Programmed cell death From worm to cancer by vwt15444

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									Programmed cell death:
 From worm to cancer
  www.ikp.unibe.ch/lab2
  reichen@ikp.unibe.ch
      Apoptosis


Mitosis
Blebbing in apoptosis
Chromatin fragmentation and DNA laddering
    The role of apoptosis and
consequences of ist dysregulation
• Development
• Elimination of damaged cells:
   – Viral infection
   – DNA damage
• Inhibition:
   – malignancies
   – autoimmune disease
• Excess:
   – Neurodegenerative disease
   – Ischemia/reperfusion injury
   – Fulminant liver failure
Caenorhabditis elegans
    Caenorhabditis elegans. Development
    http://nema.cap.ed.ac.uk/teaching/devbio4/nuclearcount.html


• During embryogenesis the         1200
  worm loses ~ 15 % if its cells
  by apoptosis.                    1000                    Total
• Time and location are exactly     800
  determined.
• The signals for apoptosis,        600                    Apoptosis
  CED (cell death abnormal)
                                    400
  are highly conserved:
   – CED3  ICE / caspase 8                                Final
                                    200
   – CED4  APAF1
   – CED9  Bcl2                      0
                                          Hatchling
                ICE
              Robert Frost

Some say the world will end in fire,
Some say in ice.
From what I've tasted of desire
I hold with those who favor fire.
But if it had to perish twice,
I think I know enough of hate
To say that for destruction ice
Is also great
And would suffice
       Apoptosis versus necrosis
• Internal / external signals   • Ischemia/toxins/radiation
• Energy dependent              • Not dependent on energy
• Single cells                  • Groups of cells
• The cell shrinks and is       • The cells swell and release
  engulfed by                     their content into the
  macrophages or                  surroundings and the
  neighbouring cells              circulation
• Normally, no                  • Marked inflammatory
  inflammatory reaction           reaction
        Apoptosis versus necrosis:
A race between caspases and ATP depletion




                                    H+

    Caspases   cyt c     ATP depletion
               AIF

       Apoptosis        Necrosis
External and internal signals for apoptosis
         HGF       TNFa   TNFa      FasL    Perforin/granzyme B




                                 Caspases
                                                       TGFb
Bcl-XL
                                              Bax
Bcl2
                                              p53

               NF-kB
                                    ROS
 FasL induced cell death

    FAS            FAS

    FADD           FADD
Procaspase 8   Procaspase 8
 FasL induced cell death

    FAS             FAS

    FADD            FADD
Procaspase 8
                  Caspase 8

               Caspase cascade


                 Proteolysis
 FasL induced cell death

    FAS             FAS          FLIP
    FADD            FADD         FAP1
Procaspase 8
                  Caspase 8

               Caspase cascade

                                 IAP
                 Proteolysis
FasL induced cell death and mitochondria

                 FAS        FAS

                            FADD
    Cytochr. c
                          Caspase 8
     APAF1
                       Caspase cascade
    Caspase 9
                         Proteolysis
    Caspase 3
        Role of FAS in hepatitis in mice
          J Ogasawara et al. (1993) Nature 364: 806-809
           T Kondo et al. (1997). Nature Med 3: 409-413

• Intraperitoneal njection of     100
  agonistic FAS antibodies
  induces fulminant hepatic        80
  failure in mice.
                                   60
• CTL specific for HBsAG                                        HBs
  induces hepatitis in mice                                     WT
                                   40
  transgenic for HBs
                                   20
• This is abolished by
  soluble FAS                       0
                                         2.5      5        10
                                               E/T ratio
  Cytotoxic lymphocyte (CTL) mediated
            hepatocyte death

                        FasL    TNFa Perforin
TCR                                                           TCR
MHC I                                                         MHC I

                        Fas    TNFaR granzyme B
        Viral peptide                             Alkylated
                                                  peptide
                               caspases

                               apoptosis
Mitochondrial phase transition and apoptosis
           HGF       TNFa   TNFa      FasL




                                   Caspases
  Bcl-XL
                                              Bax
                                              Bad
  Bcl2
                                              p53

