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.

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.

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.

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.

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.