Systemic lupus erythematosus (SLE) is characterized by the expansion of extrafollicular pathogenic B cells derived from newly activated naïve cells. Although these cells express distinct markers, their epigenetic architecture and how it contributes to SLE remains poorly understood. To address this, we determined the DNA methylomes, chromatin accessibility and transcriptomes from five human B cell subsets, including a newly defined effector B cell subset from SLE and healthy subjects. Our data define a differentiation hierarchy between the subsets and elucidate the epigenetic and transcriptional differences between effector and memory B cells. Importantly, an SLE molecular signature was already established in resting naïve cells and was dominated by accessible chromatin enriched in AP-1 and EGR transcription factor motifs. Together, these factors acted in synergy with T-BET to shape the epigenome of expanded SLE effector B cell subsets. Thus, our data define the molecular foundation of pathogenic B cell dysfunction in SLE.

Many metabolic liver disorders are refractory to drug therapy and require orthotopic liver transplantation. Here we demonstrate a new strategy, which we call metabolic pathway reprogramming, to treat hereditary tyrosinaemia type I in mice; rather than edit the disease-causing gene, we delete a gene in a disease-associated pathway to render the phenotype benign. Using CRISPR/Cas9 in vivo, we convert hepatocytes from tyrosinaemia type I into the benign tyrosinaemia type III by deleting Hpd (hydroxyphenylpyruvate dioxigenase). Edited hepatocytes (Fah−/−/Hpd−/−) display a growth advantage over non-edited hepatocytes (Fah−/−/Hpd+/+) and, in some mice, almost completely replace them within 8 weeks. Hpd excision successfully reroutes tyrosine catabolism, leaving treated mice healthy and asymptomatic. Metabolic pathway reprogramming sidesteps potential difficulties associated with editing a critical disease-causing gene and can be explored as an option for treating other diseases.

Upon stimulation, B cells assume heterogeneous cell fates, with only a fraction differentiating into antibody-secreting cells (ASC). Here we investigate B cell fate programming and heterogeneity during ASC differentiation using T cell-independent models. We find that maximal ASC induction requires at least eight cell divisions in vivo, with BLIMP-1 being required for differentiation at division eight. Single cell RNA-sequencing of activated B cells and construction of differentiation trajectories reveal an early cell fate bifurcation. The ASC-destined branch requires induction of IRF4, MYC-target genes, and oxidative phosphorylation, with the loss of CD62L expression serving as a potential early marker of ASC fate commitment. Meanwhile, the non-ASC branch expresses an inflammatory signature, and maintains B cell fate programming. Finally, ASC can be further subseted based on their differential responses to ER-stress, indicating multiple development branch points. Our data thus define the cell division kinetics of B cell differentiation in vivo, and identify the molecular trajectories of B cell fate and ASC formation.

This study suggests that, although mild decentration occurred in the early learning curve, good visual outcomes were achieved after the SMILE surgery. Special efforts to minimize induced vertical coma are necessary.

Sodium-glucose cotransporter 2 (SGLT2) inhibitors are a new class of antidiabetic oral agents indicating promising effects on cardiovascular and renal end points. However, the renoprotective effects of SGLT2 inhibitors are not fully understood. Also, metabolic effects of SGLT2 inhibition on other organ systems, such as effects on hepatic steatosis, are not fully understood. This study sought to address these questions by treating 18-wk-old uninephrectomized mice with the selective SGLT2 inhibitor dapagliflozin. Untreated mice developed progressive albuminuria, glomerular mesangial matrix expansion, and fatty liver associated with increased renal expression of TGFβ1, PAI-1, type IV collagen and fibronectin, and liver deposition of fibronectin, type I and III collagen, and laminin. Treatment with dapagliflozin (1 mg·kg·day) via gel diet from 18 to 22 wk of age not only reduced blood glucose (371.14 ± 55.02 mg/dl in treated vs. 573.53 ± 21.73 mg/dl in untreated, < 0.05) and Hb A levels (9.47 ± 0.79% in treated vs. 12.1 ± 0.73% in untreated, < 0.05) but also ameliorated the increases in albuminuria and markers of glomerulosclerosis and liver injury seen in untreated mice. Furthermore, both renal expressions of NF-kB p65, MCP-1, Nox4, Nox2, and p47phox and urine TBARS levels and liver productions of myeloperoxidase and reactive oxygen species, the markers of tissue inflammation and oxidative stress, were increased in untreated mice, which were reduced by dapagliflozin administration. These results demonstrate that dapagliflozin not only improves hyperglycemia but also slows the progression of diabetes-associated glomerulosclerosis and liver fibrosis by improving hyperglycemia-induced tissue inflammation and oxidative stress.