6 - Cell Therapy to Treat Liver Disease

Question 1

How much has liver disease increased by since 1970

Answer 1

400%

Question 2

LIver functions

Answer 2

• Prevents shortages of nutrients by storing vitamins minerals and sugar
• Produces most proteins needed by the body
• Produces bile, a compound needed to digest fat and absorb vitamins
• Produces substances that regulate blood clotting
• Helps the body fight infection by removing bacteria
• Removes toxins
• Breaks Down nutrients from food to produce energy

Question 3

LIver lobule

Answer 3

• Blood from portal vein and the hepatic artery flows towards central vein between hepatocytes through the sinusoids
• Bile produced by hepatocytes is collected into bile ducts bia the bile canaliculi
• Sinusoids are lined with endothelial cells

Question 4

Kupffer cells

Answer 4

• Resident macrophages of the liver
• Located at the luminal side of sinusoids

Question 5

Canal of hering

Answer 5

The junctional region between hepatocytes and bile ducts

Question 6

Regeneration of liver cells

Answer 6

• Gut derived factors (e.g. LPS) are upregulated, activating hepatic non parenchymal cells increasing the production of TNF and IL-6
• Other factors are released that allow the hepatocytes to overcome cell cycle checkpoint controls and move through cell cycle
• TGF is blocked

Question 7

Transforming growth factor (TGF)

Answer 7

Inhibits hepatocyte DNA synthesis

Question 8

Other factors released that allow hepatocytes to overcome cell cycle checkpoint controls

Answer 8

• Pancreas (insulin)
• Duodenum
• Salivary gland (EGF)
• Adrenal gland (norepinephrine)
• Thyroid gland (T4)

Question 9

Cholangiocytes

Answer 9

• Epithelial cells of the bile duct.
• Derived from hepatoblasts /oval cells
• Peak of proliferation occurring a few hours after hepatocytes

Question 10

Liver sinusoidal endothelial cells (LESCs)

Answer 10

• Lasts several days - weeks
• Includes precursors that migrate from the bone marrow

Question 11

Kupffer cells and immune cells

Answer 11

Local proliferation of Kupffer cells plus migration of
mononuclear cells from the blood

Question 12

Hepatic stellate cells

Answer 12

• Not well understood
• Synthesise components of the extracellular matrix
• Produce signalling molecules essential for liver regeneration

Question 13

Hepatic stem/progenitor cell (oval cells)

Answer 13

• Bipotential stem cells residing in human and animal livers that are able to differentiate towards the hepatocytic and the cholangiocytic lineages.
• Resides in canal of Hering

Question 14

Canals of Hering

Answer 14

Represent the smallest and most peripheral branches of the biliary tree connecting the bile canalicular system
with interlobular bile ducts

Question 15

Stem/progenitor cells under normal physiological conditions

Answer 15

Homeostasis is achieved predominantly by
proliferation of mature hepatocytes.

Question 16

Stem/progenitor cells under injury conditions

Answer 16

Results in extensive reprogramming of hepatocytes and cholangiocytes, activation and differentiation of LPCs, immune infiltration, and formation of several
intermediate cell types expressing markers of hepatocytes, cholangiocytes,

Question 17

Regenerative medicine

Answer 17

Process of replacing, engineering or regenerating human cells, tissues or organs to restore or establish normal function

Question 18

Cell therapy

Answer 18

The introduction of cells into the tissues of an organism (humans) to treat a disease

Question 19

Liver disease

Answer 19

• Genetic liver disease (blood proteins or inborn errors of metabolism)
• Lifestyle causes (alcohol, obesity, viral)

Question 20

Induced pluripotent stem cells to treat genetic liver disease (iPSCs)

Answer 20

• Derived from adult cells and reprogrammed using defined factors (e.g. Oct4), back into an embryonic-like pluripotent state.
• Promising alternative for an ex vivo gene therapy approach that could be used for cell therapy applications and curing diseases.

