Rand & ~Inflammation From Fungi~Toxins

[Guest guest]

Arch Toxicol. 2009 Nov 11. [Epub ahead of print]

Dectin-1 and inflammation-associated gene transcription and expression in

mouse lungs by a toxic (1,3)-beta-D: glucan.

Rand TG, Sun M, Gilyan A, Downey J, JD.

Department of Biology, Saint 's University, 923 Robie St., Halifax,

NS, B3H 3C3, Canada, thomas.rand@....

The form of (1-3)-beta-D: glucan found in the cell walls of the anamorphic

Trichocomaceae that grow on damp building materials is considered to have

potent toxic and inflammatory effects on cells of the respiratory system.

It is also considered to have a potential role in the development of

non-allergenic respiratory health effects. While human studies involving

experimental exposures all point to the inflammatory potential of pure curdlan,

a

linear (1-3)-beta-D: glucan in a triple helix configuration, animal

experiments result in conflicting conclusions concerning the inflammatory

potency of

this glucan. However, because mice appear to be a better model than guinea

pigs for exploring the respiratory effects of curdlan and because

molecular mechanisms associated with this glucan remain largely unknown, we

conducted further work to clarify the role of curdlan on the inflammatory

response

using our mouse model of lung disease. This study used in situ

hybridization (ISH) to probe dectin-1 mRNA transcription with a

digoxigenin-labeled

cDNA probe, with reverse transcription (RT)-PCR based arrays used to measure

inflammation gene and receptor transcriptional responses. Also,

immunohistochemistry (IHC) was used to probe dectin-1 as well as anti-mouse

Ccl3,

Il1-alpha, and TNF-alpha expression to evaluate dose and time-course (4 and 12

h) postexposure (PE) response patterns in the lungs of intratracheally

instilled mice exposed to a single 50 mul dose of curdlan at 10(-7), 10(-8),

10(-9), and 10(-10) M/animal (=4 mug to 4 ng curdlan/kg lung wt). Dectin-1

mRNA transcription and expression was observed in bronchiolar epithelium,

alveolar macrophages (AMs), and alveolar type II cells (ATIIs) of lungs exposed

to 4 mug to 40 ng curdlan/kg lung wt, at both time points. Compared to

controls, array analysis revealed that 54 of 83 genes assayed were

significantly modulated by curdlan. mRNA transcription patterns showed both

dose and

time dependency, with highest transcription levels in 10(-7) and 10(-8) M

treatment animals, especially at 4-h PE. Nine gene mRNA transcripts (Ccl3,

Ccl11, Ccl17, Ifng, Il1alpha, Il-20, TNF-alpha, Tnfrsf1b, and CD40lg) were

significantly expressed at all doses suggesting they may have a central role

in immunomodulating curdlan exposures. IHC revealed Ccl3, Il1-alpha, and

TNF-alpha expression in bronchiolar epithelium, AMs and ATIIs illustrate the

important immunomodulatory role that these cells have in the recognition

of, and response to glucan. Collectively, these results confirm the

inflammatory nature of curdlan and demonstrate the complex of

inflammation-associated gene responses induced by (1-3)-beta-D: glucan in

triple helical forms.

These observations also provide a biological basis for the irritant and

inflammatory response to curdlan observed in humans and animals in experimental

studies.

Chem Biol Interact. 2010 Jan 5;183(1):113-24.

Inflammation-associated gene transcription and expression in mouse lungs

induced by low molecular weight compounds from fungi from the built

environment.

JD, Sun M, Gilyan A, Roy J, Rand TG.

Department of Chemistry, Carleton University, Ottawa, Ontario, Canada K1S

5B6.

Few metabolites from fungi found indoors have been tested for inflammatory

mediators endpoints in primary cultures of alveolar macrophages or in

vivo. In this study, mice were intratracheally instilled with a single dose

comprising 4x10(-5)moletoxin/kg lung wt dose of either atranone C,

brevianamide, cladosporin, mycophenolic acid, neoechinulin A & B,

sterigmatocystin or

TMC-120A. These toxins are from fungi common on damp building materials.

