43 research outputs found
Neonatal molecular pathologies induced by maternal anti-Ro and anti-La antibodies
Maternal antinuclear antibodies with anti-Ro or anti-La specificity might be pathogenic to the fetus and could induce molecular neonatal pathologies, such as neonatal lupus (NL) with or without congenital heart block (CHB). The cutaneous manifestations of neonatal lupus appear at birth or a few weeks later, and skin lesions may persist for weeks. While CHB is characterized by intrauterine bradycardia or low heart rates at birth and may persist for months, depending on the degree of blockage. Clinical and experimental data demonstrated that anti-Ro and anti-La autoantibodies functionally inhibit L-type calcium channels and induce abnormalities in electrical conduction of the cardiac myocytes. It has been 38 years since the first clinical description of CHB. Presently, the pathophysiology of CHB has been clarified through clinical and basic research studie
Cutaneous manifestations of spondyloarthritis
Spondyloarthritis comprises a group of inflammatory rheumatic disorders with a genetic predisposition
involving multiple genes that interact with environmental factors. The skin manifestations of
spondyloarthritis are diverse, particularly psoriatic arthritis related to the overexpression of inflammatory
cytokines such as TNF, IL-6, IL-12, IL-2 and IFN-g; this psoriatic dermatitis is a common skin feature of
spondyloarthritis. Spondyloarthritis mainly affects the spine, sacroiliac joints, ligaments and other tissues.
Psoriatic lesions are erythematous plaques covered with silvery whitish scales distributed on the scalp,
elbows, knees, trunk and gluteus creases, and the fingernails are frequently involved. Individuals with
reactive arthritis and Crohn’s disease may exhibit psoriasiform dermatitis and other manifestations including
ocular inflammation, oral ulceration, erythema nodosum and/or thrombophlebitis. In the case of reactive
arthritis, male patients may exhibit circinate balanitis and keratoderma blennorrhagica. In summary,
dermatological manifestations of spondyloarthritis represent clinical clues and a unique scenario to explore
the related pathophysiology and therapeutic approaches
The Caspase Pathway as a Possible Therapeutic Target in Experimental Pemphigus
Apoptosis plays a role in pemphigus IgG-dependent acantholysis; theoretically, the blockade of the caspase pathway could prevent the blistering that is caused by pemphigus autoantibodies. Using this strategy, we attempted to block the pathogenic effect of pemphigus IgG in Balb/c mice by using the caspase inhibitor Ac-DEVD-CMK. This inhibitor was administrated before the injection of pemphigus IgG into neonatal mice. The main results of the present investigation are as follows: (1) pemphigus IgG induces intraepidermal blisters in Balb/c neonatal mice; (2) keratinocytes around the blister and acantholytic cells undergo apoptosis; (3) the caspases inhibitor Ac-DEVD-CMK prevents apoptosis; (4) the inhibition of the caspase pathway prevents blister formation. In conclusion, inhibition of the caspase pathway may be a promising therapeutic tool that can help in the treatment of pemphigus flare ups
Pathogenic effects of maternal antinuclear antibodies during pregnancy in women with lupus
Lupus is an autoimmune disease that primarily affects young women of childbearing
age. Fertility rates in lupus patients depend on various factors, including disease activity,
nephritis, and the presence of antiphospholipid antibodies; however, after lupus patients
become pregnant, different factors may affect the course of pregnancy, such as the production of autoantibodies, pre-existing renal disease, and eclampsia, among others. The placenta is a temporary hemochorial organ that prevents immunological conflict due to exposure to alloantigens at the maternal-fetal interface; placental regulatory T cells play a major role in maternal-fetal tolerance. Typically, significant amounts of maternal IgG class antibodies cross the placenta and enter the fetal circulation. This transition depends on the distribution of Fc receptors along the syncytiotrophoblast. The production of antinuclear antibodies (ANA) is a hallmark of lupus, and these autoantibodies can form immune complexes
that are typically trapped in the placenta during gestation. However, the entry of ANA into
the fetal circulation depends on the IgG-ANA concentration and the FcR placental density.
