SCPA610–Cellular and molecular pathology from

chemical and physical injuries

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Associate Professor Dr. Wannee Jiraungkoorskul

Department of Pathobiology, Faculty of Science, Mahidol University

Tel: 02-201-5563, E-mail: wannee.jir@mahidol.ac.th

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Objectives

• Explain the definition and classification of

environmental hazard.

• Discuss the cellular and molecular mechanism of lead

metal.

• Discuss the cellular and molecular effect of ultraviolet

radiation.

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Environmental hazard : Definition

• An environmental hazard is a substance, state or event which has

the potential to threaten the surrounding natural environment / or

adversely affect people's health, including pollution and natural

disasters such as storms and earthquakes.

• Any single or combination of toxic chemical, biological, or physical

agents in the environment, resulting from human activities or

natural processes, that may impact the health of exposed subjects,

including pollutants such as heavy metals, pesticides, biological

contaminants, toxic waste, industrial and home chemicals.

• Hazards can be categorized in four types:

• Chemical

• Physical

• Biological

• Psychosocial

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Environmental hazard : Classification

Chemical hazard• Chemical hazards are defined in the Globally Harmonized

System and in the European Union chemical regulations.

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• Anthrax

• Antibiotic agents in animals destined

for human consumption

• Arsenic - a contaminant of fresh water

sources (water wells)

• Asbestos - carcinogenic

• DDT

• Carcinogens

• dioxins

• Endocrine disruptors

• Explosive material

• Fungicides

• Furans

• Heavy metals

• Herbicides

• Hormones in animals destined for

human consumption

• Lead in paint

• Mercury

• Mutagens

• Pesticides

• Polychlorinated biphenyls

• Radon and other natural sources

of radioactivity

• Soil pollution

• Tobacco smoking

• Toxic waste

• Radon

Physical hazard

• A physical hazard is a type of occupational hazard that involves

environmental hazards that can cause harm with or without contact.

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• Cosmic rays

• Earthquake

• Electromagnetic fields

• E-waste

• Floods

• Fog

• Lightning

• Noise pollution

• Quicksand

• Ultraviolet light

• vibration

• X-rays

Biological hazard

• Biological hazards, also known as biohazards, refer to biological

substances that pose a threat to the health of living organisms,

primarily that of humans. This can include medical waste or

samples of a microorganism, virus or toxin (from a biological

source) that can affect human health.

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• Allergies

• Arbovirus

• Avian influenza

• Bovine spongiform

encephalopathy (BSE)

• Cholera

• Ebola

• Food poisoning

• Malaria

• Molds

• Pollen for allergic people

• Rabies

• Severe acute respiratory

syndrome (SARS)

• Sick building syndrome

Psychosocial hazard

• Psychosocial hazards are basically causing stress to a worker or

workplace stressors.

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Heavy metal

• A heavy metal is defined as trace element that has a

relatively high density (≥ 3g/cm3 ).

Copper Lead Arsenic Mercury

http://en.wikipedia.org/wiki/Heavy_metal_(chemistry) 9

http://www.elementsdatabase.com/10

• Heavy metals generate oxidizing radicals •OH (hydroxyl radicals)

from H2O2 (hydrogen peroxide) and superoxide (•O2-) leading to

metal-induced carcinogenesis.

Heavy metal reaction

The reduction of ferric ion to ferrous

Fe3+ + •O2− → Fe2+ + O2

Fe2+ + H2O2 → Fe3+ + OH− + •OH

•O2- + H2O2 → •OH + OH- + O2

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Lead• Lead symbol Pb (Latin: plumbum) and atomic number 82.

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• Lead paint

• Food container

• Petrol (tetraethyl lead)

• Toy and Jewelry

• Herbal remedy

Uses and sources of lead

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Lead in Klity Creek, Kanchanaburi

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Lead in shrimp

(Thairat newspaper 20 Feb 2002)

Lead in fish

(Thairat newspaper 12 May 2002)

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http://www.epa.nsw.gov.au/leadsafe/body.htm

Lead Lines

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Basophilic stippling

Microcytic, hypochromic hemolytic anemia

• Basophilic stippling refers to erythrocytes display small dots at the periphery.

• These dots represent accumulations of rRNA and is associated with several conditions, including:anemia, lead poisoning, beta thalassemia

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• Lead poisoning (Latin plumbum, lead ; plumbism, colica

pictonum, saturnism, Devon colic, or painter's colic) is a medical

condition caused by increased levels of the heavy metal lead in the

body.

• Radiodense “lead lines” in children, due to interference with

normal remodeling of calcified cartilage

• “Lead lines” of gums also seen - hyperpigmentation due to excess

lead

Lead toxicity

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Lead lines

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ALA = Aminolevulinic acidZn PP = Zinc protoporphyrin Lead toxicity

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Environ mental Health Perspectives 1974; 7: 121–127.

