gingival hyperplasia,Normal anatomy of the gingiva The Role of Epithelial-Mesenchymal Transition Process in Gingival Hyperplasia Fibroblasts Collagen Production and Histological Alterations in Hereditary Gingival Fibromatosis

2. Molecular mechanisms in gingival
enlargement
By
Romissaa Aly
Assistant lecturer of
Oral Medicine,
Periodontology,
Diagnosis and Dental
Radiology (Al-Azhar
University)

3. Content:
Normal anatomy of the gingiva
The Role of Epithelial Mesenchymal
Transition Process in Gingival Hyperplasia
 Fibroblasts Collagen Production and
Histological Alterations in Hereditary Gingival
Fibromatosis

5. Classification of oral mucous
membrane
1-Keratenized mucosa ( Masticatory
mucosa)
(A) Gingiva (B) Hard
palate
2- Non-keratenized mucosa (Lining
mucosa)
(A) Firmly
attached
(B) Loosely
attached
Soft
palate lip cheeck Ventral S
tongue
Floor of
mouth
Vestibule
Alveolar
mucosa
3- Specialized mucosa
Dorsal surface of the
tongue

6. Macro-anatomy of the gingiva
Free
gingiva
Free
gingival
groove
Interdental
papilla
Attached
gingiva
Mucogingival
junction
Alveolar
mucosa

7. Histology of gingiva
Stratified squamous
keratenized
epithelium
Lamina
propria
Epithelial rete
peg
C.T papilla
Tall
Numerou
s
Slender
Irregular
No submucosa

8. Gingival fibers
Dento-gingival
group
Alveolo-gingival group
Circular group
Dento-periosteal group

9. K.st .sq .epith
Non.K.st.sq.epith

10. Keratinized St. Sq. Epith.
Basal cell laye (stratum basale)
Prickle ’spinous’ cell layer (stratum spinosum)
Granular cell layer (stratum granulosum)
Cornified cell layer (stratum corneum)

11. K.st.sq epith (st.basal) Non-K.st.sq.epith
*The cells are cubiodal, contain large oval nucleus, granular basophilic
cytoplasm
*The cytoplasm contain tonofilaments
Arranged in bundles Remain dispersed
*The cells are closely attached to each other by desmosomes

12. 1- Thickening of the
adjacent cell membrane.
2- A pair of attachment
plaque.
3-
Tonofilaments.
4- An intervening extracellular
structure.
The
desmosomes

13. The hemi-desmosomes

14. Basal lamina (Basement membrane)
By EM junction of epithelium and C.T
described as Basal lamina : consistes of
1) Lamina densa (20-120nm)
consists of glycoprotein (laminin)
material run parallel to basal cells
2) Lamina lucida (20-40nm)
Appearently clear zone present between
lamina densa and basal cells
A subepithelial fibers termed (Reticular lamina)
Consists of a system of:
1) Fine argyrophilic reticular fibers
2) special anchoring fibers (small loops of fibers)
Both inserted into lamina densa and reached the
plasma membrane of basal cells mostly in the region of
hemidesmosomes
3) Collagen bundles run through loops of anchoring fibers and thu
interlocked with basal densa to form a flexible attachment

16. The lamina propria
It is the C.T that support the epithelium
It is divided into 2 layers:
1) Papillary layer
2) Reticular layer

17. The Role of Epithelial Mesenchymal
Transition Process in Inflammatory Gingival
Hyperplasia

18. Inflammatory gingival hyperplasia is an
inflammatory restraint to local irritant correlating with
the gingiva; the irritant could be microbial like plaque and
calculus.
 Clinically present as deep red or bluish, considerably friable
and fine with smooth glossy surface and commonly bleed easily
[1].

19. Histologically, inflammatory gingival enlargement
characterized by thicking of the epithelium with
increased volume of the connective tissue with
different degree of inflammation and fibrosis [2].

20. Gingival overgrowth usually treated with
traditional periodontal treatment such as scaling and
root planning, but if it include significant fibrotic
component that don't respond to the traditional
treatment so it will be treated by surgical
removal of the excess tissue [3].

22. Content
Definition of EMT
Main features of epithelial and mesenchymal cells
Types of EMT
 Major Criteria and Relevant Markers to Detect EMT
Induction and Regulation of EMT
EMT in Fibrosis and Disease

23.  EMT is a process in which epithelial cells
migrate in to the connective tissue and
transdifferentiate into fibroblast-like cells, this
occurs as the epithelial cell-cell and cell- extracellular
matrix interactions are destabilized [4].

