Biomedical subjects

R Herrera-Esparza

Publications and source records attributed to R Herrera-Esparza.

At least 19 recordsLinked to original sources

PubMed2005

Scleroderma with type III glomerulonephritis and MPO-ANCA antibodies in the serum.

Scleroderma is an autoimmune disease characterized by early inflammatory infiltrates followed by fibrosis in the skin and internal organs. CREST is a relatively benign cutaneous variant of scleroderma that features calcinosis, Raynaud's phenomenon, oesophageal dysfunction, sclerodactyly and telangiectases. Glomerulonephritis is a rare association of CREST. We are reporting a patient with CREST who developed glomerulonephritis and had anticentromere and antineutrophil cytoplasmic autoantibodies (ANCA) in her serum.

Antibodies, Antineutrophil Cytoplasmic↗

PubMed2003

Defective expression of FasL and Bax in human lung cancer.

The present studies investigated whether FasL and Bax genes are expressed in pleuro-pulmonary biopsies from patients with lung cancer. FasL, Bax, and TNFalpha mRNAs were detected in 19 biopsies of primary or metastasic lung cancer by fluorescent in situ hybridization assays. Fluorescent probes were produced by polymerase chain reaction using a human spleen lambda gt11 library and specific primers for FasL, Bax, and TNFalpha. Proteins were detected by immunohistochemistry using monoclonal anti- FasL, anti-Bax, and anti-TNFalpha antibodies. Chromatin fragmentation was detected by TUNEL. Seven negative samples from subjects without lung pathology were obtained during legal autopsies and 12 positive control biopsies from patients with lung infections were also included. Sixty-eight percent of lung cancer biopsies exhibited FasL; Bax was expressed in 68% and TNFalpha in 63%. FasL protein was detected in 21%, Bax protein in 26%, and TNFalpha was present in 31% of cancer biopsies. A low degree of apoptosis in lung cancer was demonstrated by TUNEL assays. A defect in FasL, Bax, and TNFalpha gene expression was found in lung cancer biopsies. Some tumors normally expressed the mRNA of FasL, Bax, or TNFalpha, but their proteins were absent, or were non-functional, since TUNEL assays were negative. Such a failure would contribute to cancer cell survival and dissemination.

Adult↗

PubMed2003

Possible role of Hsp70 in autoantigen shuttling to the dermo-epidermal junction in systemic lupus erythematosus.

The lupus band is the result of immune complex deposition along the dermo-epidermal junction; such complexes are formed in situ by the interaction of antinuclear antibodies with their respective autoantigens. Dermal autoantigens are released after sun exposure, concurrently a heat shock protein production take place and would participate in autoantigen transfer to the dermo-epidermal junction. In this work the presence of Hsp70 along with the lupus band was investigated by immunofluorescence in twenty SLE skin biopsies. Immune deposits were mainly composed by IgM, IgG and C3 and were found in all lupus biopsies at the dermo-epidermal junction. Immunoreagents were also present into papillary vessels and, with less extent, into epidermal keratinocytes. Hsp70 was present in 60% of lupus biopsies, and was mainly distributed along dermo-epidermal junction and around papillary vessels. Furthermore, by double fluorescence labelling assays, we found that immuno-reactants are co-localized with Hsp70. Our results suggest that Hsp70 would shuttle autoantigens to the dermo-epidermal junction.

Adolescent↗

PubMed2003

FasL and Bax genes are differentially expressed in acinar epithelium and inflammatory cells of primary Sjögren salivary glands.

AIM: Assess the expression of FasL, Bax, TNFa and IL-6, genes in salivary glands of primary Sjögren patients. METHODS: Twenty minor salivary glands from patients with primary Sjögren syndrome were studied by in situ hybridization with cDNA fluorescent probes. An equal number of control biopsies were included. RESULTS: Sjögren salivary glands differentially display the inflammatory cytokines and pro-apoptotic mRNAs as follows: mononuclear infiltrating cells exhibited IL-6 and TNFa, whereas the ductal epithelium and acinary cells mainly expressed FasL and Bax. Control biopsies were negative. CONCLUSION: Present data suggest that local production of inflammatory cytokines would induce the Fas and Bax pathways committing the ductal epithelium and the acinary cells to apoptosis.

