Inhibition of Drp1 orchestrates the responsiveness of breast cancer cells to paclitaxel but insignificantly relieves paclitaxel-related ovarian damage in mice

Chemoresistance and chemotherapy-related ovarian damage are well-reported in breast cancer (BC) young patients. Herein, the inhibition of the mitochondrial fission was invested to explore its chemosensitizing role in Paclitaxel (PTX)-resistant cells, and its ability to restore the ovarian integrity in mice receiving PTX or cisplatin chemotherapy. To establish these aims, PTX-resistance was generated in BC cells, which were treated with PTX in combination with Drp1 deficiency, via mdivi-1, or Drp1-specific siRNA transfection. Furthermore, the alterations in the ovarian structure and the endocrine-related hormones were explored in mice receiving repetitive doses of PTX or cisplatin. We found that combining PTX with mdivi-1 improved cell responsiveness to PTX, induced apoptosis- and autophagy-mediated cell death, and relieved cellular oxidative stress. Additionally, the expression of PCNA1 and cyclin B1 genes were downregulated, meanwhile, p53, p21, and mitochondrial fusion proteins (Mfu1&Mfu2) were increased. The in vivo investigations in mice demonstrated that PTX induced gonadotoxic damage similar to cisplatin, whereas dual treatment of mice with PTX+ mdivi-1 failed to restore their normal follicular count and the circulating levels of E2 and AMH hormones. These results suggested that combining Drp1 inhibition with PTX resensitized breast cancer cells to PTX but failed to offer enough protection against chemotherapy-related gonadotoxicity.

Cytotoxic Potential of Novel Quinoline Derivative: 11-(1,4-Bisaminopropylpiperazinyl)5-methyl-5H-indolo[2,3-b]quinoline against Different Cancer Cell Lines via Activation and Deactivation of the Expression of Some Proteins

The current study evaluated the cytotoxic activity of 11-(1,4-bisaminopropylpiperazinyl)5-methyl-5H-indolo[2,3-b]quinoline (BAPPN), a novel derivative of 5-methyl-5H-indolo[2,3-b]quinoline, against hepatocellular carcinoma (HepG2), colon carcinoma (HCT-116), breast (MCF-7), and lung (A549) cancer cell lines and the possible molecular mechanism through which it exerts its cytotoxic activity. BAPPN was synthesized and characterized with FT-IR and NMR spectroscopy. The binding affinity scores of BAPPN for caspase-3 PDB: 7JL7 was -7.836, with an RMSD of 1.483° A. In silico screening of ADME properties indicated that BAPPN showed promising oral bioavailability records in addition to their high gastrointestinal absorption and blood-brain barrier penetrability. BAPPN induced cytotoxicity, with IC50 values of 3.3, 23, 3.1, and 9.96 μg/mL against cancer cells HepG2, HCT-116, MCF-7, and A549, respectively. In addition, it induced cell injury and morphological changes in ultracellular structure, including cellular delayed activity, vanishing of membrane blebbing, microvilli, cytoplasmic condensation, and shrunken nucleus with more condensed chromatin autophagosomes. Furthermore, BAPPN significantly increased the protein expression of caspase-3 and tumor suppressor protein (P53). However, it significantly reduced the secretion of vascular endothelial growth factor (VEGF) protein into the medium and decreased the protein expression of proliferation cellular nuclear antigen (PCNA) and Ki67 in HepG2, HCT-116, MCF-7, and A549 cells. This study indicates that BAPPN has cytotoxic action against liver, colon, breast, and lung cancer cell lines via the up-regulation of apoptotic proteins, caspase-3 and P53, and the downregulation of proliferative proteins, VEGF, PCNA, and Ki67.

Aldo-keto reductase and sorbitol dehydrogenase enzymes in Egyptian diabetic patients with and without proliferative diabetic retinopathy

BACKGROUND

Activation of the polyol pathway due to increased aldo-keto reductase (AKR) activity has been implicated in the development of diabetic complications, including proliferative diabetic retinopathy (PDR); however, the relationship between hyperglycaemia-induced activation of the polyol pathway in the retina and PDR is still uncertain.

