Publications by authors named "Sukhleen Kaur"

4 Publications

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Delayed KCNQ1/KCNE1 assembly on the cell surface helps I fulfil its function as a repolarization reserve in the heart.

J Physiol 2021 May 7. Epub 2021 May 7.

Department of Physiology & Biophysics, Virginia Commonwealth University, Richmond, VA, USA.

Key Points: In adult ventricular myocytes, the slow delayed rectifier (I ) channels are distributed on the surface sarcolemma, not t-tubules. In adult ventricular myocytes, KCNQ1 and KCNE1 have distinct cell surface and cytoplasmic pools. KCNQ1 and KCNE1 traffic from the endoplasmic reticulum to the plasma membrane by separate routes, and assemble into I channels on the cell surface. Liquid chromatography/tandem mass spectrometry applied to affinity-purified KCNQ1 and KCNE1 interacting proteins reveals novel interactors involved in protein trafficking and assembly. Microtubule plus-end binding protein 1 (EB1) binds KCNQ1 preferentially in its dimer form, and promotes KCNQ1 to reach the cell surface. An LQT1-associated mutation, Y111C, reduces KCNQ1 binding to EB1 dimer.

Abstract: Slow delayed rectifier (I ) channels consist of KCNQ1 and KCNE1. I functions as a 'repolarization reserve' in the heart by providing extra current for ventricular action potential shortening during β-adrenergic stimulation. There has been much debate about how KCNQ1 and KCNE1 traffic in cells, where they associate to form I channels, and the distribution pattern of I channels relative to β-adrenergic signalling complex. We used experimental strategies not previously applied to KCNQ1, KCNE1 or I , to provide new insights into these issues. 'Retention-using-selected-hook' experiments showed that newly translated KCNE1 constitutively trafficked through the conventional secretory path to the cell surface. KCNQ1 largely stayed in the endoplasmic reticulum, although dynamic KCNQ1 vesicles were observed in the submembrane region. Disulphide-bonded KCNQ1/KCNE1 constructs reported preferential association after they had reached cell surface. An in situ proximity ligation assay detected I channels in surface sarcolemma but not t-tubules of ventricular myocytes, similar to the reported location of adenylate cyclase 9/yotiao. Fluorescent protein-tagged KCNQ1 and KCNE1, in conjunction with antibodies targeting their extracellular epitopes, detected distinct cell surface and cytoplasmic pools of both proteins in myocytes. We conclude that, in cardiomyocytes, KCNQ1 and KCNE1 traffic by different routes to surface sarcolemma where they assemble into I channels. This mode of delayed channel assembly helps I fulfil its function of repolarization reserve. Proteomic experiments revealed a novel KCNQ1 interactor, microtubule plus-end binding protein 1 (EB1). EB1 dimer (active form) bound KCNQ1 and increased its surface level. An LQT1 mutation, Y111C, reduced KCNQ1 binding to EB1 dimer.
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http://dx.doi.org/10.1113/JP281773DOI Listing
May 2021

Gender determination by morphometric analysis of mandibular ramus in sriganganagar population: A digital panoramic study.

Indian J Dent Res 2020 May-Jun;31(3):444-448

Department of Oral Medicine and Radiology, Surendera Dental College and Research Institute, H.H Gardens, Power House Road, Sriganganagar, Rajasthan, India.

Background: Mandible is a dimorphic, dense compact bone that makes it very durable and well preserved in mass disasters for personnel identification. Mandibular ramus morphometric measurements can be used for gender determination using orthopantomogram (OPG) or on dry mandibles.

Aim: To determine gender from morphometric analysis of mandibular ramus of 200 digital OPG of patients from Sriganganagar population.

Materials And Methods: The study was conducted on randomly selected digital OPG of 200 patients of both genders between the ages of 21 and 70 years taken using CS8000C machine from daily OPD. Morphometric analysis of mandibular ramus (maximum ramus breadth, minimum ramus breadth, condylar height, projective height of ramus, and coronoid height) was done twice by single maxillofacial radiologist independently at an interval of 1 day and mean of both the values were considered. The collected data was tabulated and analyzed using SPSS Software version 20 using independent ṯ-test and discriminant function analysis.

