Epidermal Fatty Acid-Binding Protein: A Novel Marker in the Diagnosis of Dry Eye Disease in Sjögren Syndrome.

PURPOSE: Sjögren syndrome (SS) is a chronic inflammatory autoimmune disease of the lacrimal and salivary glands. This study compared the concentrations of epidermal fatty-acid binding protein (E-FABP) in the saliva, serum, and tears of SS patients with dry eye and dry mouth, with those of healthy adults to investigate the usefulness of E-FABP as a diagnostic marker for SS. DESIGN: Prospective, observational case series. PARTICIPANTS: The subjects were 11 new patients with untreated Sjogren syndrome and 12 healthy control individuals. METHODS: The diagnosis of SS was in accordance with the Ministry of Health, Labour and Welfare (Japan) Diagnostic Criteria (1999). Saliva, serum, and tear specimens were collected during internal medicine, dental, and ophthalmological examinations. The ophthalmological tests included the Dry Eye-related Quality of life Score (DEQS), tear break-up time (BUT), vital staining with fluorescein (FS) and lissamine green (LG), and the Schirmer test-1. The E-FABP concentration in the tears, saliva, and serum was measured by enzyme-linked immunosorbent assay (ELISA). MAIN OUTCOME MEASURE: The E-FABP concentrations were compared between patients and controls. RESULTS: There were significant differences between the patient and healthy control groups in all ophthalmological test results. There were no significant differences between the groups in the E-FABP concentrations in the saliva (p = 0.1513) or the serum (p = 0.4799), but the E-FABP concentration in the tears significantly differed between groups. The E-FABP concentration in tears tended to be significantly lower in patients with SS (mean, 323.5 ± 325.6 pg/mL) than healthy control subjects (mean, 4076 pg/mL; p = 0.0136). The E-FABP concentration in tears significantly correlated with the results of dry eye parameters. CONCLUSION: The E-FABP concentration in tears appears to be related to ocular surface epithelial damage and tear stability and may be a promising novel biomarker in the diagnosis of SS.

BAFF overexpression increases lymphocytic infiltration in Sjögren's target tissue, but only inefficiently promotes ectopic B-cell differentiation.

B-cell activating factor (BAFF) levels are increased in rheumatoid arthritis, lupus and primary Sjögren's syndrome (pSS). However, BAFF contribution to pathogenesis is not completely understood. In pSS, immune infiltration of the salivary and lacrimal glands leads to xerostomia and xerophtalmia. Glandular B cell hyperactivation, differentiation into germinal center (GC)-like structures and plasma cell accumulation are histopathological hallmarks that were attributed to increased BAFF. Here, we experimentally tested this hypothesis by overexpressing BAFF in a mouse model of pSS. BAFF overexpression enhanced lymphocytic infiltration and MHCII expression on B cells. Increased BAFF also induced B cell differentiation into GC B cells within the autoimmune target tissue. However, even in these conditions, GC B cells only accounted for <1% of glandular B cells, demonstrating that BAFF is not efficiently promoting ectopic GC formation in pSS and warranting further investigation of therapeutics targeting both BAFF and the related TNF-family member APRIL.

Effects of chondrocyte-derived extracellular matrix in a dry eye mouse model.

