James Regun Karmoker

All Publications

• Mouse and Rat Oxygen-Induced Retinopathy Models to Study Vascular Features Seen in Retinopathy of Prematurity. Bio-protocol Tankersley, M. P., Beri, S., Ramshekar, A., Asare-Bediako, B., Shah, N. S., Karmoker, J. R., Huang, H. C., Hartnett, E. M. 2026; 16 (15): e5771

  Abstract

  Retinopathy of prematurity (ROP), a retinovascular disease, is a leading cause of childhood blindness worldwide. Given the constraints of studying molecular mechanisms in preterm infants, reproducible animal models are important to understand ROP pathophysiology. Mouse and rat oxygen-induced retinopathy (OIR) models are the most commonly used and recapitulate key vascular features seen in ROP. However, these models are susceptible to inherent variability that limits reproducibility, including inter-litter variability, consistency of oxygen delivery across experiments, retinal dissection technique, and immunohistochemistry. Here, we describe a comprehensive protocol for performing the most common mouse and rat OIR models, and procedures such as eye enucleation, retinal dissection and flat mounting, isolectin GS-IB4 staining, whole retina stitched fluorescence imaging from Z-stacks, and quantification of vascular features. This protocol provides important materials and procedural details to increase the reproducibility of the mouse and rat OIR models. Key features • Rat and mouse oxygen-induced retinopathy (OIR) models. • Eye enucleation of experimental rat and mouse pups. • Retinal flat mounting and immunostaining for rat and mouse eyes. • Image analysis of retinal flat mounts from rat and mouse eyes.

  View details for DOI 10.21769/BioProtoc.5771

  View details for PubMedID 42591369

  View details for PubMedCentralID PMC13461755

• Aryl hydrocarbon receptor (AhR)-mediated immune responses to degeneration of the retinal pigment epithelium BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR BASIS OF DISEASE Karmoker, J., Bounds, S. E., Cai, J. 2024; 1870 (7): 167351

  Abstract

  Injuries to the retinal pigment epithelium (RPE) trigger immune responses, orchestrating interactions within the innate and adaptive immune systems in the outer retina and choroid. We previously reported that interleukin 17 (IL-17) is a pivotal signaling molecule originating from choroidal γδ T cells, exerting protective effects by mediating functional connections between the RPE and subretinal microglia. In this current study, we generated mice with aryl hydrocarbon receptor (AhR) knockout specifically in IL-17-producing cells. These animals had deficiency in IL-17 production from γδ T cells, and exhibited increased sensitivity to both acute and chronic insults targeting the RPE. These findings imply that IL-17 plays a crucial role as a signaling cytokine in preserving the homeostasis of the outer retina and choroid.

  View details for DOI 10.1016/j.bbadis.2024.167351

  View details for Web of Science ID 001272041600001

  View details for PubMedID 39004382

  View details for PubMedCentralID PMC11330344

• Interleukin-17-mediated protective cytokine signaling against degeneration of the retinal pigment epithelium PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Chen, Y., Bounds, S. E., Ma, X., Karmoker, J., Liu, Y., Ma, J., Cai, J. 2023; 120 (51): e2311647120

  Abstract

  Injuries to the retinal pigment epithelium (RPE) and outer retina often result in the accumulation of retinal microglia within the subretinal space. These subretinal microglia play crucial roles in inflammation and resolution, but the mechanisms governing their functions are still largely unknown. Our previous research highlighted the protective functions of choroidal γδ T cells in response to RPE injury. In the current study, we employed single-cell RNA sequencing approach to characterize the profiles of immune cells in mouse choroid. We found that γδ T cells were the primary producer of interleukin-17 (IL-17) in the choroid. IL-17 signaled through its receptor on the RPE, subsequently triggering the production of interleukin-6. This cascade of cytokines initiated a metabolic reprogramming of subretinal microglia, enhancing their capacity for lipid metabolism. RPE-specific knockout of IL-17 receptor A led to the dysfunction of subretinal microglia and RPE pathology. Collectively, our findings suggest that responding to RPE injury, the choroidal γδ T cells can initiate a protective signaling cascade that ensures the proper functioning of subretinal microglia.

  View details for DOI 10.1073/pnas.2311647120

  View details for Web of Science ID 001157836300006

  View details for PubMedID 38085785

  View details for PubMedCentralID PMC10742376

• A comprehensive analysis of selected medicines collected from private drug outlets of Dhaka city, Bangladesh in a simple random survey SCIENTIFIC REPORTS Rahman, M., Yoshida, N., Tsuboi, H., Karmoker, J., Kabir, N., Schaefermann, S., Akimoto, Y., Bhuiyan, M., Reza, M., Kimura, K. 2022; 12 (1): 234

  Abstract

  Comprehensive data are needed to prevent substandard and falsified (SF) medicines as they pose a major risk to human health. To assess the quality of selected medicines, samples were collected from random private drug outlets of Dhaka North and South City Corporation, Bangladesh. Sample analysis included visual observation of the packaging, authenticity of the samples, legitimacy and registration verification of the manufacturer, physicochemical analysis, and price. Chemical analysis of the samples was performed using a portable Raman spectroscopy and high-performance liquid chromatography according to the pharmacopoeia. Several discrepancies were noted in the visual observation of samples. Among the 189 collected samples of esomeprazole (ESM), cefixime (CFIX), and amoxicillin-clavulanic acid (CVA-AMPC), 21.2% were confirmed to be authentic, 91.3% manufacturers were confirmed legitimate, and 2.1% of all samples were unregistered. Chemical analysis of the samples revealed that 9.5% (95% CI 5.7-14.6) of samples were SFs. Falsified samples and quality variation in the same generic branded samples were both detected by Raman spectroscopic analysis. Overall, sample prices were satisfactory relative to the international reference price. This study documents the availability of poor-quality medicines, demonstrating the need for immediate attention by the national medicine regulatory authority.