The dose used was comparable to the estimated doses of possible human

exposure. Hematoxylin and eosin (H & E) histology and Alcian Blue/Periodic Acid

Schiff (AB/PAS) histochemistry were used to evaluate lungs for time course (4h

and 12h post-exposure (PE)) inflammatory and toxic changes.

Reverse-transcription (RT)-PCR based arrays were also employed to evaluate time

course

inflammation-associated gene transcription in lung tissues of the different

toxins. Immunohistochemistry (IHC) was used to probe MIP-2 and Tnf-alpha

protein expression in treatment lungs to determine whether responses correspond

with gene transcription data. Both histology and histochemistry revealed

that toxin exposed lungs at 12h PE showed evidence of inflammation. H & E

revealed that bronchioli were lined with irregularly thickened and sometimes

sloughing epithelium and bronchiolar spaces supported infiltration of

leukocytes, cellular and mucus-like debris while alveolar spaces supported

swollen

macrophages and modest amorphous debris accumulations. All toxin-instilled

lungs exhibited copious mucus production and alveolar macrophages with red

stained cytoplasm on bronchiolar surfaces, especially at 12h PE. Array

analysis of 83 inflammation-associated genes extracted from lung tissue

demonstrated a number of patterns, compared to controls. 82 genes assayed at 4h

PE and 75 genes at 12h PE were significantly altered (p< or =0.05; >or

=1.5-fold or < or =-1.5-fold change) in the different treatment animal groups.

Expression of transcriptionally regulated genes was confirmed using

immunohistochemistry that demonstrated MIP-2 and Tnf-alpha staining in

respiratory

bronchiolar epithelia, alveolar macrophages and alveolar type II cells. The

transcriptional regulation in these genes in the treatment groups suggests

that they may serve central roles in the immunomodulation of toxin-induced

pro-inflammatory lung responses. Hierarchical cluster analysis revealed

significant patterns of gene transcription linking the response of the toxins

at equimolar doses in three groups: (1) brevianamide, mycophenolic acid

and neoechinulin B, (2) neoechinulin A and sterigmatocystin, and (3)

cladosporin, atranone C and TMC-120. The results further confirm the

inflammatory

nature of metabolites/toxins from such fungi can contribute to the

development of non-allergenic respiratory health effects

[Guest guest]

82 genes assayed at 4h PE and 75 genes at 12h PE were significantly altered (p<

or =0.05; >or =1.5-fold or < or =-1.5-fold change) in the different treatment

animal groups.

is this refering to cell folding ? if I understand right cells fold because of

the loss of fluid in the cell. so exposure basicly sucks the fluid out of our

cells along with the nutrients in that fluid. causeing amoung other things

malnutriention.

cell folding is also involved in tissue damage that can become fibrotic and

fibrotic pathways.

I wonder if it's what causes the inflammation that also causes the cell folding

or the inflamation itself. or both.

wouldn't cell folding be a form of mutation?

cataracts is basicly the loss of fluid from the cells in the lens,involves cell

folding

that could be from inflammation but if nanoparticles can get in there and thats

causeing inflammation than the nano's are the cause.

I'm pretty convienced that nano's can get about anywhere in the body.

[Guest guest]

oh, nevermind, I may have read that wrong, had to go take a nap, so not sure

where my head was.

>

> 82 genes assayed at 4h PE and 75 genes at 12h PE were significantly altered

(p< or =0.05; >or =1.5-fold or < or =-1.5-fold change) in the different

treatment animal groups.

>

> is this refering to cell folding ? if I understand right cells fold because of

the loss of fluid in the cell. so exposure basicly sucks the fluid out of our

cells along with the nutrients in that fluid. causeing amoung other things

malnutriention.

>

> cell folding is also involved in tissue damage that can become fibrotic and

fibrotic pathways.

>

> I wonder if it's what causes the inflammation that also causes the cell

folding or the inflamation itself. or both.

>

> wouldn't cell folding be a form of mutation?

>

> cataracts is basicly the loss of fluid from the cells in the lens,involves

cell folding

> that could be from inflammation but if nanoparticles can get in there and

thats causeing inflammation than the nano's are the cause.

> I'm pretty convienced that nano's can get about anywhere in the body.

>