Graphical Abstract for FASD review article Liyanage at al 2017
2. The potential contribution of the ‘methylation cycle’ in Autism spectrum disorders Liyanage 2016 RNA and Transcription
Figure 2. The alterations of methylation cycle in Autism Spectrum Disorders (ASD) and its potential effects on RNA methylation. The methylation cycle basically contains 3 interconnected pathways, Methionine-Homocysteine cycle/pathway, folate cycle and redox homeostasis pathway.
The Methionine-Homocysteine cycle involves the conversion of methionine to homocysteine in a series of reactions involving the conversion of
S-adenosylmethionine (SAM) to S-adenosylhomocysteine (SAH). This conversion by methyltransferases generates methyl (-CH3) groups which are used in
DNA methylation as well as RNA methylation. Homocysteine is then converted back to methionine by methionine synthase utilizing Vitamin B12. Methionine
synthase and Vitamin B12 also connects folate cycle to the Methionine-Homocysteine cycle/pathway. Conversion of homocysteine to cysteine connects
Methionine-Homocysteine cycle/pathway to the redox homeostasis where the active form of Glutathione (GSH) is oxidized to inactive form GSSG. Many of
these factors are altered (either reduced or induced) in autistic patients. The overall impact of these alterations is to reduce the cellular methylation capacity. This
would impact DNA methylation and RNA methylation. In the case of RNA methylation, the methylation status of mRNA, microRNA (miRNA and
long-noncoding-RNA (lncRNA) may be altered.
3. The ‘open’ and ‘closed’ chromatin status concept from my Ph.D. thesis Liyanage 2018-PhD thesis
Figure 6.1 Differential states of chromatin mediating gene transcription.
Chromatin conformation states can either be A) ‘open’, or an active conformation allowing gene expression (gene ON), or B) ‘condensed’, which confers an inactive and repressed conformation, thereby turning off gene expression (gene OFF). GTF: General transcription factors, TFs: Transcription factors, TBP: TATA-box binding protein, SP: SP-family TFs, ac: acetylation, me: methylation.
4. Difference between traditional and modern society
No-specific source- designed for my own interests in society
5. Electronic cigarettes – an illustration
No-specific source- designed for my own interests in electronic cigarettes or e-cigs and their impact on health