  View details for DOI 10.1038/s41598-021-04309-1

  View details for Web of Science ID 000740510500256

  View details for PubMedID 34997152

  View details for PubMedCentralID PMC8741935

• Evaluation of serum amino acids and non-enzymatic antioxidants in drug-naive first-episode major depressive disorder BMC PSYCHIATRY Islam, M., Ali, S., Karmoker, J., Kadir, M., Ahmed, M., Nahar, Z., Islam, S., Islam, M., Hasnat, A., Islam, M. 2020; 20 (1): 333

  Abstract

  The alterations of biological markers are thought to be effective tools to understand the pathophysiology and management of major depressive disorder (MDD). A lot of researches has implied many markers for depression, but any of them fully discovered the association between the markers and depression. The present study investigated the serum levels of amino acids and non-enzymatic antioxidants in major depression, and also explained their association with depression.This study examined 247 MDD patients and 248 healthy controls (HCs) matched by age and sex. The Hamilton Depression Rating Scale (Ham-D) was used to all the participants to measure the severity of depression. Quantification of serum amino acids, vitamin A and E were carried out using the HPLC system whereas vitamin C levels were measured by UV-spectrophotometer. All the statistical analysis was performed by SPSS statistical software (version 23.0). The independent sample t-test, the Mann-Whitney U test, and the Fisher's exact test were applied to detect the group differences where a Bonferroni correction applied to the p value.It was observed that serum levels of four amino acids (methionine, phenylalanine, tryptophan, and tyrosine) along with three non-enzymatic antioxidants (vitamin A, E, and C) were significantly dropped in MDD patients compared to HCs (Cohen's d (d): - 0.45, - 0.50, - 0.68, - 0.21, - 0.27, - 0.65, and - 0.24, respectively). Furthermore, Ham-D scores of cases were negatively correlated with serum levels of methionine (r = - 0.155, p = 0.015) and tyrosine (r = - 0.172, p = 0.007).The present study suggests that lowered serum methionine, phenylalanine, tryptophan, tyrosine, and non-enzymatic antioxidants are associated with depression. The reduction of these parameters in MDD patients may be the consequence, and not the cause, of major depression.

  View details for DOI 10.1186/s12888-020-02738-2

  View details for Web of Science ID 000545666900003

  View details for PubMedID 32580709

  View details for PubMedCentralID PMC7315550

• Evaluation of Serum Interleukin-6 and C-reactive Protein Levels in Drug-naive Major Depressive Disorder Patients CUREUS JOURNAL OF MEDICAL SCIENCE Nishuty, N., Khandoker, M., Karmoker, T., Ferdous, S., Shahriar, M., Qusar, M., Islam, M., Kadir, M., Islam, M. 2019; 11 (1): e3868

  Abstract

  Background Major depressive disorder (MDD) is a disabling health problem with a very high global prevalence and burden. Alteration of inflammatory markers in depression is of growing interest to many psychiatry researchers. This study aimed to examine the serum levels of interleukin-6 (IL-6) and C-reactive protein (CRP) in MDD patients to find out their association with depression. Materials and methods The present study recruited 88 MDD patients and 86 control subjects matched by age, gender, and body mass index (BMI). The Hamilton depression rating scale (Ham-D) was used on all patients to measure their severity of depression. Serum levels of IL-6 and CRP were analyzed by commercially available enzyme-linked immunosorbent assay (ELISA) kits (Abcam, Cambridge, MA, USA). Results The mean values of serum levels of IL-6 and CRP were 2.94 ± 0.12 pg/mL and 0.99 ± 0.02 mg/L for the patient group and 2.42 ± 0.21 pg/mL and 1.09 ± 0.06 mg/L for the control group, respectively. We found significantly elevated concentrations of serum IL-6 in MDD patients compared with control subjects (p < 0.001). However, the alteration of serum CRP levels was not significant between the groups (p = 0.126). Ham-D scores of patients were positively correlated with serum IL-6 (r = 0.552; p = 0.004) and CRP (r = 0.621; p < 0.001) levels. Moreover, serum IL-6 and CRP levels were observed to be positively correlated (r = 0.452; p = 0.043) with each other in depression. Conclusions The present study suggests that increased serum IL-6 level might be a contributing factor to the pathogenesis of depression.

  View details for DOI 10.7759/cureus.3868

  View details for Web of Science ID 000461357400003

  View details for PubMedID 30899619

  View details for PubMedCentralID PMC6414189