Fig 2: Anthropometric measures and BLyS serum concentrations before and after (3 months) of a very low calorie formula diet (VLCD) (approximately 800 kcal/d) as well as before and after (6 months) bariatric surgery in obese individuals.(A) Significant weight reduction (upper and middle panel) and no change of BLyS serum levels by VLCD (lower panel). Data in this figure are shown as means+SD of n = 16 obese human subjects during a VLCD. (B) Significant weight reduction (upper and middle panel) and significant increase of BLyS serum levels by bariatric surgery (lower panel). Shown are means+SD for n = 26 patients.

Fig 3: BLyS serum levels in human obesity.(A) represents significant differences between different grades of obesity (grade 1+2 (BMI≥30 to <40 kg/m2), n = 20 and grade 3 (BMI≥40 kg/m2), n = 42) and normal-weight ((BMI≤25 kg/m2), n = 10) human control subjects. (B) shows the correlation (r = 0.43, p<0.0002) between BLyS serum levels and BMI of n = 72 human subjects used in this study. Data in this figure are shown as means+SD.

Fig 4: BLyS expression in adipose tissue in humans in vivo.(A) BLyS immunohistochemistry (lower panel) and haematoxylin staining (upper panel) of subcutaneous adipose tissue biopsies of lean (left), overweight (middle) and obese+type 2 diabetes (T2D) (right) human subjects (10×). The reddish color represents BLyS-positive mature adipocytes. (B) shows 20× magnification of the immunohistochemistry of a lean adipose tissue biopsy in which the arrows demonstrate the stromal vascular fraction. The lean representative was chosen as BLyS expression was rarely detectable in their adipocytes, thus resulting in a more reliable visual interpretation of the stromal vascular fraction. (C) BLyS and BCMA protein detection revealed that BLyS and BCMA is only expressed in the mature adipocyte [A] fraction but not in the stromal vascular fraction [SVF]. Densitometry graphs data in this figure are shown as means+SEM (n = 5).

Fig 5: BAFF expression in glomerular macrophages and activated mesangial cells in the kidneys of patients with LN. (A, B) Expression of BAFF evaluated by scRNA-seq. Raw and normalized count matrixes of scRNA-seq data were analysed. Each cell population was annotated based on marker genes, and UMAP (left) and clustering (right) were visualized (A). The expression of the TNFSF13B (BAFF) in the renal cells (935 cells) derived from SLE patients was visualized based on kernel density estimation as implemented in the Nebulosa package (B). (C) Immunostaining of renal biopsy specimens of LN. BAFF (green), macrophage (magenta) and activated mesangial cells (red) in two different active LN specimens were stained by anti-BAFF, anti-CD68 and anti-αSMA antibodies, respectively (Scale bar: 100 µm). The small arrows and big arrowheads highlight the co-localization of BAFF with glomerular macrophages and mesangial cells, respectively