studies of chronic aspiration gerd associated asthma
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Studies of Chronic Aspiration GERD Associated Asthma. Asthma Chronic inflammatory disease Recurrent respiratory symptoms, wheezing, breathlessness, chest tightness, coughing, Increase airway mucus secretion Increase smooth muscle hyper-reactivity - PowerPoint PPT PresentationTRANSCRIPT
Studies of Chronic Aspiration
GERD Associated Asthma
Asthma
Chronic inflammatory disease
Recurrent respiratory symptoms,
wheezing, breathlessness, chest tightness, coughing,
Increase airway mucus secretion
Increase smooth muscle hyper-reactivity
Inflammatory cells involved: T lymphocyte, eosinophil, mast cells, epithelial cells
Risk Factors
Disease inception: viral infection
Enviromental exposure: allergen, pollution, tobacco smoke
Life style: living on farm, diet, antibiotic use
Comorbid condition: atopic dermis, obesity
Excerbating Factors
Allergens: Mites, trees, grasses, animal danger
→ chronic low level exposure to indoor allergens ( house dust ,cockaroach , Alternaria species)
► fur pet exposure reduce future risk
► pollen immunotherapy in school age also reduce
future risk
Infections
Chlamydis , Mycoplasma,Early childhood inceltion, infection of virus in established asthma
ExerciseCausing airway obstruction, bronchoapasm
Non steroid anti-inflammatory drug
→ the response to aspirin or NSAIDS , eve laceimation, severe
bronchospasm
→ reduced prostaglandin production for normal lung function
Psychological factors
→ Parental stress
Gastroesophageal reflux( GERD)
→ 45-60% of adult and children with asthma has GERD
→ microaspiration or irritation of esophagus with reflux bronchispasm
Normal airway function
remodeling
Epithelial injury
Matrix deposition
angiogenesis
Genetic predisposition for remodeling
repair
injury
Enviroment
Genetic desposition
Asthma
GERD( Gastro Esophageal Reflux Disease)
recurrent return of stomach content back up into the oesophagus
10% of pateirts with GERD develop Barrett’s oesphagus which increases the risk of cancer of the oesophagus
80% of patients with GERD also have a hiatal hernia
Theory proposed for pathophysiologic mechanism of GERD associated Asthma
Direct stimulation of airway inflammation by aspiration of gastric contents or airway hyperresponsiveness triggered by aspiration of minute amounts of acid into the lower airway
Gastric Fluid Acid
Food allergen digestive enzyme may promote inflammaion of airway and smooth muscle tissue
Airway Remodeling
Subepithelial fibrosis,
myofibroblast hyperplasia,
myocyte hyperplasia and hypotrophy
Epithelial damage
Globet cell metaplasia
oedema
Innate Immunity
Provide initial protection against microorganism infection
Cellular components of innate immunity:
neutrophil, macrophage and natural killer cells
Major target of innate immune response are pathogen associated
molecules pattern( PAMP)
Recognize microorganism through germline-encoded pattern
recognition( PRRs)
Mammalian Immune response
Innate immunity:
first line of host defense against pathogen, and mediated by phagocytes include macrophage and dendritic cells
Acquired immunity:
Characterized bt specificity and develops by clonal selectionfrom lymphocytesbearing antigen –specific receptors that are generated through gene rearrangement
PAMP molecule structure that are produced only by microbial pathogen
conserved molecule pattern that are essential for the survival of the microbes
shared by large groups of micro organisma
often represent molecule signature of microbes, i.e. LPS
PRRs
Recognize PAMP which is essential for the survival of
microorganisms
Express constitutively in the host cells
Germline encoded, nonclonal, express on all cells of a given type,
and independent of iminologic memory
TLR( Toll Like receptors)
A pattern recognition receptor
Highly preserved from Drosophilla to mammals
Toll : gene essential for fly dorsal ventral development
Induction immune-response to broad range of
pathogens: virus, bacteria, fungus, protozoa, helminths
ROS( reactive oxygen species), products of cell damage or
cell death
Lipoprotein, Gram positive, mycobacterial cell wall constituents
TLR1/
TLR2
TLR2/
TLR6
TLR3
TLR5
TLR7 TLR8
TLR9TLR10
TLR4
Poly(I-C) d.s. RNA
Gram negative bacterial LPS, HSP, fibrinogens
Flagellin
Imiguimoid Resiquimod
848
CpG DNA ?
