Dengue virus envelope protein domain III induces pro-inflammatory signature and triggers activation of inflammasome.

Dengue virus poses a considerable clinical problem, with the four closely related serotypes of dengue virus (DENV) infecting around 50-100 million people per year world-wide. The drastic increase in the dengue infection could be partly attributed to geographic expansion of the vector due to increasing urbanization, unavailability of specific antiviral therapies, licensed dengue vaccine, and poor understanding of the host immune responses. It has been reported that the immune-dominant envelope protein (E protein) domain III region (EDIII) of DENV is one of the most potent vaccine candidates because of its ability to trigger host immunity by inducing production of protective neutralizing antibodies. However, its role in the modulation of innate inflammatory responses hitherto remains unexplored. Herein, we demonstrate that EDIII protein of DENV induces pro-inflammatory signature by inducing production of inflammatory cytokines such as IL-1ß and TNF-α in THP-1 cells through NF-κB pathway. Also, we observed increase in the maturation of IL-1ß, which was found to be associated with increased ROS production and potassium efflux. Further, our findings reveal that the IL-1ß production by EDIII protein is mediated through caspase-1 and NLRP3 inflammasome activation. In conclusion this study unearths the role of DENV EDIII protein in modulating innate inflammatory responses, which might provide possible mechanism of pathogenesis and open-up new avenues for the development of therapeutics against DENV.

Transplantation of lineage-negative stem cells in pterygopalatine artery ligation induced retinal ischemia-reperfusion injury in mice.

Retinal ischemia is a condition associated with retinal degenerative diseases such as glaucoma, diabetic retinopathy, and other optic neuropathies, leading to visual impairment and blindness worldwide. Currently, there is no therapy available for ischemic retinopathies. Therefore, the aim of this study was to test a murine model of pterygopalatine artery ligation-induced retinal injury for transplantation of mouse bone marrow-derived lineage-negative (lin-ve) stem cells. The mouse external carotid artery and pterygopalatine artery were ligated for 3.5 h followed by reperfusion. The model was validated through fundus fluorescein angiography, laser Doppler and FITC dextran perfusion in whole-mounts. Lin-ve stem cells isolated from mouse bone marrow were transplanted through tail-vein, which showed migration to retina leading to decrease in GFAP expression. The neurotrophic factors such as BDNF and FGF2 showed enhanced expression in the retina. The functional analysis with electroretinogram did not demonstrate any significant changes before or after injury or stem cell transplantation. This study shows a neuroprotective potential in lin-ve stem cells in the retinal ischemia induced by pterygopalatine artery ligation and presents a practical model for validating therapies for ischemic disorders of the retina in future.

Role of iron in ischemia-induced neurodegeneration: mechanisms and insights.

Iron is an important micronutrient for neuronal function and survival. It plays an essential role in DNA and protein synthesis, neurotransmission and electron transport chain due to its dual redox states. On the contrary, iron also catalyses the production of free radicals and hence, causes oxidative stress. Therefore, maintenance of iron homeostasis is very crucial and it involves a number of proteins in iron metabolism and transport that maintain the balance. In ischemic conditions large amount of iron is released and this free iron catalyzes production of more free radicals and hence, causing more damage. In this review we have focused on the iron transport and maintenance of iron homeostasis at large and also the effect of imbalance in iron homeostasis on retinal and brain tissue under ischemic conditions. The understanding of the proteins involved in the homeostasis imbalance will help in developing therapeutic strategies for cerebral as well retinal ischemia.

Pathophysiology of stroke and stroke-induced retinal ischemia: emerging role of stem cells.