Adult↗

PubMed2002

Echinococcus granulosus down regulates the hepatic expression of inflammatory cytokines IL-6 and TNF alpha in BALB/c mice.

Hydatid disease is caused by the metacestode of Echinococcus granulosus. Different experimental models have been used to understand hydatid disease. In current studies BALB/c mice were used to evaluate the hepatic response of IL-6 and TNF alpha triggered by Echinococcus granulosus. BALB/c mice were intraperitoneally infected with protoscoleces from E. granulosus; hydatid cysts appeared on the liver eight weeks after inoculation. The RNA extracted from hepatic sections was used for RT-PCR amplification with primers for IL-6, TNF alpha, IL-10, TGF beta and G3PDH. In situ cytokine expression was assessed by FISH. Complete parasite cysts on the liver surface were observed 16 weeks after infection; controls were negative. The expression of IL-6 and TNF alpha was normal at baseline and declined progressively eight weeks after infection; in some animals such expression was abrogated 16 weeks after infection. On the other hand IL-10 and TGF beta were increased progressively. Controls expressed the cytokines normally. Present results suggest that E. granulosus induces a local immunosupression probably mediated by IL-10 and TGF beta; therefore it seems possible that such a mechanism would assist the parasite in escaping the harmful host cell-mediated response.

Animals↗

PubMed2001

Anti-idiotype antibodies neutralize in vivo the blistering effect of Pemphigus foliaceus IgG.

Idiotypes are molecular clues used to explore the specificity and diversity of immune response. In the present study, anti-idiotype antibodies were used to neutralize the pathogenic effects induced by the injection of pemphigus immunoglobulin(Ig)G into BALB/c mice. To achieve our goal, antidesmoglein 1 IgG was obtained from a patient with pemphigus foliaceus with high titer of antiepithelial antibodies. The IgG was isolated by ion exchange chromatography, then digested by pepsin. F(ab')2 fragments were purified in Sephacryl S-300 and injected in rabbits to produce anti-idiotype antibodies. The rabbit sera reacted with the pemphigus F(ab')2 fragments. Eleven pemphigus foliaceus sera were recognized by the anti-idiotype serum at the light or heavy chains whereas bullous pemphigoid and normal IgG were negative. Neonatal BALB/c mice injected with pemphigus IgG developed intraepidermal blisters, mimicking the clinical and immunopathological features of the pemphigus. In contrast, the animals treated with anti-idiotype antibodies and pemphigus IgG did not develop blisters. Thus, anti-idiotype antibodies neutralize in vivo the pathogenic effects of pemphigus IgG.

Animals↗

PubMed2001

TNFalpha and IL-6 are mediators in the blistering process of pemphigus.

BACKGROUND: Pemphigus is an autoimmune disease characterized by intraepidermal blisters induced by pemphigus IgG. In addition to autoantibodies, molecular mechanisms involved in acantholysis remain largely unknown. For this reason, we address a possible role of the inflammatory cytokines IL-6 and TNFalpha in pemphigus lesions. METHODS: Sixteen biopsies from patients with different types of pemphigus were studied by in situ hybridization using DNA fluorescent probes for IL-6 and TNFalpha mRNA. RESULTS: Fifty-six percent of lesional biopsies exhibited cytokine gene expression, which was poorly expressed in noninvolved skin. Deposits of TNFalpha and IL-6 were products of in situ transcription at the epidermal level. CONCLUSIONS: Inflammatory cytokine expression around the blister could play a mediator role in pemphigus lesions by increasing epithelial damage.

Biopsy↗

PubMed2001

Glomerular expression of Fas ligand and Bax mRNA in lupus nephritis.

