The effects of vitamin D3 supplementation on some metabolic and inflammatory markers in diabetic nephropathy patients with marginal status of vitamin D: A randomized double blind placebo controlled clinical trial

AIMS

Diabetic nephropathy is known to be an independent risk factor in the progression of renal and cardiovascular disorders. Due to the association between vitamin D deficiency and diabetic nephropathy, vitamin D deficiency in the diabetic nephropathy population, this study conducted to examine the effects of Vitamin D₃ on metabolic and inflammatory parameters in patients with diabetic nephropathy.

METHODS

This eight-week, randomized, double-blind, placebo-controlled trial was carried out on 50 diabetic nephropathy patients with marginal status of vitamin D. Participants were randomly assigned to two groups: control and intervention. Participants received a vitamin D3 (50000 IU) supplement weekly on a specific day. Fasting blood samples were collected from all patients at their entry to the study, and eight weeks after intervention.

RESULTS

Analyses showed significance differences in physical activity between the intervention and placebo groups (P = 0.018). There were no significant differences between the percentage changes of HbA1c, insulin and, inflammatory parameters such as TNF-α and IL-6 (P > 0.05), while the percentage change of FBS was significantly higher in the placebo group compared to the treatment one (P < 0.0001). Lower levels of FBS (P < 0.0001), insulin (P < 0.069), HOMA-IR (P < 0.001), TNF-α (P< 0.002) and IL-6 (P < 0.037) were found after supplementation in treatment group. However, the phosphorous and protein percentage change in urine were lower (P = 0.07) and higher (P = 0.003) between groups.

CONCLUSIONS

It was found that vitamin D supplementation can be regarded as an effective way to prevent the progression of diabetic nephropathy by reducing levels of proteinuria, and inflammatory markers such as TNF-α and IL-6.

Abstract P3-07-21: Cytotoxic potential of the RG7388 MDM2-p53 binding antagonist and the GSK2830371 WIP1 inhibitor on MX-1 and MCF-7 human breast cancer cells

Background

The tumor suppressor p53 is a central hub in molecular signaling pathways that control the integrity of the human genome. The p53 protein functions as a transcription factor and increases the expression of many cellular genes which contribute to activation of cell cycle arrest, apoptosis and DNA repair. MDM2 is another important p53 target gene, and the MDM2 protein is capable of binding directly to p53 and directing it for degradation through the ubiquitin-dependent proteolytic pathway. Inhibition of MDM2 stabilizes p53 and MDM2 inhibitors are being explored clinically as therapies. Stabilization alone may not be enough to increase the activity of p53, and posttranslational modification of p53 by phosphorylation has been proposed to be an important contributory mechanism by which p53 becomes functionally active. Therefore maintaining the phosphorylated status of p53 in tumor cells may help to enhance its growth inhibitory and pro-apoptotic role. Wild type p53 – induced phosphatase (Wip1) is a serine – threonine phosphatase which dephosphorylates central players in the DNA damage response, including p53 and may be an additional target to enhance p53-dependent treatments. Therefore this work was focused on the effect of MDM2 (RG7388) and Wip1 (GSK2830371) inhibitors on MX-1 and MCF breast carcinoma cell lines. These two cell lines were recorded to have wild type TP53 status as well as high expression of Wip1.

Trial design

RG7388 and GSK2830371 were tested for growth inhibition on MX-1 and MCF-7 breast cancer cell lines using the sulforhodamine B (SRB) assay. The results were further confirmed and mechanism explored by western blotting using extracted protein from drug treated cell lines. Contradictory evidence regarding the TP53 mutation status of the MX-1 cell line was clarified by direct sequencing of MX-1 DNA.

Results

The MCF-7 cells responded to both RG7388 and GSK2830371 with GI50 value of 0.034 µM and 2.92 µM respectively. The MX-1 cells did not respond to either drug. The results of western blotting showed there was no expression of p53 in the MX-1 cell line. Failure to respond to RG7388and also no expression of p53 in western blotting made us suspicious about the TP53 status of the MX-1 cells. The direct sequencing results confirmed that there was a 5bp deletion in exon 4 of the TP53 gene of the MX-1 cells. The c.154_158delCAATG mutation creates a stop codon at the 54th aminoacid position and results in a truncated p53 protein (p.Gln52Valfs*3).