The current review focuses on pathophysiology, animal models and molecular analysis of stroke and retinal ischemia, and the role of stem cells in recovery of these disease conditions. Research findings associated with ischemic stroke and retinal ischemia have been discussed, and efforts towards prevention and limiting the recurrence of ischemic diseases, as well as emerging treatment possibilities with endothelial progenitor cells (EPCs) in ischemic diseases, are presented. Although most neurological diseases are still not completely understood and reliable treatment is lacking, animal models provide a major step in validating novel therapies. Stem cell approaches constitute an emerging form of cell-based therapy to treat ischemic diseases since it is an attractive source for regenerative therapy in the ischemic diseases. In this review, we highlight the advantages and limitations of this approach with a focus on key observations from preclinical animal studies and clinical trials. Further research, especially on treatment with EPCs is warranted.

Immunogenic profiling of Mycobacterium tuberculosis DosR protein Rv0569 reveals its ability to switch on Th1 based immunity.

Mycobacterium tuberculosis (M.tb) is a multifaceted bacterial pathogen known to infect more than 2 billion people globally. However, a majority of the individuals (>90%) show no overt clinical symptoms of active Tuberculosis (TB) and, it is reported that M.tb in these individuals resides in the latent form. Therefore, a huge burden of latently infected population poses serious threat to the human health. Inconsistent efficacy of BCG vaccine and poor understanding of latency-associated determinants contribute to the failure of combating M.tb. The discovery of DosR as the master regulator of dormancy, opened new avenues to understand the pathophysiology of the bacterium. Though the specific functions of various DosR genes are yet to be discovered, they have been reported as potent T-cell activators and could elicit strong protective immune responses. Rv0569 is a DosR-encoded conserved hypothetical protein overexpressed during dormancy. However, it is not clearly understood how this protein modulates the host immune response. In the present study, we have demonstrated that Rv0569 has a high antigenic index and induces enhanced secretion of Th1 cytokines IL-12p40 and TNF-α as compared to Th2 cytokine IL-10 in macrophages. Mechanistically, Rv0569 induced the transcription of these pro-inflammatory signatures through the activation of NF-κB pathway. Further, immunization of mice with DosR protein Rv0569 switched the immune response towards Th1-biased cytokine pattern, characterized by the enhanced production of IFN-γ, IL-12p40, and TNF-α. Rv0569 augmented the expansion of antigen-specific IFN-γ and IL-2 producing effector CD4+and CD8+ T-cells which are hallmarks of Th1 biased protective immunity. Additionally, IgG2a/IgG1 and IgG2b/IgG1 ratio in the serum of immunized mice further confirmed the ability of Rv0569 to skew Th1 biased immune response. In conclusion, we emphasize that Rv0569 has the ability to generate signals to switch on Th1-dominated responses and further suggest that it could be a potential vaccine candidate against latent M.tb infection.

Allium cepa exerts neuroprotective effect on retinal ganglion cells of pterygopalatine artery (PPA) ligated mice.

BACKGROUND: Repeated failure to rescue the damaged retinal ganglion cells (RGCs) by various drugs has warranted the need to screen common herbal compounds available in the form of various eye formulations for their efficacy. OBJECTIVE: We aimed to investigate the neuroprotective effect of pretreatment with aqueous extract of A. cepa in Ischemia/Reperfusion (I/R) induced retinal injury. METHODS: Ischemia was induced for 2 h by pterygopalatine artery (PPA) ligation in C57BL/6J mice, followed by reperfusion. The neuroprotective role of oral pretreatment with aqueous extract of A. cepa (300 mg/kg) was analyzed with respect to control and injury only group at 7, 14, and 28 day after the surgery for expression of different genes in the retina by Real-Time PCR. RESULTS: Molecular analysis at different time points showed increased expression of BCl-2, GDNF, GFAP, and Brn3b in the retina at 14 and 28 day after A. cepa treatment in comparison to the injury alone group. However, at shorter time point (7th day), the expression of these genes was pronounced in the injury only group in comparison to the injury and pretreated group. CONCLUSION: Pretreatment with aqueous extract of A. cepa may protect from the neuronal damage in I/R-induced retinal injury in mice by altering the expression of neurotrophic factor.