METHODS

This study was conducted on 73 individuals, who were categorised into three groups: healthy individuals as normal control (15 age-matched subjects), diabetic patients treated with oral hypoglycaemic drugs (OHD, 34 patients), six of whom (17.7 per cent) were diagnosed with PDR and the rest were diagnosed with non-proliferative diabetic retinopathy (NPDR) and diabetic patients treated with insulin (INS, 24 patients), 12 of whom (50 per cent) were diagnosed with PDR and the rest had NPDR.

RESULTS

The AKR level in diabetic subjects showed a significant increase compared with the normal controls. Interestingly, AKR levels were significantly increased in the INS compared with the OHD group. Also the AKR level was significantly increased in the patients with proliferative compared with the non-proliferative retinopathy in both the insulin and oral diabetic groups. The sorbitol dehydrogenase (SDH) level in diabetic patients showed a significant decrease compared with the normal control level. Interestingly, the SDH level was significantly decreased in the INS compared with the OHD group. Also, the SDH level was significantly decreased in patients with proliferative compared with non-proliferative retinopathy in both INS and OHD groups. The HbA(1c) level in both INS and OHD subjects showed a significant increase compared with normal controls. In addition, the triglyceride level in insulin proliferative retinopathy showed a significant increase compared with other groups.

CONCLUSIONS

The AKR level was significantly increased in patients with proliferative compared with non-proliferative retinopathy in both insulin and oral diabetic groups. The SDH level was significantly decreased in patients with proliferative compared with non-proliferative retinopathy in both insulin and oral diabetic groups. Both AKR and SDH could be used as indicators for diabetic control.

Role of Urinary Tract Bacterial Infection in the Process of Bladder Carcinogenesis (Molecular and Biochemical Studies)

Objective: This work is designed to study the possible role of chronic inflammation induced by E. coli in the urinary bladder of rats, the protective role of soybean flour, in addition to the role of oxidative and nitrosative stresses during bladder carcinogenesis. Material & Methods: This study was done on one hundred and fifty adult male albino rats (50 - 60 gm) that divided into five groups; a) Normal control group, b) Dibutyl amine and sodium nitrate treated group, c)E.Coli treated group, d) Dibutyl amine and sodium nitrate treated group plus E. coli, and e) Dibutyl amine and sodium nitrate treated group plus soy bean flour. Survival rate and histopatholgical changes during the period of treatment were recorded. Level of malondialdhyde, glutathione, catalase, hydrogen peroxide, Total anti-oxidant capacity and nitric oxide were measured. RNA extracted from bladder tissues was determined in addition to P16 level and caspase-3 expression. Results: Survival analysis showed a significant decrease (p< 0.001) in E.Coli and dibutyl amine plus sodium nitrate treated groups in comparing with the normal and other treated groups. Also, E. coli infection in the bladder tissues increases the carcinogenic ability of nitrosamine precursors, and enhances oxidative and nitrosative stresses via increasing levels of nitric acid, hydrogen peroxide and malondialdhyde. Regarding the molecular changes, extra bands have been found in E. coli and E. coli + carcinogen treated groups approximately at 16-18KD which are not present in the other groups. Conclusion: Bacterial infection of the urinary bladder may play a major additive and synergistic role in bladder carcinogenesis. Our results have also shown that soy bean flour may have a protective action during induction of urinary tumors. Key Words: Bladder carcinogenesis; E. Coli; Soybean; DBA; P16 DOI: 10.3126/ajms.v2i1.3542 Asian Journal of Medical Sciences 2 (2011) 31-40

Acetoin and Diacetyl Formation by Streptococcus lactis subsp. diacetylactis DRC3

Cells of Streptococcus lactis subsp. diacetylactis DRC3 which had been grown on lactose in the presence of citrate were unable to form acetoin and diacetyl (AD) from citrate when suspended in succinate buffer, pH 4.4. Inclusion of both a source of energy and nitrogen in the buffer was necessary for AD formation. Concentrations of AD and D at pH 4.4 were about five and three times the concentrations at pH 6.4. The amounts of AD and D from citrate were about eight and two times those from pyruvate, calculated on a molar basis. It appears that D, at least, is formed not only from pyruvate arising during citrate cleavage, but also from acetyl-CoA resulting from a probable citrate breakdown in a reversible reaction of a citrate synthetase. The rate of AD formation, under optimum conditions, was 0.047 μmoles mg (dry wt^-1) cells ml^-1 min^-1. Pyruvate-grown cells produced little AD from pyruvate. AD production was inhibited partly by acetate and completely by acetaldehyde. Cetylpyridinium chloride at a concentration higher than μg ml^-1 suppressed AD production from citrate because of the absence of interfering compounds normally present in milk.

