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Impaired hemodynamic renal reserve response following recovery from established acute kidney injury and improvement by hydrodynamic isotonic fluid delivery
No full textRenal reserve capacity may be compromised following recovery from AKI and could be used to identify impaired renal function in the face of restored GFR or plasma creatinine. To investigate the loss of hemodynamic renal reserve responses following recovery in a model of AKI, rats were subjected to left unilateral renal ischemia reperfusion (I/R) injury and contralateral nephrectomy and allowed to recover for 5 weeks. Some rats were treated 24 hours post I/R, by hydrodynamic isotonic fluid delivery (AKI-HIFD) of saline through the renal vein, previously shown to improve recovery and inflammation relative to control rats receiving saline through the vena cava (AKI-VC). At 5 weeks post-surgery, plasma creatinine and GFR recovered to levels observed in uninephrectomized sham-controls. Baseline renal blood flow (RBF) was not different between AKI or sham groups, but infusion of L-arginine (7.5 mg/kg/min) significantly increased RBF in sham controls, while the RBF response to L-Arg was significantly reduced in AKI-VC rats relative to sham (22.6 ± 2.2% vs 13.8±1.8%; p<0.05). RBF responses were partially protected in AKI-HIFD rats relative to AKI-VC rats (17.0 ±2.2%) and were not significantly different from sham. Capillary rarefaction observed in AKI-VC rats was significantly protected in AKI-HIFD rats. There was also a significant increase in Th17 cell infiltration and interstitial fibrosis in AKI-VC rats vs sham, which was not present in AKI-HIFD rats. These data suggest that recovery from AKI results in impaired hemodynamic reserve and that associated CKD progression may be mitigated by HIFD in the early post AKI period
Oncolytic BHV-1 Is Sufficient to Induce Immunogenic Cell Death and Synergizes with Low-Dose Chemotherapy to Dampen Immunosuppressive T Regulatory Cells.
No full textImmunogenic cell death (ICD) can switch immunologically "cold" tumors "hot", making them sensitive to immune checkpoint inhibitor (ICI) therapy. Many therapeutic platforms combine multiple modalities such as oncolytic viruses (OVs) and low-dose chemotherapy to induce ICD and improve prognostic outcomes. We previously detailed many unique properties of oncolytic bovine herpesvirus type 1 (oBHV) that suggest widespread clinical utility. Here, we show for the first time, the ability of oBHV monotherapy to induce bona fide ICD and tumor-specific activation of circulating CD8 T cells in a syngeneic murine model of melanoma. The addition of low-dose mitomycin C (MMC) was necessary to fully synergize with ICI through early recruitment of CD8 T cells and reduced infiltration of highly suppressive PD-1 Tregs. Cytokine and gene expression analyses within treated tumors suggest that the addition of MMC to oBHV therapy shifts the immune response from predominantly anti-viral, as evidenced by a high level of interferon-s
Inhibiting WNT secretion reduces high bone mass caused by Sost loss-of-function or gain-of-function mutations in Lrp5.
No full textProper regulation of Wnt signaling is critical for normal bone development and homeostasis. Mutations in several Wnt signaling components, which increase the activity of the pathway in the skeleton, cause high bone mass in human subjects and mouse models. Increased bone mass is often accompanied by severe headaches from increased intracranial pressure, which can lead to fatality and loss of vision or hearing due to the entrapment of cranial nerves. In addition, progressive forehead bossing and mandibular overgrowth occur in almost all subjects. Treatments that would provide symptomatic relief in these subjects are limited. Porcupine-mediated palmitoylation is necessary for Wnt secretion and binding to the frizzled receptor. Chemical inhibition of porcupine is a highly selective method of Wnt signaling inhibition. We treated three different mouse models of high bone mass caused by aberrant Wnt signaling, including homozygosity for loss-of-function in Sost, which models sclerosteosis, and two strains of mice carrying different point mutations in Lrp5 (equivalent to human G171V and A214V), at 3 months of age with porcupine inhibitors for 5-6 weeks. Treatment significantly reduced both trabecular and cortical bone mass in all three models. This demonstrates that porcupine inhibition is potentially therapeutic for symptomatic relief in subjects who suffer from these disorders and further establishes that the continued production of Wnts is necessary for sustaining high bone mass in these models
A proteomic analysis of atrial fibrillation in a prospective longitudinal cohort (AGES-Reykjavik study).