33. The EMT proteome

45. Growth factor receptors and signaling
pathways
Reactive oxygen species

47. hepatocyte growth factor(HGF) RTK: receptor tyrosine kinase
MET mesenchymal–epithelial transition

50. TGF b is considered to be the prototypical cytokine
for induction of EMT because different isoforms mediate
various aspects of EMT in many diverse cellular contexts,
whereas the effects of other EMT inducers are often context
dependent and variable (Sanford et al., 1997; Xu et al., 2009).

52. Treatment of mammary epithelial cells with
repeated low doses of hydrogen peroxide, a protocol
mimicking the chronic inflammation that is common
to many human diseases, leads to a fibroblastlike
phenotype (Mori et al., 2004).

55. aSMA alpha-smooth muscle actin

56. Myofibroblasts are present in large numbers in
sites with ongoing inflammation and repair, and effectively
close wounds through the contraction of connective tissue
(Guarino et al., 2009; Hinz, 2010).

57. Myofibroblasts were originally believed to be generated
by proliferation and activation of local fibroblasts
(Barnes and Gorin, 2011; Grillo, 1963).
This was supported by the presence of fibroblasts
positive for proliferation markers at the periphery of
the wound (Grillo, 1963) that acquire smooth muscle
features during wound healing and progressive organ fibrosis
(Barnes and Gorin, 2011).

58. Reference

60. J Res Med Dent Sci, 2019, 7 (5):80-84

61. The study was carried out by Lina Ibtesam Khalid
et al 2019 in an effort to determine if EMT operates in the
pathogenesis of inflammatory gingival hyperplasia to serve as
a source of fibroblasts..
J Res Med Dent Sci, 2019, 7 (5):80-84
In this this they were sought to investigate if the
Epithelial mesenchymal transition theory
participitated in the advancement of this benign lesion.

62. Markers of the study:
E-Cadherin is considered as a prototypical epithelial
marker of EMT.
Vimentin is mainly expressed in cells of mesenchymal
origin and it is often used as a marker for epithelial
mesenchymal transition
Alpha smooth muscle actin positive myofibroblast

63. •E-Cadherin is required for the maintenance of
normal intercellular adhesion and barrier integrity in
oral tissues [12].
• Vimentin is one of the most familiar members of
intermediate filaments (IFs), as it is the major IF
protein in mesenchymal cells and it is frequently used as a
developmental marker of cells and tissues [13].

64. The reduction in epithelial expression of E-Cadherin also
called the Cadherin switch has been known to promote
EMT by facilitating weakening of the intercellular
junctions and promoting movement of epithelial cells towards
the connective tissue [6].
Alpha smooth muscle actin positive myofibroblast have
been demonstrated in type 2 EMT [7].

65. To confirm this mechanism, They investigated the
Immuno-histochemical expression of three specific
markers assessing EMT mechanism namely α-SMA,
Vimentin and E-Cadherin.
Alpha-SMA is a putative myofibroblast marker. Since
myofibroblasts are implicated in EMT induced fibrosis they
sought to analyse α – SMA expression in the samples.

68. Material and method:
The study involved 15 tissue blocks of inflammatory
gingival hyperplasia taken from the archives of oral
pathology, laboratory of oral diagnosis department,
collage of dentistry/university of Baghdad.
Immunohistochemical expression of Vimentin, E-
Chdaherin and α-SMA was assessed.

69. The mean number of vimentin& E-Chadherin positive
fibroblast were 51.43% & 48.56%, respectively, so as these
two markers are biomarkers for EMT, it is suggested
that EMT process may be involved at least partly in
the pathogenesis of inflammatory gingival hyperplasia.
Results:

70. Results:
Vimentin and E-Chadherin immunoreactivity of the
connective tissue fibroblasts showed 100% positivity, while
Alpha smooth muscle actin staining was mostly seen
in the endothelial lined blood vessels with a few
myofibroblast with in the connective tissue being
stained positive.

71. so increased expression and activation of TGF-B1 in
inflammatory gingival hyperplasia (14) promote an
epithelial cell plasticity that may progress to
EMT [15].