Maternal antinuclear antibodies with anti-Ro or anti-La specificity might be pathogenic to the fetus if transfused by the placental pathway and could induce neonatal pathologies, such as neonatal lupus and congenital heart block. Here, we review the experimental and clinical data supporting a pathogenic role for
maternal autoantibodies transmitted to the fetus
Autoimmune vitiligo in rheumatic disease in the mestizo Mexican population
Vitiligo is a chronic disease characterized
by the dysfunction or destruction of melanocytes with
secondary depigmentation. The aim of the present study
was to determine the prevalence of vitiligo associated with
autoimmune rheumatic diseases. The clinical records from
a 10-year database of patients with rheumatic diseases
and associated vitiligo was analysed, with one group of
patients having autoimmune rheumatic disease and another
non-autoimmune rheumatic disease. Available serum samples
were used to assess the anti-melanocyte antibodies. A total
of 5,251 individual clinical files were archived in the last
10 years, and these patients underwent multiple rheumatology
consultations, with 0.3% of the group presenting with vitiligo.
The prevalence of vitiligo in the autoimmune rheumatic
disease group was 0.672%, which was mainly associated with
lupus and arthritis. However, patients with more than one
autoimmune disease had an increased relative risk to develop
vitiligo, and anti-melanocyte antibodies were positive in 92%
of these patients. By contrast, the prevalence was 0.082% in
the group that lacked autoimmune rheumatic disease and
had negative autoantibodies. In conclusion, the association
between vitiligo and autoimmune rheumatic diseases was
relatively low. However, the relative risk increased when there
were other autoimmune comorbidities, such as thyroiditis or
celiac disease. Therefore, the presence of multiple autoimmune
syndromes should be suspected
Apoptosis and Redistribution of the Ro Autoantigen in Balb/c Mouse Like in Subacute Cutaneous Lupus Erythematosus
In subacute cutaneous lupus eryhematosus (SCLE) the cutaneous antigens constitute the main source of Ro and La autoantigens. The aim of this investigation was to demonstrate if UV light increases the availability of Ro autoantigen in the skin, also the blocking effect of Ac-DEVD-CMK a caspase inhibitor was assessed. For this purpose newborn Balb/c mice were UVB irradiated (5–30 mJ/cm2) equivalent to a moderate to severe sunburn. Animals were injected with monoclonal anti-Ro antibodies from SCLE patients. Apoptosis was also induced by anti-Fas antibody injection. Skin samples were examined by direct immunofluoresence, by TUNEL, and the expression of caspase 3 by RT-PCR. Major findings of present studies were: 1. UVB irradiation and anti-Fas induced apoptosis of keratinocytes. 2. Apoptosis redistribute the Ro antigen on cell surface and is better triggered by Ro antibody. 3. The caspase 3 inhibitor Ac-DEVD-CMK decreases the availability of Ro autoantigen in epidermis and prevents deposition of anti-Ro. In conclusion, the caspase pathway would be blocked to avoid anti-Ro deposition along skin; this finding would be a prospect in the treatment of SCLE patients
Apoptosis and cell proliferation: the paradox of salivary glands in sjögren’s disease
Este estudo avalia a apoptose e a proliferação nas glândulas salivares dos doentes com Síndroma de Sjögren primária.
Métodos: A apoptose foi estudada por imunohistoquímica utilizando anticorpos monoclonais anti-
-Fas, FasL e Caspase 3 e as características apoptóticas por TUNEL. Os estudos foram executados em
vinte e quatro glândulas salivares minor de doentes com Síndroma de Sjögren primária e num igual número de controlos. A proliferação foi avaliada com anticorpos monoclonais anti-PCNA e anti-Ki67.
Resultados:Todas as glândulas salivares dos doentes com Sjögren apresentavam moléculas apoptoticas no epitélio dos ductos salivares, e menos no tecido acinar, consequentemente a presença do caspase 3, Fas/FasL eram concordantes com a expressão da apoptose por TUNEL. Os marcadores de proliferação foram encontrados nas células inflamatórias presentes, mas não no epitélio ductal nem nos acinos. A expressão de marcadores de apoptose ou de proliferação nos tecidos das biopsias dos controlos foi escassa.
Conclusão: Os dados actuais sugerem que as células do epitélio ductal e dos acinos das glândulas salivares dos doentes com doença de Sjögren têm aumento da apoptose. A proliferação foi observada principalmente no infiltrado celular linfóide. Em conjunto, estes eventos constituem um paradoxo biológico relacionado com o processo inflamatório das glândulas salivares na Síndrome de Sjögren.Aim: To assess apoptosis and proliferation in salivary glands of patients with primary Sjögren’s syndrome.
Methods: Studies were performed in twenty four minor salivary glands from patients with primary
Sjögren’s syndrome and an equal number of controls. Apoptosis was studied by immunohistochemistry using monoclonal antibodies anti-Fas, FasL and Caspase 3 and apoptotic features by TUNEL. Proliferation was assessed with monoclonal anti-PCNA and anti-Ki67 antibodies.
