Diabetes and inflammatory diseases: An overview from the perspective of Ca(2+)/3'-5'-cyclic adenosine monophosphate signaling

A large amount of evidence has supported a clinical link between diabetes and inflammatory diseases, e.g., cancer, dementia, and hypertension. In addition, it is also suggested that dysregulations related to Ca(2+ )signaling could link these diseases, in addition to 3'-5'-cyclic adenosine monophosphate (cAMP) signaling pathways. Thus, revealing this interplay between diabetes and inflammatory diseases may provide novel insights into the pathogenesis of these diseases. Publications involving signaling pathways related to Ca(2+) and cAMP, inflammation, diabetes, dementia, cancer, and hypertension (alone or combined) were collected by searching PubMed and EMBASE. Both signaling pathways, Ca(2+) and cAMP signaling, control the release of neurotransmitters and hormones, in addition to neurodegeneration, and tumor growth. Furthermore, there is a clear relationship between Ca(2+) signaling, e.g., increased Ca(2+) signals, and inflammatory responses. cAMP also regulates pro- and anti-inflammatory responses. Due to the experience of our group in this field, this article discusses the role of Ca(2+) and cAMP signaling in the correlation between diabetes and inflammatory diseases, including its pharmacological implications. As a novelty, this article also includes: (1) A timeline of the major events in Ca(2+)/cAMP signaling; and (2) As coronavirus disease 2019 (COVID-19) is an emerging and rapidly evolving situation, this article also discusses recent reports on the role of Ca(2+) channel blockers for preventing Ca(2+) signaling disruption due to COVID-19, including the correlation between COVID-19 and diabetes.