The current studies were carried out to determine the expression of Fas ligand and Bax in kidneys from lupus nephritis as possible indicators of apoptosis. Twenty-four kidney biopsies from patients with lupus nephritis and 30 normal controls were studied for FasL and Bax gene expression by fluorescent in situ hybridization. Seventy percent of the lupus biopsies displayed FasL or Bax mRNAs. These genes were mainly expressed in biopsies with higher activity indices. In contrast, neither of these mediators was detected in normal glomeruli. These data suggest that FasL and Bax are up-regulated in lupus nephritis and may play a pathogenic role through apoptotic cascades.

Adolescent↗

PubMed2000

Transplacental passage of maternal pemphigus foliaceus autoantibodies induces neonatal pemphigus.

The association of maternal pemphigus foliaceus (PF) with neonatal PF is rare and may be secondary to transplacental passage of PF autoantibodies. We describe a 25-year-old patient with PF who was delivered of two consecutive babies, one with classic skin lesions of PF and another that was normal. The neonate with PF was born when the mother had widespread skin disease; the normal newborn was born when the mother was in partial remission. The titers of PF autoantibodies were higher in the mother's serum and the cord serum of the baby with PF than in the mother during partial remission and the unaffected baby. The mother and affected baby had autoantibodies to desmoglein 1. Furthermore, cord blood from the baby with PF induced skin disease when injected into mice. In this case, maternal PF was associated with neonatal PF when the titers of maternal anti-desmoglein 1 autoantibodies were elevated. The cutaneous disease in neonatal PF is due to anti-desmoglein 1 autoantibodies.

Adult↗

PubMed2000

Fas ligand and Bax gene transcription contributes to Ro60 ribonucleoprotein redistribution in UV-A irradiated human keratinocytes.

OBJECTIVES: Ro ribonucleoproteins are of particular interest because they are serologic markers of photosensitive variants of lupus such as the subacute cutaneous lupus erythematosus (SCLE), in which the polycyclic skin lesions are triggered by exposure to the sun. We study the role of apoptosis in the expression of Ro antigen. METHODS: We used UV-A irradiated keratinocytes. RESULTS: We demonstrate in cultured human UVA-irradiated keratinocytes that the enhanced expression of Ro60 ribonucleoprotein is caused by antigenic redistribution consecutive to Fas-L and Bax gene activation.

Apoptosis↗

PubMed1999

Ontogeny of Ro hYRNAs in human heart.

The Ro complex is composed of three ribonucleoproteins of 60, 54, and 52 kDa. The Ro60 is associated with the 1-5 hYRNAs. Autoantibodies against Ro are found in sera from lupus patients. Lupus frequently presents in female patients during childbearing years and transplacental passage of maternal anti-Ro/La autoantibodies has been implicated in triggering neonatal lupus and congenital heart block (CHB). Since expression of Ro ribonucleoproteins occurs before the onset of CHB, epitope spreading of Ro hYRNAs could arise during cardiac ontogeny, thus maternal autoantibodies would damage a previously developed AV node. To explore the cardiac ontogeny of Ro hYRNAs, embryonic and adult tissues were obtained from legal autopsies. In situ hybridization using oligonucleotides for hY1, hY3, hY4, hY5, and Ro60 was performed on sections of cardiac tissue; their corresponding cDNAs were amplified by RT-PCR. The principal results were as follows: expression of hY4/5RNAs was greater in fetal tissues from 8-12 weeks of development. The subcellular distribution of hYRNAs in embryonic tissues was nucleocytoplasmic, whereas in the adult heart it was cytoplasmic. In conclusion, hYRNAs expression occurs during early cardiac development.

Adult↗

PubMed1999

The 5S rRNA is associated with Ro60 ribonucleoprotein and is co-precipitated with hYRNAs by anti-Ro antibodies.