PURPOSE: The occurrence of repetitive dry eye is accompanied by inflammation. This study investigated the anti-inflammatory effects of chondrocyte-derived extracellular matrix (CDECM) on the cornea and conjunctiva in a dry eye mouse model. METHODS: Dry eyes were experimentally induced in 12- to 16-week-old NOD.B10.H2(b) mice (Control) via subcutaneous injections of scopolamine (muscarinic receptor blocker) and exposure to an air draft for 10 days (desiccation stress [DS] 10D group). Tear volume and corneal smoothness were measured at 3, 5, 7, and 10 days after the instillation of PBS (PBS group) or CDECM (CDECM group). The corneas and conjunctivas were sectioned and stained with hematoxylin and eosin (H&E) and periodic acid Schiff (PAS). The expression of inflammatory markers (i.e., tumor necrosis factor-α [TNF-α], matrix metalloproteinase-2 [MMP-2], MMP-9, intercellular adhesion molecule-1 [ICAM-1], and vascular cell adhesion molecule-1 [VCAM-1]) was detected by quantitative real-time (qRT)-PCR and western blotting. All data were statistically processed using SPSS version 18.0. RESULTS: The instillation of CDECM after the removal of the DS increased tear production by up to 3.0-fold, and corneal smoothness improved to 80% compared to the PBS group (p<0.05). In the CDECM group, the detachment of the corneal epithelial cells was reduced by 73.3% compared to the PBS group, and the conjunctival goblet cell density was significantly recovered to the control levels (p<0.05). The expression of inflammatory factors was decreased in the cornea and conjunctiva of the CDECM group compared to the PBS group. CONCLUSIONS: These observations suggest that CDECM induced effective anti-inflammatory improvements in the cornea and conjunctiva in this experimental model of dry eye.

Expression of SIRT1 and oxidative stress in diabetic dry eye.

OBJECTIVE: To explore the expression of SIRT1 with oxidative stress and observe physiological and pathological changes in the corneas as well as the association between SIRT1 and oxidative stress of diabetic dry eyes in mice. METHOD: Forty-eight C57BL/6Jdb/db mice at eight weeks of age were divided randomly into two groups: the diabetic dry eye group and the diabetic group. An additional forty-eight C57BL/6J mice at eight weeks of age were divided randomly into two groups: the dry eye group and the control group. Every mouse in the dry eye groups (diabetic and normal) was injected with scopolamine hydrobromide three times daily, combined with low humidity to establish a dry eye model. After the intervention, phenol red cotton string tests and corneal fluorescein staining were performed. In addition, HE staining and immunofluorescence were done. Expression of SIRT1 in the cornea was examined by real-time PCR and Western Blot and expression of FOXO3 and MnSOD proteins was detected by Western Blot. RESULTS: At one, four, and eight weeks post intervention, all of the groups except the controls showed significant decreases in tear production and increases in the corneal fluorescein stain (P<0.05 vs control). Between the experimental groups, the diabetic dry eye group had the least tear production and the highest corneal fluorescein stain score (P<0.05). As the disease progressed, all of the experimental groups showed obviously pathological changes in HE staining, particularly the diabetic dry eye group. In the 1(st) and 4(th) week, the expression of SIRT1, FOXO3, and MnSOD were significantly higher in the diabetic DE and DM groups but lower in the DE group compared to the controls (P<0.05). In the 8(th) week, the expression of SIRT1, FOXO3, and MnSOD was significantly down-regulated in the diabetic DE group and the DM group (P<0.05). Immunofluorescence showed similar results. CONCLUSION: In the condition of diabetic dry eye, tear production declined markedly coupled with seriously wounded corneal epithelium. Oxidative stress in the cornea was enhanced significantly and the expression of SIRT1 was decreased.

Desiccating stress-induced chemokine expression in the epithelium is dependent on upregulation of NKG2D/RAE-1 and release of IFN-γ in experimental dry eye.

