Identification of a chaperone-code responsible for Rad51-mediated genome repair.

Posttranslational modifications of Hsp90 are known to regulate its in vivo chaperone functions. Here, we demonstrate that the lysine acetylation-deacetylation dynamics of Hsp82 is a major determinant in DNA repair mediated by Rad51. We uncover that the deacetylated lysine 27 in Hsp82 dictates the formation of the Hsp82-Aha1-Rad51 complex, which is crucial for client maturation. Intriguingly, Aha1-Rad51 complex formation is not dependent on Hsp82 or its acetylation status; implying that Aha1-Rad51 association precedes the interaction with Hsp82. The DNA damage sensitivity of Hsp82 (K27Q/K27R) mutants are epistatic to the loss of the (de)acetylase hda1Δ; reinforcing the importance of the reversible acetylation of Hsp82 at the K27 position. These findings underscore the significance of the cross talk between a specific Hsp82 chaperone modification code and the cognate cochaperones in a client-specific manner. Given the pivotal role that Rad51 plays during DNA repair in eukaryotes and particularly in cancer cells, targeting the Hda1-Hsp90 axis could be explored as a new therapeutic approach against cancer.

Exploring the Landscape of General Surgery in the Adolescent Age Group: Challenges and Considerations.

INTRODUCTION: The adolescent age group typically ranges from 10 to 19 years. This age group differs from the paediatric and adult populations based on their physiological, psychological, and social behaviour. Patients of this age group usually present with trauma, swellings, burns, hernias, hydroceles, haemorrhoids, fibroadenomas, abscesses, pilonidal diseases, etc. The objective of this study was to identify various causes requiring surgical intervention in adolescent patients and to determine the demography of these patients, reasons for surgery, and surgical outcomes in the patients of the adolescent age group. MATERIALS AND METHODS: This single-centre, hospital record-based, retrospective, cross-sectional study was conducted on 445 adolescent patients who underwent various general surgical interventions from August 2022 to July 2023 in the Department of General Surgery, Rajendra Institute of Medical Sciences (RIMS), Ranchi. RESULTS: A total of 445 patients were included in this study; among them, 277 underwent elective surgeries and 168 emergency surgeries. Major surgeries included 315 patients, while 130 were daycare procedures. Males were 294, and 151 were females. Cyst excision was the most performed, followed by fibroadenoma excision. Burn (10.78%) was the most common cause requiring major intervention, followed by intestinal obstruction (6.96%) and perforation (6.51%). Mortality was observed in 6.51% of patients. CONCLUSION: In this study, the adolescent age group required more elective surgical care as compared to emergency care. Among major surgeries, abdominal laparotomy was most common, and in daycare procedures as well as overall, cyst excision was most performed.

Evaluation of the Efficacy of Thyroid Imaging Reporting and Data Systems Classification in Risk Stratification and in the Management of Thyroid Swelling by Comparing It With Fine-Needle Aspiration Cytology and Histopathological Examination.

BACKGROUND: Thyroid nodules are a common clinical challenge, with a significant proportion being cancerous. Fine-needle aspiration cytology (FNAC) is widely used for diagnosis but has limitations. Ultrasound has emerged as a promising tool for distinguishing between benign and malignant nodules. This study aims to compare the diagnostic accuracy of ultrasonography (USG) and FNAC in diagnosing malignant thyroid swelling using postoperative histopathological examinations as the gold standard. METHOD: A diagnostic accuracy study was conducted over 1.5 years at Rajendra Institute of Medical Sciences, Ranchi, India. A total of 132 patients with thyroid swellings were included. Patients underwent USG and FNAC, and 99 patients subsequently underwent surgery and histopathological examination. Statistical analysis was performed to evaluate the performance of USG and FNAC, including sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV). RESULTS: The study encompassed 132 patients, predominantly 94 (71.21%) females. Most patients, i.e., 76 out of 132 (57.58%), were aged 30-50 years, with an average age of presentation at 41 years. Socioeconomic status revealed 120 (90.9%) belonging to Classes II and III. USG and FNAC exhibited sensitivities of 77.4% and 90.3%, specificities of 94.1% and 98.5%, and accuracies of 88.9% and 96.0%, respectively. FNAC demonstrated superior diagnostic performance metrics compared to USG, with higher PPV and NPV, indicating its stronger ability to correctly identify true-positive cases. Ultrasound features and FNAC findings showed significant associations with biopsy results, reaffirming their utility in diagnosing thyroid nodules. CONCLUSION: FNAC emerged as a highly accurate diagnostic tool for distinguishing between benign and malignant thyroid nodules, outperforming USG. Understanding demographic and clinical characteristics can aid in the timely diagnosis and management of thyroid disorders. Further research is warranted to enhance diagnostic algorithms and optimize patient care in resource-constrained settings.

