STK35L1 regulates host cell cycle-related genes and is essential for Plasmodium infection during the liver stage of malaria

Protein kinases of both the parasite and the host are crucial in parasite invasion and survival and might act as drug targets against drug-resistant malaria. STK35L1 was among the top five hits in kinome-wide screening, suggesting its role in malaria's liver stage. However, the role of host STK35L1 in malaria remains elusive. In this study, we found that STK35L1 was highly upregulated during the infection of Plasmodium berghei (P. berghei) in HepG2 cells and mice liver, and knockdown of STK35L1 remarkably suppressed the sporozoites' infection in HepG2 cells. We showed that STAT3 is upregulated and phosphorylated during P. berghei sporozoites' infection, and STAT3 activation is required for both the upregulation of STK35L1 and STAT3. Furthermore, we found that ten cell cycle genes were upregulated in the sporozoite-infected hepatocytes. Knockdown of STK35L1 inhibited the basal expression of these genes except CDKN3 and GTSE1 in HepG2 cells. Thus, we identified STK35L1 as a host kinase that plays an obligatory role in malaria's liver stage and propose that it may serve as a potential drug target against drug-resistant malaria.

Novel Antiplasmodial Compounds Leveraged with Multistage Potency against the Parasite Plasmodium falciparum: In Vitro and In Vivo Evaluations and Pharmacokinetic Studies

Hydroxyethylamine (HEA)-based novel compounds were synthesized and their activity against Plasmodium falciparum 3D7 was assessed, identifying a few hits without any apparent toxicity. Hits 5c and 5d also exhibited activity against resistant field strains, PfRKL-9 and PfC580Y. A single dose, 50 mg/Kg, of hits administered to the rodent parasite Plasmodium berghei ANKA exhibited up to 70% reduction in the parasite load. Compound 5d tested in combination with artesunate produced an additional antiparasitic effect with a prolonged survival period. Additionally, compound 5d showed 50% inhibition against hepatic P. berghei infection at 1.56 ± 0.56 μM concentration. This compound also considerably delayed the progression of transmission stages, ookinete and oocyst. Furthermore, the toxicity of 5d assessed in mice supported the normal liver and kidney functions. Altogether, HEA analogues (5a-m), particularly 5d, are nontoxic multistage antiplasmodial agents with therapeutic and transmission-blocking efficacy, along with favorable preliminary pharmacokinetic properties.

Decreased classical monocytes and CD163 expression in TB patients: an indicator of drug resistance

Tuberculosis (TB) is a disease instigated by Mycobacterium tuberculosis. Peripheral blood monocytes represent highly efficient effector cells of innate immunity against TB. Little is known about monocyte subsets and their potential involvement in the development of M. tuberculosis drug resistance in patients with TB. This study was conducted to investigate alterations in monocyte subsets, CD163 expression on monocytes, and its serum level in patients without and with rifampicin resistance TB (RR-TB) and healthy controls. A total of 164 patients with TB (84 without RR-TB and 80 patients with RR-TB) and 85 healthy controls were enrolled in this study. The percentages of various monocyte subsets and surface expression of CD163 on monocytes were quantitatively determined using flow cytometry. The serum level of CD163 was determined by commercially available ELISA kits. Decreased frequency of classical monocytes was detected in patients with RR-TB. Non-classical monocytes were decreased in patients without RR-TB; however, intermediate monocytes were raised in patients with RR-TB. The serum level of CD163 was decreased in patients of RR-TB that showsed a positive correlation with the frequency of CD14++CD16-CD163+ and CD14++CD16+CD163+ monocytes. It is concluded that decreased classical monocytes and sCD163 in patients with RR-TB could be an indicator of drug resistance.

Elevated expression of RUNX3 co-expressing with EZH2 in esophageal cancer patients from India

Background

Runt related transcription factor3 (RUNX3) is considered as a tumor suppressor gene (TSG) that functions through the TGF-β dependent apoptosis. Promoter methylation of the CpG islands of RUNX3 and overexpression of enhancer of zeste homolog 2 (EZH2) has been suggested to downregulate RUNX3 in cancer.

