Iron sucrose (“rbt-3”) activates the hepatic and renal hamp1 gene, evoking renal hepcidin loading and resistance to cisplatin nephrotoxicity

2020 ◽  
Author(s):  
Richard A Zager ◽  
Ali C M Johnson ◽  
Renibus Therapeutics
Keyword(s):  
Human Kidney ◽  
Time Lapse ◽  
Healthy Human ◽  
Protein Levels ◽  
Cisplatin Nephrotoxicity ◽  
Human Volunteers ◽  
Nrf2 Activation ◽  
Plasma And Urine Samples

Abstract Background Fe sucrose (FeS) administration induces a state of renal preconditioning, protecting against selected forms of AKI. Recent evidence suggests that recombinant hepcidin also mitigates acute renal damage. Hence, the goals of this study were as follows: i) Determine whether a new proprietary FeS formulation (“RBT-3”), can acutely activate the hepcidin (HAMP1) gene in humans, raising plasma and renal hepcidin concentrations; ii) assess whether the kidney participates in this posited RBT-3-hepcidin generation response; iii) test whether RBT-3 can mitigate a clinically relevant AKI model (experimental cisplatin toxicity); and iv) explore whether mechanisms in addition to hepcidin generation are operative in RBT-3’s cytoprotective effects. Methods Healthy human volunteers (n, 9) and subjects with stage 3-4 CKD (n, 9) received 120, 240, or 360 mg of RBT-3 (IV over 2 hrs). Plasma and urine samples were collected and assayed for hepcidin levels (0-72 hrs post RBT-3 injection). In complementary mouse experiments, RBT-3 effects on hepatic vs. renal hepcidin (HAMP1) mRNA and protein levels were compared. RBT-3’s impact on the mouse Nrf2 pathway, and on experimental cisplatin nephrotoxicity, were assessed. Direct effects of exogenous hepcidin on in vivo and in vitro (HK-2 cells) cisplatin toxicity were also tested. Results RBT-3 induced rapid, dose dependent, and comparable plasma hepcidin increases in both HVs and CKD subjects (∼15x baseline within 24 hrs). Human kidney hepcidin exposure was confirmed by 4 fold urinary hepcidin increases. RBT-3 up-regulated mouse hepcidin mRNA, but much more so in kidney (>25x) vs. liver (∼2x). RBT-3 also activated kidney Nrf2 (increased Nrf2 nuclear binding; increased Nrf2-responsive gene mRNAs: HO-1, SrXN1, GCLC, NQO1). RBT-3 preconditioning (18 hr time lapse) markedly attenuated experimental cisplatin nephrotoxicity (∼50% BUN/creatinine decrements), in part, by reducing renal cisplatin uptake by 40%. Exogenous hepcidin (without RBT-3) treatment conferred protection against mild in vivo (but not in vitro) cisplatin toxicity. Conclusions RBT-3 acutely and dramatically up-regulates cytoprotective hepcidin production, increasing renal hepcidin levels. However, additional cytoprotective mechanisms are activated by RBT-3 (e.g., Nrf2 activation; reduced cisplatin uptake). Thus, RBT-3-induced preconditioning likely confers renal resistance to cisplatin via an interplay of multiple cytoprotective activities.

scholarly journals ABT-378, a Highly Potent Inhibitor of the Human Immunodeficiency Virus Protease

1998 ◽  
Vol 42 (12) ◽  
pp. 3218-3224 ◽  
Author(s):  
Hing L. Sham ◽  
Dale J. Kempf ◽  
Akhteruzammen Molla ◽  
Kennan C. Marsh ◽  
Gondi N. Kumar ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Protease Inhibitor ◽  
Response To Therapy ◽  
Hiv Protease ◽  
Healthy Human ◽  
Human Volunteers ◽  
Immunodeficiency Virus ◽  
Potent Protease Inhibitor