Amino acid starvation enhances vaccine efficacy by augmenting neutralizing antibody production.

Specific reduction in the intake of proteins or amino acids (AAs) offers enormous health benefits, including increased life span, protection against age-associated disorders, and improved metabolic fitness and immunity. Cells respond to conditions of AA starvation by activating the amino acid starvation response (AAR). Here, we showed that mimicking AAR with halofuginone (HF) enhanced the magnitude and affinity of neutralizing, antigen-specific antibody responses in mice immunized with dengue virus envelope domain III protein (DENVrEDIII), a potent vaccine candidate against DENV. HF enhanced the formation of germinal centers (GCs) and increased the production of the cytokine IL-10 in the secondary lymphoid organs of vaccinated mice. Furthermore, HF promoted the transcription of genes associated with memory B cell formation and maintenance and maturation of GCs in the draining lymph nodes of vaccinated mice. The increased abundance of IL-10 in HF-preconditioned mice correlated with enhanced GC responses and may promote the establishment of long-lived plasma cells that secrete antigen-specific, high-affinity antibodies. Thus, these data suggest that mimetics of AA starvation could provide an alternative strategy to augment the efficacy of vaccines against dengue and other infectious diseases.

The "nano to micro" transition of hydrophobic curcumin crystals leading to in situ adjuvant depots for Au-liposome nanoparticle mediated enhanced photothermal therapy.

Photothermal therapy (PTT) is emerging as a promising treatment for skin cancer. Plasmon-resonant gold-coated liposome nanoparticles (Au Lipos NPs) specifically absorb Near Infra-Red (NIR) light resulting in localized hyperthermia (PTT). In the current study, curcumin (a hydrophobic anticancer agent) was entrapped in Au Lipos NPs as nanocrystals to act as an adjuvant for the PTT of melanoma. NIR light irradiation on Au Lipos Cur NPs triggered the release of curcumin nanocrystals which coalesce to form curcumin microcrystals (CMCs). An in situ"nano to micro" transition in the crystal state of curcumin was observed. This in situ transition leads to the formation of CMCs. These CMCs exhibited sustained release of curcumin for a prolonged duration (>10 days). The localized availability of curcumin aids in enhancing PTT by inhibiting the growth and mobility of cancer cells that escape PTT. In the in vitro modified scratch assay, the Au Lipos Cur NP + Laser group showed >1.5 fold enhanced therapeutic coverage when compared with the Au Lipos NP + Laser group. In vivo PTT studies performed in a B16 tumor model using Au Lipos Cur NPs showed a significant reduction of the tumor volume along with the localized release of curcumin in the tumor environment. It was observed that the localized release of curcumin enables an immediate adjuvant effect resulting in the enhancement of PTT.

Creating a role model for "Academicians" Social Responsibility (ASR) synergizing with Swachh Bharat Abhiyaan: A campus hygiene initiative by PGIMER, Chandigarh.

BACKGROUND: The state of disarray from unhygienic conditions and excessive litter throughout urban highways, alleyways, and byways across rural and urban localities of India is abysmal. Such unsanitary conditions impinge upon the future health and welfare of its citizens, tourists and economic development. PURPOSE: The NRL volunteered PGIMER's campus hygiene initiative" is a pioneering effort spearheaded in compliance with Indian Prime Minister's call that citizens of India work together to establish a cleaner and healthier environment. METHODS: A group of 15 highly motivated students in the Neuroscience Division of the PGIMER, worked together vigorously 2 hours a week to affect a cleaner urban environment in the city. RESULT: The results were national Kayakalp and Skoch award to PGIMER as the cleanest hospital in the country, the vendors or patients no longer litter around the campus, the pot holes have been converted into greener patches, signs board adorn the campus. CONCLUSION: To inspire citizens through faculty- student led sanitation programs.