Ro particles are conserved molecules that contain a YRNA and various Ro proteins, which are recognized by autoimmune sera from patients with lupus erythematosus or Sjögren's syndrome. The Ro60 ribonucleoprotein (RNP) forms complexes with certain 5S rRNAs, in such a manner that Ro60 could participate in the control of 5S rRNA production. The present studies were carried out to explore the interaction of Ro components, and to address the question whether Ro60 RNP binds simultaneously 5S rRNA and hYRNA. Anti-Ro60 antibodies were used to immunoprecipitate the RNA. Immunoprecipitates were reverse transcribed with specific oligonucleotides and the resulting cDNAs from 5S and hY4 were amplified by PCR. We found that 5S rRNA is complexed with hY4 and hY5 RNAs by means of the Ro60 RNP. Moreover, by in situ hybridization assays we were able to demonstrate that these molecules have a similar nuclear distribution. According to these results, it seems reasonable to assume that the Ro60 protein could be involved in ribosome assembly.

Antibodies, Monoclonal↗

PubMed1999

UV-A irradiation induces transcription of IL-6 and TNF alpha genes in human keratinocytes and dermal fibroblasts.

OBJECTIVE: To determine whether UV-A irradiation induces synthesis of inflammatory cytokines in the skin. METHODS: Human keratinocytes and dermal fibroblasts were cultured and exposed to various doses of UV-A radiation. The cellular distribution of IL-6 and TNF alpha was determined by indirect immunofluorescence and by flow cytometry with monoclonal anti-IL-6 and anti-TNF alpha antibodies. Cytokine production was measured in the supernatants using an ELISA. IL-6 and TNF alpha transcription induced by UV-A was determined by reverse transcriptase-polymerase chain reaction (RT-PCR) amplification. RESULTS: IL-6 and TNF alpha were detected in small amounts in nonUV-A-irradiated cell. UV-A exposure was followed by significant increases in IL-6 and TNF alpha expression and by small increases in IL-6 and TNF alpha levels in culture supernatants. RT-PCR demonstrated a UV-A-mediated increase in the transcription of IL-6 and TNF alpha genes. CONCLUSION: Synthesis of IL-6 and TNF alpha can be induced by UV-A irradiation. This effect of UV-A may contribute to the inflammatory skin changes seen during lupus flare-ups after sun exposure.

Blotting, Western↗

PubMed1999

Ro60 ribonucleoprotein inhibits transcription by T3 RNA polymerase in vitro.

BACKGROUND: Ro60 ribonucleoprotein is a conserved molecule belonging to the family of Ro ribonucleoproteins and targeted by autoantibodies produced in patients with systemic lupus erythematosus or Sjogren's syndrome. Ro60 plays a role in postranscription events, as well as in the nucleocytoplasmic shuttling of RNA polymerase III transcripts. OBJECTIVE: To evaluate the in vitro effects of Ro60 on T3 RNA polymerase transcription. METHODS: Ro60 ribonucleoprotein was affinity-purified from human spleen extracts using 4B-Sepharose linked to anti-Ro60 monoclonal antibodies. Purified Ro60 was incorporated into the T3 RNA polymerase transcription reaction system using pTRI-beta-Actin-human DNA as a template. RESULTS: Ro60 inhibited initiation of the transcription process in a dose-dependent manner; neither elongation nor termination was affected by Ro. CONCLUSION: In vitro, Ro60 appears to inhibit the transcription of a T3 RNA polymerase-dependent template.

Adult↗

PubMed1999

Anti-NuMA antibodies: an uncommon specificity in scleroderma sera.

BACKGROUND: Serum antibodies in scleroderma patients are generally directed against the nucleolus and centromeres. A small proportion of patients have serum antibodies to the centrioles and mitotic apparatus. OBJECTIVE: To determine the prevalence of serum autoantibodies against the mitotic apparatus in scleroderma patients. MATERIAL AND METHODS: Sera from 113 patients with various forms of scleroderma were tested for antinuclear antibodies by indirect immunofluorescence on HEp-2 cells. The specificity of the antibodies was determined by Western blot. RESULTS: Only two scleroderma sera recognized the mitotic apparatus. Western blot results showed that in both cases the target was an about 235 kDa protein corresponding to the NuMA determinant. Affinity-purified anti-NuMa antibodies were used to perform immunolocalization in synchronized HEp-2 cells using scanning laser confocal microscopy. The anti-NuMA autoantibodies recognized the mitotic asters but neither the centrioles nor the microtubules. CONCLUSION: Our data suggest that anti-NuMA autoantibodies may be devoid of clinical significance in scleroderma. However, they remain useful as probes in cell biology studies.