Acetoin and Diacetyl Production by Lactobacillus plantarum Able to Use Citrate

Whole-cell suspensions of Lactobacillus plantarum grown on lactose in the presence of citrate did not produce acetoin and diacetyl (AD) (D) from citrate in succinate buffer, pH 4.4 unless both a source of energy and nitrogen was present, but did from pyruvate. The total AD and the amount of D, produced by citrate-grown cells, from citrate were about two times the amounts formed from pyruvate, calculated on a molar basis. It appears, that AD are formed not only from pyruvate resulting from cleavage of citrate but also from acetyl-coenzyme A arising during a probable breakdown of citrate in a reversible reaction of citrate synthetase. Neither acetate nor acetaldehyde had any effect on the total AD or the amount of D produced from pyruvate by pyruvate-grown cells. The rates of AD production from pyruvate by whole-cell suspensions of pyruvate-grown L. plantarum and Streptococcus subsp. diacetylactis represented only 69.7 and 6.6%, respectively, of that produced by Lactobacillus casei . These were 0.075 μmoles/mg dry wt^-1 ml^-1 min^-1 for L. casei , 0.053 for L. plantarum and 0.005 for S. lactis subsp. diacetylactis .

Acetoin and Diacetyl Production by Lactobacillus casei subsp. pseudoplantarum

The ability of Lactobacillus casei subsp. pseudoplantarum to produce acetoin and diacetyl (AD) was evaluated in succinate buffer (initial pH 4.4) containing sodium pyruvate, at 30°C. Cells grown in MRS broth containing pyruvate produced AD more rapidly than did an equal number of cells either grown in broth without pyruvate or even stored, after harvesting during logarithmic growth, in MRS broth in the presence of pyruvate for 120 minutes. One or more of the enzymes catalyzing formation of AD appears to be formed originally during growth in the presence of pyruvate. The rate of AD production by pyruvate-grown cells was exponential, being 0.08 μmoles mg dry wt^-1 ml^-1 min^-1 during the first 30 min of the reaction. Storage of pyruvate grown cells at 7°C for 6 h in 0.3 mmol/L KH₂PO₄ buffer, pH 7.0 resulted in 77% loss of activity. Inclusion of 0.5 ml of MRS broth in the assay mixture led to a considerable increase in AD production by both cells grown in the absence and presence of pyruvate. Lactose slightly stimulated AD production in cells grown on lactose, whereas glucose had practically no effect on glucose-grown cells. Acetate and acetaldehyde reduced AD production. The effect varied with the compound used and strain studied. Of 7 concentrations of cetylpyridinium chloride tested for their effect on AD production, the least and most inhibitory concentration were 1 and 10 μg ml^-1 of assay mixture.

Acetoin and Diacetyl Production by Homo- and Heterofermentative Lactic Acid Bacteria

Eleven strains of homofermentative and heterofermentative lactic acid bacteria were screened for acetoin (A) and diacetyl (D) production from pyruvate and citrate in a peptone-yeast extract-glucose broth. The homofermenters, except Streptococcus faecalis subsp. liquefaciens , produced much more AD from pyruvate than from citrate; the opposite was true for the heterofermenters. Acetoin and diacetyl were produced from pyruvate as soon as growth was initiated. The production was exponential up to 24 h. Destruction of the accumulated AD coincided with entry into the stationary phase. Production of AD from citrate did not begin until 6 h of the logarithmic phase of growth. Formation of gas from citrate by Lactobacillus plantarum did not implicate greater ability to form AD from citrate than from pyruvate. Fifty μmoles ml^-1 citrate caused about 50% inhibition of growth of Streptococcus lactis subsp. diacetylactis . All strains examined for ability to use pyruvate as a sole source of carbon were able to do so. Acetate (50 μmoles ml^-1 generally stimulated AD formation from pyruvate. With the exception of a Pediococcus sp. and S. faecalis subsp. liquefaciens , acetaldehyde (100 μg ml^-1) enhanced AD production but not growth. Concentrations higher than 100 μg ml^-1 had different effects.

