Alba6 exhibits DNase activity and participates in stress response.

Alba domain proteins, owing to their functional plasticity, play a significant role in organisms. Here, we report an intrinsic DNase activity of PfAlba6 from , an etiological agent responsible for human malignant malaria. We identified that tyrosine28 plays a critical role in the Mg driven 5'-3' DNase activity of PfAlba6.

Expanding the DNA editing toolbox: Novel lambda integrase variants targeting microalgal and human genome sequences.

Recombinase enzymes are extremely efficient at integrating very large DNA fragments into target genomes. However, intrinsic sequence specificities curtail their use to DNA sequences with sufficient homology to endogenous target motifs. Extensive engineering is therefore required to broaden applicability and robustness.

A versatile genomic transgenesis platform with enhanced integrase for human Expi293F cells.

Reliable cell-based platforms to test and/or produce biologics in a sustainable manner are important for the biotech industry. Utilizing enhanced λ integrase, a sequence-specific DNA recombinase, we developed a novel transgenesis platform involving a fully characterized single genomic locus as an artificial landing pad for transgene insertion in human Expi293F cells. Importantly, transgene instability and variation in expression were not observed in the absence of selection pressure, thus enabling reliable long-term biotherapeutics testing or production.

Nuclease activity of Plasmodium falciparum Alba family protein PfAlba3.

Plasmodium falciparum Alba domain-containing protein Alba3 (PfAlba3) is ubiquitously expressed in intra-erythrocytic stages of Plasmodium falciparum, but the function of this protein is not yet established. Here, we report an apurinic/apyrimidinic site-driven intrinsic nuclease activity of PfAlba3 assisted by divalent metal ions. Surface plasmon resonance and atomic force microscopy confirm sequence non-specific DNA binding by PfAlba3.

Honokiol, an inducer of sirtuin-3, protects against non-steroidal anti-inflammatory drug-induced gastric mucosal mitochondrial pathology, apoptosis and inflammatory tissue injury.

Background And Purpose: Mitochondrial oxidative stress, inflammation and apoptosis primarily underlie gastric mucosal injury caused by the widely used non-steroidal anti-inflammatory drugs (NSAIDs). Alternative gastroprotective strategies are therefore needed. Sirtuin-3 pivotally maintains mitochondrial structural integrity and metabolism while preventing oxidative stress; however, its relevance to gastric injury was never explored.

Rab7 of Plasmodium falciparum is involved in its retromer complex assembly near the digestive vacuole.

Background: Intracellular protein trafficking is crucial for survival of cell and proper functioning of the organelles; however, these pathways are not well studied in the malaria parasite. Its unique cellular architecture and organellar composition raise an interesting question to investigate.

Methods: The interaction of Plasmodium falciparum Rab7 (PfRab7) with vacuolar protein sorting-associated protein 26 (PfVPS26) of retromer complex was shown by coimmunoprecipitation (co-IP).

Indomethacin impairs mitochondrial dynamics by activating the PKCζ-p38-DRP1 pathway and inducing apoptosis in gastric cancer and normal mucosal cells.

The subcellular mechanism by which nonsteroidal anti-inflammatory drugs (NSAIDs) induce apoptosis in gastric cancer and normal mucosal cells is elusive because of the diverse cyclooxygenase-independent effects of these drugs. Using human gastric carcinoma cells (AGSs) and a rat gastric injury model, here we report that the NSAID indomethacin activates the protein kinase Cζ (PKCζ)-p38 MAPK (p38)-dynamin-related protein 1 (DRP1) pathway and thereby disrupts the physiological balance of mitochondrial dynamics by promoting mitochondrial hyper-fission and dysfunction leading to apoptosis. Notably, DRP1 knockdown or SB203580-induced p38 inhibition reduced indomethacin-induced damage to AGSs.

Hydrazonophenol, a Food Vacuole-Targeted and Ferriprotoporphyrin IX-Interacting Chemotype Prevents Drug-Resistant Malaria.