Conclusion

RG7388 and GSK2838371 showed cytotoxic effects on MCF-7 cells, whereas both RG7388 and GSK2838371 had no effect on the MX-1 cell line due to the truncated p53 and loss of p53 function. In conclusion, the potency of both drugs depends on the TP53 mutation status and they are likely to be mediated via p53-dependent growth inhibition and apoptosis. Further studies are needed to evaluate the combination effect of both drugs on TP53 wild type cell lines.

Citation Format: Manoharan V, Lunec J, Esfandiari A, Mahdi A, Wu C-E, Zanjirband M, Karunanayake EH, Tennekoon KH, De Silva S. Cytotoxic potential of the RG7388 MDM2-p53 binding antagonist and the GSK2830371 WIP1 inhibitor on MX-1 and MCF-7 human breast cancer cells [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-07-21.

Identification of Helicobacter spp. in gastrointestinal tract, pancreas and hepatobiliary system of stray cats

The aim of the present study was to determine the presence of Helicobacter species in different parts of gastrointestinal tract, hepatobiliary system and pancreas of stray cats. Six different sites at the level of genus, gastric (H. heilmannii and H. felis) and enterohepatic species of Helicobacter were investigated in six cats using species-specific primers by polymerase chain reaction (PCR). Interestingly, DNA of enterohepatic spp. was detected in 1/6 duodenum, 2/6 colon and 1/6 pancreas specimens. Results of sequencing revealed that all of these four positive samples belong to Helicobacter canis. While cats have not been considered as a potential zoonotic danger for non-pylori Helicobacter infections, the results of current study show prompt re-evaluation of that view. To the best of our knowledge, this is the first study about distribution of Helicobcater spp. in gastrointestinal tract of cats.

Alternative treatment of ovarian cysts with Tribulus terrestris extract: a rat model

Tribulus terrestris has long been used in traditional medicine to treat impotency and improve sexual functions in man. The aim of this study was to evaluate the efficiency of T. terrestris extract in the treatment of polycystic ovary (PCO) in Wistar rat. Estradiol valerate was injected to 15 mature Wistar rats to induce PCO. Rats were randomly divided into three groups (control, low-dose and high-dose groups) of five each and received 0, 5 and 10 mg of T. terrestris extract, respectively.Treatments began on days 50 and 61 after estradiol injection; at the same time, vaginal smear was prepared. The ovaries were removed on day 62, and histological sections were prepared accordingly. The number and diameter of corpora lutea, thickness of the theca interna layer and the number of all follicles were evaluated in both ovaries. In comparison with the control group, the number of corpora lutea and primary and secondary follicles significantly increased following T. terrestris treatment; however, the number of ovarian cysts significantly decreased. It can be concluded that T. terrestris have a luteinizing effect on ovarian cysts, which may relate to its gonadotropin-like activity; also, a high dose of the extract can efficiently remove ovarian cysts and resume ovarian activity.

Clustering of giardiosis among AIDS patients in Los Angeles County

The purpose of this study was to determine the mode of the spread of the enteric parasitic infections among HIV+/AIDS patients attending the AIDS clinic of the King/Drew Medical Center in Los Angeles. Two hundred forty three patients diagnosed with HIV+/AIDS agreed to participate. The study was conducted by several interviews, questionnaires and stool sample collections over a one year period. Stool samples were processed for protozoan cysts and Helminth Ova using standard stool concentration and staining techniques. An indirect immunofluorescence monoclonal antibody technique was also used as an alternate to detect the parasites in samples. Forty three cases were positive for Giardia Lamblia (17.7%) and 10 cases were positive for Cryptosporidium (4%). No Helminth Ova were detected. The majority of the participants were African-American (72.6%) and 27.6% were Hispanic. Clustering studies were performed to determine the mechanism of spread of the parasites among the population study. The Nearest Neighbor Clustering Technique (NNT) was used to determine if there was spatial clustering of positive cases. Geocoding with the MapInfo Program was performed to determine the precise coordinates of the residence of the subjects. Application of the NNT showed a high degree of clustering for Giardia. The NNT statistic for Giardia was significant with the p value for 0.020 using the Simes multiple comparisons correction. Examination of the map plots indicated that there were two areas with high Giardia prevalence, one in Hollywood region, the other in South-Central Los Angeles. The odds ratio for sexual orientation was 14.2 (for homosexuals vs heterosexuals) with a p value of less than 0.001. These findings strongly suggest that male homosexual contact was the main mode of transmission of observed Giardia cases.

Synergistic activities of clarithromycin and pyrazinamide against Mycobacterium tuberculosis in human macrophages

The combination of clarithromycin and pyrazinamide was found to be synergistic against Mycobacterium tuberculosis in human macrophages. MICs were four- to eightfold lower for this combination than they were for either drug alone. Clarithromycin and rifampin, however, had only an additive effect.

