BIKASH PATTNAIK - Academia.edu (original) (raw)

Papers by BIKASH PATTNAIK

Genes

The structurally and genetically distinct sigma-1 receptor (S1R) and sigma-2 receptor (S2R) compr... more The structurally and genetically distinct sigma-1 receptor (S1R) and sigma-2 receptor (S2R) comprise a unique class of drug binding sites. Their alleles are associated with human diseases involving neuronal systems, such as age-related macular degeneration (AMD) characterized by photoreceptor and retinal pigment epithelium (RPE) atrophy. Previous studies have suggested neuroprotective benefits for the brain and retina from pharmacological modulation of S1R and/or S2R. However, the effect of such modulation on AMD pathology remains underexplored. Here, we evaluated S1R- or S2R-selective modulation in an AMD-related model of Abca4−/−Rdh8−/− mice with a disrupted visual cycle that predisposes RPE and photoreceptors to illumination-induced damage. For S1R modulation, we used (+)-pentazocine, which is a high-affinity S1R-selective drug. For S2R modulation, we chose CM398, a high-affinity and highly S2R-selective ligand with drug-like properties. Abca4−/−Rdh8−/− mice received a single i.p...

Multiphoton Microscopy in the Biomedical Sciences XXII, 2022

Journal of Clinical Investigation

Clinical genome editing is emerging for rare disease treatment, but one of the major limitations ... more Clinical genome editing is emerging for rare disease treatment, but one of the major limitations is the targeting of CRISPR editors delivery. We delivered base editors to the retinal pigmented epithelium (RPE) in the mouse eye using silica nanocapsules (SNC) as a treatment for retinal degeneration. Leber Congenital Amaurosis (LCA16) is a rare pediatric blindness caused by point mutations in the KCNJ13 gene, a loss-offunction inwardly rectifying potassium channel (Kir7.1) in the RPE. SNC carrying adenine base editor (ABE8e) mRNA and single-guide RNA precisely and efficiently corrected KCNJ13 W53X/W53X mutation. Editing in both patient fibroblasts (47%) and human-induced pluripotent stem cell-derived RPE (LCA16-iPSC-RPE) (17%) had a negligible off-target response. We detected functional Kir7.1 channels in the edited LCA16-iPSC-RPE. In the LCA16 mouse model (Kcnj13 W53X/+∆R), RPE cells targeted SNC delivery of ABE8e mRNA preserved normal visual function measured by full-field electroretinogram (ERG). Moreover, multifocal ERG confirmed the topographic measure of electrical activity primarily originating from the edited retinal area at the injection site. Preserved retina structure, post-treatment, was established by Optical Coherence Tomography (OCT). This preclinical validation of targeted ion channel functional rescue, a challenge for pharmacological and genomic interventions, reinforced the effectiveness of nonviral genome editing therapy for rare inherited disorders.

Novel Therapeutics: Response and Resistance of Ovarian Cancer, 2019

Negative controls of RIP1/RIP3 proximity ligation and immunostaining. (DOCX 316Â kb)

Protein MAP1B was recently reported to link GABAC receptors to the cytoskeleton at neuronal synap... more Protein MAP1B was recently reported to link GABAC receptors to the cytoskeleton at neuronal synapses. This interaction was demonstrated in the mammalian retina, where GABAC receptors were thought to be exclusively expressed in bipolar cells. Our previous studies on cultured photoreceptors suggested however the presence of GABAC receptors in cones. To further investigate GABAC receptor expression in cones, we measured GABA responses in mammalian photoreceptors in situ, and we examined the distribution of the receptor and that of protein MAP1B in the mammalian outer retina. Photoreceptors were recorded from flat-mounted retinas of retinal degeneration mice at an age when the retina becomes cone-dominated after rod cell death. GABAA and GABAC-gated currents were produced only in cones but not rods. Recording freshly dissociated retinal cells from wild-type C57 mice confirmed the presence of GABAA and GABAC receptors in cones. Immunohistochemical labeling of mouse and rat retinal sectio...

