cfcf patient education michael y. choi, md september 12, 2009 using gastrin producing g-cell and its...

CFCF Patient Education

Michael Y. Choi, MD

September 12, 2009

Using gastrin producing G-cell and its essential gene Nkx6.3 as a model

to study gastrinoma

Mucous Cell Parietal Cell

Gastroendocrine Cell Chief Cell

Gastric Lineages

Stomach Stem Cell

Nkx6.3 Expression

Decreased G-cell Number in the Nkx6.3-null Stomach

Abrogated Gastrin mRNA Expression in Nkx6.3 Stomach

Physiology Review of G- and D-cells

Co-localization of Nkx6.3 and Gastrin in the Stomach

  Serum Gastrin Gastric pH

Wild type(N = 7)

Knockout(N = 7)

Wild type(N = 16)

Knockout(N = 7)

Mean 87.1 ng/L 37.7 ng/L 3.9 5.5

SEM 11.0 ng.L 10.8 ng/L 0.3 0.3

P-value 0.0075 0.0032

Circulating gastrin levels and stomach luminal pH in Nkx6.3-/- and control animals

Mutant mice strains that have altered G-cell numbers

  Gastric Endocrine Cell Type Number in KO Mutant

KO Strain Ref. Gastrin Somatostatin Serotonin Ghrelin

Pdx1 -/- Larsson et al. Down Unchanged Up

Pax6 -/- Larsson et al. Down Down Unchanged

Ngn3 -/- Jenny et al. Down Down Unchanged Unchanged

Lee et al. Down Down Down

CCK-B/Gastrin Receptor -/-

Langhans et al. Up Down

Gastrin -/- Zavros et al. Down Unchanged

Nkx6.3 -/- Down Up Unchanged Unchanged

Relative expression levels of Pdx1, Pax6, and Ngn3 mRNA are unchanged in adult Nkx6.3-null stomach

Nkx6.3 mRNA levels are unchanged in neonatal Ngn3-null antrum

Modified from Hochedlinger, K. et al. Development 2009

The developmental potential and epigenetic states of cells at different stages of development

PancreasStomach

Generating induced pluripotent stem cells by direct reprogramming

• Showed that iPS cells can be generated from mouse fibroblasts by retrovirus-mediated introduction of four transcription factors:

- Sox2, Oct4, Klf4, and c-Myc

Yamanaka: Convert tail fibroblasts into pluripotent cells

resembling embryonic stem cells by expressing 4 genes:Oct4

Sox2Klf4cMyc

• “An Astonishing Experiment”

– Ian Wilmut,

Cloning and Stem Cells

Generating insulin secreting cells by direct reprogramming

• Expressed 3 genes Ngn3, Pdx1, Mafa to generate -cells from exocrine cells

Cell Reprogamming: what’s the limit?

-CellsExcocrine Cells Ngn3, Pdx1, Mafa

?Cancer Cells ?

Stem CellsFibroblastsSox2, Oct4, Klf4, Myc

G-Cells (or any cell type)Non G-Cells

Nkx6.3, Pdx1, Ngn3, Pax6, etc.?

Nkx6.3 upregulates Gastrin in 293 cells

Gastrinoma

Endoscopic view and a nest of tumor cells in lamina propria mucosae

Acknowledgement

• Ramesh Shivdasani• Maina Lepourcelet• Anthony Romer• Qiufu Ma• Paul Grey

• Melissa Wu• Andrew Leiter• Yang Wang• Susumu Ito• Byeong-Moo Kim• Daniel Podolsky