1-1974

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• Objective: In vitro study of lead inclusion bodies in renal tubular cells of

rat.

• Results: The inclusion bodies are insoluble in physiological media but

dissolved in urea and sodium deoxycholate.

• They contain about 40-50 µg of lead/mg protein but only about 10% of

this is tightly bound. They also contain calcium, iron, zinc, copper, and

cadmium.

• The protein has a molecular weight of 27,500 and is rich in glutamic and

aspartic acids, glycine and cystine.

• Rat proximal tubule with intranuclear inclusion body characterized by dense

central core and fibrillary margin. A small inclusion body is located within

invaginated nuclear membrane.

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Journal of Biological Chemistry 1982; 257: 11802–11807.

2-1982

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• Objective: To investigate the characteristic of lead intranuclear

inclusion bodies from rat kidney.

• Results: It has the protein molecular weight of 32,000 and an

isoelectric point of 6.3

• It has been suggested that the inclusion bodies have a protective

effect in lead-intoxicated animals.

• TEM from a rat fed a diet including

1% lead acetate for 13 weeks reveals a

large inclusion body in kidney.

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• Three intranuclear inclusion bodies.

• The largest one surrounded by a fibrous cortex.

• L = nuclear pore complex-lamina

• M = mitochondria

• C = collagen fibers

• H = homogeneous material which appears in

the shape of circles and ribbons

Biological Trace Element Research 1999; 75: 245–251.

3-1999

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• Objective: To study the histological and histochemical techniques

on the lead intranuclear bodies in rat kidney.

• Results: The intranuclear bodies proved to be lead lipoprotein

complexes containing sulfyhydryl groups and are basic in nature

with orthochromatic, eosinophilic, argyrophilic, osmophilic,

fuchsinophilic and sudanophilic characteristics.

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4-2004

Histology Histopathology 2004; 19: 69-76.

• Objective: To investigate 24 h subcytotoxic doses of lead nitrate

(EC10 = effective concentration 10%) in renal cell line.

• Results: Inclusion bodies in the form of irregular granules of

varying size in both cytoplasm and lysosomes.

• Increase number of phagolysosomes and myeline figures

Control Buffalo Green Monkey renal cells have variable number of microvilli, spherical or oval mitochondria, abundant chromatin in nucleus

BGM-Non-lead expose

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a = inclusion bodies in lysosomes b = free in the cytoplasmic matrix c = ring-shaped inclusion bodies and myelin figures d = loss of mitochondrial cristae e = intranuclear inclusion

BGM-Lead expose

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a = inclusion bodies in lysosomes b = free in the cytoplasmic matrix c = ring-shaped inclusion bodies and myelin figures d = loss of mitochondrial cristae e = intranuclear inclusion

BGM-Lead expose

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a = ring-shaped intracytoplasmic inclusion bodies in lysosomes b = free in the cytoplasmic matrix and myelin figures c and d = intranuclear inclusion

VERO-Lead expose

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a = ring-shaped intracytoplasmic inclusion bodies in lysosomes b = free in the cytoplasmic matrix and myelin figures c and d = intranuclear inclusion

VERO-Lead expose

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5-2008

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• Lead’s movement through the blood brain barrier. Lead ions are able to permeate the blood brain barrier via ion channels. Lead interferes in the communication between astrocytes and endothelial cells

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6-2009

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Abstract• Objective: To investigate chronic lead intoxication (500 ppm in

drinking water) during 7 months on the structure, function and

biochemical properties of rat proximal tubule.

• Results: Increased lead concentration in kidney, Reduction of

calcium and amino acids uptake, Oxidative damage, Glucosuria,

proteinuria, hematuria and reduced urinary pH.

• Inclusion bodies were found in the cytoplasm and in mitochondria.

• Loss of apical microvillae, decrement of the luminal space,

formation of atypical intercellular contacts and adhesion structure.

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tl = tubular lumen mt = mitochondria am = apical membrane n = nuclei d = detritus

Proximal tubule: Non-lead expose Lead expose

Reduction of lumen, microvillus and lost of the brush border of renal proximal tubules

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Micrographs show alteration in the morphology of cellular organelles (mitochondrial swelling).

Lead expose

tl = tubular lumen am = apical membrane bm = basal membrane mt = mitochondria n = nuclei d = detritus

Proximal tubule: Non-lead expose

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Micrographs show nuclei with intranuclear inclusion bodies .

mt = mitochondria n = nuclei ib = inclusion bodies

Lead expose Proximal tubule: Non-lead expose

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Inclusion bodies in nucleus (a), mitochondria and cytoplasm (b) of proximal tubule cells of rats with intraperitoneal administration of lead (subacute intoxication).

Mitochondria (mt); nuclei (n); inclusion bodies (ib)

Lead expose Lead expose

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(a) Lost of apical microvillus and changes in membrane integrity.

Lead expose Lead expose

tubular lumen (tl); basal membrane (bm); nuclei (n)

(b) Collapse of tubule structure with intercellular apposition.

