renin receptor

Soluble prorenin receptor (sPRR), a component of the renin angiotensin system (RAS), has been identified as a plasma biomarker for hypertension and cardiovascular diseases in humans. Despite studies showing that sPRR in kidney is produced by renal collecting duct (CD) tubular cells, its biological actions modulating cardiorenal function remains unknown. Therefore, this study aimed to create a new murine model to investigate how expressing human sPRR (HsPRR) in CD influence the intrarenal RAS status and renal hemodynamics in male and female mice fed a regular chow. CD-HsPRR mice were generated by breeding human sPRR-Myc-tag transgenic mice with transgenic mice expressing Hoxb7/Cre, which showed increased renal sPRR expression but unchanged circulating levels compared to CTL mice in both sexes. Plasma RAS levels were not influenced by the expression of HsPRR in CD as well. CD-HsPRR expression showed only in female littermates: 1) increased 24-hour blood pressure, due to elevated daytime mean and systolic values, 2) impaired blood pressure response to an acute dose of losartan and reduced chronic angiotensin II (AngII)-hypertension, 3) reduced ACE activity and Ang II content in renal cortex, 4) decreased GFR, with no changes in natriuresis and kaliuresis despite the upregulation of β-ENaC in renal cortex. Taken together, these data suggest that expression of HsPRR in CD could interact with Ang II type 1 receptor mediating a sex-specific, Ang II-independent renal dysfunction and pro-hypertensive phenotype.

Controlling high-mannose (HM) content of therapeutic proteins during process intensification, reformulation for subcutaneous delivery, antibody-drug conjugate or biosimilar manufacturing represents an ongoing challenge. Even though a range of glycosylation levers to increase HM content exist, modulators specially increasing M5 glycans are still scarce. Several compounds of the polyether ionophore family were screened for their ability to selectively increase M5 glycans of mAb products and compared to the well-known α-mannosidase I inhibitor kifunensine known to increase mainly M8-M9 glycans. Maduramycin, amongst other promising polyether ionophores, showed the desired effect on different cell lines. For fed-batch processes, a double bolus addition modulator feed strategy was developed maximizing the effect on glycosylation by minimizing impact on culture performance. Further, a continuous feeding strategy for steady-state perfusion processes was successfully developed, enabling consistent product quality at elevated HM glycan levels. With kifunensine and maduramycin showing inverse effects on the relative HM distribution, a combined usage of these modulators was further evaluated to fine-tune a desired HM glycan pattern. The discovered HM modulators expand the current HM modulating toolbox for biotherapeutics. Their application not only for fed-batch processes, but also steady-state perfusion processes, make them a universal tool with regards to fully continuous manufacturing processes.

Exome sequencing (ES) is becoming a first-tier clinical diagnostic test for Mendelian diseases, drastically reducing the time and cost of diagnostic odyssey and improving the diagnosis rate. Despite its success, ES faces practical challenges in assessing the pathogenicity of numerous intronic and synonymous variants, leaving a significant proportion of patients undiagnosed. In this study, a whole blood transcriptome database was constructed, which demonstrated the expression profile of 2,981 OMIM disease genes in blood samples. Meanwhile, a workflow integrating exome sequencing, blood transcriptome sequencing, and in silico prediction tools to identify and validate splicing-altering intronic or synonymous variants was proposed. Following this pipeline, seven synonymous variants in eight patients were discovered. Of these, the functional evidence of c.981G>A (PIGN), c.1161A>G (ALPL), c.858G>A (ATP6AP2) and c.1011G>T (MTHFR) have not been previously reported. RNA-seq validation confirmed that these variants induced aberrant splicing, expanding the disease-causing variants spectrum of these genes. Overall, this study shows the feasibility of combining multi-omics data to identify splicing-altering variants, especially the power of RNA-seq. It also reveals that synonymous variants, which are often overlooked in standard diagnostic approaches, comprise an important portion of unresolved genetic diseases.