Interannual variability of seasonal succession events in a temperate lake and its relation to temperature variability

The assessment of possible implications of anthropogenic climate change requires the evaluation of results obtained with complex climate models. Here we considered the problem of assessing the impact of climate variability on successional events in a lake (Plußsee) of the temperate region between January and May. We first established a statistical link between large-scale air temperature, at about 1500 m height, and the local temperature, in order to bridge the spatial gap of information obtained from global climate models and local climate which forces processes in the lake. Secondly, the local temperatures were statistically related to biologically induced dynamic features in the lake, derived from Secchi depths readings (as integrated measures). The observed relationships were compared with results from a phyto- and zooplankton population-dynamic model run under different temperature regimes. The local temperatures approximated closely the large-scale temperature. The timing of phyto- and zooplankton maxima (clearwater phase) were negatively related to the temperature. Thus, with a temperature increase both occurred earlier. The intensity of the spring algal maximum was negatively related to its timing, whereas no clear relation between the timing and intensity of the clearwater phase (zooplankton maximum) could be obtained.     

Inbreeding effects on palmar dermatoglyphic characters in three endogamous social groups of West Bengal,India

The present study reports inbreeding effects on mean palmar dermatoglyphic characteristics: triradial count on palm, maximal atd angle, adt angle, td ridge count, ab ridge count, main line index (MLI) and ab ridge breadth. Samples were drawn from adult males belonging to three endogamous sections representing Hindu caste Telaga of Kharagpur (West Midnapore), Ansari Muslims of Nandigram (East Midnapore) and Sheik-Sunni Muslims of Braddhaman in West Bengal, India. Consistent trend of higher mean triradial number, adt angle, and lower mean td ridge count, ab ridge count, and ab ridge breadth was observed in inbred sections compared to their non-inbred relatives in three social groups.     

Bcl-2 inhibitor and apigenin worked synergistically in human malignant neuroblastoma cell lines and increased apoptosis with activation of extrinsic and intrinsic pathways

Neuroblastoma is the most common extracranial solid tumor in infants and young children. Current treatments are not always effective and new therapies are needed. We examined efficacy of combination of the small molecule Bcl-2 inhibitor HA14-1 (HA) and the dietary isoflavonoid apigenin (APG) in human malignant neuroblastoma cells. Dose-response studies indicated that treatment with HA and APG for 24 h synergistically reduced cell viability in human malignant neuroblastoma SK-N-DZ, SH-SY5Y, and IMR32 cells. For further studies, we selected SK-N-DZ cells that showed the highest sensitivity following treatment with 2.5 μM HA, 100 μM APG, or combination (2.5 μM HA + 100 μM APG). Wright staining showed increase in morphological features of apoptosis. Cell cycle distribution and Annexin V assay showed that combination therapy caused more apoptosis than either treatment alone. Western blotting revealed that combination therapy downregulated angiogenic factors and also induced extrinsic pathway of apoptosis with activation of caspase-8 for Bid cleavage to tBid. Alterations in Bax and Bcl-2 levels resulted in an increase in Bax:Bcl-2 ratio to activate intrinsic pathway of apoptosis with mitochondrial release of cytochrome c into the cytosol and activation of proteases. Increases in calpain and caspase-3 activities generated 145 kD spectrin break down product (SBDP) and 120 kD SBDP, respectively. Results showed that combination of HA and APG could be used for downregulation of angiogenic factors and activation of extrinsic and intrinsic pathways of apoptosis in malignant neuroblastoma cells.     

GC-1 mRHBDD1 knockdown spermatogonia cells lose their spermatogenic capacity in mouse seminiferous tubules

Background  

Apoptosis is important for regulating spermatogenesis. The protein mRHBDD1 (mouse homolog of human RHBDD1)/rRHBDD1 (rat homolog of human RHBDD1) is highly expressed in the testis and is involved in apoptosis of spermatogonia. GC-1, a spermatogonia cell line, has the capacity to differentiate into spermatids within the seminiferous tubules. We constructed mRHBDD1 knockdown GC-1 cells and evaluated their capacity to differentiate into spermatids in mouse seminiferous tubules.     

Cloning and expression analysis of two distinct HIF-alpha isoforms – gcHIF-1alpha and gcHIF-4alpha – from the hypoxia-tolerant grass carp,Ctenopharyngodon idellus

Background  

Hypoxia-inducible factors (HIFs) are involved in adaptive and survival responses to hypoxic stress in mammals. In fish, very little is known about the functions of HIFs.     

Effect of microwave irradiated Methanosarcina barkeri DSM-804 on biomethanation

Methanosarcina barkeri DSM-804, a methanogenic bacterium, when exposed to microwave radiation of frequencies ranging from 13.5 to 36.5 GHz, showed faster growth in comparison to the unirradiated bacterial culture. Methane concentration in the biogas generated from the irradiated culture was higher than that from unirradiated one, which was to 76.3% on the 15th day of incubation at a microwave radiation frequency of 31.5 GHz, 10 dbm power when irradiated for 2 h. Microscopic study of pure culture revealed that the cells of M. barkeri were more in number and their cell diameter was enlarged by 20%. Inoculation of the culture in a biogas digester containing a combination of jute waste and vegetable market waste as substrate increased the efficacy of biomethanation and reduced its lag phase significantly.     

