Inhibition of calcium oxalate monohydrate crystal aggregation by urine proteins

Normal urine inhibits both the growth and the aggregation of calcium oxalate monohydrate (COM) crystals but the molecules that inhibit aggregation are not well defined. We have developed a spectrophotometric assay method to measure the aggregation of COM crystals in vitro under conditions that avoid simultaneous crystal growth. At pH 7.2 and 90 mM NaCl, Tamm-Horsfall glycoprotein (THP) and nephrocalcin (NC), a major urinary inhibitor of COM crystal growth, inhibit COM crystal aggregation at concentrations as low as 2 X 10(-9) and 1 X 10(-8) M, respectively. When increasing NaCl to 270 mM or lowering pH to 5.7, inhibition by both glycoproteins, but more markedly by THP, is decreased. Urinary NC from calcium oxalate renal stone formers (SF NC) and NC isolated from calcium oxalate renal stones (stone NC) both inhibit COM crystal aggregation 10-fold less than NC from normal urine. Citrate is ineffective even at millimolar concentrations. Thus THP and NC are two major inhibitors of COM crystal aggregation in normal urine; SF NC and stone NC are defective aggregation inhibitors.

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Citrate and calcium effects on Tamm-Horsfall glycoprotein as a modifier of calcium oxalate crystal aggregation

AJP Renal Physiology ◽

10.1152/ajprenal.1993.265.6.f784 ◽

1993 ◽

Vol 265 (6) ◽

pp. F784-F791 ◽

Cited By ~ 12

Author(s):

B. Hess ◽

L. Zipperle ◽

P. Jaeger

Keyword(s):

Calcium Oxalate ◽

Healthy Volunteers ◽

Calcium Oxalate Monohydrate ◽

Calcium Oxalate Crystal ◽

Crystal Aggregation ◽

Stone Formers ◽

Stone Former ◽

Calcium Effects ◽

Citrate Inhibition

We measured the effects of Tamm-Horsfall glycoprotein (THP) on calcium oxalate monohydrate (COM) crystal aggregation (Ac) in vitro as well as intrinsic viscosities (Vi) of THP at pH 5.7 and 200 mM NaCl and studied the effects of calcium and citrate on these parameters. THP were isolated from 24-h urines of seven male recurrent calcium stone formers (RCSF) and eight age-matched male healthy volunteers (N, normal). At basal conditions, RCSF-THP inhibited Ac by 28 +/- 10% and normal THP by 60 +/- 6% (P = 0.028). In the presence of calcium, increasing THP concentrations from 16 to 28 and 40 mg/l progressively lowered inhibition by RCSF-THP, but not by N-THP. At 40 mg/l, inhibition by N-THP was 27 +/- 9% vs. -43 +/- 8% by RCSF-THP (P = 0.001), i.e., all stone former THP promoted Ac. With an additional 3.5 mM of citrate, inhibition of Ac was 56 +/- 5% by normal and 34 +/- 6% by stone former THP (P = 0.021), and all seven stone former THP again inhibited Ac. Vi of RCSF-THP was higher than that of N at basal conditions (162 +/- 21 vs. 93 +/- 15 ml/g, P = 0.021) and in the presence of 5 mM calcium (352 +/- 54 vs. 118 +/- 17 ml/g, P = 0.001), i.e., RCSF-THP were more self-aggregated, but not when citrate was added (185 +/- 29 vs. 123 +/- 19 ml/g). (ABSTRACT TRUNCATED AT 250 WORDS)

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Urinary Crystal Growth: Effect of Inhibitor Mixtures

Clinical Science ◽

10.1042/cs0610487 ◽

1981 ◽

Vol 61 (4) ◽

pp. 487-491 ◽

Cited By ~ 24

Author(s):

P. G. Werness ◽

Jan H. Bergert ◽

Karen E. Lee

Keyword(s):

Crystal Growth ◽

Calcium Oxalate ◽

Inhibitory Activity ◽

Calcium Oxalate Monohydrate ◽

Growth Effect ◽

Growth Inhibitory ◽

Growth Inhibitory Activity ◽

Measured Activity ◽

Normal Urine ◽

The Individual

1. The crystal growth inhibitory activity of mixtures of known inhibitors and of mixtures of known inhibitors with normal urine was determined in calcium oxalate monohydrate and hydroxyapatite seeded crystal growth systems. 2. The inhibitory activity of the mixtures was compared with the measured activity of the individual components of the mixtures. All mixtures had inhibitory activity equal to the sum of the activities of their components, with the exception of RNA/urine mixtures in the calcium oxalate monohydrate system. 3. RNA/urine mixtures had inhibitory activity toward calcium oxalate monohydrate crystal growth which was less than would be predicted from the activity of the RNA and of the urine which were added. This reduced inhibitory activity was shown to be due probably to hydrolysis of RNA by the ribonuclease activity normally present in urine. 4. The results of these experiments make it possible to determine quantitatively the contribution of various naturally occurring urinary crystal growth inhibitors to the total measured inhibition observed in urine.

