Lymphocytic infiltration leads to degradation of lacrimal gland extracellular matrix structures in NOD mice exhibiting a Sjögren's syndrome-like exocrinopathy☆
Introduction
Proteases such as matrix metalloproteinases (MMPs) and lysosomal cysteine proteinases (cathepsins) play important roles during normal embryonic development, including the morphological development of glandular structures (Thompson and Spooner, 1983, de la Cuadra-Blanco et al., 2006, Patel et al., 2006). Their degradation of extracellular matrix (ECM) proteins alters the tissue microenvironment, allowing cellular migration and differentiation (Thompson and Spooner, 1983, Patel et al., 2006); however, numerous studies have demonstrated their close association with various diseases, including rheumatoid arthritis and osteoarthritis (Xue et al., 2007, Takaishi et al., 2008). Increased levels of MMPs have also been implicated in the progression of the autoimmune disease Sjögren's syndrome (SjS) in which lymphocytes infiltrate lacrimal (LGs) and salivary glands (SGs) (Perez et al., 2000; Goicovich et al., 2004, Molina et al., 2006, Schenke-Layland et al., 2008). These events lead to atrophy and ultimately destruction of these tissues, resulting in severe dry eye and dry mouth symptoms which are characteristic of this disease state (Fox et al., 1983, Fox et al., 1986, Matsumoto et al., 1996). Because the LGs are seriously affected, patients cannot produce reflex tears, resulting in severe damage to the ocular surface including squamous metaplasia of the ocular surface epithelium, pain, corneal scarring and in severe cases, blindness (Tsubota et al., 1996).
Although a number of theories have been proposed to explain the onset and progression of lymphocytic infiltration into the LG and SG, the disease is still very poorly understood. The use of mouse models has been important in advancing our knowledge of the etiology of SjS. Perhaps one of the best known models is the male non-obese diabetic (NOD) mouse (Robinson et al., 1997, Yamachika et al., 1998, Humphreys-Beher and Peck, 1999, da Costa et al., 2006). This strain spontaneously develops diabetes as well as lymphocytic infiltration in SGs (sialoadenitis) and LGs (dacryoadenitis), an effect that is associated with reduced secretory flow (van Blokland and Versnel, 2002, Barabino and Dana, 2004, da Costa et al., 2006). The two autoimmune processes of diabetes and SjS occur independently in the same animal. For reasons not yet understood, male NOD mice are more susceptible to dacryoadenitis than female mice, whereas SjS is more prevalent in female patients. Lymphocytic infiltration into the LGs, which is accompanied by decreased production of lacrimal fluid, is typically detected in male mice from ∼6 to 10 weeks. The severely immunocompromised congenic strain (NODscid) also exhibits abnormalities in SG and LG function (Yamachika et al., 2000, van Blokland et al., 2003, Robinson et al., 1997, Kong et al., 1998), suggesting that the disease process exhibited in this model includes both exocrine tissue-dependent as well as inflammatory cell-dependent events. The comparison between the LGs of NOD and the NODscid strains provides a powerful tool for distinguishing processes initiated within the exocrine tissue versus processes initiated by the immune system.
It is clear from different studies of mouse models of SjS that abnormalities in protease activity participate in disease development and progression. For instance, prior to the appearance of glandular infiltrating lymphocytes, aberrant expression of specific apoptotic proteases (caspases) is detectable in the salivary gland lysates of NOD mice (Robinson et al., 1997, Yamachika et al., 1998, Yamachika et al., 2000). Another study in a different mouse model of SjS implicated aberrant cathepsin S activation sialoadenitis, showing that inhibition of cathepsin S was able to prevent SG-specific autoimmunity (Saegusa et al., 2002). Each of these previous studies has linked the enhanced expression of proteases to changes in the acinar cells rather than to immune cell infiltrates. Recently, we were able to demonstrate in the LG of male NOD mice with established disease (e.g., 18 weeks of age) that they exhibited significant degradation of ECM structures as well as increased expression of MMPs (Schenke-Layland et al., 2008). In order to understand the origin of the increased protease levels and the contribution of these changes to disease pathogenesis, we have here explored in depth the changes in ECM structures and ECM protease expression at the onset of disease (6 weeks) versus later stage disease (18 weeks) in male NOD mouse LGs, relative to NODscid and BALB/c mice. We have also characterized the profile of the infiltrating immune cells under each condition. Our results show that the initial infiltrating cells at 6 weeks of age, which are responsible for the increased MMP and cathepsin H expression, initiate the ECM degradation.