Characteristics of Salt-Tolerant Lactic Acid Bacteria, in Particular Lactobacilli, Leuconostocs and Pediococci, Isolated from Salted Raw Milk

One hundred and fourty five lactobacilli, leuconostocs and pediococci were isolated from salted raw milks incubated at 30°C for 4 to 21 d. Of 126 lactobacilli isolated, mostly from 9 to 12% salted milk, 115 were identified as homofermentative, nonthermophilic lactobacilli-73 were classified as Lactobacillus plantarum , 31 Lactobacillus casei , 8 strains were motile and 3 Lactobacillus xylosus . The remaining 11 isolates were heterofermentative lactobacilli-8 were Lactobacillus cellobiosus and 3 Lactobacillus brevis - buchneri . Strains of L. plantarum fermented many oligosaccharides, produced DL lactate and gas from L(+) but not from D(-) tartrate and their cell wall peptidoglycan was of the mesodiaminopimelic acid type. Eight strains of L. casei proved to be subsp. pseudoplantarum on the basis of inactive lactic acid production; 8 were subsp. rhamnosus and 2 subsp. alactosus , according to their pattern of sugar fermentation. L. xylosus simulated L. casei morphologically but differed from it in fermentation of xylose. The motile strains fermented arabinose and mostly sucrose but not lactose and produced 73.2 to 94 μmoles ml^-1 inactive lactate from 1 % glucose. None of 10 Leuconostoc isolates produced dextran from sucrose but they fermented trehalose and were identified with Leuconostoc paramesenteroides . Three strains belonged to Pediococcus and produced 62 μmoles ml^-1 of inactive lactate, whereas other six strains were atypical pediococci. Nineteen strains representing L. plantarum , L. casei , motile strains and Pediococcus gave, on examination for isomers of lactic acid, 32.8 to 171 μmoles ml^-1 inactive lactate; the L(+) enanthiomorph generally predominated.

Use of Salt-Tolerant Lactic Acid Bacteria for Manufacture of White Pickled Cheese (Domiati) Ripened Without Salted Whey in Sealed Polyethylene Pouches

White pickled cheeses of the Domiati type were made from a 1:1 mixture of raw cows' and buffaloes' milk (5.5% fat) with and without heating momentarily to 72°e. To cheese milk were added: (a) 6.5% salt + 2% Lactobacillus casei subsp. pseudoplantarum 333C starter, (b) 9% salt + 2% Lactobacillus casei starter, (c) 9% salt + 2% Pediococcus sp. 452 starter, (d) 9% salt + 2% Leuconostoc paramesenteroides II47 starter; control cheeses were made from raw milk with either 6.5 or 9% salt. Finished cheeses were sealed in polyethylene pouches without salted whey and ripened at ambient temperature (10-25°C) for up to 5 months. Pouch-cheeses ripened without salted whey were generally attractive, uniform creamy in color, had a firm body, waxy buttery smooth texture and a pleasant flavor. Milk with 6.5% salt appeared to be preferable to milk with 9% salt for making the cheese. The highest organoleptic scores were achieved by cheese made from milk heated momentarily to 72°C and which received 6.5% salt and 2% L. casei starter. Inoculation of both raw and heated milk containing 9% salt with either L. casei subsp. pseudoplantarum 333C, Pediococcus sp. 452 or L. paramesenteroides II47 improved cheese flavor. Limburger cheese flavor was occasionally and yeasty flavor most frequently encountered. All cheeses had high DM, fat, total and soluble N, and amino acid N, with only little loss of their nutritive constituents when compared with reported values for cheese ripened in the normal way. Increasing the salt percentage in cheese milk reduced the total protein recovered in cheese. None of the cheese components examined seemed to be associated with high flavor scores. No correlation could be established between the number and types of lactic acid bacteria found and flavor intensity.