Chlorophyll rich biomolecular fraction of A. cadamba loaded into polymeric nanosystem coupled with Photothermal Therapy: A synergistic approach for cancer theranostics.

Development of multifunctional biodegradable nanomaterials to encapsulate hydrophobic drugs and their triggered release in cancer theranostics is a challenge. In the current study, we report the encapsulation of potent anticancer - chlorophyll rich biomolecular fraction from the plant Anthocephalus cadamba into a polymeric nanosystem. The biomolecular fraction was combined with an NIR dye IR-780 to make it photo-thermally active. It was evaluated for its combinatorial (biomolecular extract and photothermal mediated) synergistic cytotoxicity in skin cancer cells. The inherent fluorescence of chlorophyll in the fraction was deployed to understand the cellular uptake and drug release. Cellular uptake of hydrophobic CFAc was enhanced with the aid of nanoformulation. It was observed that photo stability of IR-780 improved when incorporated with CFAc in polymeric nanosystem, which resulted in enhanced photothermal transduction efficiency. The combinational approach exhibited synergistic cytotoxicity which can be applied for skin cancer theranostics.

Role of Ionizing Radiation in Neurodegenerative Diseases.

Ionizing radiation (IR) from terrestrial sources is continually an unprotected peril to human beings. However, the medical radiation and global radiation background are main contributors to human exposure and causes of radiation sickness. At high-dose exposures acute radiation sickness occurs, whereas chronic effects may persist for a number of years. Radiation can increase many circulatory, age related and neurodegenerative diseases. Neurodegenerative diseases occur a long time after exposure to radiation, as demonstrated in atomic bomb survivors, and are still controversial. This review discuss the role of IR in neurodegenerative diseases and proposes an association between neurodegenerative diseases and exposure to IR.

Amino Acid Sensing via General Control Nonderepressible-2 Kinase and Immunological Programming.

Metabolic adaptation to the changing nutrient levels in the cellular microenvironment plays a decisive role in the maintenance of homeostasis. Eukaryotic cells are equipped with nutrient sensors, which sense the fluctuating nutrients levels and accordingly program the cellular machinery to mount an appropriate response. Nutrients including amino acids play a vital role in maintaining cellular homeostasis. Therefore, over the evolution, different species have developed diverse mechanisms to detect amino acids abundance or scarcity. Immune responses have been known to be closely associated with the cellular metabolism especially amino acid sensing pathway, which influences innate as well as adaptive immune-effector functions. Thus, exploring the cross-talk between amino acid sensing mechanisms and immune responses in disease as well as in normal physiological conditions might open up avenues to explore how this association can be exploited to tailor immunological functions toward the design of better therapeutics for controlling metabolic diseases. In this review, we discuss the advances in the knowledge of various amino acid sensing pathways including general control nonderepressible-2 kinase in the control of inflammation and metabolic diseases.

Hypoxia in CNS Pathologies: Emerging Role of miRNA-Based Neurotherapeutics and Yoga Based Alternative Therapies.

Cellular respiration is a vital process for the existence of life. Any condition that results in deprivation of oxygen (also termed as hypoxia) may eventually lead to deleterious effects on the functioning of tissues. Brain being the highest consumer of oxygen is prone to increased risk of hypoxia-induced neurological insults. This in turn has been associated with many diseases of central nervous system (CNS) such as stroke, Alzheimer's, encephalopathy etc. Although several studies have investigated the pathophysiological mechanisms underlying ischemic/hypoxic CNS diseases, the knowledge about protective therapeutic strategies to ameliorate the affected neuronal cells is meager. This has augmented the need to improve our understanding of the hypoxic and ischemic events occurring in the brain and identify novel and alternate treatment modalities for such insults. MicroRNA (miRNAs), small non-coding RNA molecules, have recently emerged as potential neuroprotective agents as well as targets, under hypoxic conditions. These 18-22 nucleotide long RNA molecules are profusely present in brain and other organs and function as gene regulators by cleaving and silencing the gene expression. In brain, these are known to be involved in neuronal differentiation and plasticity. Therefore, targeting miRNA expression represents a novel therapeutic approach to intercede against hypoxic and ischemic brain injury. In the first part of this review, we will discuss the neurophysiological changes caused as a result of hypoxia, followed by the contribution of hypoxia in the neurodegenerative diseases. Secondly, we will provide recent updates and insights into the roles of miRNA in the regulation of genes in oxygen and glucose deprived brain in association with circadian rhythms and how these can be targeted as neuroprotective agents for CNS injuries. Finally, we will emphasize on alternate breathing or yogic interventions to overcome the hypoxia associated anomalies that could ultimately lead to improvement in cerebral perfusion.