The Th1-associated chemokines CXCL9, CXCL10, and CXCL11 coordinate migration of CXCR3(+) Th1 cells. The objective of this study was to evaluate the role of the innate immune system in stimulating chemokine expression in an experimental model of dry eye and bridge the gap between innate and adaptive immunity. Desiccating stress (DS) induced very early (6 h) expression and production of Th1-associated chemokines in cornea and conjunctiva of C57BL/6 and RAG1 knockout (KO) mice, demonstrating that chemokine expression does not require innate T cells. We then demonstrated that activating the innate immune system prior to adoptive transfer of T cells to RAG1KO mice increased disease severity. Interestingly, lack of induction of chemokines CXCL9, CXCL10, and CXCL11 in IFN-γKO mice provided evidence that their expression requires IFN-γ for induction. Treatment of RAG1KO mice with anti-NK1.1 prevented the increase of CXCL9, CXCL10, and CXCL11 in response to DS, compared with isotype controls. Additionally, DS increased the expression of NKG2D in the conjunctiva. The expression of the NKG2D ligand, retinoic acid early inducible gene 1, also increased at the ocular surface at both the protein and gene levels. Neutralization of NKG2D at the ocular surface decreased the expression of CXCL9, CXCL10, CXCL11, and IFN-γ. In summary, upregulation of CXCL9, CXCL10, and CXCL11 expression in experimental dry eye is T cell-independent, requiring IFN-γ-producing NKG2D(+) NK cells that are activated in response to DS-induced stress signals. This study provides insight into the events that trigger the initial immune response in dry eye pathology.

miR-146a and miR-155 expression in PBMCs from patients with Sjögren's syndrome.

BACKGROUND: An increasing number of studies have revealed that microRNA (miRNA) contributes to the pathogenesis of autoimmune diseases. The objective of this study is to investigate the miR-146a and miR-155 levels in peripheral mononuclear blood cells from patients with primary Sjögren's syndrome (pSS) who were not receiving medications and to examine the correlations between these miRNA levels and the clinical features of the disease. METHOD: Using real-time polymerase chain reaction analysis of miRNAs, the miR-146a and miR-155 expression levels were assessed in peripheral mononuclear blood cells from 27 patients with pSS and 22 healthy controls, and the relationships between these miRNA levels and the visual analog scale (VAS) scores for dry mouth, dry eyes, and parotid gland swelling were investigated. RESULTS: Compared with the healthy controls, the miR-146a expression level was significantly increased in the patients with pSS (P = 0.0182) and was positively correlated with the VAS scores for parotid swelling (r = 0.4475, P = 0.0192) and dry eyes (r = 0.4051, P = 0.0361). Although the miR-155 expression level was significantly decreased in the patients with pSS (P = 0.0131), the miR-155 expression positively correlated with the VAS score for dry eyes (r = 0.4894, P = 0.0096). CONCLUSION: Our results demonstrated miR-146a overexpression and miR-155 underexpression in the peripheral mononuclear blood cells of the patients with pSS. Furthermore, the expression levels of these miRNAs correlated with the patients' clinical features. Our data suggest that miR-146a and miR-155 might play important roles in the pathogenesis of pSS and that their expression levels may be useful for diagnosing pSS and for predicting disease activity and therapeutic responses.

Chemokine receptors CCR6 and CXCR3 are necessary for CD4(+) T cell mediated ocular surface disease in experimental dry eye disease.

CD4(+) T cells are essential to pathogenesis of ocular surface disease in dry eye. Two subtypes of CD4(+) T cells, Th1 and Th17 cells, function concurrently in dry eye to mediate disease. This occurs in spite of the cross-regulation of IFN-γ and IL-17A, the prototypical cytokines Th1 and Th17 cells, respectively. Essential to an effective immune response are chemokines that direct and summon lymphocytes to specific tissues. T cell trafficking has been extensively studied in other models, but this is the first study to examine the role of chemokine receptors in ocular immune responses. Here, we demonstrate that the chemokine receptors, CCR6 and CXCR3, which are expressed on Th17 and Th1 cells, respectively, are required for the pathogenesis of dry eye disease, as CCR6KO and CXCR3KO mice do not develop disease under desiccating stress. CD4(+) T cells from CCR6KO and CXCR3KO mice exposed to desiccating stress (DS) do not migrate to the ocular surface, but remain in the superficial cervical lymph nodes. In agreement with this, CD4(+) T cells from CCR6 and CXCR3 deficient donors exposed to DS, when adoptively transferred to T cell deficient recipients manifest minimal signs of dry eye disease, including significantly less T cell infiltration, goblet cell loss, and expression of inflammatory cytokine and matrix metalloproteinase expression compared to wild-type donors. These findings highlight the important interaction of chemokine receptors on T cells and chemokine ligand expression on epithelial cells of the cornea and conjunctiva in dry eye pathogenesis and reveal potential new therapeutic targets for dry eye disease.

