Molecular characterization of microRNAs produced by the human cytomegalovirus in a group of miscarriage women in Iraq

Human Cytomegalovirus (HCMV) is a widespread herpesvirus infecting a large portion of the global population. While typically asymptomatic in healthy individuals, it poses significant risks in immunocompromised patients and during pregnancy. Human Cytomegalovirus (HCMV) infection during pregnancy can lead to adverse outcomes, including spontaneous abortion. HCMV is known to cross the placenta and infect the fetus, potentially causing developmental abnormalities and fetal demise. Understanding the impact of HCMV on pregnancy outcomes is crucial for developing strategies to prevent vertical transmission and mitigate its effects on maternal and fetal health. Human Cytomegalovirus (HCMV) expresses microRNAs (miRNAs) during infection, which play crucial roles in regulating viral and host gene expression. These viral miRNAs manipulate cellular processes to facilitate viral replication, evade host immune responses, and establish latency. Studying HCMV miRNAs provides insights into viral pathogenesis and potential targets for antiviral therapies. The study was started in 15/2/2023 by collection of blood samples from attended the obstetrics and gynecology departments of Babylon Maternity and Children's Teaching Hospital and Al-Hashimiya General Hospital in bayblon Directorate of Health. This study was conducted case of control study for a group of miscarriage women, the number of which was 50(35.7%) seropositive HCMV out of 140 miscarriage women. The CMV antibody positive in miscarriage women was CMV IgM 3(6.0%), and both CMV (IgM and IgG) 8(16.0%), and CMV IgG 39(78.0%), the result significant. CMV IgM positive in miscarriage women in the Rural were 9(18%), the P-value was (0.0001**) highly significant and CMV IgG positive in miscarriage women in the Rural was 33(66%), the P-value was (0.0001**) highly significant. The CMVviral load was measured by RT-PCR. The relative gene expression for (Mir-UL148D,Mir-UL22A-3P,Mir-UL36-3P,Mir-UL36-5P), done by RT-PCR and primers specially designed for this study from south Korea. The our study revealed increase in the fold change and area under curve for the (hcmv- miR-UL36-5P), the fold change was (3.11) and area under curve (0.97±0.32) compared to the control group fold change was (1±0.0) , and the result was significant and the as well as for the (hcmv- miR-UL36-3P), which had a fold change (21.16) and area under curve (0.94±0.1) compared to the control group fold change was (1±0.0) the result was significant, and the (hcmv- miR-UL22A-3P) had a fold change (2.92), and area under curve (0.94±0.1) compared to the control group folf change was (1±0.0) the result was significance and the (hcmv-mir-UL148D) with fold change (2.66) and area under curve (0.94±0.4) compared to the control group fold change was (1±0.0). In our study the alignment of nucleic acid sequences of the B1–B4 samples with the most homologous reference sequences of HCMV5 (GenBank acc. no. U88704.1) revealed the presence of four novel nucleic acid variants (155C>T in B1, 160T>C and 161T>C in B3, and 177T>G in B4) that were not available in this reference sequences. The translation of these variants showed that 155C>T exhibited a missense effect on the GP55 encoded protein of p.59Ser>Phe. Likewise, both 160T>C and 161T>C contributed to exerting a missense effect of p.61Phe>Pro on the glycoprotein B variable region. Whereas the third variant 177T>G exhibited a silent effect of p.65Gly= on the encoded glycoprotein. The mutation p.59Ser>Phe involves the conversion of polar uncharged serine to hydrophobic phenylalanine at position 59. This change is expected to significantly alter the protein's 3D structure, affecting folding stability and interactions with the host receptor. Similarly, the mutation p.61Phe>Pro converts hydrophobic phenylalanine to cyclic and rigid proline at position 61, leading to anticipated structural changes, including kinks and bends, potentially influencing overall folding and stability.