Transperons: RNA operons as effectors of coordinated gene expression in eukaryotes.

Coordinated gene expression allows spatiotemporal control of cellular processes and is achieved by the cotranscription/translation of functionally related genes/proteins. Prokaryotes evolved polycistronic messages (operons) to confer expression from a single promoter to efficiently cotranslate proteins functioning on the same pathway. Yet, despite having far greater diversity (e.g., gene number, distribution, modes of expression), eukaryotic cells employ individual promoters and monocistronic messages. Although gene expression is modular, it does not account for how eukaryotes achieve coordinated localized translation. The RNA operon theory states that mRNAs derived from different chromosomes assemble into ribonucleoprotein particles (RNPs) that act as functional operons to generate protein cohorts upon cotranslation. Work in yeast has now validated this theory and shown that intergenic associations and noncanonical histone functions create pathway-specific RNA operons (transperons) that regulate cell physiology. Herein the involvement of chromatin organization in transperon formation and programmed gene coexpression is discussed.

Communication with Patients on Mechanical Ventilation: A Review of Existing Technologies.

How to cite this article: Anand A, Nair RR, Kodamanchili S, Panda R, Bhardwaj KK, Gowthaman TB. Communication with Patients on Mechanical Ventilation: A Review of Existing Technologies. Indian J Crit Care Med 2022;26(6):756-757.

Immune-endocrine crosstalk during pregnancy.

The success of pregnancy depends mostly on a synchronized immune-endocrine crosstalk at the maternal-fetal interface. Hormones are important in terms of maintaining the suitable environment and sufficient nutrition for the developing fetus. They also play a major role during the process of parturition and lactation. Maternal immunomodulation is important for the tolerance of semiallogeneic fetus. This is achieved in concert with a variety of endocrine stimulation. Estrogen, progesterone, and Human Chorionic Gonadotropin play a major role in immune modulation during pregnancy. Hormones modulate B cells, dendritic cells, uterine natural killer cells, macrophages, neutrophils to adopt fetal friendly immune phenotypes. Recently the use of hormones in assisted reproductive technology has been found to improve the pregnancy outcome. The present review focuses on the pregnancy-related hormones, their role in immunomodulation for successful pregnancy outcome. This also shed light on the immune-endocrine crosstalk at maternal-fetal interface during pregnancy.

A Giant Frontoethmoidal Ivory Osteoma Causing Cosmetic and Visual Problem: A Case Report.

Osteomas are slow growing fibro-osseous lesions. Very rare to occur in paranasal sinuses. Small osteomas don't require any intervention. Giant osteomas may require surgical intervention due to its cosmetic and functional compromises. A 28 year old male presented with swelling over forehead and left orbit for more than 4 years. The swelling is around 6 × 5 cm with gross lateral and inferior deviation of left eyeball. Extradural fronto-ethmoidectomy was done with combined external and endoscopic approach. There was pearly white bony hard, fixed tumor mass seen infiltrating anterior and posterior table of frontal bone. All the tumors removed in piecemeals. Wait and watch policy is the usual treatment policy for small and asymptomatic osteomas. Combine external and endoscopic approach is the treatment of choice for giant frontoethmoid osteoma.

Malignancy of Nose and Paranasal Sinuses: An Institutional Study in Central India.

INTRODUCTION: Malignancy of the nose and paranasal sinuses is a highly heterogeneous tumor group that arises from various cell types commonly seen in the fifth to sixth decades of life, with twice as much commonness in males. Patients present with varied clinical presentations like nasal obstruction, facial swelling, orbital complications, etc. Squamous cell carcinoma and adenocarcinoma are the most common variant. Surgery followed by adjuvant chemo or radiotherapy is the treatment of choice. METHODS: The study was undertaken in the Department of Otorhinolaryngology All India Institute of Medical Sciences, Bhopal, India, from 2021 to 2023. It was a retrospective study in which patients diagnosed and underwent treatment in the last 2 years were enrolled. Data were retrieved from the medical record department and surgical registry. Twenty-eight patients were recruited for the study. Detailed history, clinical examination, imaging findings, surgical plans, postoperative adjuvant therapy details, and histopathological findings were recorded. RESULTS: There were 18 (64.2%) males and 10 (35.8%) females, with a male-to-female ratio of 1.8: 1. The mean age of patients was 50.5 years. Facial swelling was the most frequent symptom (n=15, 54%). Twenty-one (75%) patients use chewable tobacco, while sixteen (57%) are smokers. All our patients belong to the lower socioeconomic group. Endoscopic resection was done in 15 (62.5%) patients, and combined open and endoscopic approaches were used in 9 (37.5%) patients. The most common histological variant was squamous cell carcinoma (n=8, 28%). CONCLUSION: Malignancy of the nose and paranasal sinus is very rare. They presented with varied masked clinical presentations of benign diseases. Early identification and high clinical suspicion, along with imaging studies, are pivotal in managing malignancy of the nose and paranasal sinuses.