ABSTRACT The valine at position 82 (Val 82) in the active site of the human immunodeficiency virus (HIV) protease mutates in response to therapy with the protease inhibitor ritonavir. By using the X-ray crystal structure of the complex of HIV protease and ritonavir, the potent protease inhibitor ABT-378, which has a diminished interaction with Val 82, was designed. ABT-378 potently inhibited wild-type and mutant HIV protease (Ki = 1.3 to 3.6 pM), blocked the replication of laboratory and clinical strains of HIV type 1 (50% effective concentration [EC50], 0.006 to 0.017 μM), and maintained high potency against mutant HIV selected by ritonavir in vivo (EC50, ≤0.06 μM). The metabolism of ABT-378 was strongly inhibited by ritonavir in vitro. Consequently, following concomitant oral administration of ABT-378 and ritonavir, the concentrations of ABT-378 in rat, dog, and monkey plasma exceeded the in vitro antiviral EC50 in the presence of human serum by >50-fold after 8 h. In healthy human volunteers, coadministration of a single 400-mg dose of ABT-378 with 50 mg of ritonavir enhanced the area under the concentration curve of ABT-378 in plasma by 77-fold over that observed after dosing with ABT-378 alone, and mean concentrations of ABT-378 exceeded the EC50 for >24 h. These results demonstrate the potential utility of ABT-378 as a therapeutic intervention against AIDS.

scholarly journals Comparative Bioavailabilitv Studv of Two Brands of Terbutaline Sulphate Tablets in Healthy Human Volunteers

2004 ◽  
Vol 72 (3) ◽  
pp. 227-237
Author(s):  
Nahla S. Barakat ◽  
Nawal M. Khalafallah ◽  
Said A. Khalil
Keyword(s):  
Single Dose ◽  
Reference Product ◽  
Hplc Method ◽  
Fasting State ◽  
Unchanged Drug ◽  
Healthy Human ◽  
Terbutaline Sulphate ◽  
Human Volunteers

The purpose of this study was to evaluate the bioavailability of locally produced 2.5 mg terbutaline sulphate tablets (brand A ) relative to a reference product, Bricanyl 2.5 mg tablets (brand 6). The study was a single dose 5 mg randomized crossover one in 15 healthy volunteers in the fasting state. Urine was collected at intervals of 24 h. Total terbutaline excreted in urine as unchanged drug and as conjugates (sulphate and glucuronide) was determined by a developed and validated HPLC method. In-vitro characteristics of both brands were similar. Based on percent of the dose excreted in urine, the oral bioavailability ranged from 33.5% to 75.8% for both brands. Statistics were applied to judge bioequivalence according to USP 24 in-vivo bioequivalence guidance. Results indicated that brand A and B were bioequivalent and hence interchangeable in medical practice.

In vivo generation of human dendritic cell subsets by Flt3 ligand

Blood ◽  
2000 ◽  
Vol 96 (3) ◽  
pp. 878-884 ◽  
Author(s):  
Eugene Maraskovsky ◽  
Elizabeth Daro ◽  
Eileen Roux ◽  
Mark Teepe ◽  
Charlie R. Maliszewski ◽  
...  
Keyword(s):  
T Cell Immunity ◽  
Human Dendritic Cell ◽  
Flt3 Ligand ◽  
Healthy Human ◽  
Cell Immunity ◽  
Human Volunteers ◽  
Immune Response Regulation ◽  
Dendritic Cell Subsets

Abstract Dendritic cells (DCs) represent a family of ontogenically distinct leukocytes involved in immune response regulation. The ability of DCs to stimulate T-cell immunity has led to their use as vectors for immunotherapy vaccines. However, it is unclear whether and to what degree in vitro–generated DCs are representative of DCs that develop in vivo. Treatment of mice with human Flt3 ligand (FL) dramatically increases the number of DCs. We report here that administration of FL to healthy human volunteers increased the number of circulating CD11c+ IL-3Rlow DC (mean 44-fold) and CD11c− IL-3Rhigh DC precursors (mean 12-fold). Moreover, the CD11c+ DCs were efficient stimulators of T cells in vitro. Thus, FL can expand the number of circulating, functionally competent human DCs in vivo.

scholarly journals Assessment of Drug Delivery Kinetics to Epidermal Targets In Vivo

2021 ◽  
Vol 23 (3) ◽  
Author(s):  
M. Hoppel ◽  
M. A. M. Tabosa ◽  
A. L. Bunge ◽  
M. B. Delgado-Charro ◽  
R. H. Guy
Keyword(s):  
Experimental Approach ◽  
Input Function ◽  
Drug Uptake ◽  
Tape Stripping ◽  
Healthy Human ◽  
Topical Product ◽  
Human Volunteers ◽  
Dermal Pharmacokinetics