In vivo efficacy of trovafloxacin (CP-99,217), a new quinolone, in experimental intra-abdominal abscesses caused by Bacteroides fragilis and Escherichia coli

The efficacy of trovafloxacin in treating Bacteroides fragilis and Escherichia coli infections was investigated and compared to the efficacy of combined clindamycin and gentamicin therapy in an experimental model of intra-abdominal abscesses in rats. Rats were treated with different doses of CP-116,517-27, a parenteral prodrug of trovafloxacin. Response to treatment was evaluated by mortality rate and elimination of infection (cure rate). Mortality in the control group was 85.4%, whereas in rats treated with trovafloxacin, it was close to 0%. The highest cure rate (89.3%) resulted from the administration of 40 mg of CP-116,517-27 per kg of body weight three times a day (TID) for 10 days (equivalent to 18.15 mg of active drug trovafloxacin per rat per day). The therapeutic response with trovafloxacin was comparable to that of a combination therapy of clindamycin (75 mg/kg) plus gentamicin (20 mg/kg) TID (cure rate, 74%; mortality rate, 5%). The measured peak levels of trovafloxacin in serum and abscess pus were 2.6 +/- 0.3 and 5.2 micrograms/ml, respectively. The tumor necrosis factor alpha levels in the untreated animals were high compared to those for rats treated with trovafloxacin or clindamycin plus gentamicin. These results demonstrate that trovafloxacin as a single agent appears to be as successful as clindamycin plus gentamicin in the treatment of experimental intra-abdominal abscesses in rats.

Inhibition of fatty acid beta-oxidation in rat brain cultured astrocytes exposed to the neurotoxin 3-nitropropionic acid

We describe the effects of the neurotoxin 3-nitropropionic acid (3-NPA) on fatty acid oxidation in neonatal rat brain astrocytes in primary culture, using a sensitive assay for beta-oxidation which depends on the release of 3H2O from [9,10(n)-3H]palmitic acid. 3-NPA is a suicide inhibitor of succinate dehydrogenase, a constituent of both Krebs cycle and complex II of the mitochondrial respiratory chain. It is widely distributed in plants and fungi. Neurotoxicity of 3-NPA to humans and animals, leading to selective neuronal cell death, appears mediated by the reduced level of ATP induced by the toxin. We demonstrated that 3-NPA can also impair energy metabolism in astrocytes. Exposure of astroglial cells in culture to 3-NPA leads to inhibition of the release of 3H2O from [9,10(n)-3H]palmitic acid. Addition of 2 mM 3-NPA to the culture medium caused a rapid decrease in beta-oxidation activity, which reached a plateau after 90 min. This inhibition was concentration-dependent. Concentration as low as 0.05 mM for 5 h significantly decreased beta-oxidation activity (25% inhibition). Half-maximal inhibition was obtained after treatment with 0.5 mM 3-NPA, and 3 mM induced a maximal response (63% inhibition) 3-NPA is clearly a potent inhibitor of beta-oxidation activity. We also show that 3-NPA 3 mM inhibits partially complex II (succinate ubiquinone reductase) and aspartate aminotransferase by 60 and 49% after 4 h treatment respectively. It has been shown that fatty acid is the preferred substrate for energy production in cultured astrocytes from developing brain. As astrocytes may also provide substrates alternative for energy metabolism in neurons and oligodendrocytes, it is likely that the inhibition of beta-oxidation by 3-NPA may contribute significantly to the damage induced by this toxin in the central nervous system.

The effects of first-season strategic and tactical ivermectin treatments on trichostrongylosis in the first- and second-season grazing