Association of GSTT1 and GSTM1 polymorphisms with early pregnancy loss in an Indian population and a meta-analysis.

Glutathione S-transferase theta 1 (GSTT1) and glutathione S-transferase Mu 1 (GSTM1) enzymes of the glutathione detoxification pathway protect the embryo from oxidative stress. This study investigated GSTT1 and GSTM1 in relation to their role in conferring genetic susceptibility to pregnancy loss. In a case-control study, 174 early pregnancy loss (EPL) patients, of which 130 were recurrent pregnancy loss (RPL) patients, and 180 healthy controls were investigated. Null genotypes of GSTT1 and GSTM1 were identified in duplex PCR reaction systems. Age-adjusted odds ratios (aOR) were calculated by logistic regression analysis. A meta-analysis was also conducted. The GSTT1 null genotype was significantly associated with EPL (aOR 4.47, P=0.004) and RPL (aOR 4.39, P=0.006). No significant association of the GSTM1 null genotype was found with RPL. In a meta-analysis study, the presence of the GSTM1 null genotype was shown to be a risk for RPL. The GSTT1 null genotype was not found to be a risk factor for pregnancy loss in the pooled population but its association with RPL was found in the Indian population. This study suggests that women carriers of GSTT1 and GSTM1 null genotypes are more often at genetic risk of pregnancy loss. Glutathione S-transferase theta 1 (GSTT1) and glutathione S-transferase mu 1 (GSTM1), enzymes of detoxification pathway, protect the embryo from oxidative stress. In the present study we have investigated GSTT1 and GSTM1 in relation to their role in conferring genetic susceptibility for early pregnancy loss (EPL) and recurrent pregnancy loss (RPL). Meta-analysis on the polymorphisms was conducted to support our findings that the presence of mutant genotypes at this site increases the risk of pregnancy loss. The GSTT1 null genotype was significantly associated with both EPL and RPL. In the meta-analysis, the overall result showed that the association between GSTM1 null genotype and risk for RPL was statistically significant. On comparing the GSTT1 studies, great heterogeneity was found between studies. A subgroup analysis was performed based on ethnicity. Our results showed a significantly increased risk with the GSTT1 null genotype in the Indian population, but no risk was found in the pooled population. In conclusion, the data of the present study clearly suggest that GSTT1 and GSTM1 polymorphisms are genetic risk factors for pregnancy loss in the study population.

Functional SNP -1562C/T in the promoter region of MMP9 and recurrent early pregnancy loss.

Angiogenesis, invasion and decidualization play an important role in uterine preparation and embryo development. Matrix metalloproteinases (MMP) are crucial for the degradation/remodelling of the extracellular matrix and are involved in spiral artery formation and invasion of endometrium during implantation. A functional single-nucleotide polymorphism (SNP) in the MMP9 promoter, 1562C/T, is known to influence expression in an allele-specific manner. The present study evaluated the association between maternal genotype of SNP 1562C/T of MMP9 and recurrent early pregnancy loss (REPL) risk. This case­control study was comprised of REPL patients (n = 106) and women having one healthy child as controls (n = 111). Genotyping for SNP 1562C/T of MMP9 was performed by PCR/restriction fragment length polymorphism followed by DNA sequencing. Allele and genotype distribution did not differ significantly between patients and controls (by allele, chi-squared 0.228, odds ratio 1.12, 95% confidence interval 0.695­1.816; by genotype, chi-squared 0.893). Thus SNP 1562C/T of MMP9 was not associated with REPL risk in this population and further study in other populations will verify whether it is associated with REPL risk or not. REPL is a multifactorial pathology and other genetic or environmental factors may be contributing to the complex aetiology of REPL.