Mesoporous ZnO nanocapsules for the induction of enhanced antigen-specific immunological responses.

The application of nanotechnology in vaccinology has fuelled rapid advancement towards the design and development of nanovaccines. Nanoparticles have been found to enhance vaccine efficacy through the spatiotemporal orchestration of antigen delivery to secondary lymphoid organs and antigen-presentation by Antigen Presenting Cells (APCs) synchronized with stimulation of innate and adaptive immune responses. Metal based nanoparticles (MNPs) have been extensively engineered for the generation of nanovaccines owing to their intrinsic adjuvant-like properties and immunomodulatory functions. Furthermore, mesoporous nanocapsules of late have attracted researchers due to their precise size and exclusive capacity to encapsulate a wide range of biomolecules and their sustained release at the targeted sites. Herein, we have designed a novel mesoporous ZnO nanocapsule (mZnO) having a size of ∼12 nm with an average pore diameter of 2.5 nm, using a surfactant-free sonochemical method and investigated its immunomodulatory properties by using Ova loaded mZnO nanocapsules [mZnO(Ova)] in a mice model. Our findings show that mZnO(Ova) administration steered the enhanced expansion of antigen-specific T-cells and induction of IFN-γ producing effector CD4+ and CD8+ T-cells. Also, antigen-specific IgG levels were enriched in both the serum and lymph nodes of mZnO(Ova) immunized mice. Further, we noticed a substantial increase in serum IgG2a or IgG2b levels and IFN-γ secretion in Ova restimulated splenocytes from mZnO(Ova) immunized mice, indicating that mZnO(Ova) skew Th1 type immune response. Overall, the uniqueness of mZnO nanocapsules in terms of the defined particle to pore numbers ratio (maximum of three cavities per particle) allows loading antigens efficiently. Given these features in combination with its immunomodulatory characteristics reinforces the idea that mZnO could be used as an effective antigen-adjuvant platform for the development of novel nano-based vaccines against multiple diseases.

Cellular Stress Response and Immune Signaling in Retinal Ischemia-Reperfusion Injury.

Ischemia-reperfusion injury is a well-known pathological hallmark associated with diabetic retinopathy, glaucoma, and other related retinopathies that ultimately can lead to visual impairment and vision loss. Retinal ischemia pathogenesis involves a cascade of detrimental events that include energy failure, excitotoxic damage, calcium imbalance, oxidative stress, and eventually cell death. Retina for a long time has been known to be an immune privileged site; however, recent investigations reveal that retina, as well as the central nervous system, elicits immunological responses during various stress cues. Stress condition, such as reperfusion of blood supply post-ischemia results in the sequestration of different immune cells, inflammatory mediators including cytokines, chemokines, etc., to the ischemic region, which in turn facilitates induction of inflammatory conditions in these tissues. The immunological activation during injury or stress per se is beneficial for repair and maintenance of cellular homeostasis, but whether the associated inflammation is good or bad, during ischemia-reperfusion injury, hitherto remains to be explored. Keeping all these notions in mind, the current review tries to address the immune response and host stress response mechanisms involved in ischemia-reperfusion injury with the focus on the retina.

