FL-926-16, a novel bioavailable carnosinase-resistant carnosine derivative, prevents onset and stops progression of diabetic nephropathy in db/db mice - PubMed (original) (raw)

FL-926-16, a novel bioavailable carnosinase-resistant carnosine derivative, prevents onset and stops progression of diabetic nephropathy in db/db mice

Carla Iacobini et al. Br J Pharmacol. 2018 Jan.

Abstract

Background and purpose: The advanced glycation end products (AGEs) participate in the pathogenesis of diabetic nephropathy (DN) by promoting renal inflammation and injury. L-carnosine acts as a quencher of the AGE precursors reactive carbonyl species (RCS), but is rapidly inactivated by carnosinase. In this study, we evaluated the effect of FL-926-16, a carnosinase-resistant and bioavailable carnosine derivative, on the onset and progression of DN in db/db mice.

Experimental approach: Adult male db/db mice and coeval db/m controls were left untreated or treated with FL-926-16 (30 mg·kg-1 body weight) from weeks 6 to 20 (prevention protocol) or from weeks 20 to 34 (regression protocol).

Key results: In the prevention protocol, FL-926-16 significantly attenuated increases in creatinine (-80%), albuminuria (-77%), proteinuria (-75%), mean glomerular area (-34%), fractional (-40%) and mean (-42%) mesangial area in db/db mice. This protective effect was associated with a reduction in glomerular matrix protein expression and cell apoptosis, circulating and tissue oxidative and carbonyl stress, and renal inflammatory markers, including the NLRP3 inflammasome. In the regression protocol, the progression of DN was completely blocked, although not reversed, by FL-926-16. In cultured mesangial cells, FL-926-16 prevented NLRP3 expression induced by RCS but not by the AGE Nε -carboxymethyllysine.

Conclusion and implications: FL-926-16 is effective at preventing the onset of DN and halting its progression in db/db mice by quenching RCS, thereby reducing the accumulation of their protein adducts and the consequent inflammatory response. In a future perspective, this novel compound may represent a promising AGE-reducing approach for DN therapy.

© 2017 The British Pharmacological Society.

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Figures

Figure 1

Figure 1

Prevention protocol: renal structure. PAS staining of kidney sections from representative animals (A) and quantification of mGA (B), fMA (C) and mMA (D) in untreated and FL‐926‐16 (FL)‐treated db/m control (Ctrl) and db/db diabetic (Diab) mice (mean ± SD; n = 10 per group). Scale bar = 50 μm. Post hoc multiple comparison: *P < 0.05 versus Ctrl; †P < 0.05 versus Diab.

Figure 2

Figure 2

Prevention protocol: glomerular extracellular matrix and cell apoptosis. IHC of kidney sections from representative animals and quantification of fibronectin (A) and collagen IV α1 chain (B); kidney mRNA expression of FN1 (C), Col4a1 (D) and Tgfb (E); IHC of kidney sections (original quantification 1000×) from representative animals and quantification of active caspase‐3 (F, arrows indicate positive cells) in untreated and FL‐926‐16 (FL)‐treated db/m control (Ctrl) and db/db diabetic (Diab) mice (mean ± SD; n = 5 per group). Scale bar = 50 μm. Post hoc multiple comparison: *P < 0.05 versus Ctrl; †P < 0.05 versus Diab.

Figure 3

Figure 3

Prevention protocol: renal oxidative and carbonyl stress. IHC of kidney sections from representative animals and quantification of CML (A), HNE (B), AGER (C) and Nox4 (D) in untreated and FL‐926‐16 (FL)‐treated db/m control (Ctrl) and db/db diabetic (Diab) mice (mean ± SD; n = 5 per group). Scale bar = 50 μm. Post hoc multiple comparison: *P < 0.05 versus Ctrl; †P < 0.05 versus Diab.

Figure 4

Figure 4

Prevention protocol: renal inflammation. IHC of kidney sections from representative animals and quantification of F4/80 (A) and MCP‐1 (B) and kidney mRNA expression of Adgre1 (C), Mcp1 (D) and Tnfa (E) in untreated and FL‐926‐16 (FL)‐treated db/m control (Ctrl) and db/db diabetic (Diab) mice (mean ± SD; n = 5 per group). Scale bar = 50 μm. Post hoc multiple comparison: *P < 0.05 versus Ctrl, †P < 0.05 versus Diab.

Figure 5

Figure 5

In vivo and in vitro studies: NLRP3 expression. IHC of kidney sections from representative animals and quantification of NLRP3 (A) and kidney mRNA expression of Nlrp3 (B) in untreated and FL‐926‐16 (FL)‐treated db/m control (Ctrl) and db/db diabetic (Diab) mice (mean ± SD; n = 5 per group). Scale bar = 50 μm. Post hoc multiple comparison: *P < 0.05 versus Ctrl; †P < 0.001 versus Diab. Expression levels of Nlrp3 in mouse mesangial cells incubated with vehicle (Ctrl), 100 μg·mL−1 CML, 100 μM glyoxal (Gly) or 5 μM HNE, without and with FL‐926‐16 20 mM (C) (mean ± SD; n = 5 experiments in triplicate). Pairwise comparison: *P < 0.05 versus Ctrl; †P < 0.05 versus untreated.

Figure 6

Figure 6

Regression protocol: renal structure. PAS staining of kidney sections from representative animals (A) and quantification of mGA (B), fMA (C) and mMA (D) in untreated and FL‐926‐16 (FL)‐treated db/m control (Ctrl) and db/db diabetic (Diab) mice (mean ± SD; n = 5 per group). Scale bar = 50 μm. Post hoc multiple comparison: *P < 0.05 versus Ctrl, †P < 0.05 versus Diab.

Figure 7

Figure 7

Prevention and regression protocols: renal structure. PAS staining of kidney sections from representative animals (A) and quantification of mGA (B), fMA (C) and mMA (D) in untreated and FL‐926‐16 (FL)‐treated db/db diabetic mice (Diab and Diab‐FL) of 34 weeks of age versus untreated Diab mice of 20 weeks of age (mean ± SD; n = 10 for 20‐week‐old mice and 5 for 34‐week‐old mice). Scale bar = 50 μm. Pairwise comparison: *P < 0.05 versus Diab‐20 weeks.

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References

    1. Ahluwalia TS, Lindholm E, Groop LC (2011). Common variants in CNDP1 and CNDP2, and risk of nephropathy in type 2 diabetes. Diabetologia 54: 2295–2302. - PubMed
    1. Ahmed N (2005). Advanced glycation endproducts – role in pathology of diabetic complications. Diabetes Res Clin Pract 67: 3–21. - PubMed
    1. Aldini G, Facino RM, Beretta G, Carini M (2005). Carnosine and related dipeptides as quenchers of reactive carbonyl species: from structural studies to therapeutic perspectives. Biofactors 24: 77–87. - PubMed
    1. Alexander SPH, Kelly E, Marrion NV, Peters JA, Faccenda E, Harding SD et al (2017a). The Concise Guide to PHARMACOLOGY 2017/18: Overview. Br J Pharmacol 174: S1–S16. - PMC - PubMed
    1. Alexander SPH, Fabbro D, Kelly E, Marrion NV, Peters JA, Faccenda E et al (2017b). The Concise Guide to PHARMACOLOGY 2017/18: Catalytic receptors. Br J Pharmacol 174: S225–S271. - PMC - PubMed

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