Identifying and Characterizing a Novel Protein Kinase STK35L1 and Deciphering Its Orthologs and Close-Homologs in Vertebrates

The human kinome containing 478 eukaryotic protein kinases has over 100 uncharacterized kinases with unknown substrates and biological functions. The Ser/Thr kinase 35 (STK35, Clik1) is a member of the NKF 4 (New Kinase Family 4) in the kinome with unknown substrates and biological functions. Various high throughput studies indicate that STK35 could be involved in various human diseases such as colorectal cancer and malaria. In this study, we found that the previously published coding sequence of the STK35 gene is incomplete. The newly identified sequence of the STK35 gene codes for a protein of 534 amino acids with a N-terminal elongation of 133 amino acids. It has been designated as STK35L (STK35 long). Since it is the first of further homologous kinases we termed it as STK35L1. The STK35L1 protein (58 kDa on SDS-PAGE), but not STK35 (44 kDa), was found to be expressed in all human cells studied (endothelial cells, HeLa, and HEK cells) and was down-regulated after silencing with specific siRNA. EGFP-STK35L1 was localized in the nucleus and the nucleolus. By combining syntenic and gene structure pattern data and homology searches, two further STK35L1 homologs, STK35L2 (previously known as PDIK1L) and STK35L3, were found. All these protein kinase homologs were conserved throughout the vertebrates. The STK35L3 gene was specifically lost during placental mammalian evolution. Using comparative genomics, we have identified orthologous sets of these three protein kinases genes and their possible ancestor gene in two sea squirt genomes. We found the full-length coding sequence of the STK35 gene and termed it as STK35L1. We identified a new third STK35-like gene, STK35L3, in vertebrates and a possible ancestor gene in sea squirt genome. This study will provide a comprehensive platform to explore the role of STK35L kinases in cell functions and human diseases

STK35L1 Associates with Nuclear Actin and Regulates Cell Cycle and Migration of Endothelial Cells

BACKGROUND: Migration and proliferation of vascular endothelial cells are essential for repair of injured endothelium and angiogenesis. Cyclins, cyclin-dependent kinases (CDKs), and cyclin-dependent kinase inhibitors play an important role in vascular tissue injury and wound healing. Previous studies suggest a link between the cell cycle and cell migration: cells present in the G(1) phase have the highest potential to migrate. The molecular mechanism linking these two processes is not understood. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we explored the function of STK35L1, a novel Ser/Thr kinase, localized in the nucleus and nucleolus of endothelial cells. Molecular biological analysis identified a bipartite nuclear localization signal, and nucleolar localization sequences in the N-terminal part of STK35L1. Nuclear actin was identified as a novel binding partner of STK35L1. A class III PDZ binding domains motif was identified in STK35L1 that mediated its interaction with actin. Depletion of STK35L1 by siRNA lead to an accelerated G(1) to S phase transition after serum-stimulation of endothelial cells indicating an inhibitory role of the kinase in G(1) to S phase progression. Cell cycle specific genes array analysis revealed that one gene was prominently downregulated (8.8 fold) in STK35L1 silenced cells: CDKN2A alpha transcript, which codes for p16(INK4a) leading to G(1) arrest by inhibition of CDK4/6. Moreover in endothelial cells seeded on Matrigel, STK35L1 expression was rapidly upregulated, and silencing of STK35L1 drastically inhibited endothelial sprouting that is required for angiogenesis. Furthermore, STK35L1 depletion profoundly impaired endothelial cell migration in two wound healing assays. CONCLUSION/SIGNIFICANCE: The results indicate that by regulating CDKN2A and inhibiting G1- to S-phase transition STK35L1 may act as a central kinase linking the cell cycle and migration of endothelial cells. The interaction of STK35L1 with nuclear actin might be critical in the regulation of these fundamental endothelial functions

Improved upper limb function in non-ambulant children with SMA type 2 and 3 during nusinersen treatment: a prospective 3-years SMArtCARE registry study

