Chemistry of Medicine I
医用化学第一Lecture II11.4 Mechanism to control BGL
血糖値の調節機構

2

Appetite 食欲4

Mechanism of satiety (満腹) response
1. Satiety hormones (leptin fromadipose, and insulin frompancreas) reaches to brain(arcuate nucleus, 弓状核).
2. Activating Pomc/Cart neuron, andsuppressing Agrp/Npy neuron.
3. Pomc/Cart neuron releases Mc4(neurotransmitter, 神経伝達ホルモン) to activate downstream
neurons.
4. Energy expenditure response.

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Mechanism of hunger response
1. Huger hormone (ghrelin fromstomach) induce opposite
response with satiety response.

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2002 Nat Rev Genetics 589

Glucose intake -> incretin -> insulin -> reduction of BGL

b-cell of pancreas
incretininsulin4

Insulin releasefrom b cell

5

GIP & GLP-1-responsive insulin release of b cell2010 J. Diabetes Invest 86

Islet of Langerhans

7Insulin-responsive glucose storage in liver and muscle
insulininsulinreceptor

pathway 2

pathway 1

1. Membrane fusion of GLUT4containing endosome to influx
glucose.
2. Activation of GS (glycogensynthase) to store glucose asglycogen.
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Glycogen Size: 20-50 nm.
 composed of 3,000 glucose. 240 branches and 480 termini ( 3,000x~8%; 2009 Int J Biol Macrmol 478).
 Polymerized by a-1,4 bond and branched at about every 8 to 12 residue by α-1,6-bond.
 hyper-branched structure enables rapid polymerization (energy storage) and degradation(energy consumption) from many termini.
 Glycogenin is a primer of polymerization.
Polymerization direction

Glycogenin

200 nm9

BGL control mechanism

insulin(b-cell)incretin(intestine)

glucagon(a-cell)
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Usage of intake glucose *5-hours after eatingof 68 g glucose
brain
CO2 20%liver
glycogen + fat 28%
23%

29%

blood
glucose26%

muscleglycogen 9%
CO2 13%glycolysis metabolites 4%

100%
3%

intestine

adipose tissue
fat
CO2
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Glucose metabolism
brain cell

aerobic
glycolysis
promoted by insulin

glucosepromoted by glucagon②

hepatocyte

gluconeogenesis
lactic acid,glucagonalanineglycogen②
glucoseblood glucose②③

insulinanaerobic
glycolysis

skeletal muscle cell

glucoselactic acidinsulininsulinglycogenintestinal epithelium①②

adiposeinsulinglucoseinsulin

glucoseinsulinglyceroltriglyceride

Fatty acid

Fatty acid12

Glucose transporter
GLUT
Passive transporter (no need of ATP energy). Bidirectional transport.

SGLT (sodium-glucose transporter)

Active transporter utilizing Na+ ion-gradient. One-directional transport.

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1. 5 Cause of DM

糖尿病の原因：insulin resistanceインスリン抵抗性

inflammation 炎症
glucose addiction

グルコース依存症

autoimmunity (type 1) 自己免疫疾患（一型）

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Obese adipose cause inflammation

M2 macrophage

M1 macropahge

2011 Annu Rev Pathol Mech Dis 275

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Insulin resistance インスリン抵抗性

Excess fatty acid andinflammatory cytokines
cause insulin resistance.

2013 Frontiers Endocrinol. 71

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RAGE induces damaging of tissue(case of nephron in mouse)normalDM

DM
RAGE transgenic

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2001 J. Clin. Invest. 261

Receptors for AGE (RAGE)

2011 Trend Biochem Sci 625

 Expressed in many organs especiallyin endothelium and lymphocytes.
 Removing AGE from blood.
 Inducing chronic inflammation andbeing related to many diseases(diabetes, Alzheimer’s disease,atherosclerosis, cancer)

 Receptor not only for AGE but also forother negatively charged proteins.

Ligand of RAGE
Amyloid b 1-40

S100Bfibrilformation
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Cell singling of RAGE
1. AGE binds to RAGE to induce intracellular signaling.
2. NADPH oxidase produces ROS to activate NF-kB (transcription factor).
3. NF-kB expresses more RAGE and proinflammatory cytokines.
4. Repeating this process to cause chronic inflammation. 慢性炎症
loop1423319

Autoimmunity (Type 1 DM)

2013 Trends Immunol 583

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Misidentification of self-peptides

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Glucose addiction via reward system
報酬系による糖分依存症
Reward system

