Summary Sjögren's syndrome is a chronic illness manifested characteristically by immune injury to the salivary and lacrimal glands, resulting in dry mouth/eyes. Anti-Ro [Sjögren's syndrome antigen A (SSA)] and anti-La [Sjögren's syndrome antigen B (SSB)] autoantibodies are found frequently in Sjögren's subjects as well as in individuals who will go on to develop the disease. Immunization of BALB/c mice with Ro60 peptides results in epitope spreading with anti-Ro and anti-La along with lymphocyte infiltration of salivary glands similar to human Sjögren's. In addition, these animals have poor salivary function/low saliva volume. In this study, we examined whether Ro-peptide immunization produces a Sjögren's-like illness in other strains of mice. BALB/c, DBA-2, PL/J, SJL/J and C57BL/6 mice were immunized with Ro60 peptide-274. Sera from these mice were studied by immunoblot and enzyme-linked immunosorbent assay for autoantibodies. Timed salivary flow was determined after pharmacological stimulation, and salivary glands were examined pathologically. We found that SJL/J mice had no immune response to the peptide from Ro60, while C57BL/6 mice produced antibodies that bound the peptide but had no epitope spreading. PL/J mice had epitope spreading to other structures of Ro60 as well as to La, but like C57BL/6 and SJL/J had no salivary gland lymphocytic infiltration and no decrement of salivary function. DBA-2 and BALB/c mice had infiltration but only BALB/c had decreased salivary function. The immunological processes leading to a Sjögren's-like illness after Ro-peptide immunization were interrupted in a stepwise fashion in these differing mice strains. These data suggest that this is a model of preclinical disease with genetic control for epitope spreading, lymphocytic infiltration and glandular dysfunction.
Autoimmune thyroid disease is common in systemic lupus erythematosus (SLE). About 20% of SLE patients have secondary Sjšgren9s syndrome. We undertook this study to determine whether autoimmune thyroid disease is associated with secondary Sjšgren9s syndrome in SLE. Families with more than one SLE patient were identified. All patients met the revised classification criteria, while SLE-unaffected relatives were confirmed not to satisfy these criteria. Diagnosis of autoimmune thyroid disease and Sjšgren9s syndrome was made on the basis of medical records review, interview, and questionnaire in the SLE patients and by questionnaire in the SLE-unaffected subjects. Of a total of 1138 SLE patients, 169 had Sjšgren9s syndrome. Fifty of these 169 (29.6%) also had autoimmune thyroid disease. Of the 939 SLE patients without Sjšgren9s syndrome, 119 (12.7%) had autoimmune thyroid disease (Π2 = 20.1, p < .000009). There was no association of hypertension with secondary Sjšgren9s syndrome (42% versus 47%). Among 2291 SLE-unaffected relatives, 44 had primary Sjšgren9s syndrome and 16 (36.3%) of these also had autoimmune thyroid disease. 265 of 2247 (11.8%) had autoimmune thyroid disease but no Sjšgren9s syndrome (Π2 = 24.2, p < .000009). Autoimmune thyroid disease is found in excess among SLE patients with secondary Sjšgren9s syndrome as well as among their SLE-unaffected relatives with primary Sjšgren9s syndrome.
The article by Narayanan et al.1 demonstrating the protective effect of curcumin and resveratrol in prostate cancer gives an interesting insight regarding the use of phytochemical combination therapy. It is of interest to note that liposome encapsulated curcumin was used for in vivo experimental animal use in this study to resolve the bioavailability issue of curcumin, resulting from poor absorption.1 It is very likely that poor absorption is a consequence of the fact that curcumin is practically insoluble in water. Therefore, solubility is an important issue in in vitro and in vivo experiments. Here, we would like to point out that we have shown increased solubility of curcumin (12-fold) and turmeric (3-fold) by the use of heat.2 The treatment with heat did not destroy curcumin's biological activity, as shown by its inhibition of 4-hydroxy-2-nonenal (HNE)-mediated modification (80% inhibition of HNE-modification) of a multiple antigenic peptide3 substrate in an enzyme-linked immunosorbent assay4 that employed HNE modification of a solid-phase antigen substrate. Mass spectrometric (matrix-assisted laser desorption ionization time of flight) and spectrophotometric (400–700 nm) analysis of curcumin solubilized by heat did not demonstrate any heat-mediated disintegration of curcumin.3, 5 In addition, we have also shown that curcumin solubilized in mild alkali (pH 7.6, 130 μM) also significantly inhibited HNE-antigen modification.6 It has been shown that most of the curcumin (90%) in phosphate buffered saline and serum-free media (pH 7.2, at 37°C) was broken down in 30 min.7 The treatment with heat, however, appears