The rapid emergence of resistance against frontline antimalarial drugs essentially warrants the identification of new-generation antimalarials. Here, we describe the synthesis of ( E)-2-isopropyl-5-methyl-4-((2-(pyridin-4-yl)hydrazono)methyl)phenol (18), which binds ferriprotoporphyrin-IX (Fe-PPIX) ( K = 33 nM) and offers antimalarial activity against chloroquine-resistant and sensitive strains of Plasmodium falciparum in vitro. Structure-function analysis reveals that compound 18 binds Fe-PPIX through the -C═N-NH- moiety and 2-pyridyl substitution at the hydrazine counterpart plays a critical role in antimalarial efficacy.

Macrophage migration inhibitory factor regulates mitochondrial dynamics and cell growth of human cancer cell lines through CD74-NF-κB signaling.

The indispensable role of macrophage migration inhibitory factor (MIF) in cancer cell proliferation is unambiguous, although which specific roles the cytokine plays to block apoptosis by preserving cell growth is still obscure. Using different cancer cell lines (AGS, HepG2, HCT116, and HeLa), here we report that the silencing of MIF severely deregulated mitochondrial structural dynamics by shifting the balance toward excess fission, besides inducing apoptosis with increasing sub-G cells. Furthermore, enhanced mitochondrial Bax translocation along with cytochrome release, down-regulation of Bcl-xL, and Bcl-2 as well as up-regulation of Bad, Bax, and p53 indicated the activation of a mitochondrial pathway of apoptosis upon MIF silencing.

Detection of retromer assembly in Plasmodium falciparum by immunosensing coupled to Surface Plasmon Resonance.

Retromer complex plays a crucial role in intracellular protein trafficking and is conserved throughout the eukaryotes including malaria parasite, Plasmodium falciparum, where it is partially conserved. The assembly of retromer complex in RBC stages of malarial parasite is extremely difficult to explore because of its complicated physiology, small size, and intra-erythrocytic location. Nonetheless, understanding of retromer assembly may pave new ways for the development of novel antimalarials targeting parasite-specific protein trafficking pathways.

Acute mental stress induces mitochondrial bioenergetic crisis and hyper-fission along with aberrant mitophagy in the gut mucosa in rodent model of stress-related mucosal disease.

Psychological stress, depression and anxiety lead to multiple organ dysfunctions wherein stress-related mucosal disease (SRMD) is common to people experiencing stress and also occur as a side effect in patients admitted to intensive care units; however the underlying molecular aetiology is still obscure. We report that in rat-SRMD model, cold restraint-stress severely damaged gut mitochondrial functions to generate superoxide anion (O), depleted ATP and shifted mitochondrial fission-fusion dynamics towards enhanced fission to induce mucosal injury. Activation of mitophagy to clear damaged and fragmented mitochondria was evident from mitochondrial translocation of Parkin and PINK1 along with enhanced mitochondrial proteome ubiquitination, depletion of mitochondrial DNA copy number and TOM 20.

Selective scavenging of intra-mitochondrial superoxide corrects diclofenac-induced mitochondrial dysfunction and gastric injury: A novel gastroprotective mechanism independent of gastric acid suppression.

Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used to treat multiple inflammatory diseases and pain but severe gastric mucosal damage is the worst outcome of NSAID-therapy. Here we report that mitoTEMPO, a mitochondrially targeted superoxide (O) scavenger protected as well as healed gastric injury induced by diclofenac (DCF), the most commonly used NSAID. Common existing therapy against gastric injury involves suppression of gastric acid secretion by proton pump inhibitors and histamine H receptor antagonists; however, dyspepsia, vitamin B12 deficiency and gastric microfloral dysbalance are the major drawbacks of acid suppression.

Antimalarial Activity of Small-Molecule Benzothiazole Hydrazones.

We synthesized a new series of conjugated hydrazones that were found to be active against malaria parasite in vitro, as well as in vivo in a murine model. These hydrazones concentration-dependently chelated free iron and offered antimalarial activity. Upon screening of the synthesized hydrazones, compound 5f was found to be the most active iron chelator, as well as antiplasmodial.

Expression, purification and characterization of Plasmodium falciparum vacuolar protein sorting 29.

Translocation of various proteins to the subcellular organelles is an essential mechanism to regulate the metabolic pathways and often vacuolar protein sorting (VPS) proteins are involved in this transportation. Plasmodium falciparum VPS29 (PfVPS29) is predicted to be a functional component in the assembly of the retromer complex; however, so far detailed characterization of PfVPS29 in its native form is not yet done. We report the successful expression and purification of tag-free recombinant PfVPS29 with a yield of 5.