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Does urine from stone-formers contain macromolecules which promote the crystal growth rate of calcium oxalate crystals in vitro?

Clinica Chimica Acta ◽

10.1016/0009-8981(80)90294-6 ◽

1980 ◽

Vol 108 (1) ◽

pp. 75-80 ◽

Cited By ~ 16

Author(s):

J.Chr. Gjaldbaek ◽

W.G. Robertson

Keyword(s):

Growth Rate ◽

Crystal Growth ◽

Calcium Oxalate ◽

Crystal Growth Rate ◽

Calcium Oxalate Crystals ◽

Oxalate Crystals ◽

Stone Formers

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Effects of urine dilution on quantity, size and aggregation of calcium oxalate crystals induced in vitro by an oxalate load

Clinical Chemistry and Laboratory Medicine (CCLM) ◽

10.1515/cclm.2005.102 ◽

2005 ◽

Vol 43 (6) ◽

Cited By ~ 15

Author(s):

Angela Guerra ◽

Franca Allegri ◽

Tiziana Meschi ◽

Giuditta Adorni ◽

Beatrice Prati ◽

...

Keyword(s):

Calcium Oxalate ◽

Renal Stones ◽

Normal Subjects ◽

Normal Male ◽

Urinary Volume ◽

Aggregation Index ◽

Calcium Oxalate Dihydrate ◽

Stone Formers ◽

Crystalline Aggregates

AbstractIncreasing urinary volume is an important tool in the prevention of calcium renal stones. However, the mechanism of how it actually works is only partially understood. This study aimed at assessing how urine dilution affects urinary calcium oxalate crystallization. A total of 16 male idiopathic calcium oxalate (CaOx) stone-formers and 12 normal male subjects were studied and 4 h urine samples were taken twice, under low (undiluted urine) and high hydration conditions (diluted urine). An equal oxalate load (1.3mmol/L) was added to both types of urine and the crystallization parameters were assessed. In both stone-formers and normal subjects, the crystallization processes were significantly (p<0.05 or less) more marked in the undiluted urine than in the diluted urine in terms of: a) total quantity of calcium oxalate dihydrate (COD) and calcium oxalate monohydrate (COM) crystals; b) total quantity of crystalline aggregates; and c) aggregation index (i.e., ratio between the area occupied by crystalline aggregates and the area occupied by all the crystals present). The comparison between stone-formers and normal subjects showed that the greatest difference was for the size of COD crystals, which were larger in the urine of the stone-formers. A further important finding was an inverse relationship between changes in urinary volume and in the aggregation index (r=–0.53, p=0.004). In conclusion, urine dilution considerably reduces crystallization phenomena induced in vitro by an oxalate load in both calcium stone-formers and normal subjects.

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Antiurolithiatic activity of Berberis asiatica by In vitro calcium oxalate crystallization methods

International Journal of Research in Pharmaceutical Sciences ◽

10.26452/ijrps.v11i4.3303 ◽

2020 ◽

Vol 11 (4) ◽

pp. 6233-6237

Author(s):

Kishore Bandarapalle ◽

Prasanna Raju Yalavarthi ◽

Chandra Sekhar Kothapalli Bannoth

Keyword(s):

Crystal Growth ◽

Calcium Oxalate ◽

Positive Control ◽

Primary Objective ◽

Crystal Nucleation ◽

Standard Drug ◽

Crystal Aggregation ◽

Ic50 Values ◽

Growth Assay

The primary objective of this research was to investigate the antiurolithiatic effect of the aqueous Heartwood extract of Berberis asiatica (AEBA) on in vitro crystallization methods. The antiurolithiatic behaviour was carried out in the presence and absence of AEBA at the concentration range of 100-1000 μg/ml by employing crystal nucleation, crystal aggregation, and crystal growth assay methods. Standard drug Cystone was made use of positive control in the concentration range of 100-1000 μg/ml. Inhibition efficiency of AEBA on crystal nucleation, crystal aggregation and crystal growth was spectrophotometrically validated. The percentage inhibition rate of crystal nucleation, crystal aggregation and crystal growth by AEBA and standard drug cystone was endorsed to be dose-dependent in nature. The half maximal inhibitory concentration (IC50) values of standard drug cystone on crystal nucleation, crystal aggregation and crystal growth were estimated to be 415.30±21.35, 573.7±65.53 and 566.20±62.06 μg/ml, respectively, while the AEBA, IC50 values were reckoned to be 839±69.13, 927.10±69.98 and 851±86.60 μg/ml, respectively. The findings of in vitro crystallization study disclosed that an aqueous Heartwood extract of Berberis asiatica possesses calcium oxalate crystal inhibition activity on crystal nucleation, crystal aggregation, and crystal growth recommended it as a potent and promising antiurolithiatic activity.