A 2 year study was conducted to evaluate the effects of first-season strategic or tactical treatments with ivermectin on trichostrongylosis in heifer calves in the first and second-season grazing. Three groups of each eight Holstein-Friesian calves were turned out in early May onto a permanent pasture naturally contaminated with trichostrongyle larvae. Two of these groups were given ivermectin either as strategic treatments (Weeks 3, 8 and 13 after turnout) or as tactical treatments (Weeks 14, 18 and 22 after turnout); the third group served as untreated controls. The strategic ivermectin treatments prevented build-up of high herbage infectivity from mid-summer onwards as shown by low trichostrongyle egg outputs, serum pepsinogen levels and serum antibody responses. In spite of exposure to continuous high larval challenge in late season, the pathogenic effects of worm loads in calves receiving the tactical ivermectin treatment were significantly suppressed. The performance of the strategically treated calves tended to be higher than that of the tactically treated calves in the first-season grazing; yet, there was no statistical difference. During the following summer, all three groups were grazed in a single herd together with a new group of eight first-season calves. No anthelmintic treatments were given to any animals during the season. From late August until the end of the season all animals were given weekly experimental challenge infections. Following the challenge infections, the first-season calves developed clinical parasitic gastroenteritis, whereas the second-season heifers showed no symptoms. At post-mortem it was found that worm burdens mainly consisted of early fourth-stage larvae (L4) of Ostertagia ostertagi (> 97%). Fewer adult worms were recovered from the untreated animals than from the treated ones. However, serum anti-parasite IgG1 responses and post-mortem worm counts suggested that the untreated heifers harboured markedly fewer adult O. ostertagi than the previously treated ones, indicating a higher level of immunity against adult worms. However, this difference did not have any clinical impact in this experiment.

Evidence that type III iodothyronine deiodinase in rat astrocyte is a selenoprotein

A type III iodothyronine deiodinase (D-III) that inactivates thyroid hormones has been recently cloned and identified as a selenoprotein in neonatal rat skin. However, selenium (Se) deficiency does not affect the D-III activity in the rat placenta and decreases the D-III in the rat brain only slightly. This study examines the effect of Se on the D-III activity in cultures of rat brain astrocytes. Astrocytes were depleted in Se by maintaining them in Se-free chemically defined medium for 7 days. These conditions decreased the activity of a recognized selenoprotein, glutathione peroxidase, 3-10-fold. D-III activity induced by 12-0-tetradecanoylphorbol-13-acetate (TPA) was also decreased 2-6-fold. Addition of 30 nM Se to the culture medium caused a rapid increase in TPA-induced D-III activity visible within 1 h. This Se effect was maximal at 3 h (4-fold increase) and dose-dependent. Se also increased the induction of D-III by acidic Fibroblast Growth Factor, 8-bromo-cAMP, T4, or retinoic acid. Cycloheximide blocked the effect of Se on TPA-induced D-III activity, whereas actinomycin D did not. Thus the rapid effect of Se does not require messenger RNA synthesis but requires protein synthesis. We conclude that the D-III in astrocytes is probably a selenoprotein.

Sulfation after deiodination of 3,5,3'-triiodothyronine in rat cultured astrocytes

The metabolism of [125I]T3 by rat astrocytes in culture was analyzed by Sephadex LH-20 chromatography and HPLC. The conjugates isolated on LH-20 were not hydrolyzed by glucuronidase, indicating the absence of glucuroconjugates. 3,3'-Diiodothyronine (3,3'T2) sulfate (3,3'T2-S) was the main product that accumulated in the medium over the T3 concentration explored (10 pM to 10 nM). The identity of the peak eluted as 3,3'T2-S was ascertained by its hydrolysis with sulfatase and the generation of 3,3'T2 identified by HPLC. 3'-Monoiodothyronine sulfate was also found in cells treated with 1 microM retinoic acid, i.e. with high type III deiodinase activity. No T3 sulfate (T3-S) was found as a metabolite of T3. Astrocytes did not break down 1 nM [125I]T3-S added to the medium. Astrocytes pretreated for 3 days with 10 nM T3 showed increased production of 3,3'T2-S from 10 nM [125I]T3. Exogenous [125I]3,3'T2 (20 nM) was conjugated to 3,3'T2-S released into the medium. Pretreatment of astrocytes with 10 nM T3 did not alter the production of 3,3'T2-S from 3,3'T2. Thus, T3 is metabolized in astrocytes by direct 5-deiodination, followed by sulfation. Whereas T3 induces its own deiodination and type III deiodinase activity, T3 does not regulate the sulfation of its main metabolite, 3,3'T2. This demonstration of sulfation of iodothyronines in cells originating from the brain raises the question of the role of this TH metabolic pathway in the brain.