Methods

Here, we studied the expression of RUNX3 and EZH2 in 58 esophageal tumors along with paired adjacent normal tissue. mRNA levels, protein expressions and cellular localizations of EZH2 and RUNX3 were analyzed using real-time PCR and immunohistochemistry, respectively. DNA methylation was further assessed by the methylation specific-PCR.

Results

Compared to normal tissue, a significant increase in expression of RUNX3 mRNA in 31/57 patient’s tumor tissue (p < 0.04) was observed. The expression of EZH2 was found to be upregulated compared to normal, and a significant positive correlation between EZH2 and RUNX3 expression was observed (p = 0.002). 22 of the 27 unmethylated cases at the promoter region of the RUNX3 had elevated RUNX3 protein expression (p < 0.001).

Conclusion

The data presented in this study provide new insights into the biology of RUNX3 and highlights the need to revisit our current understanding of the role of RUNX3 in cancer.

Valve-in-Valve for Degenerated Transcatheter Aortic Valve Replacement Versus Valve-in-Valve for Degenerated Surgical Aortic Bioprostheses: A 3-Center Comparison of Hemodynamic and 1-Year Outcome

Background

As transcatheter aortic valve replacement (TAVR) is expected to progress into younger patient populations, valve‐in‐TAVR (ViTAVR) may become a frequent consideration. Data on ViTAVR, however, are limited. This study investigated the outcome of ViTAVR in comparison to valve in surgical aortic valve replacement (ViSAVR), because ViSAVR is an established procedure for higher‐risk patients requiring repeated aortic valve intervention.

Methods and Results

Clinical and procedural data of patients who underwent ViTAVR at 3 sites in the United States and Germany were retrospectively compared with data of patients who underwent ViSAVR at Cedars‐Sinai Medical Center, according to Valve Academic Research Consortium‐2 criteria. A total of 99 consecutive patients, 52.5% women, with a median Society of Thoracic Surgeons score of 7.2 were identified. Seventy‐four patients (74.7%) underwent ViSAVR, and 25 patients (25.3%) underwent ViTAVR. Balloon‐expandable devices were used in 72.7%. ViSAVR patients presented with smaller index devices (21.0 versus 26.0 mm median true internal diameter; P<0.001). Significantly better postprocedural hemodynamics (median prosthesis mean gradient, 12.5 [interquartile range, 8.8–16.2] versus 16.0 [interquartile range, 13.0–20.5] mm Hg; P=0.045) were observed for ViTAVR compared with the ViSAVR. Device success, however, was not different (79.2% and 66.2% for ViTAVR and ViSAVR, respectively; P=0.35), as were rates of permanent pacemaker implantation (16.7% versus 5.4%; P=0.1). One‐year‐mortality was 9.4% and 13.4% for ViTAVR and ViSAVR, respectively (log‐rank P=0.38).

Conclusions

Compared with ViSAVR, ViTAVR provides acceptable outcomes, with slightly better hemodynamics, similar device success rates, and similar 1‐year mortality.

Olax scandens Mediated Biogenic Synthesis of Ag-Cu Nanocomposites: Potential Against Inhibition of Drug-Resistant Microbes

In the present study, we have synthesized silver-copper nanocomposites (Ag-Cu NCs) using an Olax scandens leaf extract (green synthesis method) and evaluated their antimicrobial potential against less susceptible pathogens. The kinetics of Ag-Cu NCs synthesis was followed by UV-VIS and fluorescence spectroscopy. The physicochemical characterization of as-synthesized Ag-Cu NCs was executed using electron microscopy, Energy Dispersive X-Ray, Fourier Transform Infrared Spectroscopy, and a Differential Light Scattering method. As-synthesized Ag-Cu NCs induced the formation of Reactive Oxygen Species (ROS), thereby causing alteration and decrementation of cellular proteins, DNA, lipids, etc., and eventually leading to cell death, as determined by a Live/Dead assay. Next, we assessed the anti-biofilm potential of as-synthesized Ag-Cu NCs against biofilm forming bacteria. The as-synthesized Ag-Cu NCs, when compared to monometallic silver nanoparticles, exhibited significantly higher anti-microbial activity against both sensitive as well as drug resistant microbial isolates.

