Neuroprotective Effects of Withania somnifera on 4-Hydroxynonenal Induced Cell Death in Human Neuroblastoma SH-SY5Y Cells Through ROS Inhibition and Apoptotic Mitochondrial Pathway

Neurochemical Research - The antioxidant, anti-inflammatory, and anticancer activities of Withania somnifera (WS) are known for a long time. This study was aimed to examine whether WS also...     

Nematicidal activity of Lysobacter capsici YS1215 and the role of gelatinolytic proteins against root-knot nematodes

Lysobacter capsici YS1215 is a soil-borne strain that could inhibit the growth of phytopathogenic fungi, including Phytophthora capsici, Rhizoctonia solani and Fusarium oxysporum, as well as root-knot nematodes. The effect of different concentrations of bacterial culture filtrate (BCF) of L. capsici YS1215 on the mortality of second-stage juveniles (J2) of Meloidogyne incognita was studied using 24-well plates. The J2 mortality increased with increasing concentrations of BCF. YS1215 also produces gelatinases in the culture filtrate. To study its role in nematicidal activities, the partial purification and the characterisation of gelatinolytic proteins were done from the culture medium of the YS1215. The partially purified proteins showed three clear bands with molecular weights estimated using zymography to be 255.7, 232.1 and 146.4 kDa. The optimal pH and temperature for the proteins were 8.0 and 40°C, respectively. The activity of the proteins was inhibited by ethylenediaminetetraacetic acid, FeCl₃ and 1,10-phenanthroline, whereas it was activated by MnCl₂. The proteins may belong to the group of metalloproteases. Moreover, the proteins could hydrolyse skimmed milk, collagen, gelatin and bovine serum albumin (BSA) as substrates, but not casein. The proteins could induce 75% J2 mortality in five days and degrade the J2 bodies. The present study demonstrates the role of the gelatinolytic proteins in the nematicidal potential of L. capsici YS1215.     

Caspase-3 mediated release of SAC domain containing fragment from Par-4 is necessary for the sphingosine-induced apoptosis in Jurkat cells

Background

Prostate apoptosis response-4 (Par-4) is a tumor-suppressor protein that selectively activates and induces apoptosis in cancer cells, but not in normal cells. The cancer specific pro-apoptotic function of Par-4 is encoded in its centrally located SAC (Selective for Apoptosis induction in Cancer cells) domain (amino acids 137–195). The SAC domain itself is capable of nuclear entry, caspase activation, inhibition of NF-κB activity, and induction of apoptosis in cancer cells. However, the precise mechanism(s) of how the SAC domain is released from Par-4, in response to apoptotic stimulation, is not well explored.

Results

In this study, we demonstrate for the first time that sphingosine (SPH), a member of the sphingolipid family, induces caspase-dependant cleavage of Par-4, leading to the release of SAC domain containing fragment from it. Par-4 is cleaved at the EEPD131G site on incubation with caspase-3 in vitro, and by treating cells with several anti-cancer agents. The caspase-3 mediated cleavage of Par-4 is blocked by addition of the pan-caspase inhibitor z-VAD-fmk, caspase-3 specific inhibitor Ac-DEVD-CHO, and by introduction of alanine substitution for D131 residue. Moreover, suppression of SPH-induced Akt dephosphorylation also abrogated the caspase dependant cleavage of Par-4.

Conclusion

Evidence provided here shows that Par-4 is cleaved by caspase-3 during SPH-induced apoptosis. Cleavage of Par-4 leads to the generation of SAC domain containing fragment which may possibly be essential and sufficient to induce or augment apoptosis in cancer cells.

     

Bioaccumulation of heavy metals in Channa punctatus (Bloch) in river Ramganga (U.P.), India

Ganga is the largest riverine system of India with a fragile ecosystem. Its prone to anthropogenic disturbances because of its cultural, economic and environmental values. The contamination of river Ganga by heavy metals (HM) is due to biotic (anthropogenic sources) and abiotic (pesticides, fertilizers) sources that poses a devastating health hazard to human, plant and edible fish life. The chemical analysis with the help of atomic absorption spectrometer performed on its water samples demonstrated the accumulation of heavy metals such as Arsenic (As), Lead (Pb), Cadmium (Cd), Iron (Fe), Zinc (Zn). Moreover, the spectrophotometric analysis indicated clearly the accumulation of heavy metals in order of occurrence (Fe > As > Cd > Zn > Pb) in liver and (Zn > Fe > As > Cd > Pb) in kidney of edible fish Channa punctatus. The present study has be used to sensitively monitor the extent of heavy metals pollution in the biotic aqua life of river Ramganga system and its suggested that the bioaccumulation of heavy metal in Channa punctatus has reached above permissible limits for human consumption, indicating potential health risks. Necessary biological steps should be taken to handle such food pollution and prevent the environmental risk and food chain disruption.     

Targeted Delivery of Probiotics: Perspectives on Research and Commercialization

Probiotics and Antimicrobial Proteins - Considering the significance of the gut microbiota on human health, there has been ever-growing research and commercial interest in various aspects of...     