No full textAtrial fibrillation (AF) is associated with high risk of comorbidities and mortality. Our aim was to examine causal and predictive relationships between 4137 serum proteins and incident AF in the prospective population-based Age, Gene/Environment Susceptibility-Reykjavik (AGES-Reykjavik) study.The study included 4765 participants, of whom 1172 developed AF. Cox proportional hazards regression models were fitted for 4137 baseline protein measurements adjusting for known risk factors. Protein associations were tested for replication in the Cardiovascular Health Study (CHS). Causal relationships were examined in a bidirectional, two-sample Mendelian randomization analysis. The time-dependent area under the receiver operating characteristic curve (AUC)-statistic was examined as protein levels and an AF-polygenic risk score (PRS) were added to clinical risk models. The proteomic signature of incident AF consisted of 76 proteins, of which 63 (83%) were novel and 29 (38%) were replicated in CHS. The signature included both N-terminal prohormone of brain natriuretic peptide (NT-proBNP)-dependent (e.g. CHST15, ATP1B1, and SVEP1) and independent components (e.g. ASPN, AKR1B, and LAMA1/LAMB1/LAMC1). Nine causal candidates were identified (TAGLN, WARS, CHST15, CHMP3, COL15A1, DUSP13, MANBA, QSOX2, and SRL). The reverse causal analysis suggested that most AF-associated proteins were affected by the genetic liability to AF. N-terminal prohormone of brain natriuretic peptide improved the prediction of incident AF events close to baseline with further improvements gained by the AF-PRS at all time points.The AF proteomic signature includes biologically relevant proteins, some of which may be causal. It mainly reflects an NT-proBNP-dependent consequence of the genetic liability to AF. N-terminal prohormone of brain natriuretic peptide is a promising marker for incident AF in the short term, but risk assessment incorporating a PRS may improve long-term risk assessment
Optimal weighted Bonferroni tests and their graphical extensions
No full textRegulatory guidelines mandate the strong control of the familywise error rate in confirmatory clinical trials with primary and secondary objectives. Bonferroni tests are one of the popular choices for multiple comparison procedures and are building blocks of more advanced procedures. It is usually of interest to find the optimal weighted Bonferroni split for multiple hypotheses. We consider two popular quantities as the optimization objectives, which are the disjunctive power and the conjunctive power. The former is the probability to reject at least one hypothesis and the latter is the probability to reject all hypotheses. We investigate the behavior of each of them as a function of different Bonferroni splits, given assumptions about the alternative hypotheses and the correlations between test statistics. Under independent tests, unique optimal Bonferroni weights exist; under dependence, optimal Bonferroni weights may not be unique based on a fine grid search. In general, we propose an optimization algorithm based on constrained non-linear optimization and multiple starting points. The proposed algorithm efficiently identifies optimal Bonferroni weights to maximize the disjunctive or conjunctive power. In addition, we apply the proposed algorithm to graphical approaches, which include many Bonferroni-based multiple comparison procedures. Utilizing the closed testing principle, we adopt a two-step approach to find optimal graphs using the disjunctive power. We also identify a class of closed test procedures that optimize the conjunctive power. We apply the proposed algorithm to a case study to illustrate the utility of optimal graphical approaches that reflect study objectives
Evolution of Biocatalysis at Novartis over Last 40 Years
No full textThe fortieth anniversary of biocatalysis started at Ciba-Geigy later at Novartis is a great time to pause and reflect on development of science and technology in this space. Enzyme-based synthesis became a highly valued enabling tool for pharmaceutical research and development over the last decades. In this perspective we aim to discuss how the scientific approaches and trends evolved over the time and present future challenges and opportunities
Drug delivery breakthrough technologies – A perspective on clinical and societal impact
No full textThe way a drug molecule is administered has always had a profound impact on people requiring medical interventions - from vaccine development to cancer
therapeutics. In the Controlled Release Society Fall Symposium 2022, a trans-institutional group of scientists from industry, academia, and non-governmental or�ganizations discussed what a breakthrough in the field of drug delivery constitutes. On the basis of these discussions, we classified drug delivery breakthrough
technologies into three categories. In category 1, drug delivery systems enable treatment for new molecular entities per se, for instance by overcoming biological
barriers. In category 2, drug delivery systems optimize efficacy and/or safety of an existing drug, for instance by directing distribution to their target tissue, by
replacing toxic excipients, or by changing the dosing reqimen. In category 3, drug delivery systems improve global access by fostering use in low-resource settings, for
instance by facilitating drug administration outside of a controlled health care institutional setting. We recognize that certain breakthroughs can be classified in more
than one category. It was concluded that in order to create a true breakthrough technology, multidisciplinary collaboration is mandated to move from pure technical
inventions to true innovations addressing key current and emerging unmet health care needs
Transcriptional linkage analysis with in vivo AAV-Perturb-seq.