Reaction to sugar imaged byPET scan

Neurotransmitter for rewardsystem

Dopamine ドーパミン
221. 6 Therapy of DM 糖尿病の治療：

Insulin, GLP-1 インシュリン、GLP-1Medication 薬物治療
Implantation of pancreas 膵臓移植

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Insulin

C-peptide also secretedwith insulin from b cell24Insulin

aspartlispro

AspProLys

A chain 21aa

B chain 30aa

chelator

Zn2+
hexagonal crystal

hexamer exist as crystal in b-cell.
hexamer (top view)

25Insulin-containing granule in b-cell

300 nm2x105 insulins/granule

104 granules/b-cell
2x109 insulins/b-cell26

Engineered insulins for rapid or sustained release・deletion of some residues
to raise solubility

・mix with・myr-modif.
cationic peptide (levemir)・hexadecane dioicacid-modif.
(degludec)

Combination of rapid and sustained insulin

Rapid insulin: for abrupt increase of BGL
after meal

Sustained insulin: basal BGL reduction27

Degludec

Binding with HSA forlong blood half-life

Binding with HSA
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Human serum protein (HSA): a suitable drug carrier
HSA and IgG can recycle back to blood by FcRn.
Cys34

IgG

1

5

HSA

4

73

2

6
Red: high affinity
Blue: low affinity

FcRnLong blood half life: 3 weeks
High blood conc.: 50 g/L

Carrier of fatty acid: Kd ~ 10-7 M

29Conc. of proteins in blood

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Blood half-lifeInsulin
5.8 kDa
4-6 m

0Smallmolecule< 1 kDa~ minLevamir
(C14)
5-7 h

Fab-conjugated
HSA-IFNa
with albumin140-159 hbinding peptide
32 h
HSA-GLP15d1h
30 min6 h 12 h 18 h

4dIFNa neutrophil
12 h
20 kDa3~8h
LDL60 hFab60 kDa
0.3-0.8 d

HSA
60 kDa3 weeks
1 mo1w

1dscFv
30 kDa0.1 d

Red: PEGylation
Blue: HSA-related
Green: antibody-related

2w

3w

1y
3 mo 6 mo 9 mo

RBC
3 months
IgA1,2IgM
6d10 dIgD
IgG33d7d
Doxil
55 h

PEGylated IFNa
20+40 kDa
~ 65 hIgG1,2,4120 kDa
3 weeksEngineered GLP-1 for long blood half-life

GLP-1

linker

Fc of IgG4

Liraglutide• Long blood half-life due to thehigh affinity to HSA.
• Once in a day (subcutaneousinjection).

Dulaglutide• Long blood half-life due to the fusion withFc.
• Once in a week (subcutaneous injection).

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Sulfonyl urea: activation of insulin releasesulfonyl urea compounds
1. Glucose raises ATP conc.
2. Closing of K+ channel

3. Opening of Ca2+ channel
4. Membrane fusion ofgranule to release insulin

ATPSulfonyl urea compounds
close K+ channel to releaseinsulin.

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Metformin: raising AMP/ATP ratio to accelerate glycolysis in liver
1. Binding to mito. membrane to disturb ATP synthesis
2. Increase of AMP/ATP (lacking of energy)
3. Activation of AMPK (transcription factor)
4. Accelerating glycolysis

2

metformin

34134Islet graft for type I-DM （一型DMへの膵島移植）(Brain death)35Islet graft for type I-DM （一型DMへの膵島移植）
1. Pre-transplantation• anti-thymocyte globulin (killing lymphocytes)• Immunosuppressant
2. Transplantation
3. Post-transplantation• Anti-IL-2R antibody (killing T cell) on post transpl. day 4.
• Immunosuppressant (twice a day)• Patients who did not need insulin injection were 10% (after 5years from transplantation). 治療5年後までインスリン注射が不要だった症例は約10%• Requiring immunosuppressant -> risk of opportunistic infection.
免疫抑制剤が必要。日和見感染のリスク。
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Creating human’s organ in living animal• No need of immunosuppressant.
• No need of human donor.

Prof. Hiromitsu Nakauchi
中内啓光教授(Stanford U, U Tokyo)

pancreas-lacking pig

Patient’s iPS cell

Implantation of human
iPS cell into Blastocyst of
pancreas-lacking pig
patient

Generation of pancreases
from iPS cell in living pig

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Treg can suppress Th: re-education of immunity totreat autoimmunity
helper T (Th)anergy (不応答)

Shimon Sakaguchi
坂口 志文 (Osaka U)DCanti-inflammatory
cytokines (IL-10, TGF-b)

regulatory T (Treg)

Treg is more activated by DC than Th because ofhigher affinity TCR
higher affinity co-receptor (CTLA-4)
higher affinity IL-2R

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Quiz 2:
Please deepen your question from thestandpoint of evolutionary medicine for DM
and suggest your original therapy.

糖尿病に関して、進化医学の立場からした

先日の質問をより深めて問題を明らかにし、独自の治療法を提案してください。

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