Ellagic Acid, a Dietary Polyphenol, Inhibits Tautomerase Activity of Human Macrophage Migration Inhibitory Factor and Its Pro-inflammatory Responses in Human Peripheral Blood Mononuclear Cells.

Ellagic acid (EA), a phenolic lactone, inhibited tautomerase activity of human macrophage migration inhibitory factor (MIF) noncompetitively (Ki = 1.97 ± 0.7 μM).

Humoral immune responses to a recombinant Plasmodium vivax tryptophan-rich antigen among Plasmodium vivax-infected patients and its localization in the parasite.

Our recent studies have focused on the identification and characterization of the tryptophan-rich proteins of the Plasmodium vivax parasite where their role in the elicitation of humoral and cellular responses and erythrocyte-binding activity was investigated. Here, we report the humoral responses of a 32.4-kDa P.

Association of heme oxygenase 1 with the restoration of liver function after damage in murine malaria by Plasmodium yoelii.

The liver efficiently restores function after damage induced during malarial infection once the parasites are cleared from the blood. However, the molecular events leading to the restoration of liver function after malaria are still obscure. To study this, we developed a suitable model wherein mice infected with Plasmodium yoelii (45% parasitemia) were treated with the antimalarial α/β-arteether to clear parasites from the blood and, subsequently, restoration of liver function was monitored.

Fine specificity of Plasmodium vivax Duffy binding protein binding engagement of the Duffy antigen on human erythrocytes.

Plasmodium vivax invasion of human erythrocytes requires interaction of the P. vivax Duffy binding protein (PvDBP) with its host receptor, the Duffy antigen (Fy) on the erythrocyte surface. Consequently, PvDBP is a leading vaccine candidate.

Expression, purification, and characterization of the immunological response to a 40-kilodalton Plasmodium vivax tryptophan-rich antigen.

We describe here an approximately 40-kDa Plasmodium vivax tryptophan-rich antigen (PvTRAg40) which contains 321 amino acids and 11.4% tryptophan residues. This protein shows 65% homology (35% identity) with the previously described PvTRAg, besides sharing 23 of 27 positionally conserved tryptophan residues and similar genomic organization.

Expression and purification of a Plasmodium vivax antigen - PvTARAg55 tryptophan- and alanine-rich antigen and its immunological responses in human subjects.

Despite the immense global efforts, the malaria vaccine is not yet available and requires the identification of newer target molecules. Since tryptophan-rich proteins of P. yoelii have been proposed as vaccine candidates, we describe here the expression, purification and immunological characterization of a 55kDa Plasmodium vivax tryptophan- and alanine-rich antigen (PvTARAg55).

Expression and purification of HtpX-like small heat shock integral membrane protease of an unknown organism related to Methylobacillus flagellatus.

The M48 conserved family of peptidases contains a single catalytic zinc ion tetrahedrally co-ordinated by two histidines within an HEXXH motif. The proteases of this class are generally toxic to the cell and thus difficult to express and purify. Here, we report the expression and purification of the small HtpX-like heat shock metalloprotease from an unknown organism related to the obligate methylotrophic anaerobic bacterium, Methylobacillus flagellatus.

Plasmid DNA acquires immunogenicity on exposure to singlet oxygen.

In the present study, the effect of singlet oxygen (1O2) (generated by ultraviolet (UV) irradiation of methylene blue) on plasmid DNA has been analyzed by UV spectroscopy, fluorescence spectroscopy, and S1 nuclease digestibility. Both native and 1O2-modified plasmid DNA were treated with a number of restriction enzymes to map out the sites damaged by 1O2. It was also observed that, on exposure to 1O2, native plasmid DNA that is non-immunogenic acquired the ability to elicit an immune response in experimental animals.

Prevalence of anti-3-nitrotyrosine antibodies in the joint synovial fluid of patients with rheumatoid arthritis, osteoarthritis and systemic lupus erythematosus.

Background: Increased reactive nitrogen species (RNS) production has been suggested in the pathogenesis of rheumatoid arthritis (RA), osteoarthritis (OA) as well as in systemic lupus erythematosus (SLE). They are known to have direct toxicity to cells. High concentrations of serum nitrite/nitrate and elevated urinary nitrate:creatine ratio has been found in patients with RA, OA and SLE.