No full textThe ever-growing compendium of genetic variants associated with human pathologies demands new methods to study genotype-phenotype relationships in complex tissues in a high-throughput manner1,2. Here we introduce adeno-associated virus (AAV)-mediated direct in vivo single-cell CRISPR screening, termed AAV-Perturb-seq, a tuneable and broadly applicable method for transcriptional linkage analysis as well as high-throughput and high-resolution phenotyping of genetic perturbations in vivo. We applied AAV-Perturb-seq using gene editing and transcriptional inhibition to systematically dissect the phenotypic landscape underlying 22q11.2 deletion syndrome3,4 genes in the adult mouse brain prefrontal cortex. We identified three 22q11.2-linked genes involved in known and previously undescribed pathways orchestrating neuronal functions in vivo that explain approximately 40% of the transcriptional changes observed in a 22q11.2-deletion mouse model. Our findings suggest that the 22q11.2-deletion syndrome transcriptional phenotype found in mature neurons may in part be due to the broad dysregulation of a class of genes associated with disease susceptibility that are important for dysfunctional RNA processing and synaptic function. Our study establishes a flexible and scalable direct in vivo method to facilitate causal understanding of biological and disease mechanisms with potential applications to identify genetic interventions and therapeutic targets for treating disease
QM assisted ML for 19F NMR chemical shift prediction.
No full textLigand-observed 19F NMR detection is an efficient method for screening libraries of fluorinated molecules in fragment-based drug design campaigns. Screening fluorinated molecules in large mixtures makes 19F NMR a high-throughput method. Typically, these mixtures are generated from pools of well-characterized fragments. By predicting 19F NMR chemical shift, mixtures could be generated for arbitrary fluorinated molecules facilitating for example focused screens.In a previous publication, we introduced a method to predict 19F NMR chemical shift using rooted fluorine fingerprints and machine learning (ML) methods. Having observed that the quality of the prediction depends on similarity to the training set, we here propose to assist the prediction with quantum mechanics (QM) based methods in cases where compounds are not well covered by a training set.Beyond similarity, the performance of ML methods could be associated with individual features in compounds. A combination of both could be used as a procedure to split input data sets into those that could be predicted by ML and those that required QM processing. We could show on a proprietary fluorinated fragment library, known as LEF (Local Environment of Fluorine), and a public Enamine data set of 19F NMR chemical shifts that ML and QM methods could synergize to outperform either method individually. Models built on Enamine data, as well as model building and QM workflow tools, can be found at https://github.com/PatrickPenner/lefshift and https://github.com/PatrickPenner/lefqm
Valhidepsin Lipopeptides from Chromobacterium vaccinii: Structures, Biosynthesis, and Coregulation with FR900359 Production.
No full textMicrobial secondary metabolites continue to provide a valuable source of both chemical matter and inspiration for drug discovery in a broad range of therapeutic areas. Beyond this, the corresponding microorganisms represent a sustainable modality for biotechnological production of structurally complex molecules at the quantities required for drug development or even commercial manufacturing. Chromobacterium vaccinii, which has recently been reported as a producer of the pharmacologically highly important Gq inhibitor FR900359 (FR), represents such an example. The characterization of an orphan biosynthetic gene cluster (BGC) located directly downstream of the frs BCG led to the discovery of eight new lipopeptides, valhidepsins A-H (1-8), produced by C. vaccinii. Their chemical structures were elucidated through analysis of 1D and 2D NMR data and high-resolution MS/MS fragmentation methods. The valhidepsins did not display significant antibiotic nor cytotoxic activities but showed surfactant properties. The cluster-compound correlation was demonstrated by generation of a knockout mutant, which abolished production of valhidepsins. This knockout mutant yielded a significantly increased isolated yield of FR