AbstractIt has proven challenging to quantify ‘drug input’ from a formulation to the viable skin because the epidermal and dermal targets of topically applied drugs are difficult, if not impossible, to access in vivo. Defining the drug input function to the viable skin with a straightforward and practical experimental approach would enable a key component of dermal pharmacokinetics to be characterised. It has been hypothesised that measuring drug uptake into and clearance from the stratum corneum (SC) by tape-stripping allows estimation of a topical drug’s input function into the viable tissue. This study aimed to test this idea by determining the input of nicotine and lidocaine into the viable skin, following the application of commercialised transdermal patches to healthy human volunteers. The known input rates of these delivery systems were used to validate and assess the results from the tape-stripping protocol. The drug input rates from in vivo tape-stripping agreed well with the claimed delivery rates of the patches. The experimental approach was then used to determine the input of lidocaine from a marketed cream, a typical topical product for which the amount of drug absorbed has not been well-characterised. A significantly higher delivery of lidocaine from the cream than from the patch was found. The different input rates between drugs and formulations in vivo were confirmed qualitatively and quantitatively in vitro in conventional diffusion cells using dermatomed abdominal pig skin.

scholarly journals Extensive preclinical evaluation of lutetium-177-labeled PSMA-specific tracers for prostate cancer radionuclide therapy

2020 ◽  
Author(s):  
Eline A. M. Ruigrok ◽  
Nicole van Vliet ◽  
Simone U. Dalm ◽  
Erik de Blois ◽  
Dik C. van Gent ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Radionuclide Therapy ◽  
Specific Binding ◽  
Human Kidney ◽  
Careful Evaluation ◽  
Healthy Human ◽  
Binding Characteristics ◽  
Preclinical Evaluation

Abstract Purpose Various radiolabeled prostate-specific membrane antigen (PSMA)–targeting tracers are clinically applied for prostate cancer (PCa) imaging and targeted radionuclide therapy. The PSMA binding affinities, biodistribution, and DNA-damaging capacities of these radiotracers have not yet been compared in detail. A major concern of PSMA-targeting radiotracers is the toxicity in other PSMA-expressing organs, such as the salivary glands, thus demanding careful evaluation of the most optimal and safest radiotracer. In this extensive preclinical study, we evaluated the clinically applied PSMA-targeting small molecule inhibitors DOTA-PSMA-617 (PSMA-617) and DOTAGA-PSMA-I&T (PSMA-I&T) and the PSMA nanobody DOTA-JVZ-007 (JVZ-007) using PSMA-expressing cell lines, a unique set of PCa patient-derived xenografts (PDX) and healthy human tissues. Methods and results In vitro displacement studies on PSMA-expressing cells and cryosections of a PSMA-positive PDX revealed high and specific binding affinity for all three tracers labeled with lutetium-177 with IC50 values in the nanomolar range. Interestingly, [177Lu]Lu-JVZ-007 could not be displaced by PSMA-617 or PSMA-I&T, suggesting that this tracer targets an alternative binding site. Autoradiography assays on cryosections of human salivary and renal tissues revealed [177Lu]Lu-PSMA-617 to have the lowest binding to these healthy organs compared with [177Lu]Lu-PSMA-I&T. In vivo biodistribution assays confirmed the in vitro results with comparable tumor uptake of [177Lu]Lu-PSMA-617 and [177Lu]Lu-PSMA-I&T at all timepoints, resulting in induction of similar levels of DNA double-strand breaks in the tumors. However, [177Lu]Lu-PSMA-I&T demonstrated approximately 40× higher renal uptake at 4 and 8 h post injection resulting in an unfavorable tumor-to-kidney ratio. Conclusion [177Lu]Lu-PSMA-617 has the most favorable biodistribution in mice as well as more favorable binding characteristics in vitro in PSMA-positive cells and human kidney and salivary gland specimens compared with [177Lu]Lu-PSMA-I&T and [177Lu]Lu-JVZ-007. Based on our preclinical evaluation, [177Lu]Lu-PSMA-617 is the best performing tracer to be taken further into clinical evaluation for PSMA-targeted radiotherapeutic development although with careful evaluation of the tracer binding to PSMA-expressing organs.

scholarly journals SpoIID-Mediated Peptidoglycan Degradation Is Required throughout Engulfment during Bacillus subtilis Sporulation

2010 ◽  
Vol 192 (12) ◽  
pp. 3174-3186 ◽  
Author(s):  
Jennifer Gutierrez ◽  
Rachelle Smith ◽  
Kit Pogliano
Keyword(s):  
Bacillus Subtilis ◽  
Time Lapse ◽  
Protein Levels ◽  
Degradation Activity ◽  
Septal Localization ◽  
Activity Dependent ◽  
Conserved Amino Acids ◽  
Reduced Activity