Section snippets
Animals
This study was conducted using LGs isolated from male BALB/c (Jackson Labs, Bar Harbor/ME, USA), NOD and NODscid (both Taconic Farms, Germantown/NY, USA) mice at the ages of 6 and 18 weeks as previously described (Schenke-Layland et al., 2008). All procedures conformed to the standards and procedures for the proper care and use of animals in accordance with the institutional guidelines, and as described in the Declaration of Helsinki and the Guiding Principles in the Care and Use of Animals
Histology and immunohistostaining reveal significant changes in ECM protein expression patterns in NOD LGs
No evidence of inflammation was observed within LG tissues isolated from BALB/c (Supplmentary Fig. 1A and D) or the lymphocyte-deficient NODscid (Supplementary Fig. 1C and F) mice. In contrast, and similar to our previously reported results (Schenke-Layland et al., 2008), routine histological analysis demonstrated an infiltration of mononuclear inflammatory cells into the glandular parenchyma of NOD LGs, predominantly around acini and ducts, starting at the age of 6 weeks, which was further
Discussion
In our previous study, we provided a detailed analysis of the LG matrix structure in combination with a qualitative matrix protein evaluation (Schenke-Layland et al., 2008), representing the first comprehensive identification and characterization of the composition of LG ECM. Using routine histology, biochemistry, immunohistochemistry and gene expression analyses in combination with novel multiphoton imaging, we could demonstrate that healthy murine LGs are composed of collagen types I, III,
Acknowledgments
The authors would like to thank Yekaterina Butylkova for her excellent technical assistance and Dr. Ali Nsair for his helpful comments. This work was supported by the NIH (5T32HL007895-10 to K.S-L.; EY-11386 to S.H-A.) and by the Canadian Institutes of Health Research (MOP-68836 to D.P.R.).
References (44)
- et al.
Integrin adhesion in regulation of lacrimal gland acinar cell secretion
Exp. Eye Res.
(2006) - et al.
Apoptosis and apoptosis-related molecules in the submandibular gland of the nonobese diabetic mouse model for Sjogren's syndrome: limited role for apoptosis in the development of sialoadenitis
Lab. Invest.
(2003) - et al.
Pathogenesis of Sjogren's syndrome: characteristics of different mouse models for autoimmune exocrinopathy
Clin. Immunol.
(2002) - et al.
Male NOD mouse external lacrimal glands exhibit profound changes in the exocytotic pathway early in postnatal development
Exp. Eye Res.
(2006) - et al.
Fibrillin-1 interactions with fibulins depend on the first hybrid domain and provide an adaptor function to tropoelastin
J. Biol. Chem.
(2007) - et al.
Pathophysiology of Sjögren's syndrome
Arch. Med. Res.
(2006) - et al.
Lacrimal gland epithelial cells stimulate proliferation in autologous lymphocyte preparations
Exp. Eye Res.
(2000) - et al.
New concepts for the development of autoimmune exocrinopathy derived from studies with the NOD mouse model
Arch. Oral Biol.
(1999) - et al.
Matrix metalloproteinases: multifunctional effectors of inflammation in multiple sclerosis and bacterial meningitis
Brain Res. Rev.
(2001) - et al.
Homo- and heterotypic fibrillin-1 and -2 interactions constitute the basis for the assembly of microfibrils
J. Biol. Chem.
(2002)
Quantitative imaging assay for NF-kappaB nuclear translocation in primary human macrophages
J. Immunol. Methods
Salivary gland branching morphogenesis
Differentiation
Telomerase deficiency promotes oxidative stress by reducing catalase activity
Free Radic. Biol. Med.