An Aptamer-based mRNA Affinity Purification Procedure (RaPID) for the Identification of Associated RNAs (RaPID-seq) and Proteins (RaPID-MS) in Yeast.

RNA-RNA and RNA-protein interactions are involved in the regulation of gene expression. Here, we describe an updated and extended version of our RNA purification and protein identification (RaPID) protocol for the pulldown of aptamer-tagged mRNAs by affinity purification. The method takes advantage of the high affinity interaction between the MS2 RNA aptamer and the MS2 coat protein (MCP), as well as that between streptavidin-binding peptide (SBP) and streptavidin. Thus, it employs MCP-SBP fusions to affinity purify MS2-tagged target RNAs of interest over immobilized streptavidin. Purified aptamer-tagged mRNAs, along with any associated RNAs and proteins, are then sent for RNA sequencing (RaPID-seq) or mass spectrometry (RaPID-MS), which allows for the identification of bound cohort RNAs and proteins, respectively.

Multiplexed mRNA assembly into ribonucleoprotein particles plays an operon-like role in the control of yeast cell physiology.

Prokaryotes utilize polycistronic messages (operons) to co-translate proteins involved in the same biological processes. Whether eukaryotes achieve similar regulation by selectively assembling and translating monocistronic messages derived from different chromosomes is unknown. We employed transcript-specific RNA pulldowns and RNA-seq/RT-PCR to identify yeast mRNAs that co-precipitate as ribonucleoprotein (RNP) complexes. Consistent with the hypothesis of eukaryotic RNA operons, mRNAs encoding components of the mating pathway, heat shock proteins, and mitochondrial outer membrane proteins multiplex in trans, forming discrete messenger ribonucleoprotein (mRNP) complexes (called transperons). Chromatin capture and allele tagging experiments reveal that genes encoding multiplexed mRNAs physically interact; thus, RNA assembly may result from co-regulated gene expression. Transperon assembly and function depends upon histone H4, and its depletion leads to defects in RNA multiplexing, decreased pheromone responsiveness and mating, and increased heat shock sensitivity. We propose that intergenic associations and non-canonical histone H4 functions contribute to transperon formation in eukaryotic cells and regulate cell physiology.

High Level of APOA1 in Blood and Maternal Fetal Interface Is Associated With Early Miscarriage.

Early miscarriage (EM) is one of the most devastating obstetrical complications globally affecting the quality of women's life. In the present study, we aimed to identify proteins that correlate with and could act as biomarkers for EM. We performed 2-dimensional gel electrophoresis in chorionic villi samples followed by mass spectrometry for identification of differential protein expression with EM. Proteomic studies detected a total 124 protein spots, out of which 83 spots were differentially expressed between EM and controls in chorionic villi samples. Matrix assisted laser desorbtion/ionization-time of flight (MALDI-TOF) mass spectrometry analysis revealed Apolipoprotein A1 (APOA1) to be the most upregulated protein in the EM group that was validated by Western blotting and Enzyme-linked immunosorbent assay (ELISA) . We found low but not statistically significant level of APOA1 on 21st day of menstruation in comparison to the 7th day. APOA1 level was observed to be the lowest in the first trimester. Hence, this study suggests that low APOA1 expression is critical in establishing pregnancy and elevated APOA1 expression in chorionic villi correlates with EM. Similar observation in serum samples suggests its potential as a marker for the risk of EM.

Altered crosstalk of estradiol and progesterone with Myeloid-derived suppressor cells and Th1/Th2 cytokines in early miscarriage is associated with early breakdown of maternal-fetal tolerance.