Soybean (Glycine max) isoflavone conjugate hydrolysing ß-glucosidase (GmICHG): a promising candidate for soy isoflavone bioavailability enhancement.

Isoflavones are a sub-class of phenylpropanoids having health benefits and a role in plant defence and plant-rhizobium interaction. Isoflavone conjugate hydrolysis is crucial in determining the bioactivity and bioavailability of these isoflavones inside the human body. This study examined the different characteristics of soy isoflavone conjugate hydrolysing ß-glucosidase (GmICHG) to explore its potential for isoflavone bioavailability enhancement. We cloned the full-length GmICHG cDNA from the soybean seedling roots from the DS2706 variety of 1545 bp. The bioinformatics analysis revealed secretion and glycosylation of this protein. The evolutionary relatedness of this gene to the other glucosidases interestingly had related sequences outside the Papilionaceae family. The protein had a pI above neutral of 7.62 and optimum pH of 6.0, indicating its activity in the extracellular acidic environment. The GmICHG gene expression at three stages of seedling roots gradually rose to 1.84 ± 0.54 fold and a concomitant increase in the ß-glucosidase activity. The enzyme kinetics of GmICHG showed a K m of 6.38 mM and V max of 2.82 U/ml and an optimum temperature of 40 °C. These hint that soy ICHG can be a potent candidate for the isoflavone bioavailability enhancement by hydrolysing their ß-glycosidic bonds. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-022-03427-5.

Discerning Modulation of α-Synuclein Amyloid Assembly by α-Crystallin.

Altered protein folding leading to the formation of structured aggregates such as amyloid fibrils has gained significant attention due to its association with neurodegenerative diseases. α-Synuclein, a small intrinsically disordered protein, gets transformed into amyloid fibrils under unfavorable conditions and contributes to the progression and pathology of Parkinson's disease (PD). Under normal physiological conditions, amyloid formation is controlled by many chaperones and chaperone-like proteins. However, with aging, the protein homeostasis machinery becomes less efficient, causing the loss of proper functioning of chaperones and leading to aberrant protein folding and amyloid formation. Here, we provide in-depth information on the modulation of α-synuclein amyloid assembly by a heterogeneous complex of bovine eye lens protein, α-crystallin, which is known to possess chaperone-like activity. We have used a multiparametric approach to discern the critical events through which α-crystallin abolishes α-synuclein amyloid formation. Our biochemical and biophysical data analysis revealed that α-crystallin, at substoichiometric ratios, alleviates α-synuclein amyloid assembly and drives it into soluble dead-end intermediates. We also demonstrated that α-crystallin was equally efficient in arresting amyloid assembly by some of the PD-related mutants suggesting the significance of chaperone-like activity of α-crystallin under pathological conditions. Finally, we validated our results using human crystallin derived from cataract patients. Based on our findings, we propose that the interaction of α-crystallin directs α-synuclein into a soluble amyloid-incompetent form. Our results suggest that the generic antiamyloid property of chaperone-like proteins, such as α-crystallin, can be harnessed to design protein and peptide-based novel therapeutics for prevention and treatment of deadly neurodegenerative diseases.

Effects of the aspect ratio of plasmonic gold nanorods on the inhibition of lysozyme amyloid formation.

Amyloid formation due to altered protein folding and aggregation has gained significant attention due to its association with neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease, Huntington's disease, and systemic lysozyme amyloidosis. Amyloids are characterized by parallel and anti-parallel cross-ß-strands arranged to form stacks of sheets that provide stability and rigidity to the amyloid core. The prototypic protein Hen Egg White Lysozyme (HEWL) has been extensively used to understand protein hydrolysis, fragmentation, folding, misfolding, and amyloid formation. In the present study, we have examined the efficacy of plasmonic gold nanorods (GNRs) as an anti-amyloid agent against HEWL amyloids. Our results reveal that (i) the amyloid inhibition by plasmonic GNRs is dependent on their aspect ratio, (ii) the large aspect ratio GNRs ameliorate amyloid assembly completely, and (iii) GNRs interfere at several stages along the lysozyme fibril-formation pathway and block the conversion of monomeric and oligomeric intermediates into mature fibrils. Using a multi-parametric approach, we demonstrate that GNRs drive HEWL into off-pathway and amyloid-incompetent forms. To establish GNRs as generic amyloid inhibitors, we extended our studies to another archetypal protein, Bovine Serum Albumin (BSA), and observed similar results of GNRs inhibiting BSA aggregation. We believe that our results will pave the way for the potential use of GNRs with current therapeutics to reduce the burden of amyloid-related diseases.