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(c) Formation of intercellular adhesion junctions between apposed cells.

Lead expose Lead expose

Tubular lumen (tl); nuclei (n). Arrows indicate the cell adhesion structures in abnormal junctions.

(d) Abnormal junction apical-apical membrane with formation of intercellular junctions.

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(e) Lost of lumen and sealing of apical membranes. basal membrane (bm). Arrows indicate the cell adhesion structures in abnormal junctions.

Lead expose

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7-2012

50Interdiscrplinary Toxicology 2012; 5: 47-58.

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Ultraviolet light : Definition

• Ultraviolet (UV) is an electromagnetic radiation with a wavelength

from 10 nm to 400 nm, shorter than that of visible light but longer

than X-rays.

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Ultraviolet light

• It is also produced by electric arcs and specialized lights, such

as mercury-vapor lamps, tanning lamps, and black lights.

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Mercury vapor street light

Electric arcs

Black light tubes

Health effects of UV radiation

56https://sites.google.com/site/uvraysallyouneedtoknow/_/rsrc/1291158047136/general-information-1/uv_ray_graphic_560w.jpg

UVA = Aging ray

UVB = Burning ray

Case study

• Unilateral Dermatoheliosis

• New England Journal of

Medicine 2012; 366:e25

• A 69-year-old man presented

with a 25-year history of

gradual, asymptomatic

thickening and wrinkling of

the skin on the left side of his

face.

• The physical examination

showed hyperkeratosis with

accentuated ridging, multiple

open comedones, and areas of

nodular elastosis.57

• Histopathological analysis showed an accumulation of elastolytic

material in the dermis and the formation of milia within the vellus hair

follicles.

• Findings were consistent with the Favre–Racouchot syndrome of

photodamaged skin, known as dermatoheliosis.

• The patient reported that he had driven a delivery truck for 28 years.

• Ultraviolet A (UVA) rays transmit through window glass, penetrating

the epidermis and upper layers of dermis.

• Chronic UVA exposure can result in thickening of the epidermis and

stratum corneum, as well as destruction of elastic fibers.

• This photoaging effect of UVA is contrasted with photocarcinogenesis.

• Although exposure to ultraviolet B (UVB) rays is linked to a higher

rate of photocarcinogenesis, UVA has also been shown to induce

substantial DNA mutations and direct toxicity, leading to the formation

of skin cancer.

• The use of sun protection and topical retinoids and periodic monitoring

for skin cancer were recommended for the patient.58

The Translational Basis of Human Cutaneous Photoaging

• Comparison between youthful skin (as normal), skin from an older

individual showing loss of rete ridges and thinning of dermal collagen

bundles, and photodamaged skin with superimposed aggregates of

amorphous, pale blue-gray elastin in the superficial dermis.

59The American Journal of Pathology, Vol. 174, No. 2, February 2009

Histology of photoaged skin

• The predominant

histological finding of

photodamaged skin is

solar elastosis, which is

basophilic degeneration of

elastotic fibers in the

dermis.

• Solar elastosis separates

from the epidermis by a

narrow band of normal-

appearing collagen (grenz

zone) with collagen fibers

arranged horizontally.

60https://www.intechopen.com/books/molecular-mechanisms-of-the-aging-process-and-rejuvenation/molecular-mechanisms-of-skin-aging-and-rejuvenation

Possible Involvement of Basement Membrane Damage in

Skin Photoaging

• Basement membrane (BM) structure at the dermal–epidermal junction (DEJ) and

damaged BM structure. The DEJ is visualized at stepwise magnification from light

microscopic scale to transmission electron microscopic scale.

• Hemidesmosome (HD), anchoring filament (af), lamina densa, and anchoring fibrils (AF)

are observed and form a special anchoring complex for the attachment of epidermis to

dermis.

61Journal of Investigative Dermatology 2009; 4: 2-7.

Possible Involvement of Basement Membrane Damage in

Skin Photoaging

• DEJ of human skin: Disruption and reduplication of the lamina densa can be seen at the

DEJ in the sun-exposed cheek skin of a 30-year-old woman, whereas neither duplication

nor disruption can be observed in the sun-protected abdomen skin of a 34-year-old

woman.

62Journal of Investigative Dermatology 2009; 4: 2-7.

63https://www.intechopen.com/books/molecular-mechanisms-of-the-aging-process-and-rejuvenation/molecular-mechanisms-of-skin-aging-and-rejuvenation

Schematic representation of pathogenesis of

premature/extrinsic skin aging

ROS: reactive oxygen species, AhR: arylhydrocarbon receptor, NF-kB: nuclear factor kappa‐B, IL-1:

interleukin‐1, TNF-α: tumor necrosis factor, CCN1: cysteine-rich protein 61, MAPK: mitogen‐activated

protein kinase, AP‐1: activator protein 1, and MMPs: matrix metalloproteinases.

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Reference