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Escherichia coli Aggravates Calcium Oxalate Stone Formation via PPK1/Flagellin-Mediated Renal Oxidative Injury and Inflammation

Oxidative Medicine and Cellular Longevity ◽

10.1155/2021/9949697 ◽

2021 ◽

Vol 2021 ◽

pp. 1-16

Author(s):

Lingyue An ◽

Weizhou Wu ◽

Shujue Li ◽

Yongchang Lai ◽

Dong Chen ◽

...

Keyword(s):

Escherichia Coli ◽

Calcium Oxalate ◽

Stone Formation ◽

Bacterial Species ◽

Oxidative Injury ◽

Wild Type ◽

E Coli ◽

Crystal Aggregation ◽

Stone Formers

Escherichia coli (E. coli) is closely associated with the formation of kidney stones. However, the role of E. coli in CaOx stone formation is not well understood. We explored whether E. coli facilitate CaOx stone formation and its mechanism. Stone and urine cultures were reviewed from kidney stone formers. The ability of calcium oxalate monohydrate (COM) aggregation was detected to evaluate the influence of uropathogenic E. coli, then gel electrophoresis and nanoLC-MS/MS to detect the crystal-adhered protein. Flagellin (Flic) and polyphosphate kinase 1 (PPK1) were screened out following detection of their role on crystal aggregation, oxidative injury, and inflammation of HK-2 cell in vitro. By transurethral injection of wild-type, Ppk1 mutant and Flic mutant strains of E. coli and intraperitoneally injected with glyoxylate in C57BL/6J female mice to establish an animal model. We found that E. coli was the most common bacterial species in patients with CaOx stone. It could enhance CaOx crystal aggregation both in vitro and in vivo. Flagellin was identified as the key molecules regulated by PPK1, and both of them could facilitate the crystal aggregation and mediated HK-2 cell oxidative injury and activated the inflammation-related NF-κB/P38 signaling pathway. Wild-type strain of E. coli injection significantly increased CaOx deposition and enhanced oxidative injury and inflammation-related protein expression, and this effect could be reversed by Ppk1 or Flic mutation. In conclusion, E. coli promotes CaOx stone formation via enhancing oxidative injury and inflammation regulated by the PPK1/flagellin, which activated NF-κB/P38 pathways, providing new potential drug targets for the renal CaOx calculus precaution and treatment.

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The Relation between the Concentration of Calcium Salts in the Urine and Renal Stone Composition in Patients with Calcium-Containing Renal Stones

Clinical Science ◽

10.1042/cs0430433 ◽

1972 ◽

Vol 43 (3) ◽

pp. 433-441 ◽

Cited By ~ 30

Author(s):

R. W. Marshall ◽

M. Cochran ◽

W. G. Robertson ◽

A. Hodgkinson ◽

B. E. C. Nordin

Keyword(s):

Calcium Phosphate ◽

Calcium Oxalate ◽

Renal Stones ◽

Urine Ph ◽

Stone Composition ◽

Calcium Oxalate Stones ◽

Urine Oxalate ◽

The Difference ◽

Normal Urine ◽

Normal Men

1. Diurnal variations in urine calcium oxalate and calcium phosphate activity products were observed in normal men and patients with recurrent calcium oxalate or mixed oxalate—phosphate renal stones. 2. Maximum and minimum calcium oxalate products were higher in the patients than in the controls, the difference being most marked in the patients with calcium oxalate stones. 3. Maximum and minimum calcium phosphate products expressed as octocalcium phosphate [(Ca8H2(PO4)6], brushite or hydroxyapatite, were significantly higher than normal in the patients with mixed stones but not in the patients with calcium oxalate stones. 4. The raised calcium oxalate products in the patients were due mainly to increased concentrations of Ca2+ ions; these, in turn, were due mainly to an increased rate of excretion of calcium. Raised calcium phosphate products were due mainly to hypercalciuria, combined with abnormally high urine pH values. 5. Patients with recurrent calcium stones appear to fall into two types: (1) patients with calcium oxalate stones associated with hypercalciuria, a normal or raised urine oxalate and a normal urine pH; (2) patients with mixed oxalate—phosphate stones associated with hypercalciuria, a normal or raised urine oxalate and a raised urine pH. 6. The implications of these findings in regard to treatment are discussed.

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