3D genome alterations in T cells associated with disease activity of systemic lupus erythematosus.

OBJECTIVES: Three-dimensional (3D) genome alterations can dysregulate gene expression by rewiring physical interactions within chromosomes in a tissue-specific or cell-specific manner and lead to diseases. We aimed to elucidate the 3D genome structure and its role in gene expression networks dysregulated in systemic lupus erythematosus (SLE). METHODS: We performed Hi-C experiments using CD4+ T cells from 7 patients with SLE and 5 age-matched and sex-matched healthy controls (HCs) combined with RNA sequencing analysis. Further integrative analyses, including transcription factor motif enrichment, SPI1 knockdown and histone modifications (H3K27ac, H3K4me1, H3K4me3), were performed for altered loop-associated gene loci in SLE. RESULTS: We deciphered the 3D chromosome organisation in T cells of patients with SLE and found it was clearly distinct from that of HCs and closely associated with the disease activity of SLE. Importantly, we identified loops within chromosomes associated with the disease activity of SLE and differentially expressed genes and found some key histone modifications close to these loops. Moreover, we demonstrated the contribution of the transcription factor SPI1, whose motif is located in the altered loop in SLE, to the overexpression of interferon pathway gene. In addition, we identified the potential influences of genetic variations in 3D genome alterations in SLE. CONCLUSIONS: Our results highlight the 3D genome structure alterations associated with SLE development and provide a foundation for future interrogation of the relationships between chromosome structure and gene expression control in SLE.

Clinical features and prognostic factors of severe cutaneous adverse drug reactions: A single-center retrospective study of 209 cases in China.

BACKGROUND: Severe cutaneous adverse drug reactions (SCAR) are life-threatening and contain drug reactions with eosinophilia and systemic symptoms (DRESS), Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and acute generalized exanthematous pustulosis (AGEP). METHODS: We aimed to evaluate clinical features and prognostic factors for SCAR patients. From January 2010 to April 2022, 209 patients with SCAR (DRESS, n = 46, SJS/TEN, n = 128, AGEP, n = 35) were included in this study. Clinical symptoms, laboratory tests, causative drugs, disease courses, treatments, and outcomes were investigated. RESULTS: Antibiotics ranked first (35.9 %) followed by traditional Chinese medicine (15.8 %) and antiepileptic drugs (14.8 %) among causative drugs of SCAR. One patient (2.2 %) with DRESS and seven patients (5.5 %) with SJS/TEN died in the hospital, while there was no AGEP-related mortality. The multivariate logistic regression analysis showed that high Registry of Severe Cutaneous Adverse Reactions score (OR = 2.340, 95 % CI = 1.192-4.591) and hemoglobin < 100 g/L (OR = 0.126, 95 % CI = 0.016-0.983) were independent risk factors of DRESS. Anemia (OR = 0.191, 95 % CI = 0.037-0.984) and body surface area detached involved at day 1 (OR = 2.749, 95 % CI = 1.115-6.778) were independent risk factors of SJS/TEN for severe acute complications and hospital death (P < 0.05). Lymphocytopenia (OR = 0.004, 95 % CI = 0.000-0.553) was a risk factor of AGEP for acute complications (P = 0.028). CONCLUSION: This study reveals the clinical features and independent prognostic factors for SCAR, which may be helpful in the clinical management for SCAR patients.

Ultraviolet light induces HERV expression to activate RIG-I signalling pathway in keratinocytes.

Skin inflammation and photosensitivity are common in lupus erythematosus (LE) patients, and ultraviolet (UV) light is a known trigger of skin and possibly systemic inflammation in systemic lupus erythematosus (SLE) and discoid lupus erythematosus (DLE) patients. Type I interferons (IFN) are upregulated in LE skin after UV exposure; however, the mechanisms to explain UVB-induced inflammation remain unclear. Here, we demonstrated that UVB irradiation-induced activation of human endogenous retroviruses (HERVs) plays a major role in the immune response. UVB-induced HERV-associated dsRNA transcription and subsequent activation of the innate antiviral RIG-I/MDA5/IRF7 pathway led to downstream transcription of interferon-stimulated genes, which promotes UVB-induced apoptosis and proliferation inhibition in keratinocytes through RIG-I and MDA5 pathways. Our findings indicate that UVB irradiation induces HERV-dsRNA overexpression, and the dsRNA-sensing innate immunity pathway promotes type I IFN production, which may be a potential mechanism of skin inflammatory response and skin lesion of SLE/DLE.

Discrimination of Single Living Rat Pancreatic α, ß, δ, and Pancreatic Polypeptide (PP) Cells Using Raman Spectroscopy.

Primary pancreatic α, ß, δ, and pancreatic polypeptide (PP) cells are reliable cell models for diabetes research. However, the separation and purification of these cells in living conditions remains an obstacle for researchers. The interaction of visible light with cellular molecules can produce Raman scattering, which can be analyzed to obtain cellular intrinsic molecular fingerprints. It has been speculated that primary pancreatic α, ß, δ, and PP cells can be identified and separated from each other according to their spectral differences. To test this hypothesis, Raman spectra detection was performed on rat islet cells. Single islet cells identified by Raman scattering under living conditions were verified using immunohistochemistry. Thus, Raman data were acquired from a pure line of islet cells as a training sample and then used to establish the discriminant function. Then, using the principal component analysis-linear discriminate analysis (PCA-LDA) method, the four types of islet cells could be identified and discriminated by Raman spectroscopy. This study provides a label-free and noninvasive method for discriminating islet cell types in a randomly distributed mixed islet cell population via their physical properties rather than by using antibodies or fluorescence labeling.