Cancers, 2021

The high mortality of OvCa is caused by the wide dissemination of cancer within the abdominal cav... more The high mortality of OvCa is caused by the wide dissemination of cancer within the abdominal cavity. OvCa cells metastasize to the peritoneum, which is covered by mesothelial cells, and invade into the underlying stroma, composed of extracellular matrices (ECM) and stromal cells. In a study using a three-dimensional quantitative high-throughput screening platform (3D-qHTS), we found that β-escin, a component of horse chestnut seed extract, inhibited OvCa adhesion/invasion. Here, we determine whether β-escin and structurally similar compounds have a therapeutic potential against OvCa metastasis. Different sources of β-escin and horse chestnut seed extract inhibited OvCa cell adhesion/invasion, both in vitro and in vivo. From a collection of 160 structurally similar compounds to β-escin, we found that cardiac glycosides inhibited OvCa cell adhesion/invasion and proliferation in vitro, and inhibited adhesion/invasion and metastasis in vivo. Mechanistically, β-escin and the cardiac gly...

International Journal of Molecular Sciences, 2020

Ion channels are membrane-spanning integral proteins expressed in multiple organs, including the ... more Ion channels are membrane-spanning integral proteins expressed in multiple organs, including the eye. In the eye, ion channels are involved in various physiological processes, like signal transmission and visual processing. A wide range of mutations have been reported in the corresponding genes and their interacting subunit coding genes, which contribute significantly to an array of blindness, termed ocular channelopathies. These mutations result in either a loss- or gain-of channel functions affecting the structure, assembly, trafficking, and localization of channel proteins. A dominant-negative effect is caused in a few channels formed by the assembly of several subunits that exist as homo- or heteromeric proteins. Here, we review the role of different mutations in switching a “sensing” ion channel to “non-sensing,” leading to ocular channelopathies like Leber’s congenital amaurosis 16 (LCA16), cone dystrophy, congenital stationary night blindness (CSNB), achromatopsia, bestrophin...

Poster Presentations - Proffered Abstracts, 2020

Scientific Reports, 2020

Oxidative stress inhibits Na+/K+-ATPase (NKA), the ion channel that maintains membrane potential.... more Oxidative stress inhibits Na+/K+-ATPase (NKA), the ion channel that maintains membrane potential. Here, we investigate the role of oxidative stress-mediated by plumbagin and atovaquone in the inhibition of NKA activity. We confirm that plumbagin and atovaquone inhibit the proliferation of three human (OVCAR-3, SKOV-3, and TYKNu) and one mouse (ID8) ovarian cancer cell lines. The oxygen radical scavenger, N-acetylcysteine (NAC), attenuates the chemotoxicity of plumbagin and atovaquone. Whole-cell patch clamping demonstrates that plumbagin and atovaquone inhibit outward and the inward current flowing through NKA in SKOV-3 and OVCAR-3. Although both drugs decrease cellular ATP; providing exogenous ATP (5 mM) in the pipet solution used during patch clamping did not recover NKA activity in the plumbagin or atovaquone treated SKOV-3 and OVCAR-3 cells. However, pretreatment of the cells with NAC completely abrogated the NKA inhibitory activity of plumbagin and atovaquone. Exposure of the S...

Drug Response and Resistance to Therapy, 2018

Genetics, 2019

One major aspect of the aging process is the onset of chronic, low-grade inflammation that is hig... more One major aspect of the aging process is the onset of chronic, low-grade inflammation that is highly associated with age-related diseases. The molecular mechanisms that regulate these processes have not been fully elucidated. We have identified a spontaneous mutant mouse line, small with kinky tail (skt), that exhibits accelerated aging and age-related disease phenotypes including increased inflammation in the brain and retina, enhanced age-dependent retinal abnormalities including photoreceptor cell degeneration, neurodegeneration in the hippocampus, and reduced lifespan. By positional cloning, we identified a deletion in chondroitin sulfate synthase 1 (Chsy1) that is responsible for these phenotypes in skt mice. CHSY1 is a member of the chondroitin N-acetylgalactosaminyltransferase family that plays critical roles in the biosynthesis of chondroitin sulfate, a glycosaminoglycan (GAG) that is attached to the core protein to form the chondroitin sulfate proteoglycan (CSPG). Consisten...