                 NF-kB
                                      ROS
Central role of mitochondria in apoptosis
            C Brenner & G Kroemer (2000) Science 289: 1150-1151

       Calcineurin   Irradiation   Ceramide    Caspase 8           Activation


                        JNK            bax           bid


             bad                              bax                casp7
                            bclx                                          Phorbol
                                                       ?                  ester
DNA damage

                         hsp70                        ?      PKCd
               p53
                                                                          micro-
                                   ?          bcl2                        tubule
Ca2+
                                                                          damage
                     TR3                                   Bim
EXPRESSION OF MODULATORS OF APOPTOSIS IN
 BEC AFTER ROUX-EN-Y ANASTOMOSIS IN RATS
         Stähelin BJ (1999). Virchow‘s Arch 434: 333-339
                                                           bcl-2
   100              *                   *
                           *
                               *
    75



  % 50                                                     Bax



    25



     0
         BDL    R-Y 1 d   R-Y 2 d   R-Y 3 d   R-Y 7 d
EXPRESSION OF MODULATORS OF APOPTOSIS IN
BDEC AFTER ROUX-EN-Y ANASTOMOSIS IN RATS
         Stähelin BJ (1999). Virchow‘s Arch 434: 333-339

30

25

20
                                                           Apoptosis
15                                                         Bcl2/Bax
                                                           BDEC
10

 5

 0
     0           1         2          3         7
Reactive metabolite induced apoptosis
  Drug

  Reactive metabolite                 DNA damage

   GSH Covalent binding              p53
                                      bax
   protein thiols
                                      Ca2+
                                      Ca2+
  Inactivation of
  Ca2+ translocase

                     Transglutaminase Endonuclease AIF cytochrome c


                     Crosslinked proteins     DNA fragmentation
Feathery degeneration in cholestasis
Bile salts and apoptosis in cholestasis
      Jones & Gores (1997). Am. J. Physiol. 273: G1174-11188
       Bile salt                 TNFa      FasL

         ntcp



PKC                                     Caspases

         Endo-
       nucleases       bsep                            Bax

                                                       p53
Cathepsin B
                                           ROS
Integration of life and death by mitochondria
            Pessayre D et al. (1999) J. Hepatol. 31: 760-770
             HGF          TNFa      TNFa      FasL       Perforin/granzyme B




                                           Caspases
                                                                    TGFb
 Bcl-XL
                                                           Bax
 Bcl2
              Mg2+                            Ca2+, Pi     p53

            High DYm                        Low DYm
          Mn-SOD/NF-kB                ROS, drugs, bile salts
    MTTP closed : life               MTTP open: death
HCC in chronic hepatitis C (stage 1)
    Molecular pathogenesis of human HCC
                                   p53 mutation
                                      P21waf1                            Metastatic HCC


           Aberrant DNA methylation
                                                  Hepatocellular Ca.


  HBV
                               Dysplatic nodules
  HCV
  EtOH
               Chronic hepatitis                                       Rb dysfunction
                  cirrhosis

                                             p16 inactivation
Normal liver
    Apoptosis and proliferation in HCC
       B Grasl-Kraupp et al. (1997). Hepatology 25: 906-912


6

5

4
                                                        Proliferation
3
                                                        Apoptosis
2

1

0
    Normal    HCC      Normal    Adenoma      HCC

         Human                    Rat
Inhibition of apoptosis by HCV core protein
           DI Tai et al. (2000). Hepatology 31:656-664


• NF-kB activated in HCV          25000
  infected liver and HCV
                                  20000
  core transfected cells.
                                  15000                            CTR
• EMSA correlated with
                                  10000                            core
  immunohistochemical
  expression of NF-kB.             5000

• Caspase 3 assay in                  0
  transfected HepG2 cells;




                                                    N


                                                              TC
                                            F
                                          TN



                                                    IF


                                                             D
                                                  F+


                                                          +P
  NF-kB inhibition by



                                                TN


                                                         N
                                                       IF
                                                     F+
  pyrrolidine thiocarbamate



                                                   TN
Apoptosis – from worm to cancer
Apoptosis – not yet i hope...

								
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