to protect curcumin from breaking down faster. Heat-solubilized curcumin amounts decreased 47% in 12 hr compared to starting levels, and 67% in 72 hr compared to starting levels.2 Curcumin (1,7-bis[4-hydroxy-3-methoxyphenyl]-1,6-heptadiene-3,5-dione) is the most active ingredient of turmeric obtained from the rhizome Curcuma longa.7 This yellow pigment is a polyphenol that has been shown to be efficacious against a variety of diseases, including cancer.2, 7-9 Several vehicles have been employed to deliver curcumin in vivo or topically. Dimethyl sulfoxide (DMSO) has been used for curcumin administration in vivo.10 A combination of hydroxypropyl-β-cyclodextrin and propylene glycol alginate have been found to be best with respect to solubility of curcumin and release from the vehicle11 for topical delivery of curcumin. Incorporation of curcumin in an oil-in-water microemulsion12 has also been used for topical application. Another group13 has shown the potential of poly(ethylene oxide)-b-poly(ε-caprolactone)micelles as an injectable formulation for efficient solubilization, stabilization and controlled delivery of curcumin in in vitro studies. Kunwar et al.14 have attempted curcumin binding to albumin and the use of liposomes as vehicles to deliver curcumin to live cells. For delivery of drugs in vivo or topically, water is indisputably the simplest and the most nontoxic vehicle, provided the drug is soluble in aqueous medium. We have already demonstrated a significant increase in solubility of curcumin in water. Here, we suggest the possibility of considering heat-solubilized curcumin15 for future in vivo and in vitro studies. Supported by NIH grants ARO4973, ARO48940 (to R.H.S.) and Oklahoma Medical Research Foundation. Yours sincerely, Biji T. Kurien, R. Hal Scofield.
Sjögren's disease (SjD) is a complex systemic autoimmune disease with substantial morbidity and 21 known genetic associations. The International Sjögren's Genetics Network (SGENE) is a growing international collaboration focused on understanding how genetic variants influence SjD pathology. As sample sizes increase, we are focusing our efforts on the analyses of clinical subsets, which few studies have done.
Objectives:
Our genome-wide association study (GWAS) aimed to identify additional risk loci of genome-wide significance (GWS, p<5E-08; suggestive, p<5x10E-5) in European-derived subsets of SjD.
Methods:
This study was conducted with IRB/EC approvals. All SjD patients met the 2002 AECG criteria for SjD. A total of 5058 cases and 25943 controls were genotyped on GWAS arrays. After QC, 4855 cases and 25408 controls were included in the analyses. Logistic regression was calculated, adjusting for ancestry using the first 4 principal components to identify SjD-associated SNPs. Cases were split into Ro/SSA+ (n=2898) and Ro/SSA- (n=1313), and analyzed vs. each other, controls, and all-SjD.
Results:
We observed many differences in the genomic architecture of Ro/SSA- compared to Ro/SSA+ and all SjD (Figure 1a,b), most notably, a complete loss of the significance of the association with MHC on chromosome 6 in the Ro/SSA- cases(Figure 1b). The Ro/SSA+ subjects had a much stronger HLA association with OR ≈ 4 (Figure 1a), while the overall SjD showed OR ≈ 3. While none of the associations observed in the Ro/SSA- population reached GWS, 8 regions (near PLXNA2, PCDH7, IRF5-TNPO3, DLD, LOC100134229, JAK3, LOC643529, and TMTC1) show suggestive associations (Figure. 1a). Of these, only two, IRF5-TNPO3 and LOC643529, are also suggestive in the Ro/SSA+ subset. However, while the Ro/SSA+ have both the IRF5 promoter effect and the extended haplotype through TNPO3, the Ro/SSA- lack the IRF5 promoter effect. Interestingly, previous studies have shown that lupus and systemic sclerosis have both haplotypes while primary biliary cholangitis only has the haplotype extending into TNPO3, similar to Ro/SSA- SjD [1]. When comparing Ro/SSA- to the all-SjD dataset, PLXNA2 and LOC100134229 showed no association; PCDH7, DLD, and TMTC1 showed some association but did not reach suggestive levels; and LOC643529, IRF5-TNPO3, and JAK3 surpassed the suggestive threshold, the latter two nearing or surpassing GWS. Two of the novel suggestive associations in Ro/SSA- are particularly intriguing. PLXNA2 is a member of a semaphorin co-receptor family that mediates repulsive effects on axon pathfinding during nervous system development; interestingly, Ro/SSA- SjD has a higher frequency of neurological involvement. JAK3 is a member of the Janus kinase (JAK) family of tyrosine kinases involved in cytokine receptor-mediated intracellular signal transduction; it is predominantly expressed in immune cells. Mutations in this gene are associated with autosomal severe combined immunodeficiency disease. Novel drugs target the JAK-STAT pathways, making this finding markedly relevant.