Unraveling Comparative Anti-Amyloidogenic Behavior of Pyrazinamide and D-Cycloserine: A Mechanistic Biophysical Insight

Amyloid fibril formation by proteins leads to variety of degenerative disorders called amyloidosis. While these disorders are topic of extensive research, effective treatments are still unavailable. Thus in present study, two anti-tuberculosis drugs, i.e., pyrazinamide (PYZ) and D-cycloserine (DCS), also known for treatment for Alzheimer’s dementia, were checked for the anti-aggregation and anti-amyloidogenic ability on Aβ-42 peptide and hen egg white lysozyme. Results demonstrated that both drugs inhibit the heat induced aggregation; however, PYZ was more potent and decelerated the nucleation phase as observed from various spectroscopic and microscopic techniques. Furthermore, pre-formed amyloid fibrils incubated with these drugs also increased the PC12/SH-SY5Y cell viability as compare to the amyloid fibrils alone; however, the increase was more pronounced for PYZ as confirmed by MTT assay. Additionally, molecular docking study suggested that the greater inhibitory potential of PYZ as compare to DCS may be due to strong binding affinity and more occupancy of hydrophobic patches of HEWL, which is known to form the core of the protein fibrils.     

New evidence for a 67,000-year-old human presence at Callao Cave, Luzon, Philippines

Documentation of early human migrations through Island Southeast Asia and Wallacea en route to Australia has always been problematic due to a lack of well-dated human skeletal remains. The best known modern humans are from Niah Cave in Borneo (40-42 ka), and from Tabon Cave on the island of Palawan, southwest Philippines (47 ± 11 ka). The discovery of Homo floresiensis on the island of Flores in eastern Indonesia has also highlighted the possibilities of identifying new hominin species on islands in the region. Here, we report the discovery of a human third metatarsal from Callao Cave in northern Luzon. Direct dating of the specimen using U-series ablation has provided a minimum age estimate of 66.7 ± 1 ka, making it the oldest known human fossil in the Philippines. Its morphological features, as well as size and shape characteristics, indicate that the Callao metatarsal definitely belongs to the genus Homo. Morphometric analysis of the Callao metatarsal indicates that it has a gracile structure, close to that observed in other small-bodied Homo sapiens. Interestingly, the Callao metatarsal also falls within the morphological and size ranges of Homo habilis and H. floresiensis. Identifying whether the metatarsal represents the earliest record of H. sapiens so far recorded anywhere east of Wallace’s Line requires further archaeological research, but its presence on the isolated island of Luzon over 65,000 years ago further demonstrates the abilities of humans to make open ocean crossings in the Late Pleistocene.     

Acute outcome of treating patients admitted with electrical storm in a tertiary care centre

Background

Electrical storm (ES) is a life threatening emergency. There is little data available regarding acute outcome of ES.

Aims

The study aimed to analyze the acute outcome of ES, various treatment modalities used, and the factors associated with mortality.

Methods

This is a retrospective observational study involving patients admitted with ES at our centre between 1/1/2007 and 31/12/2013.

Results

41 patients (mean age 54.61 ± 12.41 years; 86.7% males; mean ejection fraction (EF) 44.51 ± 16.48%) underwent treatment for ES. Hypokalemia (14.63%) and acute coronary syndrome (ACS) (14.63%) were the commonest identifiable triggers. Only 9 (21.95%) patients already had an ICD implanted. Apart from antiarrhythmic drugs (100%), deep sedation (87.8%), mechanical ventilation (24.39%) and neuraxial modulation using left sympathetic cardiac denervation (21.95%) were the common treatment modalities used. Thirty-three (80.49%) patients could be discharged after a mean duration of 14.2 ± 2.31 days. Eight (19.5%) patients died in hospital. The mortality was significantly higher in those with EF < 35% compared to those with a higher EF (8 (42.11% vs 0 (0%), p = 0.03)). There was no significant difference in mortality between those with versus without a structural heart disease (8 (21.1% vs 0 (0%), p = 0.32)). Comparison of mortality an ACS with ES versus ES of other aetiologies (3 (50%) vs 5 (14.29) %, p = 0.076)) showed a trend towards significance.

Conclusion

With comprehensive treatment, there is reasonable acute survival rate of ES. Hypokalemia and ACS are the commonest triggers of ES. Patients with low EF and ACS have higher mortality.     

Ntg1p, the base excision repair protein, generates mutagenic intermediates in yeast mitochondrial DNA

Mitochondrial DNA is predicted to be highly prone to oxidative damage due to its proximity to free radicals generated by oxidative phosphorylation. Base excision repair (BER) is the primary repair pathway responsible for repairing oxidative damage in nuclear and mitochondrial genomes. In yeast mitochondria, three N-glycosylases have been identified so far, Ntg1p, Ogg1p and Ung1p. Ntg1p, a broad specificity N-glycosylase, takes part in catalyzing the first step of BER that involves the removal of the damaged base. In this study, we examined the role of Ntg1p in maintaining yeast mitochondrial genome integrity. Using genetic reporters and assays to assess mitochondrial mutations, we found that loss of Ntg1p suppresses mitochondrial point mutation rates, frameshifts and recombination rates. We also observed a suppression of respiration loss in the ntg1-Delta cells in response to ultraviolet light exposure implying an overlap between BER and UV-induced damage in the yeast mitochondrial compartment. Over-expression of the BER AP endonuclease, Apn1p, did not significantly affect the mitochondrial mutation rate in the presence of Ntg1p, whereas Apn1p over-expression in an ntg1-Delta background increased the frequency of mitochondrial mutations. In addition, loss of Apn1p also suppressed mitochondrial point mutations. Our work suggests that both Ntg1p and Apn1p generate mutagenic intermediates in the yeast mitochondrial genome.