Survivin knockdown increased anti-cancer effects of (-)-epigallocatechin-3-gallate in human malignant neuroblastoma SK-N-BE2 and SH-SY5Y cells

Neuroblastoma is a solid tumor that mostly occurs in children. Malignant neuroblastomas have poor prognosis because conventional chemotherapeutic agents are hardly effective. Survivin, which is highly expressed in some malignant neuroblastomas, plays a significant role in inhibiting differentiation and apoptosis and promoting cell proliferation, invasion, and angiogenesis. We examined consequences of survivin knockdown by survivin short hairpin RNA (shRNA) plasmid and then treatment with (-)-epigallocatechin-3-gallate (EGCG), a green tea flavonoid, in malignant neuroblastoma cells. Our Western blotting and laser scanning confocal immunofluorescence microscopy showed that survivin was highly expressed in malignant neuroblastoma SK-N-BE2 and SH-SY5Y cell lines and slightly in SK-N-DZ cell line. Expression of survivin was very faint in malignant neuroblastoma IMR32 cell line. We transfected SK-N-BE2 and SH-SY-5Y cells with survivin shRNA, treated with EGCG, and confirmed knockdown of survivin at mRNA and protein levels. Survivin knockdown induced morphological features of neuronal differentiation, as we observed following in situ methylene blue staining. Combination of survivin shRNA and EGCG promoted neuronal differentiation biochemically by increases in the expression of NFP, NSE, and e-cadherin and also decreases in the expression of Notch-1, ID2, hTERT, and PCNA. Our in situ Wright staining and Annexin V-FITC/PI staining showed that combination therapy was highly effective in inducing, respectively, morphological and biochemical features of apoptosis. Apoptosis occurred with activation of caspase-8 and cleavage of Bid to tBid, increase in Bax:Bcl-2 ratio, mitochondrial release of cytochrome c, and increases in the expression and activity of calpain and caspase-3. Combination therapy decreased migration of cells through matrigel and inhibited proliferative (p-Akt and NF-κB), invasive (MMP-2 and MMP-9), and angiogenic (VEGF and b-FGF) factors. Also, in vitro network formation ability of cells was significantly inhibited by survivin silencing and completely by combination of survivin silencing and EGCG treatment. Collectively, survivin silencing potentiated anti-cancer effects of EGCG in human malignant neuroblastoma cells having survivin overexpression.     

Photofrin Based Photodynamic Therapy and miR-99a Transfection Inhibited FGFR3 and PI3K/Akt Signaling Mechanisms to Control Growth of Human Glioblastoma In Vitro and In Vivo

Glioblastoma is the most common malignant brain tumor in humans. We explored the molecular mechanisms how the efficacy of photofrin based photodynamic therapy (PDT) was enhanced by miR-99a transfection in human glioblastoma cells. Our results showed almost similar uptake of photofrin after 24 h in different glioblastoma cells, but p53 wild-type cells were more sensitive to radiation and photofrin doses than p53 mutant cells. Photofrin based PDT induced apoptosis, inhibited cell invasion, prevented angiogenic network formation, and promoted DNA fragmentation and laddering in U87MG and U118MG cells harvoring p53 wild-type. Western blotting showed that photofrin based PDT was efficient to block the angiogenesis and cell survival pathways. Further, photofrin based PDT followed by miR-99a transfection dramatically increased miR-99a expression and also increased apoptosis in glioblastoma cell cultures and drastically reduced tumor growth in athymic nude mice, due to down regulation of fibroblast growth factor receptor 3 (FGFR3) and PI3K/Akt signaling mechanisms leading to inhibition of cell proliferation and induction of molecular mechanisms of apoptosis. Therefore, our results indicated that the anti-tumor effects of photofrin based PDT was strongly augmented by miR-99a overexpression and this novel combination therapeutic strategy could be used for controlling growth of human p53 wild-type glioblastomas both in vitro and in vivo.     

Increased enzyme secretion by 2-deoxy-D-glucose in presence of succinate by suppression of metabolic enzymes in Termitomyces clypeatus

Regulatory mode of secretion of proteins was detected for the industrial glycosidase, cellobiase, under secreting conditions (in presence of TCA cycle intermediates like succinate etc.) in the filamentous fungus Termitomyces clypeatus. The titers of key metabolic enzymes were investigated under secreting and non-secreting conditions of growth and compared to the corresponding production of intra and extracellular levels of cellobiase. Results were compared in presence of 2-deoxy-D-glucose, a potent glycosylation inhibitor in the secreting media. Inclusion of 2-deoxy-D-glucose in presence of succinate caused about 10 to 100 times decrease in titers of the metabolic enzymes hexokinase, fructose-1,6-bisphosphatase, isocitrate lyase and malate dehydrogenase leading to increased secretion of cellobiase by more than 100 times. The intracellular concentration of cAMP (86-fold decrease in presence of 2-deoxy-D-glucose under secreting conditions) and turnover rate of proteins also dropped significantly. In this suppressed metabolic state, a 10-fold increase in the titer of the secreted cellobiase was noticed. The results indicated elucidation of carbon catabolite repression like phenomenon in the fungus under secreting conditions which was more pronounced by 2-deoxy-D-glucose. The interdependence between secretion and regulation of metabolic enzymes will help in better understanding of the physiology of these highly adapted organisms for increasing their secretion potential of glycosidases like cellobiase with high industrial value.