Untapped renewable energy potential of crop residues in Pakistan: Challenges and future directions

Sustainability in power generation mainly depends on the transition from fossils to sustainable energy resources. Biomass from the crop residue has huge potential for renewable power generation, but it is still not utilized to its full potential. This study presents a comprehensive methodology to evaluate and forecast the current and future availability of selective crop residue to generate renewable energy. A forecast model incorporating historical trends in the crop yield has been developed in MATLAB and implemented for crop residue based biomass resource assessment of five primary crops (wheat straw, rice husk, rice straw, cotton straw, corn stover, and bagasse) in order to estimate the energy generation potential for Pakistan from 2018 till 2035. It was found that about 40 million tonnes of crop residue was available in Pakistan for power generation in the year 2018 considering a residue removal (availability) factor of 50%. This translates to an estimated potential of about 11,000 MW of electricity generation capacity using crop residue derived biomass for 2018. This capacity is predicted to gradually increase up to 16,000 MW by the year 2035 based on the trends in the growth of crop production since 2001. The suitability of a potential region for the installation of 100 MW biomass-fired power plants was also assessed by calculating crop residue density and an equivalent collection radius (R_e) of 50 km (km). Punjab province of Pakistan, being an agricultural province, with relatively better road infrastructure can sustain crop residue based power plants of up to 7000 MW cumulative capacity at various locations. The challenges, such as economic, logistics, regulatory and political barriers, in generating renewable energy from biomass along with their potential solutions were also discussed. The study also provides a baseline for future research to evaluate and forecast the growth in bio-power generation potential of any biomass resource in a region based on crop yield and area of the region.

Identification and characterization of protective CD8+ T-epitopes in a malaria vaccine candidate SLTRiP

INTRODUCTION

Efforts are required at developing an effective vaccine that can inhibit malaria prevalence and transmission. Identifying the critical immunogenic antigens and understanding their interactions with host proteins forms a major focus of subunit vaccine development. Previously, our laboratory showed that SLTRiP conferred protection to the liver stage of Plasmodium growth in rodents. In the follow-up of earlier research, we demonstrate that SLTRiP-mediated protection is majorly concentrated in specific regions of protein.

METHOD

To identify particular protective regions of protein, we synthesized multiple nonoverlapping fragments from SLTRiP protein. From this, we designed a panel of 8-20mer synthetic peptides, which were predicted using T-epitope-based prediction algorithm. We utilized the IFN-γ enzyme-linked immunosorbent spot assay to identify immunodominant peptides. The latter were used to immunize mice, and these mice were challenged to assess protection.

RESULTS

The protective polypeptide fragment SLTRiP C3 and SLTRiP C4 were identified, by expressing and testing multiple fragments of PbSLTRiP protein. The immune responses generated by these fragments were compared to identify the immunodominant fragment. The T-epitopes were predicted from SLTRiP protein using computer-based algorithms. The in vitro immune responses generated by these peptides were compared with each other to identify the immunodominant T-epitope. Immunization using these peptides showed significant reduction in parasite numbers during liver stage.

CONCLUSION

Our findings show that the protective efficacy shown by SLTRiP is localized in particular protein fragments. The peptides designed from such regions showed protective efficacy equivalent to whole protein. The sequence conservation analysis with human Plasmodium species also showed that these peptides were conserved. In conclusion, these peptides or their equivalent from other Plasmodium species could impart protection against malaria in their respective hosts too. Our studies provide a basis for the inclusion of these peptides in clinical vaccine constructs against malaria.

Multistage antiplasmodial activity of hydroxyethylamine compounds, in vitro and in vivo evaluations