An Innate Host Defense Protein ß2-Microglobulin Keeps a Check on α-Synuclein amyloid Assembly: Implications in Parkinson's Disease.

Amyloid formation due to protein misfolding has gained significant attention due to its association with neurodegenerative diseases. α-Synuclein (α-syn) is one such protein that undergoes a profound conformational switch to form higher order cross-ß-sheet structures, resulting in amyloid formation, which is linked to the pathophysiology of Parkinson's disease (PD). The present status of research on α-syn aggregation and PD reveals that the disease progression may be linked with many other diseases, such as kidney-related disorders. Unraveling the link between PD and non-neurological diseases may help in early detection and a better understanding of PD progression. Herein, we investigated the modulation of α-syn in the presence of ß2-microglobulin (ß2m), a structural protein associated with dialysis-related amyloidosis. We took a multi-disciplinary approach to establish that ß2m mitigates amyloid formation by α-syn. Our fluorescence, microscopy and toxicity data demonstrated that sub-stoichiometric ratio of ß2m drives α-syn into off-pathway non-toxic aggregates incompetent of transforming into amyloids. Using AlphaFold2 and all-atom MD simulation, we showed that the ß-strand segments (ß1 and ß2) of α-synuclein, which frequently engage in interactions within amyloid fibrils, interact with the last ß-strand at the C-terminal of ß2m. The outcome of this study will unravel the yet unknown potential linkage of PD with kidney-related disorders. Insights from the cross-talk between two amyloidogenic proteins will lead to early diagnosis and new therapeutic approaches for treating Parkinson's disease. Finally, disruption of the nucleation process of α-syn amyloids by targeting the ß1-ß2 region will constitute a potential therapeutic approach for inhibiting amyloid formation.

Facile Synthesis of Multifunctional Carbon Dots Derived from Camel Milk for Mn7+ Sensing and Antiamyloid and Anticancer Activities.

Carbon dots (CDs) are promising biocompatible fluorescent nanoparticles mainly used in bioimaging, drug delivery, sensing, therapeutics, and various other applications. The utilization of natural sources and green synthetic approaches is resulting in highly biocompatible and nontoxic nanoparticles. Herein, we report an unprecedented facile and green synthesis of highly luminescent carbon dots derived from camel milk (CM) for sensing manganese (Mn7+) ions and for identifying the anticancer potential and antiamyloid activity against α-synuclein amyloids. α-Synuclein amyloid formation due to protein misfolding (genetic and environmental factors) has gained significant attention due to its association with Parkinson's disease and other synucleinopathies. The as-synthesized CM-CDs possess an average hydrodynamic diameter ranging from 3 to 15 nm and also exhibit strong photoluminescence (PL) emission in the blue region. The CM-CDs possess good water dispersibility, stable fluorescence under different physical states, and outstanding photostability. Moreover, the CM-CDs are validated as an efficient sensor for the detection of Mn7+ ions in DI water and in metal ion-polluted tap water. In addition, the CM-CDs have demonstrated a very good quantum yield (QY) of 24.6% and a limit of detection (LOD) of 0.58 µM for Mn7+ ions with no incubation time. Consequently, the exceptional properties of CM-CDs make them highly suitable for a diverse array of biomedical applications.

Correlation of the Stature with Arch and Chord Dimensions in Young Subjects using Carrea's Index- An Anthropometric Study.

Background: Forensic identifications have utilized the height or stature of an individual in their field. Teeth and dentition can act as reliable tools to estimate the stature in cases where the only skull is presented as evidence. The Carrea's index assesses the stature in a subject from the lower anterior teeth dimensions. Aim: The present study was aimed to judge the reliability of Carrea's index in Indian subjects. Materials and Methods: From 80 subjects who were undergraduate students, plaster models were made and each was assessed individually making 160 hemiarches. These hemiarches were divided based on the teeth alignment into normal, diastema, and crowded forms. This was followed by measurement with a vernier caliper into chord and arch. Results: In both genders, the difference seen was statistically significant between dental arch types concerning various alignments with 95.23% and 83.75% success for males and females in normal dentition and 92.30% and 85.71% in crowded dentition. Also, a significant difference was seen for the type of arch with P ≤ 0.001 and 0.003, respectively. Lesser success was seen for spacing in both the genders and arches. Conclusion: The present study concludes that Carrea's index is a dependable and efficient tool for estimating height in subjects having arches with crowded and normal dentition which is functional for both the gender on the left and right side of the dental arches. However, in hemiarches with diastema, this method is not reliable.

