3' Untranslated Region Structural Elements in CYP24A1 Are Associated With Infantile Hypercalcemia Type 1.

Loss-of-function mutations in the CYP24A1 protein-coding region causing reduced 25 hydroxyvitamin D (25OHD) and 1,25 dihydroxyvitamin D (1,25(OH)2 D) catabolism have been observed in some cases of infantile hypercalcemia type 1 (HCINF1), which can manifest as nephrocalcinosis, hypercalcemia and adult-onset hypercalciuria, and renal stone formation. Some cases present with apparent CYP24A1 phenotypes but do not exhibit pathogenic mutations. Here, we assessed the molecular mechanisms driving apparent HCINF1 where there was a lack of CYP24A1 mutation. We obtained blood samples from 47 patients with either a single abnormality of no obvious cause or a combination of hypercalcemia, hypercalciuria, and nephrolithiasis as part of our metabolic and stone clinics. We used liquid chromatography tandem mass spectrometry (LC-MS/MS) to determine serum vitamin D metabolites and direct sequencing to confirm CYP24A1 genotype. Six patients presented with profiles characteristic of altered CYP24A1 function but lacked protein-coding mutations in CYP24A1. Analysis upstream and downstream of the coding sequence showed single nucleotide variants (SNVs) in the CYP24A1 3' untranslated region (UTR). Bioinformatics approaches revealed that these 3' UTR abnormalities did not result in microRNA silencing but altered the CYP24A1 messenger RNA (mRNA) secondary structure, which negatively impacted translation. Our experiments showed that mRNA misfolding driven by these 3' UTR sequence-dependent structural elements was associated with normal 25OHD but abnormal 1,25(OH)2 D catabolism. Using CRISPR-Cas9 gene editing, we developed an in vitro mutant model for future CYP24A1 studies. Our results form a basis for future studies investigating structure-function relationships and novel CYP24A1 mutations producing a semifunctional protein. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Parkinson's Disease and the Environment.

Parkinson's disease (PD) is a heterogeneous neurodegenerative disorder that affects an estimated 10 million sufferers worldwide. The two forms of PD include familial and sporadic, and while the etiology of PD is still largely unknown, the condition is likely to be multifactorial with genetic and environmental factors contributing to disease genesis. Diagnosis of the condition is attained through the observation of cardinal clinical manifestations including resting tremor, muscle rigidity, slowness or loss of movement, and postural instability. Unfortunately, by the time these features become apparent extensive neurological damage has already occurred. A cure for PD has not been identified and the current therapy options are pharmaceutical- and/or surgical-based interventions to treat condition symptoms. There is no specific test for PD and most diagnoses are confirmed by a combination of clinical symptoms and positive responses to dopaminergic drug therapies. The prevalence and incidence of PD vary worldwide influenced by several factors such as age, gender, ethnicity, genetic susceptibilities, and environmental exposures. Here, we will present environmental factors implicated in sporadic PD onset. By understanding the mechanisms in which environmental factors interact with, and affect the brain we can stride toward finding the underlying cause(s) of PD.

There is gold in them hills: Predicting potential acid mine drainage events through the use of chemometrics.

Disused mines and mining legacy require significant manpower to ameliorate the contaminated environmental surroundings following their disbanding coupled with extraordinary funding to manage these issues. Water (pH, temperature, dissolved oxygen, conductance, metals, sulphate) and total suspended solids (TSS) quality are environmental parameters that are affected by legacy mining activity and often require monitoring and rapid response if events (e.g. rainfall) occur which might affect the surrounding areas. In this study, we have monitored a famous mine site in Queensland, Australia for a number of water and sediment parameters known to be associated with acid mine drainage. This study performed analysis of water and sediment over three years, as well as rainfall data. Principal component analysis (PCA) and partial least squares (PLS) regression was undertaken to investigate the data obtained. It was found that the use of PCA can predict the effect of year and site on the environmental influence of the abandoned mine site, based on the combination of chemical properties and meteorological data.

A Small-Scale Process for Predicting Donnan and Volume Exclusion Effects During Ultrafiltration/Diafiltration Process Development.

Achieving the desired final protein formulation using ultrafiltration/diafiltration (UF/DF) operations is an essential component of many protein purification processes. It is well documented that differences in the excipient and buffer concentrations exist between the DF and retentate solutions when they have achieved equilibrium. Several publications have proposed ways to calculate these differences. However, the accuracy of these methods has been limited by the use of an estimated protein charge value. In this article, a small-scale system is described, which can accurately determine the protein charge by making buffer and excipient concentration measurements and applying the determined values to the Donnan and volume exclusion equations. This information can be utilized to generate a standard curve, which in turn can be applied to at-scale UF/DF operations. For 2 different antibodies, the standard curve generated by the small-scale system yielded buffer concentrations and pH values that agreed well with those generated after UF/DF operations, whereas using the theoretical protein charge caused a departure from the measured results. This model also provides good estimates as to how the final formulation pH and buffer concentration vary as a function of the pH and buffer concentration in the DF buffer. This information is of important utility for the accurate formulation of high-concentration protein solutions (>100 mg/mL) where the coconcentration of buffers and the volume exclusion of certain excipients are amplified. The low material requirements of the small-scale system are a major benefit for early phase formulation and process development when sufficient time and material may not be available, in particular to ensure successful UF/DF operations for the development of high protein concentration formulations.