PROBLEM: Decline in myeloid-derived suppressor cells (MDSCs) and Th2 cytokines levels lead to early miscarriage (EM) but how the hormonal milieu of the body regulates MDSCs and Th1/Th2 cytokine balance is still a matter of investigation. METHOD OF STUDY: Peripheral blood and decidua samples were collected from 20 EM patients, and 20 healthy pregnant women opted for elective abortion. MDSCs and G-MDSCs levels were analyzed in peripheral blood mononuclear cells, and Th1/Th2 cytokines levels were determined in serum via flow cytometry. Estrogen (E2), Progesterone (P4), and Testosterone levels were measured via ELISA. Further, proliferation and apoptosis in decidual samples were checked via immunoblot/immunohistochemistry of estrogen receptor -α (ER-α), STAT-3/pSTAT-3, and caspase-3, respectively. RESULTS: Our results clearly indicate that in EM patients; decline in E2 and P4 significantly correlates with decline in MDSCs, particularly with subtype granulocytic MDSCs (G-MDSCs) and skewness of the Th1/Th2 cytokines balance toward Th1 response. Downregulation of ER- α and increased caspase-3 expression in endometrium decidua signifies poor endometrial receptivity in EM. STAT-3 activation regulates proliferation, differentiation and suppressive potency of MDSCs. In decidua of EM, significantly lower expression of pSTAT-3 indicates that these processes pertaining to MDSCs are compromised. CONCLUSION: Altogether, this unfavorable systemic milieu may drive toward early breakdown of maternal-fetal tolerance in EM. Therefore, regulated crosstalk of E2, P4 with MDSCs and balanced Th1/Th2 cytokines is prerequisite for successful pregnancy.

Association of increased S100A8 serum protein with early pregnancy loss.

PROBLEM: The contribution of systemic S100A8 protein in menstrual cycle, pregnancy, and early pregnancy loss (EPL) is not known. Altered expression of S100A8 in maternal decidua is associated with recurrent early pregnancy loss. The objective of this study was to investigate the systemic level of S100A8 in different phases of menstrual cycle, different trimester of pregnancy, and in EPL. METHOD OF STUDY: Level of S100A8 was investigated in serum samples of the subjects through enzyme-linked immunosorbent assay (ELISA). RESULT AND CONCLUSION: S100A8 levels were elevated during proliferative phase of menstrual cycle. We found no statistical difference in S100A8 level in different trimester of pregnancy. S100A8 level was found to be significantly elevated in patients with EPL. This is the first study evaluating the systemic level of S100A8 predicting its role during menstrual cycle and pregnancy. It opens a new perspective in which S100A8 can be used as a prognostic marker for EPL.

Reduced Myeloid-derived Suppressor Cells in the Blood and Endometrium is Associated with Early Miscarriage.

PROBLEM: The contribution of myeloid-derived suppressor cells (MDSC) in patients suffering from early or recurrent miscarriage is unknown. MDSC are implicated in modulation of T-cell response in healthy pregnancies; however, the role of MDSC in patients suffering from miscarriage has not been studied. We hypothesized that MDSC play major role in inducing maternal-fetal tolerance and this tolerance is compromised in patients suffering from miscarriage. METHOD OF STUDY: MDSC level was assessed by flow cytometry and immunostaining in blood and endometrial decidua, respectively. Activation of T cells was determined by MTT proliferation and IL-2 ELISA assays. RESULTS AND CONCLUSION: The miscarriage patients harbor reduced level of functionally suppressive MDSC in blood and endometrium as compared to healthy control women with successful pregnancies. These results suggest MDSC regulate maternal tolerance in healthy pregnancies and that drug inducing MDSC could have therapeutic implication in the miscarriage patients.

Association of maternal and fetal MTHFR A1298C polymorphism with the risk of pregnancy loss: a study of an Indian population and a meta-analysis.

