HDL-proteome enrichment with apolipoprotein A-IV compensates for HDL loss of function in diabetes mellitus kidney disease
Abstract Background and aims: Diabetes mellitus kidney disease (DKD) is associated with lipid derangements worsening kidney function and enhancing cardiovascular (CV) risk. The management of dyslipidemia, hypertension and other traditional risk factors does not completely prevent CV complications bringing up the participation of untraditional risk factors such as advanced glycation end products (AGEs), carbamoylation and changes in HDL proteome and functionality. We analyzed HDL composition, proteome, chemical modification and functionality in non-dialytic DKD subjects categorized according to glomerular filtration rate (GFR) and urinary albumin excretion rate (AER). Methods: DKD individuals were divided in GFR > 60 mL/min/1.73 m2 plus AER stages A1 and A2 (n = 10) and GFR < 60 plus A3 (n = 25) and matched by age with control subjects (GFR > 60; n = 8). Results: Targeted proteomic analyses quantified 29 proteins associated with HDL in all groups, although only 2 were more expressed in GFR < 60 + A3 group in comparison to controls: apolipoprotein D (apo D) and apo A-IV. HDL from GFR < 60 + A3 presented higher levels of total AGEs, pentosidine and carbamoylation (1.2, 1.1 and 4.2 times, respectively) and a reduced ability in removing 14C-cholesterol from macrophages (33%) in comparison to controls. The antioxidant role of HDL (lag time for LDL oxidation) was similar among groups but HDL from GFR < 60 + A3 presented a higher ability in inhibiting the secretion of IL6 and TNF alpha (95%) in LPS-elicited macrophages in comparison to control group. Conclusion: The increment in apo A-IV that presents many antiatherogenic actions seems to counteract the HDL chemical modification by AGE and carbamoylation and its increment in apo D that occurred in well-established DKD.