Evidence for an early green/red photocycle that precedes the diversification of GAF domain photoreceptor cyanobacteriochromes.

Phytochromes are linear tetrapyrrole-binding photoreceptors in eukaryotes and bacteria, primarily responding to red and far-red light signals reversibly. Among the GAF domain-based phytochrome superfamily, cyanobacteria-specific cyanobacteriochromes show various optical properties covering the entire visible region. It is unknown what physiological demands drove the evolution of cyanobacteriochromes in cyanobacteria. Here, we utilize ancestral sequence reconstruction and biochemical verification to show that the resurrected ancestral cyanobacteriochrome proteins reversibly respond to green and red light signals. pH titration analyses indicate that the deprotonation of the bound phycocyanobilin chromophore is crucial to perceive green light. The ancestral cyanobacteriochromes show only modest thermal reversion to the green light-absorbing form, suggesting that they evolved to sense the incident green/red light ratio. Many cyanobacteria can utilize green light for photosynthesis using phycobilisome light-harvesting complexes. The green/red sensing cyanobacteriochromes may have allowed better acclimation to changing light environments by rearranging the absorption capacity of the phycobilisome through chromatic acclimation.

Assessment of the Diagnostic Utility of Serum Omentin 1 and IL-6 in Early Stages of Diabetic Nephropathy.

In India, diabetic nephropathy (DN) is the most common cause of chronic kidney disease. Timely detection of microalbuminuria and appropriate intervention can reverse or arrest the progress of nephropathy. The pathogenesis of diabetic nephropathy has revealed that during the early onset of kidney involvement in diabetics, inflammation and fibrosis progress from tubular to glomerular damage. This study was designed to elucidate the association of chemokines, Omentin 1, and interleukin 6 (IL-6) with microalbuminuria. MATERIAL: Settings and Design: This cross-sectional observational study was conducted as a collaborated study in the Departments of General Medicine and Biochemistry, All India Institute of Medical Sciences, Bhubaneswar, India, during 2019-2020. METHODS AND MATERIAL: Our study group comprised 116 diabetes mellitus patients. They were grouped into two, each of 58 on the basis of their urine albumin levels; Group 1 (controls) had UACR < 30 µg/mg, eGFR> 90ml/ min and Group 2 (cases) had UACR ≥ 30 µg/mg and < 300 µg/mg, eGFR>60ml/min and < 90ml/min. Serum omentin 1 and IL-6, creatinine, glycated haemoglobin (HbA1c), fasting (FBS) and postprandial blood sugar (PPBS), lipid profile, total protein, albumin, and fasting insulin, HOMA-IR were studied. OBSERVATION: Our study showed that Omentin 1 levels were decreased, and IL-6 levels were increased in the DN group compared to the T2DM without DN. The risk estimates calculated revealed that diabetes mellitus patients having an IL-6: omentin ratio ≥ 0.26 had Odds of 3.97 of developing DN, which was statistically significant (CI 2.36-6.68). Therefore, a ratio of ≤ 0.26 was found to be kidney protective among diabetes mellitus patients. CONCLUSION: From the results of this present study, we recommend that estimation of serum IL-6: omentin 1 ratio of T2DM will aid in identifying early stages of DN before the onset of microalbuminuria.

Assessment of Serum Omentin-1 and Interleukin-6 in the Diagnosis of Early Stages of Diabetic Nephropathy: A Cross-Sectional Observational Study.

Introduction The pathogenesis of diabetic nephropathy highlights the progression of inflammation and fibrosis from tubular to glomerular damage during the early stages of kidney involvement in diabetic individuals. As urine albumin serves as a marker for glomerular function, its detection indicates a stage of diabetic nephropathy where the glomerulus is already compromised. Consequently, relying solely on urine albumin for diagnosis becomes questionable. In our pursuit of identifying innovative biomarkers for the early detection of diabetic nephropathy, this study was crafted to explore the relationship between chemokines, omentin-1, interleukin-6, and microalbuminuria. Materials and methods Our study cohort comprised 116 patients diagnosed with diabetes mellitus. In our study, participants were stratified into two groups based on their urine albumin levels: Group 1, characterized by urine albumin creatinine ratio <30 mg/gm and estimated glomerular filtration rate >90 ml/min, and Group 2, with urine albumin creatinine ratio ≥30 mg/gm and <300 mg/gm, and estimated glomerular filtration rate >60 ml/min and <90 ml/min. Serum creatinine, glycated hemoglobin (HbA1c), fasting blood sugar and post-prandial blood sugar, lipid profile, total protein, albumin, fasting insulin, omentin-1, and interleukin-6 were estimated. Result There was a significant difference in the medians of serum urea, creatinine, omentin-1, interleukin-6, urine albumin creatinine ratio, and estimated glomerular filtration rate levels in the two groups. There was no difference in fasting blood sugar, post-prandial blood sugar, HbA1c, serum lipids, fasting insulin, and homeostatic model assessment for insulin resistance. The receiver operating characteristic curve plotted for the newer biomarkers of diabetic nephropathy showed that there was a significant diagnostic utility in diabetic nephropathy detection of serum omentin (p=0.000), interleukin-6 (p=0.002), and interleukin-6: omentin-1 ratio (p=0.000), which correlated well with the routine test that is urine microalbumin estimation. Risk assessment demonstrated that type 2 diabetes mellitus patients with an interleukin-6: omentin-1 ratio ≥0.26 had significantly higher odds, with an odds ratio of 3.97, for developing diabetic nephropathy, which was statistically significant. Conversely, a ratio of ≤0.26 was associated with kidney protection among patients with type 2 diabetes mellitus. Conclusion Our findings revealed decreased levels of omentin-1 and increased levels of interleukin-6 in the group with diabetic nephropathy compared to those without diabetic nephropathy among patients with type 2 diabetes mellitus. Interleukin-6: omentin-1 ratio of ≤0.26 was associated with kidney protection among patients with type 2 diabetes mellitus. Based on the results obtained from this study, we propose that measuring the serum interleukin-6: omentin-1 ratio in patients with type 2 diabetes mellitus may assist in identifying the early stages of diabetic nephropathy before the onset of microalbuminuria. Timely intervention in these patients predisposed to diabetic nephropathy can aid in better treatment outcomes in type 2 diabetes mellitus.