OBJECTIVE: To study the genetic association between methylenetetrahydrofolate reductase (MTHFR) A1298 polymorphism and recurrent pregnancy loss (RPL). DESIGN: Prospective case-control study, systematic review, and meta-analysis using an electronic database up to July 27, 2012. SETTING: Meta-analysis of four studies on RPL and three studies on spontaneously aborted embryos, including the present study. PATIENT(S): A total of 129 RPL patients and 202 healthy control women with successful pregnancy were analyzed including 40 spontaneously aborted embryos and 40 aborted embryos as control samples. For meta-analysis, 1,080 case and 709 control subjects were included of RPL and 375 case and 384 control samples of spontaneously aborted embryos. INTERVENTION(S): Blood was collected by peripheral venous punctures, and spontaneously aborted embryos were collected by curettage or manual vacuum aspiration. Meta-analysis was done on the basis of heterogeneity of the studies. MAIN OUTCOME MEASURE(S): Genotyping was done by polymerase chain reaction (PCR)-restriction-fragment-length polymorphism (RFLP). DNA sequencing was used to ascertain PCR-RFLP results. Age-adjusted odds ratios were calculated by logistic regression analysis. Meta-analysis on this polymorphism was conducted to support our findings. RESULT(S): We found that presence of rare allele "C" and heterozygous and rare homozygous genotypes significantly increased the risk of RPL. No significant change in the fetal MTHFR A1298C genotype frequency was observed, regardless of chromosomal integrity. Meta-analysis of A1298C polymorphism on both RPL and in spontaneously aborted embryos showed significantly increased risk in the carriers of AC and CC genotypes. CONCLUSION(S): The data of the present study clearly suggests that MTHFR A1298C polymorphism is a genetic risk factor for pregnancy loss.

Association of FAS -1377 G>A and FAS -670 A>G functional polymorphisms of FAS gene of cell death pathway with recurrent early pregnancy loss risk.

Apoptosis during the early stages of pregnancy enables the remodeling of the uterus for proper placentation. Apoptosis in the maternal activated cytotoxic T lymphocytes allows maternal immune tolerance to pregnancy and in glandular and stromal cells it helps with trophoblastic endometrial invasion. FAS gene is expressed at the maternal-fetal interface and is involved in the regulation of immune response and implantation. Altered FAS expression may result in altered apoptosis and ultimately affects both immune response and implantation. FAS -1377 G>A and FAS -670 A>G functional polymorphisms in the promoter region of FAS gene modulate its expression at transcriptional level. In a case-control study the contribution of FAS -1377 G>A and FAS -670 A>G polymorphisms to the risk of recurrent early pregnancy loss (REPL) was evaluated. DNA from 134 cases with a history of three or more REPL and 124 healthy controls with successful pregnancy outcomes were genotyped through PCR-RFLP. DNA sequencing was used to ascertain PCR-RFLP results. The genotype and allele frequencies for FAS -1377 G>A and FAS -670 A>G polymorphisms were compared in REPL and controls. FAS -1377 AA and AG genotypes were associated with an increased risk of REPL (OR, 3.25; 95%CI, 1.52-6.98 and OR, 2.62; 95%CI, 1.48-4.64, respectively), whereas FAS -670 genotypes conferred no risk. The -1377 AA/-670 GG genotypes combination of FAS polymorphisms showed highest risk (OR, 8.15; 95%CI, 2.75-25.81). Genotype combinations -1377 GA/-670 AA and -1377 GA/-670 AG were also statistically significant, suggestive of their role in REPL risk.

MTHFR C677T polymorphism and recurrent early pregnancy loss risk in north Indian population.

Recurrent early pregnancy loss (REPL) is a multifactorial disorder as both genetic and environmental factors contribute to the development of disease. Folate metabolism is an important mechanism to ensure proper fetal growth. Hyperhomocysteinemia leads to a number of disorders and REPL is one of them. In a case-control study DNA from 106 cases with the history of 3 or more REPL and 140 healthy fertile controls with successful pregnancy outcomes were genotyped for C677T single-nucleotide polymorphism (SNP) of the MTHFR (methylenetetrahydrofolate reductase) gene through polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), which was further confirmed by sequencing. Allele frequencies of REPL cases were compared with healthy controls and a statistically significant association was found between REPL and the mutant T allele (χ² = 8.786, odds ratio [OR] = 2.20, 95% confidence interval [CI] = 1.323-3.9658, P = .003). The genotype frequencies of SNP C677T also differ significantly between these 2 groups (χ² = 8.237, P = .016). The OR for heterozygous CT in the REPL versus controls is 1.9591 (95% CI = 1.0285-3.7318, P = .04). The OR for TT homozygous is 6.3009 (95% CI = 1.2065, P = .02). Combined odds ratio of CT and TT against the control has been calculated as 2.2194 (95% CI = 1.2029-4.0952, P = .02) which is also significant. Thus the present study clearly indicates that homozygosity and heterozygosity for the MTHFR C677T polymorphism confer a 6.3009- and 1.9591-fold increased risk of idiopathic REPL, respectively.