Background The development and approval of disease modifying treatments have dramatically changed disease progression in patients with spinal muscular atrophy (SMA). Nusinersen was approved in Europe in 2017 for the treatment of SMA patients irrespective of age and disease severity. Most data on therapeutic efficacy are available for the infantile-onset SMA. For patients with SMA type 2 and type 3, there is still a lack of sufficient evidence and long-term experience for nusinersen treatment. Here, we report data from the SMArtCARE registry of non-ambulant children with SMA type 2 and typen 3 under nusinersen treatment with a follow-up period of up to 38 months. Methods SMArtCARE is a disease-specific registry with data on patients with SMA irrespective of age, treatment regime or disease severity. Data are collected during routine patient visits as real-world outcome data. This analysis included all non-ambulant patients with SMA type 2 or 3 below 18 years of age before initiation of treatment. Primary outcomes were changes in motor function evaluated with the Hammersmith Functional Motor Scale Expanded (HFMSE) and the Revised Upper Limb Module (RULM). Results Data from 256 non-ambulant, pediatric patients with SMA were included in the data analysis. Improvements in motor function were more prominent in upper limb: 32.4% of patients experienced clinically meaningful improvements in RULM and 24.6% in HFMSE. 8.6% of patients gained a new motor milestone, whereas no motor milestones were lost. Only 4.3% of patients showed a clinically meaningful worsening in HFMSE and 1.2% in RULM score. Conclusion Our results demonstrate clinically meaningful improvements or stabilization of disease progression in non-ambulant, pediatric patients with SMA under nusinersen treatment. Changes were most evident in upper limb function and were observed continuously over the follow-up period. Our data confirm clinical trial data, while providing longer follow-up, an increased number of treated patients, and a wider range of age and disease severity

Evidenzbasierte Arzneimittelversorgung bei Seltenen Erkrankungen: die Rolle der Digitalisierung

Knowledge generation in the field of drug development for people with rare diseases (RDs) faces particular difficulties. This paper will show what improvements are expected from increasing digitalisation from the perspective of three healthcare institutions: the Federal Institute for Drugs and Medical Devices, the Institute for Quality and Efficiency in Health Care and the Federal Joint Committee. First, the potential of digitalisation to increase the efficiency of clinical development and regulatory decision-making through earlier collaboration of all stakeholders is proposed. Subsequently, it is argued that digitalisation should be used to reduce barriers to the implementation of care-associated randomised controlled trials, including those based on registries. High-quality registry studies should not only be started after approval but during the approval process, so that the evidence necessary for therapy decisions is available promptly after approval. Finally, it is stated that improving the evidence base through qualitative improvement of the data sources and their linkages directly benefits patients. Usable evidence that can be generated over a longer period of time – also beyond approval – and contribute to decisions within healthcare system ensures effective drug provision. The institutions agree that high-quality indication registries should be developed as product-independent, standing infrastructures so that high-quality data can be accessed early in the development of medicines for RD.Bei der Wissensgenerierung im Bereich der Arzneimittelentwicklung für Menschen mit Seltenen Erkrankungen (SE) sind besondere Schwierigkeiten zu überwinden. Welche Verbesserungen durch eine zunehmende Digitalisierung erwartet werden, wird in diesem Beitrag aus der Perspektive von 3 Institutionen im Gesundheitswesen aufgezeigt: dem Bundesinstitut für Arzneimittel und Medizinprodukte, dem Institut für Qualität und Wirtschaftlichkeit im Gesundheitswesen und dem Gemeinsamen Bundesausschuss. Zunächst wird das Potenzial der Digitalisierung vorgestellt, auch durch eine frühere Zusammenarbeit aller Beteiligten die Effizienz der klinischen Entwicklung und der regulatorischen Entscheidungsprozesse zu erhöhen. Im Anschluss wird argumentiert, dass mit Hilfe der Digitalisierung Hürden bei der Durchführung versorgungsnaher, auch registerbasierter randomisiert kontrollierter Studien abgebaut werden sollten. Hochwertige Registerstudien sollten nicht erst nach der Zulassung, sondern bereits während des Zulassungsprozesses begonnen werden, damit die für Therapieentscheidungen notwendige Evidenz zeitnah nach Zulassung vorliegt. Abschließend wird festgestellt, dass die Verbesserung der Datenlage durch qualitative Verbesserung der Datenquellen und deren Vernetzung unmittelbar den Patient*innen zugutekommt. Verwertbare Evidenz, die über einen längeren Zeitraum – auch über die Zulassung hinaus – generiert werden kann und geeignet ist, in Entscheidungen für das Gesundheitssystem einzufließen, stellt eine effektive Arzneimittelversorgung sicher. Die Institutionen sind sich einig, dass qualitativ hochwertige Indikationsregister als produktunabhängige, stehende Infrastrukturen entwickelt werden sollten, damit bereits früh in der Entwicklung von Arzneimitteln für SE auf hochwertige Daten zurückgegriffen werden kann