Malaria, a global threat to the human population, remains a challenge partly due to the fast-growing drug-resistant strains of Plasmodium species. New therapeutics acting against the pathogenic asexual and sexual stages, including liver-stage malarial infection, have now attained more attention in achieving malaria eradication efforts. In this paper, two previously identified potent antiplasmodial hydroxyethylamine (HEA) compounds were investigated for their activity against the malaria parasite's multiple life stages. The compounds exhibited notable activity against the artemisinin-resistant strain of P. falciparum blood-stage culture with 50% inhibitory concentrations (IC₅₀) in the low micromolar range. The compounds' cytotoxicity on HEK293, HepG2 and Huh-7 cells exhibited selective killing activity with IC₅₀ values > 170 μM. The in vivo efficacy was studied in mice infected with P. berghei NK65, which showed a significant reduction in the blood parasite load. Notably, the compounds were active against liver-stage infection, mainly compound 1 with an IC₅₀ value of 1.89 μM. Mice infected with P. berghei sporozoites treated with compound 1 at 50 mg kg⁻¹ dose had markedly reduced liver stage infection. Moreover, both compounds prevented ookinete maturation and affected the developmental progression of gametocytes. Further, systematic in silico studies suggested both the compounds have a high affinity towards plasmepsin II with favorable pharmacological properties. Overall, the findings demonstrated that HEA and piperidine possessing compounds have immense potential in treating malarial infection by acting as multistage inhibitors.

Malaria, a global threat to the human population, remains a challenge partly due to the fast-growing drug-resistant strains of Plasmodium species.

AgNPs from Nigella sativa Control Breast Cancer: An In Vitro Study

In our current study, we synthesized silver nanoparticles (AgNPs) from an aqueous seed extract of Nigella sativa. The seed extract contains phytochemical compounds including phenols, terpenoids, and flavonoids that may act as reducing agents and are able to convert metal ions to metal nanoparticles. The formation of synthesized AgNPs was characterized using UV-visible spectroscopy, Fourier transform infra-red spectroscopy (FT-IR), scanning electron microscopy (SEM) and energy dispersive analysis of X-rays (EDX). The efficacy of N-AgNPs against human breast cancer (MCF-7) cells was tested. The synthesized AgNPs displayed dose-dependent cytotoxicity (1-200 µg/mL) against MCF-7 cells. Morphological alterations of the cells also appeared as bright field images. Treatment of synthesized AgNPs altered the expression of Bax and Bcl-2 (apoptotic proteins) and COX-2 (inflammatory marker) in MCF-7 cells. To our knowledge, this is the first report demonstrating that N-AgNPs from Nigella sativa can induce apoptosis in MCF-7 cells.

Repurposing Glyburide as Antileishmanial Agent to Fight Against Leishmaniasis

BACKGROUND

Leishmaniasis is caused by a protozoan parasite, Leishmania. It is common in more than 98 countries throughout the world. Due to insufficient availability of antileishmanial chemotherapeutics, it is an urgent need to search for new molecules which have better efficacy, low toxicity and are available at low cost.

OBJECTIVES

There is a high rate of diabetic cases throughout the world that is why we planned to test the antileishmanial activity of glyburide, an effective sugar lowering drug used for the treatment of diabetes. In this study, glyburide showed a significant decrease in the parasite growth and survival in vitro in a dose-dependent manner.

METHODS

Anti-leishmanial activity of glyburide was checked by culturing Leishmania donovani promastigotes in the presence of glyburide in a dose and time dependent manner. Docking study against Leishmania donovani-Trypanothione synthetase (LdTrySyn) protein was performed using Autodock Vina tool.

RESULTS

Growth reversibility assay shows that growth of treated parasite was not reversed when transferred to fresh culture media after 7 days. Moreover, docking studies show efficient interactions of glyburide with key residues in the catalytic site of Leishmania donovani- Trypanothione synthetase (LdTrySyn), a very important leishmanial enzyme involved in parasite's survival by detoxification of Nitric Oxide (NO) species, generated by the mammalian host as a defense molecule. Thus this study proves that the drug-repurposing is a beneficial strategy for identification of new and potent antileishmanial molecules.

CONCLUSION

The results suggest that glyburide binds to LdTrySyn and inhibits its activity which further leads to the altered parasite morphology and inhibition of parasite growth. Glyburide may also be used in combination with other anti-leishmanial drugs to potentiate the response of the chemotherapy. Overall this study provides information about combination therapy as well as a single drug treatment for the infected patients suffering from diabetes. This study also provides raw information for further in vivo disease model studies to confirm the hypothesis.