Incidence of physician-diagnosed primary Sjogren syndrome in residents of Olmsted County, Minnesota
Mayo Clin. Proc.
Comparative study of cellular and extracellular matrix composition of native and tissue engineered heart valves
Matrix Biol.
Increased degradation of extracellular matrix structures of lacrimal glands implicated in the pathogenesis of Sjögren's syndrome
Matrix Biol.
Interactions of fibrillin-1 with heparin/heparan sulfate, implications for microfibrillar assembly
J. Biol. Chem.
Effect of inflammation on lacrimal gland function
Exp. Eye Res.
Animal models of dry eye: a critical assessment of opportunities and limitations
Invest. Ophthalmol. Vis. Sci.
The biochemical, biological, and pathological kaleidoscope of cell surface substrates processed by matrix metalloproteinases
Crit. Rev. Biochem. Mol. Biol.
Role of laminin-1, collagen IV, and an autocrine factor(s) in regulated secretion by lacrimal acinar cells
Am. J. Physiol.
Morphogenesis of the human excretory lacrimal system
J. Anat.
Cited by (29)
TNF is a critical cytokine in age-related dry eye disease
2023, Ocular SurfaceTargeting macrophages in systemic diseases
2022, Macrophages in the Human Body: A Tissue Level ApproachImpact of Precipitation of Antibody Therapeutics After Subcutaneous Injection on Pharmacokinetics and Immunogenicity
2019, Journal of Pharmaceutical SciencesCitation Excerpt :Cryosections (5-μm thick) mounted on glass coverslips were rinsed with Dulbecco’s phosphate-buffered saline (DPBS), then fixed with ice-cold acetone for 10 min, rinsed with DPBS, and blocked with 5% normal goat serum in DPBS. Cryosections were then incubated with appropriate primary and secondary fluorophore-conjugated antibodies or fluorescent probes as previously described.16,18,20 Slides were viewed using a Zeiss LSM 510 META imaging system equipped with 405, argon, green HeNe, and red HeNe lasers attached to an inverted Zeiss Axiovert 200M microscope.
NOD and NOR mice exhibit comparable development of lacrimal gland secretory dysfunction but NOD mice have more severe autoimmune dacryoadenitis
2018, Experimental Eye ResearchCitation Excerpt :At both ages, the extent of lymphocytic infiltration in the NOD mice was significantly greater than that measured in the NOR mice, however. In this study, BALB/c mice showed no detectable LG lymphocytic infiltration at either age (Fig. 3) although previous studies have shown low levels of lymphocytic infiltration (Li et al., 2010; Schenke-Layland et al., 2010). Previously, our laboratory has demonstrated that CTSS activity in male NOD mouse tear fluid was significantly increased when compared with age-matched BALB/c controls (Li et al., 2010).
A thermo-responsive protein treatment for dry eyes
2015, Journal of Controlled ReleaseCitation Excerpt :NOD mice have been established as a model for type-1 insulin-dependent diabetes mellitus [49] and one of the most utilized models for the study of DED symptomatic of Sjögren's syndrome [50–52], which is characterized by reduced production of aqueous tears [53] and autoimmune infiltration of LGs and salivary tissues [54]. Paradoxically, although Sjögren's syndrome is more prevalent in female patients, the 10–12 week male NOD mice feature earlier symptoms of autoimmune inflammation in LG, including severe lymphocytic infiltration (Fig. 5C), decreased production of lacrimal fluid, significant extracellular matrix degradation and increased expression of matrix metalloproteinases [55]. At 10–12 weeks of age female NOD mice maintain normal LG morphology (Fig. 5D); however, they do develop severe pathology in salivary tissues [54].
Cathepsin H
2013, Handbook of Proteolytic Enzymes
- ☆
All abbreviations for mouse genes are as designated in the NCBI database with the first letter capitalized and the rest of the letters in lower case.