Molecular and Cellular Biology / Genetics, 2019

SSRN Electronic Journal, 2019

Dominantly inherited disorders are not typically considered therapeutic candidates for gene augme... more Dominantly inherited disorders are not typically considered therapeutic candidates for gene augmentation (GA). We tested whether GA or genome editing (GE) could serve as a solo therapy for autosomal dominant Best disease (adBD), a macular dystrophy linked to over 100 mutations in the BEST1 gene, which encodes a homo-pentameric calcium-activated chloride channel (CaCC) in the retinal pigment epithelium (RPE). Since no suitable animal models of adBD exist, we generated RPE from patient-derived induced pluripotent stem cells (iPSC-RPE) and found that GA restored CaCC activity and improved rhodopsin degradation in a subset of adBD lines. iPSC-RPE harboring adBD mutations in calcium clasp or chloride binding domains of the channel, but not in a putative structural region, were responsive to GA. However, reversal of the iPSC-RPE CaCC deficit was demonstrated in every adBD line following targeted CRISPR-Cas9 GE of the mutant allele. Importantly, 95% of GE events resulted in premature stop codons within the mutant allele, and single cell profiling demonstrated no adverse perturbation of RPE transcriptional programs post-editing. These results show that GA is a viable approach for a subset of adBD patients depending on the functional role of the mutated residue. Further, GA non-responders are candidates for targeted GE of the mutant allele. Similar scenarios likely exist for other genotypically diverse dominant diseases, expanding the therapeutic landscape for affected patients.

The Journal of Neuroscience, 2000

Physiological reports, 2017

Pregnancy-derived uterine artery endothelial cells (P-UAEC) express P2Y2 receptors and at high ce... more Pregnancy-derived uterine artery endothelial cells (P-UAEC) express P2Y2 receptors and at high cell density show sustained and synchronous [Ca2+]i burst responses in response to ATP Bursts in turn require coupling of transient receptor potential canonical type3 channel (TRPC3) and inositol 1,4,5-triphosphate receptor type 2 (IP3R2), which is upregulated in P-UAEC in a manner dependent on connexin 43 (Cx43) gap junctions. While there is no known direct interaction of TRPC3 with Cx43, early descriptions of TRPC3 function showed it may also be influenced by altered membrane potential (). Herein, we ask if enhanced TRPC3 Ca2+ bursting due to enhanced Cx43 coupling may be coupled via dynamic alterations in in P-UAEC, as reported in some (HUVEC) but not all endothelial cells. Following basic electrical characterization of UAEC, we employed a high sensitivity cell imaging system to simultaneously monitor cell and [Ca2+]i in real time in continuous monolayers of UAEC Our findings show that ...

Stem cells (Dayton, Ohio), Mar 12, 2017

Cell type-specific investigations commonly use gene reporters or single-cell analytical technique... more Cell type-specific investigations commonly use gene reporters or single-cell analytical techniques. However, reporter line development is arduous and generally limited to a single gene of interest, while single-cell RNA (scRNA)-sequencing (seq) frequently yields equivocal results that preclude definitive cell identification. To examine gene expression profiles of multiple retinal cell types derived from human pluripotent stem cells (hPSCs), we performed scRNA-seq on optic vesicle (OV)-like structures cultured under cGMP-compatible conditions. However, efforts to apply traditional scRNA-seq analytical methods based on unbiased algorithms were unrevealing. Therefore, we developed a simple, versatile, and universally applicable approach that generates gene expression data akin to those obtained from reporter lines. This method ranks single cells by expression level of a bait gene and searches the transcriptome for genes whose cell-to-cell rank order expression most closely matches that...