Biogenic AgNPs synthesized via endophytic bacteria and its biological applications

In this present study, the endophytic bacteria were isolated from the drought-tolerant ornamental plant Pennisetum setaceum. The biomass of endophytic bacteria was utilized for the biogenic synthesis of silver nanoparticles (AgNPs). The synthesis of AgNPs was confirmed by UV-Visible and FTIR spectroscopy followed by SEM analysis. The antibacterial studies were performed through MIC, MBC, and biofilm assays. Efficacy of AgNPs against the human breast cancer (MCF-7) cells was also tested, and the IC₅₀ was determined by MTT assay. In our study, we have observed that the synthesized AgNPs exhibited a dose-dependent cytotoxicity (1-100 μg/mL) against MCF-7 cells and morphological alterations of the cells were also visualized and the IC₅₀ was observed at 50 μg/mL. The treatment of synthesized AgNPs altered the expression of apoptotic proteins including Bax, Bcl-2, and inflammatory marker COX-2 in MCF-7 cells. To the best of our knowledge, this is the first report that demonstrates the AgNPs from endophytic bacteria isolated from the plant Pennisetum setaceum can induce apoptosis in human breast cancer MCF-7 cells. Our results suggest that AgNPs used in this study can be utilized to control human pathogens and can also be utilized to induce apoptosis in breast cancer cells.

Metacaspase-3 of Plasmodium falciparum: An atypical trypsin-like serine protease

Metacaspases are clan CD cysteine peptidases found in plants, fungi and protozoa that possess a conserved Peptidase_C14 domain, homologous to the human caspases and a catalytic His/Cys dyad. Earlier reports have indicated the role of metacaspases in cell death; however, metacaspases of human malaria parasite remains poorly understood. In this study, we aimed to functionally characterize a novel malarial protease, P. falciparum metacaspase-3 (PfMCA3). Unlike other clan CD peptidases, PfMCA3 has an atypical active site serine (Ser1865) residue in place of canonical cysteine and it phylogenetically forms a distinct branch across the species. To investigate whether this domain retains catalytic activity, we expressed, purified and refolded the Peptidase_C14 domain of PfMCA3 which was found to express in all asexual stages. PfMCA3 exhibited trypsin-like serine protease activity with ser1865 acting as catalytic residue to cleave trypsin oligopeptide substrate. PfMCA3 is inhibited by trypsin-like serine protease inhibitors. Our study found that PfMCA3 enzymatic activity was abrogated when catalytic serine1865 (S1865A) was mutated. Moreover, PfMCA3 was found to be inactive against caspase substrate. Overall, our study characterizes a novel metacaspase of P. falciparum, different from human caspases and not responsible for the caspase-like activity, therefore, could be considered as a potential chemotherapeutic target.

Screening of Novel Inhibitors Against Leishmania donovani Calcium ion Channel to Fight Leishmaniasis

Leishmania is an intracellular protozoan parasite which causes Leishmaniasis, a global health problem affecting millions of people throughout 89 different countries in the world. The current treatment which includes use of amphotericin B, antimonials, and others has major drawbacks due to toxicity, resistance, and extraordinary high cost. So there is an urgent need of development of new drug targets to fight against leishmaniasis. In this regard we have selected Leishmania donovani Ca2+ ion channel (Ld-CC) as potential drug target. Ld-CC regulates concentration of Ca2+ ions which is involved in several functions like flagellar motion, mitochondrial oxidative metabolism and entry inside the macrophages. Since Ld-CC has not been characterised yet, we performed homology modelling of Leishmania donovani Ca2+ ion channel (Ld-CC) and docking studies of ligand library against this channel. 542 compound library of National Cancer Institute (NCI) diversity 3 dataset selected for screening studies. The ligands ZINC17287336 and ZINC29590262 were selected as best energy conformers because they show highest binding affinity towards its target (Ld-CC). They interact with the active site residues in the pocket of Ld-CC which suggests that the docked conformations are good and acceptable. Moreover, these two selected compounds also have relatively high binding affinity than nifedipine and verapamil, known human calcium channel blockers which had been reported to have mild anti-leishmanial activity. Among these two top screened inhibitors the ligand ZINC29590262 shows poor binding affinity towards the Human voltagedependent L-type calcium channel subunit alpha-1C in comparison to the Ld-CC. Therefore, we proposed this ligand as the best inhibitor which shows 40% more binding affinity with Ld-CC than the human-VDCC. These results suggest that our screened ligand ZINC29590262 could act as novel drug and may show much better antileishmanial activity.