Question 21

Gene correction to treat genetic liver disease

Answer 21

• Viral vectors (adeno associated virus)
• CRISPR/CAS9

Question 22

Gene correction in hemophilia B

Answer 22

• Bleeding disorder caused by a deficiency of clotting factor IX
• Gene therapy using viral vectors, such as adeno-associated virus (AAV), has shown success in increasing factor IX levels and reducing bleeding episodes in patients.

Question 23

Gene correction in alpha 1 antitrypsin deficiency

Answer 23

• Genetic disorder that leads to liver and lung diseases
• Researchers have been exploring CRISPR-based approaches to correct the genetic mutation responsible

Question 24

Wilson disease

Answer 24

• Genetic disorder that causes copper to accumulate in the liver, leading to liver damage
• AAV mediated gene therapy and CRISPR treatment

Question 25

Metabolic liver disease progression

Answer 25

Healthy --> NAFLD --> NASH --> Cirrhosis --> Hepato-cellular Carcinoma

Question 26

Non-Alcoholic Fatty Liver Disease (NAFLD)

Answer 26

- Affects 30% of population - Condition in which fat builds up in liver

Question 27

Nonalcoholic steatohepatitis (NASH)

Answer 27

- Is a type of NAFLD - If you have NASH, you have inflammation and liver cell damage, along with fat in your liver.

Question 28

Early stage liver disease treatment

Answer 28

Resection (needs early diagnosis)

Question 29

End stage liver disease treatment

Answer 29

Transplant

Question 30

Treatment for liver cancer

Answer 30

- Radiofrequency, cryoablation, radiotherapy - Partial hepatectomy - Transplantation - Immunotherapy

Question 31

Bio artificial liver device

Answer 31

The patient’s plasma passes through 4 cartridges where it contacts human liver cells allowing appropriate two-way transfer of toxins, metabolites and nutrients, mimicking liver function.

Question 32

Hepatocyte transplantation limitations

Answer 32

- Rejection (better understanding of immunological mechanisms and improvement of immunosuppression required) - Lack of donors - Needs high grade of cell engraftment

Question 33

Stem cells

Answer 33

- Capable of self renewal - Can divide and produce cells that have the potential to become other more specific cell types, tissues or organs.

Question 34

Mesenchymal Stem Cells

Answer 34

- Multipotent adult stem cells - Candidate stem cell types for treatment of liver fibrosis/cirrhosis - Can attenuate acute or chronic liver inflammation and consequent hepatocyte injury by modulating the immune cell function including HSCs

Question 35

Hepatic stellate cells (HSC)

Answer 35

- Activated when the liver is injured triggered by cytokines and growth factors - Can change to a myofibroblast-like phenotype. - Activated HSCs become the main source of excessive ECM production in the liver (synthesize collagen, fibronectin) - Activated HSCs also secrete various profibrogenic factors such as TGF-β, PDGF, and CTGF which promote the activation and proliferation of HSCs and stimulate the production of ECM. - Targeting HSC activation and function is an important therapeutic strategy for treating fibrotic liver diseases.

Question 36

Human pluripotent stem cells

Answer 36

Generating hepatocyte-like cells from pluripotent stem cells by using various growth factors eg FOXA2, HNF1a.

Question 37

Limitations of human pluripotent stem cells

Answer 37

- Incomplete gene expression - Scale-up limitations - Heterogenous culture

Question 38

Hepatocyte characteristics

Answer 38

- Cytochrome p450 enzyme activity - Uptake LDL - Store glycogen - Synthesize urea

Question 39

Improving hepatocyte like cell function and number

Answer 39

- Use of chemically defined conditions (e.g. laminin) - Small molecules to induce rapid proliferation (e.g. TGFb)

Question 40

Complex liver organoids for transplantation

Answer 40

- Two cell types are isolated from the samples liver progenitor cells that change into the main cells that make up the organ, and liver endothelial cells which form the blood vessels. - Uses a unique liver gel made from human liver tissue samples to provide additional factors - A third cell that stimulates growth is combined with the gel and cells and injected into a scaffold that holds the 3mm organoid together.