72. Figure 1: Section of
inflammatory ginigival
hyperplasia showing vimentin
expression in fbroblast cells of
connective tissue (40x)
(A) Positive cytoplasmic
expression of spindle cell
fibroblast.
(B) Negatively stained.
Figure

73. Figure 2: Section of inflammatory ginigival hyperplasia showing
Echadherin expression in fibroblast cells of connective (40x).
(A)Surface epithelia (internal control for E-chadherin) positive
membranous and negative cytoplasmic and nuclear staining.
(B) positive membranous expression of spindle cell fibroblast

74. Figure 3: Section of inflammatory ginigival hyperplasia
showing alpha smooth muscle actin expression in fibroblast
cells of connective tissue(40x). (A) positive cytoplasmic
expression of spindle cell fibroblast.

75. Jeopardized E-Chadherin expression could alter the
cell phenotype from epithelial to fibroblast with
spindle shape morphology [17].
 Okada H and coworkers, (2000) have shown that the
epithelial cells migrate from the epithelial layer, travel through
the basement membrane and accumulate in the interstititium
of the tissue; here they eventually get rid of their epithelial
markers and gain a fully fibroblastic phenotype [18,19].

76. referance

77. Content
Normal anatomy of gingiva
The Role of Epithelial Mesenchymal
Transition Process in Inflammatory
hyperplasia
Fibroblasts Collagen Production and
Histological Alterations in Hereditary Gingival
Fibromatosis

79. Content:
Hereditary gingival fibromatosis (HGF)
•Chronic Periodontitis is related to
oxidative stress
•Case report

80. Hereditary gingival fibromatosis (HGF), also called
elephantiasis gingivae, hereditary gingival
hyperplasia, and hypertrophic gingiva, is a disorder
characterized by progressive enlargement of the gingiva.
This enlargement results from an increase in the connective
tissue elements of the submucosa and displays different
severities,
Diseases 2019, 7, 39

81. sometimes covering the entire crowns of the teeth
and deforming the palate, thereby creating occlusal and
aesthetic problems, as well as causing difficulties in
speech and mastication.

82. •Thickening of the alveolar ridge rarely appears
at birth, typically initiates with the eruption of
deciduous or permanent dentition, exacerbates during
adolescence, and can persist within adulthood [1].
•However radiographic imaging shows no specific
changes in the teeth or alveolar bone.

83. •HGF may also exhibit an autosomal dominant or recessive
mode of inheritance.
• The recessive pattern usually linked to other
syndromes: Cowden, Jones, Goltz-Gorlin,; and other
systemic diseases: cherubism, hypothyroidism,
chondrodystrophy, growth hormone deficiency craniofacial
dysmorphism or leukemia [3–6].

84. Histologically, HGF shows gingival features relatively
acellular and with an increased amount of randomly
arranged bundles of collagen.
The overlying epithelium may be variable in
thickness and have prominent, elongated rete
ridges extending into the underlying connective
tissue [8].

85. In rare cases, the description includes deposition of
amyloids and islands of odontogenic epithelium [10].
•However, these histological features are
nonspecific, and the diagnosis should be based
on clinical findings and family history [11].

86. •These conditions are presented with the epithelial
to mesenchymal transition (EMT), where the
basal lamina show disruptions and epithelial cells
migrate into connective tissue and change their
phenotypes to fibroblast-like cells [12].

87. Fibroblasts are the key cells involved in the
gingival production of collagen and respond to
the local stress depending on the environmental
conditions.
Therefore, is essential that they have to maintain a good
metabolic statement to respond to all aggressions.

88. Chronic Periodontitis is related to
oxidative stress [14], and previous studies
have found a relationship between oxidative
stress and cyclosporine-induced gingival
overgrowth [15], but to date, no studies have
linked this oxidative stress to HGF.

92. Diseases 2019, 7, 39

98. 3.4.CoQ10 Level Determination:

99. 3.5: Lipid Peroxidation
Lipid peroxidation could be a consequence of basal ROS
overproduction or fewer antioxidants capacity and could
indicate high levels of oxidative stress in gingival fibroblasts
from the father compared to the control and his daughter
(Figure 4D).

100. Conclusions
The histological data showed basal lamina disruption,
epithelial cell migration into connective tissue and a lack of
laminin 5 in their basal membrane.
In vitro results have demonstrated, for the first time,
that collagen synthesis is influenced by an oxidant
and can be restored by an antioxidant in HGF
fibroblasts.