Advances in experimental medicine and biology

Majority of RNAs expressed in animal cells lack protein-coding ability. Unlike other cellular RNAs, circular (circ)RNAs include a large family of noncoding (nc)RNAs that lack the 5' or 3' ends. The improvements in high-throughput RNA sequencing and novel bioinformatics tools have led to the identification of thousands of circRNAs in various organisms. CircRNAs can regulate gene expression by influencing the transcription, the mRNA turnover, and translation by sponging RNA-binding proteins and microRNAs. Given the broad impact of circRNA on miRNA activity, there is huge interest in understanding the impact of miRNA sponging by circRNA on gene regulation. In this review, we summarize our current knowledge of the miRNA-circRNA interaction and mechanisms that influence gene expression.

From 2000 to 2019, the global malaria death toll fell from 864,000 to 576,000 deaths; however, progress on reducing this toll has since slowed, with the COVID-19 pandemic contributing to an increase in the mortality rate since 2020. The emergence of widespread resistance in the major malaria parasite ( Plasmodium falciparum ) to first-line treatment drugs has highlighted the need for new antimalarials and smarter drug delivery strategies. Nevertheless, recent successes of the first malaria vaccines (RTS,S/AS01 and R21/MM) have renewed the promise of widely applicable vaccines in the future. Since 2015, the Eastern Mediterranean Region has experienced an overall increase in malaria cases and deaths. In the Arabian Peninsula, while most of the Gulf Cooperation Council (GCC) countries have been declared free of indigenous malaria (Bahrain, Kuwait, Qatar, and the United Arab Emirates), malaria is still endemic in two GCC countries (Saudi Arabia and Oman) and their neighbors (Yemen). Furthermore, a number of factors threaten malaria control in this region, especially antimalarial drug resistance, the emergence of highly invasive mosquito species, increasing average temperatures, and imported malaria. In this review, we assess the current worldwide status of malaria before providing a critical evaluation of the malaria situation in the GCC countries.