Association of killer cell immunoglobulin-like receptor and human leukocyte antigen-C genotype with dry eye disease in a Chinese Han population.

Dry eye is one of the most prevalent eye diseases and dry eye disease (DED) is associated with ocular surface inflammation. The interaction between killer cell immunoglobulin-like receptors (KIRs) and human leukocyte antigens (HLAs) regulates the activation of natural killer (NK) cells and certain T cell subsets in response to inflammation. The objective of this study was to explore whether KIR gene and HLA-C allele polymorphisms were associated with DED in a Chinese Han population. Polymerase chain reaction with sequence-specific primers method was used to genotype KIR genes and HLA-C alleles in 106 DED patients and 220 healthy controls. Framework genes KIR2DL4, KIR3DL2, KIR3DL3, and KIR3DP1 were present in all individuals. There were no significant differences in the frequencies of inhibitory KIR genes between the two groups. However, the frequency of KIR2DS2 was significantly higher in severe DED patients than that in healthy controls (p=0.031, odds ratio [OR]=1.828, 95% confidence interval [CI]=1.05-3.17). Significantly different distributions of HLA-C allele groups were not observed in severe DED patients and controls. The frequency of the combination of HLA-C1 allele group with KIR2DS2 was significantly higher in severe DED patients compared with controls (p=0.013, OR=2.083, 95% CI=1.16-3.74). These data suggested that this genotype combination was associated with susceptibility to severe DED and that NK cells might have a role in the pathogenesis of DED. The results led to an interesting future research question of whether or not KIR and HLA-C genotypes were involved in the predisposition to or pathogenesis of DED.

Proinflammatory gene polymorphisms are potentially associated with Korean non-Sjogren dry eye patients.

PURPOSE: To determine whether proinflammatory cytokine genes were potential susceptibility candidate genes for Korean patients with non-Sjogren dry eye, we investigated the association of the interleukin 1 beta (IL1B), interleukin 6 (IL6), and interleukin 6 receptor (IL6R) variations with this disease in Korean patients. METHODS: Genomic DNA was extracted from blood samples of unrelated non-Sjogren dry eye patients and healthy control individuals who visited the Eye Center and Health Promotion Center of St. Mary's Hospital in Seoul, Korea. For screening genetic variations in proinflammatory cytokine genes, the 511 (rs16944) and 31 (rs1143627) positions in the promoter region of IL1B, rs1143634 in exon 5 of IL1B, rs1800795 of the IL6 promoter, and Asp358Ala (rs8192284) of IL6R were genotyped using the polymerase chain reaction, restriction fragment length polymorphisms, and direct sequencing. RESULTS: Among the polymorphisms, rs1143634 (F105F) in exon 5 of IL1B was significantly different between the patient and control groups. The frequency of the C/T genotype in dry eye patients was decreased relative to that of the control subjects (10.4% versus 3.9%, p=0.043, OR=3.337). For the IL6R gene, the genotypic and allelic distribution of rs8192284 was different between the dry eye patients and the controls: CC genotype (p=0.017, OR=2.12) and C allele (OR=1.26). CONCLUSIONS: This is the first report of genetic variation screening of proinflammatory cytokine genes in Korean non-Sjogren dry eye patients. It is suggested that rs1143634 of IL1B and rs8192284 of IL6R act as susceptibility variations in Korean non-Sjogren dry eye patients.

Comparison of telomere length and association with progenitor cell markers in lacrimal gland between Sjögren syndrome and non-Sjögren syndrome dry eye patients.

