失常性右心室心肌病

Coat Variation in the Domestic Dog Is Governed by Variants in Three Genes

Cadieu et al. (2009) Science 326, 150-153

Combinations of alleles at three genes create seven different coat phenotypes

Cadieu et al. (2009) Science 326, 150-153

人類毛髮的生長

• Life quality

•無窮商機

A model is for reference!

Needs to be validated in human.

不得已也 !

Waardenburg syndrome

•hearing loss•white forelock

Defect in migration of neural crest cells

黑色素原細胞 (melanoblasts) 的遷移

belted KitWLacZ/+

piebald Pax3Spl/+

Baxter et al (04) Pigment Cell Res. 17:215-224

Mouse mutantsSteel (Sl)Dominant White Spotting (W)

Defects in migration and proliferation White spotting (Melanocyte)Sterile (Germ cells)Anemia (hematopoietic stem cells)

Transplantation experimentsSl affected the environment (non-autonomous)W affected these cells (cell-autonomous)

W = Kit (receptor tyrosine kinase) (Kit)Sl (Steel) = Kit ligand (Kitl): survival factor

絲羽烏骨雞 Silkie bantam

台灣畜產種原知識庫

黑色素原細胞的遷移： 失去路障

中興鄭旭辰老師