Results: All salivary glands from Sjögren’s display apoptotic molecules along the epithelia of salivary
ducts, and in a smaller amount in acinar tissue. The presence of Caspase 3, Fas/FasL was concordant
with the expression of apoptosis by TUNEL. Proliferation markers were encountered in inflammatory emigrant cells, but not in ductal epithelia nor in acini. Control biopsies poorly expressed apoptotic or proliferation markers.
Conclusion: Present data suggests that the ductal epithelial and acinar cells of salivary glands from
Sjögren’s disease patients exhibit increased apoptosis. Proliferation was mainly observed in infiltrating lymphoid cells. Both events constitute a biological paradox related to the inflammatory process of salivary glands in Sjögren’s disease
Camptothecin induces the transit of fASl trimers to the cell surface in apoptotic heP-2 cells
Fas ligand (L) is a membrane protein from the tumor necrosis factor
(TNF) family. It induces apoptosis upon contact with its Fas/CD95/APO1
receptor. Trimerization of FasL on the surface of effector cells is essential in the
binding of the Fas trimer of the target cells. The receptor then recruits an adaptor
and caspase-like proteins which lead apoptosis. This paper reports on the fate of
FasL in HEp-2 cells committed to apoptosis by induction with campthotecin.
Our main results demonstrated that in non-apoptotic cells, FasL aggregates in
the cytoplasm forming trimers of 120 kDa. Apoptosis increases the trimeric
FasL species, but also induces its dissociation into monomers of 35 kDa. In
conclusion, camptothecin appears to perturb the Fas and FasL segregation in the
cytoplasm by promoting the transit of FasL to the cell surface, thus fostering
a process of autocrine or paracrine apoptosis. FasL is trimerized prior to
Fas/FasL complex formation, and after apoptosis, FasL undergoes an intense
turnover
shRNA targeting caspase-3 inhibits apoptosis and cell detachment induced by Pemphigus Vulgaris autoantibodies
Pemphigus is an organ-specific autoimmune disease that affects the skin and mucous
membranes. It is induced by the deposition of pemphigus IgG autoantibodies, which mainly
target Dsg1 and 3 and cause a loss of cell adhesion in a phenomenon known as
acantholysis, and clinically is reflected as intraepidermal blistering. The present work
assessed the effect of pemphigus vulgaris IgG (PV-IgG) on cell adhesion and caspase 3-
dependent apoptosis in HaCaT cells. The expression of caspase-3 induced by PV-IgG was
silenced in cells pre-treated with caspase 3-shRNA. PV-IgG induced cell detachment and
apoptotic changes as demonstrated by the annexin-FITC assays. Treatment of cell cultures
with normal IgG (control; N-IgG) did not have relevant effects on the aforementioned
parameters. Then, the effect of PV-IgG on cells previously treated with shRNA was tested.
The results demonstrated that shRNA reduced apoptotic features and the relative expression
of caspase-3 measured by qRT-PCR, which showed a decrease of 96%. In conclusion
shRNA prevented cell detachment and apoptosis of HaCaT cells induced by PV-IgG. The
presented results further our understanding of the molecular pathophysiologic mechanisms
involved in pemphigus diseases.Pemphigus is an organ-specific autoimmune disease that affects the skin and mucous
membranes. It is induced by the deposition of pemphigus IgG autoantibodies, which mainly
target Dsg1 and 3 and cause a loss of cell adhesion in a phenomenon known as
acantholysis, and clinically is reflected as intraepidermal blistering. The present work
assessed the effect of pemphigus vulgaris IgG (PV-IgG) on cell adhesion and caspase 3-
dependent apoptosis in HaCaT cells. The expression of caspase-3 induced by PV-IgG was
silenced in cells pre-treated with caspase 3-shRNA. PV-IgG induced cell detachment and
apoptotic changes as demonstrated by the annexin-FITC assays. Treatment of cell cultures
with normal IgG (control; N-IgG) did not have relevant effects on the aforementioned
parameters. Then, the effect of PV-IgG on cells previously treated with shRNA was tested.
The results demonstrated that shRNA reduced apoptotic features and the relative expression
of caspase-3 measured by qRT-PCR, which showed a decrease of 96%. In conclusion
shRNA prevented cell detachment and apoptosis of HaCaT cells induced by PV-IgG. The
presented results further our understanding of the molecular pathophysiologic mechanisms
involved in pemphigus diseases