Molecular Determinants of Survival Motor Neuron (SMN) Protein Cleavage by the Calcium-Activated Protease, Calpain

Spinal muscular atrophy (SMA) is a leading genetic cause of childhood mortality, caused by reduced levels of survival motor neuron (SMN) protein. SMN functions as part of a large complex in the biogenesis of small nuclear ribonucleoproteins (snRNPs). It is not clear if defects in snRNP biogenesis cause SMA or if loss of some tissue-specific function causes disease. We recently demonstrated that the SMN complex localizes to the Z-discs of skeletal and cardiac muscle sarcomeres, and that SMN is a proteolytic target of calpain. Calpains are implicated in muscle and neurodegenerative disorders, although their relationship to SMA is unclear. Using mass spectrometry, we identified two adjacent calpain cleavage sites in SMN, S192 and F193. Deletion of small motifs in the region surrounding these sites inhibited cleavage. Patient-derived SMA mutations within SMN reduced calpain cleavage. SMN(D44V), reported to impair Gemin2 binding and amino-terminal SMN association, drastically inhibited cleavage, suggesting a role for these interactions in regulating calpain cleavage. Deletion of A188, a residue mutated in SMA type I (A188S), abrogated calpain cleavage, highlighting the importance of this region. Conversely, SMA mutations that interfere with self-oligomerization of SMN, Y272C and SMNΔ7, had no effect on cleavage. Removal of the recently-identified SMN degron (Δ268-294) resulted in increased calpain sensitivity, suggesting that the C-terminus of SMN is important in dictating availability of the cleavage site. Investigation into the spatial determinants of SMN cleavage revealed that endogenous calpains can cleave cytosolic, but not nuclear, SMN. Collectively, the results provide insight into a novel aspect of the post-translation regulation of SMN

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field

A Cross-Sectional Analysis into the Willingness and Hesitancy to Test and Vaccinate Against COVID-19 Among the Elderly Population in the Kingdom of Saudi Arabia

Reem S AlOmar,1 Nouf A AlShamlan,1 Marwa Mahmoud Shafey,1 Assim M AlAbdulKader,1 Khalid S AlHarkan,1 Wejdan M Al-Johani,1 Sameerah Motabgani,1 Nourah K Alkaltham,1 Abdullah A Alharbi2 1Department of Family and Community Medicine, College of Medicine, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia; 2Family and Community Medicine Department, Faculty of Medicine, Jazan University, Jazan City, Jazan, Saudi ArabiaCorrespondence: Reem S AlOmar, Email [email protected]: COVID-19 remains a public health concern. Vaccinations, testing and tracing have been proven to provide strong protection against severe illness and death. Older adults are amongst the groups with an increased risk of severe illness. This study aimed to explore the willingness and hesitancy of the elderly population in the Kingdom of Saudi Arabia to test and vaccinate against COVID-19.Methods: This cross-sectional study targeted participants aged 65 years and above. The questionnaire included both sociodemographic variables, and variables related to willingness and hesitancy to vaccinate and test for COVID-19 that were mainly based on existing literature. Bivariate analyses were performed to test for associations. Significance was set at the 0.05 level.Results: The total sample of respondents was 502. The results show that 52.4% were not aware of a previous infection. Participants aged above 70 years and females were found to be more aware of a previous infection (51.6% and 53.1% respectively) (P < 0.05). Also, 54.7% felt it necessary to test against COVID-19, and among those, 70.8% believed that testing would contain and control the spread. The results also show that 3.2% were not vaccinated to date, compared to 95.41% who had the complete dose as well as the recommended booster dose for elderlies. Age, sex and level of education were significantly associated with vaccine uptake, where participants aged between 65 and 70 years, males and high levels of education were associated with a complete vaccine uptake.Discussion: The current findings add to the epidemiological evidence and show that the social network theory within the context of health may have played a role in self-awareness of previous infections. Also, social factors should be incorporated in public health interventions and public health campaigns targeting the elderly are still needed especially with the continued discovery of variants of interests.Keywords: COVID-19, public health, health promotion, prevention, elderl

HPV Vaccine Uptake, Willingness to Receive, and Causes of Vaccine Hesitancy: A National Study Conducted in Saudi Arabia Among Female Healthcare Professionals

Nouf A AlShamlan,1 Reem S AlOmar,1 Assim M AlAbdulKader,1 Marwa Mahmoud Shafey,1 Faisal A AlGhamdi,2 Abdullah A Aldakheel,2 Saud A AlShehri,2 Lyana A Felemban,3 Shahad A AlShamlan,2 Malak A Al Shammari1 1Department of Family and Community Medicine, College of Medicine, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia; 2College of Medicine, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia; 3College of Medicine, Fakeeh College of Medical Sciences, Jeddah, Saudi ArabiaCorrespondence: Nouf A AlShamlan, Department of Family and Community Medicine, College of Medicine, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia, Tel +966504901406, Email [email protected]: Epidemiological evidence has shown that human papillomavirus (HPV) is the most frequent cause of sexually transmitted infection, and vaccination is an essential measure to prevent associated diseases and complications. This study aimed to assess the HPV vaccine uptake and its associated factors as well as HPV vaccine hesitancy by female healthcare workers (HCWs) in Saudi Arabia.Methods: This online, questionnaire-based, cross-sectional study involved female HCWs in Saudi Arabia between July and October 2022. The study tool included questions about sociodemographic, occupational, and reproductive characteristics, uptake of HPV vaccination, and reasons of hesitancy. Chi-squared and t-tests were used for bivariate analyses, and multivariable logistic regression was used to adjust for confounders.Results: The total number of participants was 1857. Around 20% of HCWs received at least one dose of the HPV vaccine, and around 45% were willing to take it this year. Lower odds of vaccine uptake were reported among older participants and those with a higher level of education. However, nurses, HCWs with a previous HPV infection, those with a family history of cervical cancer, or those with a previous cervical cancer screening test had higher odds of receiving the vaccine. On the other hand, older participants and diploma degree holders were less willing to take the HPV vaccine. Higher odds of willingness were reported in married HCWs, those with a previous HPV infection, those who received a previous HPV vaccine dose, or those who were screened for cervical cancer. Lack of knowledge and some misconceptions were the most reported reasons for hesitancy.Conclusion: Certain factors that affect HCWs personal decisions to take the vaccine were identified. By targeting these issues, epidemiologists, public health officials and women’s health care providers can work to increase HPV vaccine uptake and reduce the burden of HPV-related diseases in this population.Keywords: HPV vaccine, epidemiology, public health, women’s health, healthcare worker, uptak