Antibodies, Antinuclear↗

PubMed1998

Renal expression of IL-6 and TNFalpha genes in lupus nephritis.

These studies were carried out to examine the presence of the inflammatory cytokines IL-6 and TNFalpha in kidneys of patients with lupus nephritis as an indicator of their possible role in its pathogenesis. A total of 19 kidney biopsies from patients with type III or IV lupus nephritis were processed by direct immunofluorescence using monoclonal anti-IL-6 and TNFalpha antibodies. Local expression of these genes was demonstrated both by in situ hybridization and by reverse transcriptase-PCR amplification of total RNA isolated from kidney tissue. Fifty-two percent of the biopsies exhibited IL-6 and TNFalpha deposited along the glomeruli and tubules; in situ expression of these cytokines was demonstrated in 6 biopsies with type IV, and 1 with type III nephritis. Inflammatory cytokines are actively synthesized in the kidneys of patients with lupus nephritis and therefore, may play a role in its pathogenesis.

Adolescent↗

PubMed1998

Localization of the centromere protein CENP-B using scleroderma sera and evidence for a role in centromere survival.

OBJECTIVE: To determine whether centromeric CENP A, B and C proteins play a role in centromere survival. METHODS: Sixteen anti-centromere sera from scleroderma patients were used. The most common reactivity demonstrated by Western blot was anti-CENP-A, followed by anti-CENP-B and -C, in that order. The reactivity of these sera with HEp-2 cells was studied using an indirect immunofluorescence assay with and without prior digestion by a DNase, Aspergillus nuclease and the restriction endonucleases Bam HI, Hind III, and Eco RI. CENP-B was purified using affinity chromatography and anti-CENP-B antibody. The interaction between CENP-B and the CENP-B box was evaluated using immunoprecipitation. Precipitates containing alphaDNA were amplified using a PCR method with specific primers for the CENP-B box. RESULTS: None of the nucleases altered the fluorescence pattern. PCR amplification showed that CENP-B adsorbed on a Sepharose-4B/anti-CENP-B antibody column retained alphaDNA satellites. No retention was seen in the absence of CENP-B. CONCLUSIONS: CENP-B protects alphaDNA from digestion by nucleases and prevents DNase or restriction enzyme digestion from affecting the morphology and location of centromeres. CENP-B may promote and maintain joining of DNA satellites in the centromere.

Antibodies, Antinuclear↗

PubMed1998

Tyrosine kinase participates in phosphorylation of the Ro60 ribonucleoprotein.

Studies of Ro ribonucleoprotein are important in rheumatology, since anti-Ro antibodies are probably involved in the pathogenesis of congenital heart block and subacute cutaneous lupus erythematosus. In addition, the phosphorylation-dephosphorylation cycle modulates binding of ribonucleoproteins to RNA, a process that might affect the antigenicity and function of the Ro protein. The present study was designed to determine whether Ro can be phosphorylated by tyrosine kinase. To answer this question, synchronized HEp-2 cells were phosphorylated in vivo with exogenous 32P, and Ro ribonucleoprotein previously subjected to metabolic radiolabeling was immunoprecipitated by monoclonal anti-Ro antibodies and examined by SDS-PAGE and autoradiography. The main results were as follows: first, Ro ribonucleoprotein was phosphorylated in vivo; second, Ro was found to have phosphorylable tyrosine residues; third, tyrosine kinase participated in the phosphorylation of Ro; and fourth, phosphorylation did not change the recognition pattern of Ro by anti-Ro antibodies. In conclusion, Ro60 is phosphorylated by tyrosine kinase.

Antibodies, Monoclonal↗