Conclusion:
Our findings highlight the relevance of expanding genetic studies to specific subphenotypes of the disease. While we continue to increase our GWAS sample size and explore other subphenotypes, more work is needed to increase the power of these studies to determine if the suggestive regions will surpass the GWS threshold.
REFERENCES:
[1] Kottyan LC, et al. Hum Mol Genet. 2015 Jan 15;24(2):582-96.
Astrid Rasmussen: None declared, Marcin Radziszewski: None declared, Bhuwan Khatri: None declared, Kandice L Tessneer: None declared, Elena Pontarini: None declared, Michele Bombardieri: None declared, Maureen Rischmueller: None declared, Marie Wahren-Herlenius: None declared, Marika Kvarnström: None declared, Torsten Witte: None declared, Hendrika Bootsma: None declared, Gwenny M. Verstappen: None declared, Frans G.M. Kroese: None declared, Arjan Vissink: None declared, Sarah Pringle: None declared, Athanasios Tzioufas: None declared, Clio Mavragani: None declared, Alan Baer Received consulting fees from Bristol Myers Squibb (BMS) and iCell Gene Therapeutics., Marta Alarcon-Riquelme: None declared, Javier Martin: None declared, Xavier Mariette: None declared, Gaetane Nocturne: None declared, Jacques-Olivier Pers: None declared, Jacques-Eric Gottenberg: None declared, Wan-Fai Ng I have consulted for Novartis, BMS, Janssen, Sanofi, Abbvie, IQVIA, Argenx, Resolve Therapeutics., Caroline Shiboski: None declared, Kimberly E Taylor: None declared, Lindsey Criswell: None declared, Blake M Warner: None declared, A Darise Farris Grant/research support from Johnson and Johnson Innovative Medicine (formerly Janssen; ended 12/31/2023)., Judith A. James: None declared, R Hal Scofield Received consulting fees from Johnson and Johnson Innovative Medicine (formerly Janssen) and Merk Pharmaceuticals., Joel M Guthridge: None declared, Daniel J Wallace: None declared, Swamy Venuturupali: None declared, Michael T Brennan: None declared, Juliana Imgenberg-Kreuz: None declared, Lars Ronnblom: None declared, Eva Baecklund: None declared, Maija-leena Eloranta: None declared, Lara A Aqrawi: None declared, Øyvind Palm: None declared, Johan G Brun: None declared, Daniel Hammenfors: None declared, Malin V Jonsson: None declared, Silke Appel: None declared, Sara Magnusson Bucher: None declared, Helena Forsblad-d'Elia: None declared, Thomas Mandl Employee of UCB., Per Eriksson: None declared, Gunnel Nordmark: None declared, Christopher J Lessard Grant/research support from Johnson and Johnson Innovative Medicine (formerly Janssen; ended 12/31/2023).
Abstract The antidiabetic medication metformin has been proposed to be the first drug tested to target aging and extend healthspan in humans. While there is extensive epidemiological support for the health benefits of metformin in patient populations, it is not clear if these protective effects apply to those free of age-related disease. Our previous data in older adults without diabetes suggest a dichotomous change in insulin sensitivity and skeletal muscle mitochondrial adaptations after metformin treatment when co-prescribed with exercise. Those who entered the study as insulin sensitive had no change to detrimental effects while those who were insulin resistant had positive changes. The objective of this clinical trial is to determine if 1) antecedent metabolic health and 2) skeletal muscle mitochondrial remodeling and function mediate the positive or detrimental effects of metformin monotherapy, independent of exercise, on the metabolism and biology of aging. In a randomized, double blind clinical trial, adults free of chronic disease (n=148, 40-75 years old) are stratified as either insulin sensitive or insulin resistant based on HOMA-IR (≤2.2 or ≥2.5) and take 1500 mg/day of metformin or placebo for 12 weeks. Hyperinsulinemic-euglycemic clamps and skeletal muscle biopsies are performed before and after 12 weeks to assess primary outcomes of peripheral insulin sensitivity and mitochondrial remodeling and function. Findings from this trial will identify clinical characteristics and cellular mechanisms involved in modulating the effectiveness of metformin treatment to target aging that could inform larger phase 3 clinical trials aimed at testing aging as an indication for metformin.