A tale of topoisomerases and the knotty genetic material in the backdrop of Plasmodium biology.

The untangling or overwinding of genetic material is an inevitable part of DNA replication, repair, recombination, and transcription. Topoisomerases belong to a conserved enzyme family that amends DNA topology during various processes of DNA metabolism. To relax the genetic material, topoisomerases transiently break the phosphodiester bond on one or both DNA strands and remain associated with the cleavage site by forming a covalent enzyme-DNA intermediate. This releases torsional stress and allows the broken DNA to be re-ligated by the enzyme. The biological function of topoisomerases ranges from the separation of sister chromatids following DNA replication to the aiding of chromosome condensation and segregation during mitosis. Topoisomerases are also actively involved in meiotic recombination. The unicellular apicomplexan parasite, Plasmodium falciparum, harbors different topoisomerase subtypes, some of which have substantially different sequences and functions from their human counterparts. This review highlights the biological function of each identified Plasmodium topoisomerase along with a comparative analysis of their orthologs in human or other model organisms. There is also a focus on recent advancements towards the development of topoisomerase chemical inhibitors, underscoring the druggability of unique topoisomerase subunits that are absent in humans. Plasmodium harbors three distinct genomes in the nucleus, apicoplast, and mitochondria, respectively, and undergoes non-canonical cell division during the schizont stage of development. This review emphasizes the specific developmental stages of Plasmodium on which future topoisomerase research should focus.

DNA damage-induced nuclear import of HSP90α is promoted by Aha1.

The interplay between yHSP90α (Hsp82) and Rad51 has been implicated in the DNA double-strand break repair (DSB) pathway in yeast. Here we report that nuclear translocation of yHSP90α and its recruitment to the DSB end are essential for homologous recombination (HR)-mediated DNA repair in yeast. The HsHSP90α possesses an amino-terminal extension which is phosphorylated upon DNA damage. We find that the absence of the amino-terminal extension in yHSP90α does not compromise its nuclear import, and the nonphosphorylatable-mutant HsHSP90αT7A could be imported to the yeast nucleus upon DNA damage. Interestingly, the flexible charged-linker (CL) domains of both yHSP90α and HsHSP90α play a critical role during their nuclear translocation. The conformational restricted CL mutant yHSP90α∆(211-259), but not a shorter deletion version yHSP90α∆(211-242), fails to reach the nucleus. As the CL domain of yHSP90α is critical for its interaction with Aha1, we investigated whether Aha1 promotes the nuclear import of yHSP90α. We found that the nuclear import of yHSP90α is severely affected in ∆aha1 strain. Moreover, Aha1 is accumulated in the nucleus during DNA damage. Hence Aha1 may serve as a potential target for inhibiting nuclear function of yHSP90α. The increased sensitivity of ∆aha1 strain to genotoxic agents strengthens this notion.

Thyroid function in patients with idiopathic nephrotic syndrome.

BACKGROUND: Albumin is the major protein excreted in urine in patients with nephrotic syndrome (NS). However, low-molecular-weight proteins including some binding proteins are also excreted. Thyroid hormone and its binding globulins are excreted in urine in excess in nephrotic syndrome. Therefore, it has been postulated that patients with nephrotic syndrome may show hypothyroidism, subclinical or overt. METHODS: In this prospective observational study, patients of idiopathic nephrotic syndrome aged 1-40 years of both gender were included. Serum T3, T4 and TSH were assayed at diagnosis and repeated at 12 weeks or at remission whichever was earlier. Renal biopsy was performed as required. RESULTS: Among 100 patients taken for analysis (42 children, 58 adult), 30 cases were of first episode, 40 were of frequent relapse/steroid-dependent NS, and 30 patients had steroid-resistant NS (SRNS). Three (3%) cases had overt hypothyroidism and 18 (18%) patients had subclinical hypothyroidism. Most hypothyroid cases belonged to SRNS subgroup. Mean Serum T3, T4 and TSH values showed significant improvement in remission in comparison to nephrosis state (P < 0.01). Serum TSH had significant positive correlation (r = 0.391, P < 0.01) with 24-h proteinuria and negative correlation with serum albumin (r = - 0.303, P < 0.01) in nephrosis. CONCLUSION: Hypothyroidism is common among nephrotic syndrome patients especially in SRNS subgroup. Therefore, routine screening is recommended in steroid-resistant nephrotic syndrome patients.