PURPOSE: Indicators of aging such as disruption of telomeric function due to shortening may be more frequent in dysfunctional lacrimal gland. The aims of this study were to 1) determine the viability of quantitative fluorescence in situ hybridization of telomeres (telo-FISH) for the assessment of telomere length in lacrimal gland in Sjögren and non- Sjögren syndrome patients; and 2) investigate the relationship between progenitor cell markers and telomere length in both groups. METHODS: Quantitative fluorescence in situ hybridization with a peptide nucleic acid probe complementary to the telomere repeat sequence was performed on frozen sections from human lacrimal gland tissues. The mean fluorescence intensity of telomere spots was automatically quantified by image analysis as relative telomere length in lacrimal gland epithelial cells. Immunostaining for p63, nucleostemin, ATP-binding cassette, sub-family G, member 2 (ABCG2), and nestin was also performed. RESULTS: Telomere intensity in the Sjögren syndrome group (6,785.0±455) was significantly lower than that in the non-Sjögren syndrome group (7,494.7±477; p=0.02). Among the samples from the non-Sjögren syndrome group, immunostaining revealed that p63 was expressed in 1-3 acinar cells in each acinar unit and continuously in the basal layer of duct cells. In contrast, in the Sjögren syndrome group, p63 and nucleostemin showed a lower level of expression. ABCG2 was expressed in acinar cells in both sjogren and non-Sjogren syndrome. CONCLUSIONS: The results of this study indicate that 1) telo-FISH is a viable method of assessing telomere length in lacrimal gland, and 2) telomere length in Sjögren syndrome is shorter and associated with lower levels of expression of p63 and nucleostemin than in non-Sjögren syndrome.

Cellular localization of 17 natural mutant variants of ALADIN protein in triple A syndrome - shedding light on an unexpected splice mutation.

The triple A syndrome is a complex and multisystemic autosomal recessive disease with the 3 main symptoms of adrenal insufficiency, alacrima, and achalasia accompanied by neurological impairment. Mutations in the AAAS gene on chromosome 12q13 are responsible for the disorder. AAAS encodes a protein named ALADIN, which belongs to the family of WD-repeat-containing proteins and has been shown to localize to nuclear pore complexes. The function of the protein is not clear. It is supposed that ALADIN plays an important role in RNA and (or) protein trafficking between the nucleus and cytoplasm. With transfection experiments, we analyzed the cellular localization of the wild-type and 17 natural mutant variants (9 missense, 5 nonsense, 3 frameshift mutations) of ALADIN. We show that most mutations cause mislocalization of the mutant ALADIN proteins in the cytoplasm. In contrast, some variants with mutations located at the N-terminus (Q15K, L25P) and 3 artificial C-terminus mutations (Q490X, R493X, and V497X) remain at the nuclear pore. Using a patient cell line, we show that the mutation 43C>A in exon 1 does not cause a missense mutation Q15K but, rather, results in aberrant splicing.

Association of chronic symptomatic neutropenia with the triple A syndrome.

Chronic neutropenia syndromes include distinct hereditary disorders with varying degrees of neutropenia. Among the more common inherited disorders associated with symptomatic neutropenia are cyclic neutropenia, severe congenital neutropenia (Kostmann disease), and Schwachman-Diamond syndrome. The authors describe a 17-year-old girl with triple A syndrome who developed a progressive decrease in the granulocyte count, finally resulting in long-standing neutropenia. Its probable pathogenesis may be related to dysfunction of ALADIN (the protein known to be mutated in triple A syndrome), resulting in abnormal nucleocytoplasmic transport of essential proteins, in myeloid precursor cells. Chronic neutropenia should therefore be considered among the clinical manifestations of triple A syndrome.

Mutant WD-repeat protein in triple-A syndrome.