Association of ACL tears and single nucleotide polymorphisms in the collagen 12 A1 gene in the Indian population - a preliminary case-control study.

BACKGROUND: Genetic predisposition to ACL tears has received tremendous interest in the past few years with many SNPs of different genes being linked to ACL tear. STUDY OBJECTIVES: To examine if specific sequence variants in COL12A1 gene are associated with ACL tears in Indian population. STUDY DESIGN: Case-control study. MATERIALS AND METHODS: 50 patients with surgically diagnosed ACL tear and 52 healthy, age-matched controls without any ligament/tendon injuries were genotyped for rs970547 and rs240736 SNPs using real time PCR method. RESULTS: The AG and GG genotypes were significantly under-represented in study group patients in rs970547 region (p=0.0361). However, there was no significant difference in genotype/allele frequencies in the rs240736 region. CONCLUSIONS: The COL12A1 rs970547 SNP is associated with ACL tears in the Indian population. However, these results need to be validated further so that predisposed individuals can be screened in the future for counselling and intervention. LEVEL OF EVIDENCE: III.

Modeling transient retinal ischemia in mouse by ligation of pterygopalatine artery.

BACKGROUND: Retinal ischemia is a major cause of visual impairment and blindness worldwide. The available therapeutic strategies have limited potential. PURPOSE: In order to understand the pathophysiology and validating therapies for retinal ischemia, establishment of reproducible animal models is necessary. METHODS: In the model discussed in this article, the pterygopalatine artery (PPA) is ligated along with the external carotid artery for 3.5 hours and thereafter allowed to reperfuse. Because PPA supplies the blood to the ophthalmic artery, the ligation of this artery causes retinal ischemia. RESULTS: This article describes the validation of retinal ischemia-reperfusion model in mouse through PPA ligation and its validation through fluorescein fundus angiography (FFA) and immunofluorescence staining for glial fibrillary acidic protein (GFAP), a glial injury marker. CONCLUSIONS: In conclusion this article describes the creation of mouse model of retinal ischemia-reperfusion injury which can be reproduced in a shorter time duration resulting in reduced mortality.

Characterization of Lin-ve CD34 and CD117 cell population reveals an increased expression in bone marrow derived stem cells.

The purpose of the study was to evaluate the expression of CD45, CD34, Sca-1 and CD117 in mouse bone marrow, Lin-ve and Lin+ve population. Bone marrow cells were isolated from C57/BL6J mouse and mononuclear population was separated from rest of the cell population. With the help of Magnetic associated cell sorter (MACS), Linve and Lin+ve cells were separated from the bone marrow. The expression of CD45, CD34, Sca1 and CD117 was evaluated in bone marrow, Lin-ve and Lin+ve population by flow cytometry. We found a significant increase in the expression of CD34 and CD117 in Lin-ve as compared to the bone marrow and Lin+ve population. These findings suggest that Lin-ve population has higher expression of stem cell progenitor markers and could be useful for tissue repair and regeneration.

Preclinical models to investigate retinal ischemia: advances and drawbacks.

Retinal ischemia is a major cause of blindness worldwide. It is associated with various disorders such as diabetic retinopathy, glaucoma, optic neuropathies, stroke, and other retinopathies. Retinal ischemia is a clinical condition that occurs due to lack of appropriate supply of blood to the retina. As the retina has a higher metabolic demand, any hindrance in the blood supply to it can lead to decreased supply of oxygen, thus causing retinal ischemia. The pathology of retinal ischemia is still not clearly known. To get a better insight into the pathophysiology of retinal ischemia, the role of animal models is indispensable. The standard treatment care for retinal ischemia has limited potential. Transplantation of stem cells provide neuroprotection and to replenish damaged cells is an emerging therapeutic approach to treat retinal ischemia. In this review we provide an overview of major animal models of retinal ischemia along with the current and preclinical treatments in use.