Induction of type III-deiodinase activity in astroglial cells by retinoids

Thyroid hormones and retinoic acid (RA) are important modulators of growth, development, and differentiation. Type III deiodinase (D-III), which catalyzes thyroid hormones degradation in the brain and in cultured astroglial cells, is induced in astroglial cells by multiple pathways, including cAMP, 12.0-tetradecanoylphorbol-13-acetate (TPA), fibroblast growth factors, and thyroid hormones themselves. In the present study, the effects of retinoids on D-III activity were examined in astroglial cells cultures in a chemically defined medium devoid of hormones and growth factors. Incubation of astroglial cells with 5 microM all-trans-RA caused up to 200-fold increase in D-III activity, which reached a plateau after 48 h. The retinoid-induced increase in D-III activity was concentration dependent (0.5 microM all-trans-RA and 9-cis-RA producing half-maximal effect). Retinol was effective at physiological concentrations (1 and 10 microM). The 48 h effects of 5 microM all-trans-RA and 10 nM thyroid hormones on D-III activity were at least additive. Addition of 2 nM acidic fibroblast growth factor or 1 mM 8-bromo-cAMP for the last 8 h of a 48 h incubation with 5 microM all-trans-RA did not alter the induction by all-trans-RA, whereas 0.1 microM TPA in the same conditions produced an additive effect with all-trans-RA. All-trans-RA (5 microM) had little or no effect on type II deiodinase, the enzyme which catalyzes the activation of thyroxine to 3,5,3'-triiodothyronine.(ABSTRACT TRUNCATED AT 250 WORDS)

12-O-tetradecanoylphorbol 13-acetate and fibroblast growth factor increase the 30-kDa substrate binding subunit of type II deiodinase in astrocytes

Type II 5'-deiodinase (D-II) catalyzes the intracellular conversion of thyroxine (T4) to 3,5,3'-triiodothyronine (T3) in the brain. The D-II activity in astroglial cell cultures is induced by several pathways including cyclic AMP (cAMP), 12-O-tetradecanoylphorbol 13-acetate (TPA), and fibroblast growth factors (FGFs). We have examined the effect of TPA and FGFs on the 30-kDa substrate binding subunit of D-II, by affinity labeling with N-bromoacetyl-[125I]T4 in astroglial cells. TPA (0.1 microM), 20 ng/ml acidic FGF (aFGF), and 1 mM 8-bromo cyclic AMP all caused an increase in the 30-kDa protein. cAMP induced the greatest increase (fivefold) followed by TPA (3.2-fold) and FGF (2.8-fold). Glucocorticoids acted synergistically with cAMP and aFGF and promoted the effect of TPA. Affinity labeling was competitively inhibited by bromoacetyl-T4 > bromoacetyl-T3 > T4 > reverse T3 > iopanoic acid > T3 > 3,5,3'-triiodothyroacetic acid. The effect of TPA (0.1 microM) was maximum at 8 h and then gradually decreased. aFGF (20 ng/ml) plus heparin (17 micrograms/ml) induced a maximal 30-kDa increase at 8 h, which stayed stable for up to 24 h. The effect of aFGF was concentration dependent. Of the other growth factors studied, only basic FGF and platelet-derived growth factor induced small increases in the 30-kDa protein. Epidermal growth factor had little effect. In vitro labeling of cAMP, TPA, and aFGF-stimulated cell sonicates resulted in an increase in the 30-kDa protein that paralleled the increase in D-II activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Induction of type III deiodinase activity in astroglial cells by thyroid hormones

The type III deiodinase (D-III) activity in astroglial cells is induced by multiple pathways activated by cAMP, 12-O-tetradecanoylphorbol-13-acetate (TPA), and fibroblast growth factors (FGFs). This study examines the effects of thyroid hormones on D-III activity in astroglial cells with or without induction by these factors. Addition of 10 nM T3 to the culture medium caused a slow increase in D-III activity, which reached a plateau after 48 h. This increase was concentration dependent (maximal response at 10 nM). Doses as low as 0.3 nM caused significant increases in D-III activity. The effect of T3 was reversible. A dose of 10 nM L-T3, D-T3, T4, 3,5,3'-triiodothyroacetic, or 3'-isopropyl-3,5-diiodothyronine produced 5- to 15-fold increases in D-III activity after 48 h. In contrast, 10 nM L-thyronine, 3-monoiodothyronine, 3,3'-diiodothyronine, 3,5-diiodothyronine, and rT3 were without effect. A dose of 10 nM T3 or T4 amplified the D-III activity stimulated by 0.1 microM TPA, 20 ng/ml acidic FGF, or 1 mM 8-bromo-cAMP 3- to 8-fold. Otherwise, T3 rapidly inhibited D-II activity. This inhibition was concentration dependent, with a half-maximal effect around 10 nM. In conclusion, thyroid hormones induce D-III activity and potentiate the D-III activity induced by cAMP, TPA, and FGFs in astroglial cells. These reversible effects together with inhibition of D-II activity may contribute to protect the brain against hyperthyroidism.