Toll receptors and their ligands
pIRF-3
pIRF-3
MyD88
IL-1R
TLR4
TLR-signaling pathway
TRAM
TRAF6
IKK-I
TBK1
NF-κB
IKK complex
NF-κBP PUbK48
TIRAP
NF-κB
TAB1TAB2TAK1
JNK P38
IRF-5AP-1
NEMO/IKKIKK-
IKK-
Ubk63
TRAF6IRF-5ubc13
Uev1A
IL-1R TLR4
TLR-signaling pathway
IRAK-1
IRAK-4
MyD88
JNK P38
NF-κB
P P
IRF-5
AP-1
ubc13Uev1A
Ubk63
IKK complex
NEMO/IKKIKK-
IKK-
Ubk63Pi
TAB1TAB2TAK1
MyD88
IRAK-1 IRAK-4
TRAF6IRF-5
UbK48
IB
NF-κB
IKK-i
TBK1
TRAM
TLR4
p
IRF-3
TRAF6
RIP1
Th1/2 biasingTLR activation
Activation of neutrophilic and monocytic inflammation
Cytokine production
DC/T cell
Activation
Th-1 and Th-2
activation
Protective immunity
septic shock
Asthma
COPD (chronic obstructive pulmonary disease)
ARDS (acute respiratory distress syndrom)
Clearance of infection
Bronchiolitis
The potentials of TLRs to influence respiratory disease
TLR express in
Endothelium
Fibroblast
Vascular smooth muscle
Memory T cell
Mast cell
Dendritic cell
By nature a pro-inflammatory signaling receptors
Rho/Rock pathway
Smooth muscle cell differentiation gene expresion
Rho A– small GTPase( 20kDa)
RhoA-GTP
Ca+2 sensitize forcce
RLC phosphorylation
RockRock
GPCR GPCR
Tyrosine kinase
Src, FAK…
RhoGDI
RhoA-GDP
Gene transcription
Rock
Dissociation of MLCK activity
PKC
AA
PLC PIP2
IP3
SR
Ca+2
DAG
GPCR
Gq
RockRockGqG12/13
RhoA-GTP
MyosinIIRLC20
MyosinIIRLC20 P
MLCP
Ca-CaMMLCP MYPT1 P
inhibited
+PPIC
Asthmatic epithelial cells
Reduced demosomal contact which may cause epithelial damage
More susceptable to apoptosis
Slower repair response
Increase in number of mucus- containing cells
Increase in the size of submucosal gland
Airway epithelial cell recognition of microorganisms is considered as an protective response in innate immunity
Air way epithelial cells secret large arrays of molecules that involves in inflammatory
Secretion causes chemotract and innate immunity
Damaged epithelial cells
TGF- release which promote the transformation of
fibroblast to myofibroblast
Synthesis of cytokines, remodeling of airway, chronic
inflammatipn
release of Endothelin-1: smooth muscle mitogen)
ectaxin : chemotractant for eosinophil
vascular endothelial growth factor :
promote growth of new blood vessel
Communication of asthmatic epithelium and mesenchyme by growth factors
►Susceptable to damage and repair leads to chronic inflammatory cycles
Chemokines
Eotaxin
IL-
MCA1,2,3
MIP1
RANTES
Other modulators
Cox-2
IFN-
Stem cell factor
TNF
VEGF
CytokinesIL-1IL-5IL-6IL-11GM-CSF
stimuli IL-1 IL-13
IL-5 TNF
Signal transduction IKK
JAKERK1/2
JNK
NFB
STATP38 MAPK
Stimuli and signals mediating synthesis of immune modulators in smooth muscle cells
Cytokine
Chemokine
Growth factor
EosinophilT-cell
Mast cell
Normal mouseIL-13 transgenic mouse
Airway remodling in mouse overexpressin IL-13
Increased deposition of extracellular matrix( ECM)
ECM: secret polysaccharides and proteins
i.e. proteoglycan → modify binding of cytokines to cell surface receptors
→ storage of soluble factors in matrix
In asthma patients → increase numbers cells in synthesize matrix protein
→ difference in degradation of existing proteins
→ more collegen I, III, V in submucosa membrane
increase level of tenacin, lumican, biglycan, verican…..
MMP( Metalopreteinase) : degrade ECM release cryptic information from ECM to liberate
bioactive fragments
lower MMP2, MMP-3 activity higher MMP-9 activity
higher TMP-1( tissue-specific inhibitors
of metalopreteinaase)
Comparative study of Airway smooth muscle remodeling
Gastric fluid acid ???
Ovalbumin ????
Other excerbating factors ????
Gastric fluid aspiration
8 weeks
control
8 weeks
OVA sensitize
8 weeks
1st year
Serum collection and BAL collection Trachea
Immunohistochemistry of tracheal and lung tissue
Animal sacrifice
Provocative testLung function assesment
Evaluation of pro-inflammatory cytokines and immunoglobulin
Matrix protein profile assesment
MMP profile assesment
MMP AssayCell surface protein Elisa assay
Rho/Rho kinase activity assesmentApoptotic assay
Migration assay
Primary culture of air way smooth muscle cells
In vitro study of airway smooth muscle remodeling
Treatment of gastric fluid acid, or Rho kinase inhibitor
Smooth muscle cell
Hyperplasia
Extracellular matrix protein
migration
Chemotaxis activation
Rat gastric fluid acid
apoptosis