Results: Out of total 200 subjects, 37% were male and 63% were female. Mean of minimum ramus breadth, maximum ramus height, and projected ramus height was noted significantly more among males while maximum ramus breadth was noted slightly higher in females. The overall accuracy for determining sex from mandibular ramus was found to be 77.6%, whereas for determining male and female, the accuracy was 78.4% and 76.8%, respectively.

Conclusion: Mandibular ramus can be used for sexual dimorphism by morphometric analysis done on OPG among Sriganganagar population.
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http://dx.doi.org/10.4103/ijdr.IJDR_547_17DOI Listing
August 2020

Evaluation of mandibular anterior nutrient canals in hypertensive and diabetes mellitus patients: A comparative radiographic study.

Ci Ji Yi Xue Za Zhi 2019 Apr-Jun;31(2):118-123

Department of Oral Medicine and Radiology, Surendera Dental College and Research Institute, Sri Ganganagar, Rajasthan, India.

Objective: Radiographic evaluation of nutrient canals (NCs) in the mandibular anterior region using intraoral periapical radiographs (IOPARs) and to determine whether they can be used as a potential marker for hypertension (HT) and diabetes mellitus (DM).

Materials And Methods: Randomly selected 600 patients of 21-60 years age group (Group I: 200 HT; Group II: 200 DM; Group III: Healthy subjects) were considered. The case history was recorded including details for DM and HT (duration, type, and medication). Blood pressure was measured, followed by blood examination for blood sugar levels. Selected patients were subjected to IOPARs using CS-2100C machine by the paralleling technique. Selected radiographs were evaluated by two observers independently for the presence/absence, number, and location of NCs between #33 and #43. Data obtained were tabulated and subjected to statistical analysis using SPSS 20.0 statistical software and intergroup reliability was checked using Cohen's kappa test.

Results: Evaluation of various parameters of NCs showed an insignificant interobserver bias. The incidence of NCs presence was noted maximum in Group II (93.5%), followed by Group I (88.5%) and III (44.5%). Of total 888 NCs found, maximum were found in Group I, followed by II and III. On comparing the incidence of NCs present among both genders and location in study groups, no statistical correlation was found.

Conclusion: Statistically significant increase in the incidence and number of NCs in Group I and II compared to controls can act as an adjunct diagnostic marker for the detection of DM and HT; although, no significant correlation was obtained between gender and location of NCs in different study groups. Furthermore, there was no significant correlation was found between the severity of disease and incidence of the presence of NCs.
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http://dx.doi.org/10.4103/tcmj.tcmj_43_18DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6450156PMC
April 2019

Evaluation of sexual dimorphism using permanent maxillary first molar in Sri Ganganagar population.

Indian J Dent Res 2017 Sep-Oct;28(5):482-486

Department of Oral Medicine and Radiology, Surendera Dental College and Research Institute, Sri Ganganagar, Rajasthan, India.

Aim Of Study: The aim is to evaluate existence of sexual dimorphism by variation in right and left permanent maxillary molars using buccolingual width (BLW) and mesio-distal width (MDW) measured intraorally and on study casts among Sri Ganganagar population.

Materials And Methods: Fifty patients (25 males and 25 females) with 17-25 years of age were selected. Impressions of maxillary arch were taken and the BLW and MDW were measured using digital Vernier calipers on study casts and intraorally.

Results: Highly significant correlation was found between MDW and BLW of both the maxillary permanent first molars for both genders (P < 0.05) intraorally. The MDW and BLW on study cast of both sides in both gender were more on left side in males while on right side in females.

Conclusion: Left maxillary permanent first molar showed minimum mean difference of measurements on study cast and introrally than right, thus better predictor for gender dimorphism in forensics.
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http://dx.doi.org/10.4103/ijdr.IJDR_606_16DOI Listing
July 2018