Triple-A syndrome (MIM 231550; also known as Allgrove syndrome) is an autosomal recessive disorder characterized by adrenocorticotropin hormone (ACTH)-resistant adrenal insufficiency, achalasia of the oesophageal cardia and alacrima. Whereas several lines of evidence indicate that triple-A syndrome results from the abnormal development of the autonomic nervous system, late-onset progressive neurological symptoms (including cerebellar ataxia, peripheral neuropathy and mild dementia) suggest that the central nervous system may be involved in the disease as well. Using fine-mapping based on linkage disequilibrium in North African inbred families, we identified a short ancestral haplotype on chromosome 12q13 (<1 cM), sequenced a BAC contig encompassing the triple-A minimal region and identified a novel gene (AAAS) encoding a protein of 547 amino acids that is mutant in affected individuals. We found five homozygous truncating mutations in unrelated patients and ascribed the founder effect in North African families to a single splice-donor site mutation that occurred more than 2,400 years ago. The predicted product of AAAS, ALADIN (for alacrima-achalasia-adrenal insufficiency neurologic disorder), belongs to the WD-repeat family of regulatory proteins, indicating a new disease mechanism involved in triple-A syndrome. The expression of the gene in both neuroendocrine and cerebral structures points to a role in the normal development of the peripheral and central nervous systems.

Chronic bilateral dacryo-adenitis in identical twins: a possible incomplete form of Sjögren syndrome.

We report an unusual case of chronic bilateral dacryo-adenitis in 10-year-old identical twin sisters. Both girls presented with bilateral lacrimal gland enlargement and developed moderate xerophthalmia and keratitis. Both the lacrimal and minor salivary gland biopsies showed a non-granulomatous inflammatory infiltration of mono-nuclear cells. All granulomatous diseases and neoplasms could therefore be ruled out and only Sjögren syndrome and very few other forms of chronic dacryo-adenitis remained as possible diagnoses. Both patients and their parents were evaluated for auto-antibodies. Very low titres of smooth muscle antibodies were found in one, antinuclear antibodies in two and anti-dsDNA antibodies in all four members of the family. Even though the titres of antinuclear and anti-dsDNA antibodies increased in one of the sisters, both patients did not develop any sign or symptom of a systemic connective tissue disease. During the 6 years' follow up, both patients showed persistent tarsal gland enlargement but no other symptoms apart from a moderate xerophthalmia and occasional mild keratitis.

Primary Sjögren's syndrome and other autoimmune diseases in families. Prevalence and immunogenetic studies in six kindreds.

The relationships of human leukocyte antigen (HLA) and heavy chain immunoglobulin (Gm) haplotypes to disease and autoantibody expression were examined in six large kindreds, each having one or more members with primary Sjögren's syndrome. Various other autoimmune diseases and autoantibodies occurred among the 117 relatives in these families. The HLA and Gm haplotypes did not necessarily segregate persons into those with Sjögren's syndrome, other autoimmune disorders, or serologic abnormalities, but HLA alleles DR3 and DR2 occurred in significant excess in relatives with Sjögren's syndrome, irrespective of HLA haplotype. Segregation analysis suggested a Mendelian dominant genetic defect common to the many autoimmune diseases and serologic reactions that was not linked to HLA or Gm. A significant effect of female sex was also documented. These studies suggest that Sjögren's syndrome results from the interaction of several HLA-linked and non-HLA-linked genes.

[About 2 cases of "dry syndrome" associating xerophthalmy, xerostomy and cutaneous dryness. A new entity or an unrecognized diagnostic? (author's transl)]. / Sur deux cas de "syndrome sec" associant xérophtalmie, xérostomie et sécheresse cutanée. Entité nouvelle ou diagnostic méconnu?

Two cases, in children of distinct families, of a particular form of "dry syndrome", are described. This syndrom, which associates xerophthalmy, xerostomy and cutaneous dryness, is congenital and familial. He looks different from previously described diseases or syndroms which include one or several of these three components.