ABSTRACT SpoIID is a membrane-anchored enzyme that degrades peptidoglycan and is essential for engulfment and sporulation in Bacillus subtilis. SpoIID is targeted to the sporulation septum, where it interacts with two other proteins required for engulfment: SpoIIP and SpoIIM. We changed conserved amino acids in SpoIID to alanine to determine whether there was a correlation between the effect of each substitution on the in vivo and in vitro activities of SpoIID. We identified one amino acid substitution, E88A, that eliminated peptidoglycan degradation activity and one, D210A, that reduced it, as well as two substitutions that destabilized the protein in B. subtilis (R106A and K203A). Using these mutants, we show that the peptidoglycan degradation activity of SpoIID is required for the first step of engulfment (septal thinning), as well as throughout membrane migration, and we show that SpoIID levels are substantially above the minimum required for engulfment. The inactive mutant E88A shows increased septal localization compared to the wild type, suggesting that the degradation cycle of the SpoIID/SpoIIP complex is accompanied by the activity-dependent release of SpoIID from the complex and subsequent rebinding. This mutant is also capable of moving SpoIIP across the sporulation septum, suggesting that SpoIID binding, but not peptidoglycan degradation activity, is needed for relocalization of SpoIIP. Finally, the mutant with reduced activity (D210A) causes uneven engulfment and time-lapse microscopy indicates that the fastest-moving membrane arm has greater concentrations of SpoIIP than the slower-moving arm, demonstrating a correlation between SpoIIP protein levels and the rate of membrane migration.

scholarly journals The safety profile of Bald’s eyesalve for the treatment of bacterial infections

2020 ◽  
Author(s):  
Blessing O Anonye ◽  
Valentine Nweke ◽  
Jessica Furner-Pardoe ◽  
Rebecca Gabrilska ◽  
Afshan Rafiq ◽  
...  
Keyword(s):  
Topical Application ◽  
Safety Profile ◽  
Bacterial Infections ◽  
Ex Vivo ◽  
Corneal Opacity ◽  
Healthy Human ◽  
Patch Tests ◽  
Human Volunteers

AbstractThe rise in antimicrobial resistance has prompted the development of alternatives, such as plant-derived compounds, to combat bacterial infections. Bald’s eyesalve, a remedy used in the Early Medieval period, has previously been shown to have efficacy against Staphylococcus aureus grown in an in vitro model of soft tissue infection. This remedy also had bactericidal activity against methicillin-resistant S. aureus (MRSA) in a chronic mouse wound. However, the safety profile of Bald’s eyesalve has not yet been demonstrated, and this is vital before testing in humans. Here, we determined the safety potential of Bald’s eyesalve using in vitro, ex vivo, and in vivo models representative of skin or eye infections. We also confirmed that Bald’s eyesalve is active against an important eye pathogen, Neisseria gonorrhoeae. Low levels of cytotoxicity were observed in eyesalve-treated cell lines representative of skin and immune cells. Results from a bovine corneal opacity and permeability test demonstrated slight irritation to the cornea that resolved within 10 minutes. The slug mucosal irritation assay revealed that a low level of mucus was secreted by slugs exposed to eyesalve, indicating mild mucosal irritation. We obtained promising results from mouse wound closure experiments; no visible signs of irritation or inflammation were observed. Our results suggest that Bald’s eyesalve could be tested further on human volunteers to assess safety for topical application against bacterial infections.ImportanceAlternative treatment for bacterial infections are needed to combat the ever increasing repertoire of bacteria resistant to antibiotics. A medieval plant-based remedy, Bald’s eyesalve, shows promise as a substitute for the treatment of these infections. For any substance to be effective in the treatment of bacterial infections in humans, it is important to consider the safety profile. This is a key consideration in order to have the necessary regulatory approval. We demonstrate the safety profile of Bald’s eyesalve using a variety of models, including whole-organ and whole-animal models. Our results show that Bald’s eyesalve is mildly toxic to cultured human cells, but potentially suitable for patch tests on healthy human volunteers to assess safety for later clinical trials. Our work has the potential to transform the management of diseases caused by bacterial infections, such as diabetic foot ulcers, through topical application of a natural product cocktail based on Bald’s eyesalve.

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