Growth and Aflaxtoxin Production by Aspergillus parasiticus in the Presence of Lactobacillus casei

When a mineral salts-glucose broth was inoculated simultaneously with Aspergillus parasiticus and Lactobacillus casei and incubated at 28 C for 10 days, (a) larger numbers of L. casei survived than when the bacterium was grown alone, (b) growth of A. parasiticus initially was more rapid but total growth during the incubation was comparable to that of the mold growing alone, (c) production of aflatoxin was less than when the mold grew alone and (d) degradation of aflatoxin by the mold was somewhat greater than when the mold grew alone. Growth of L. casei for 3 days before adding A. parasiticus resulted in (a) better survival of L. casei than when it grew alone but not better than when the two organisms were added to broth simultaneously, (b) slower growth of A. parasiticus than when it grew alone, (c) production of less aflatoxin than when the mold grew alone or when both organisms were added to broth simultaneously and (d) no apparent degradation of aflatoxin during the 10-day incubation period.

Heat-stability of peroxidase in mycelia of some toxigenic and nontoxigenic aspergilli and penicillia

Seven-day-old mycelia from 19 cultures of Aspergillus and 12 cultures of Penicillium were heated to 50, 60, 65, 70, 75, 80, 85, 90 or 95 C for no more than 1 min, and tested for residual peroxidase. The peroxidase from all aspergilli survived heating at 50 through 80 C. Peroxidase from toxigenic strains of Aspergillus flavus, Aspergillus parasiticus and Aspergillus ochraceus survived heating at 85 C and often at 90 C, whereas peroxidase from non-toxigenic strains of A. flavus was inactivated at 90 C and markedly reduced in activity at 85 C. Peroxidase from all penicillia survived heating at all temperatures through 80 C, although the activity of several cultures was reduced at 80 C. Peroxidase activity in mycelia of two strains of Penicillium cyclopium and one of Penicillium puberulum failed to survive heating at 85 C. One strain each of Penicillium roqueforti and Penicillium viridicatum exhibited some peroxidase activity after heating at 90 C, whereas the peroxidase of all other penicillia was inactivated at this temperature.

Survival and Growth of Clostridium Species in the Presence of Hydrogen Peroxide

Some bacteria in the genus Clostridium can occur as contaminants in milk. If cheese is made from milk with such contaminants, the bacteria can cause the "late gas" or "late blowing" defect in the cheese. Since hydrogen peroxide can be used to treat milk for cheesemaking, this investigation was initiated to determine effects of the peroxide on viability and growth of Clostridium tyrobutyricum NIZO, C. tyrobutyricum 144, Clostridium perfringens 115 and Clostridium sporogenes T9. Presence of 0.01% hydrogen peroxide in litmus milk retarded but did not prevent growth of and gas production by the clostridia. Presence of 0.02% peroxide inhibited growth and gas production when litmus milk contained, per milliliter, 50 or 100 spores of any of the clostridia being studied. These numbers of clostridial spores are greater than those normally found in raw milk produced under ordinary conditions.

Proteolytic and Lipolytic Activities of some Toxigenic and Nontoxigenic Aspergilli and Penicillia

Eighteen strains of Aspergillus flavus or Aspergillus parasiticus , one of Aspergillus ochraceus and 12 strains or species of Penicillium , many of them isolated from cheese, were evaluated for their proteolytic and lipolytic activities. Strains of A. flavus exhibited considerable proteolytic and little lipolytic activity, whereas the reverse was true for strains of A. parasiticus . Of the Penicillium cultures tested, 10 exhibited considerable lipolytic activity, but only five had marked proteolytic activity. Two cultures, Penicillium patulum M59, and Penicillium cyclopium No. 8, were markedly lipolytic and proteolytic. Of the other cultures, greatest lipolytic activity was associated with Penicillium roqueforti 849, Penicillium puberulum No. 33, A. parasiticus NRRL 3145 and NRRL 465 and A. ochraceus NRRL 3174, whereas greatest proteolytic activity of all the cultures was associated with P. patulum M59, P. cyclopium No. 25 and A. flavus WB500, 4018, 4098 and NRRL 5565.

Growth and biosynthesis of aflatoxin by Aspergillus parasiticus in cultures containing nisin

Nisin, 200 or 5000 Reading units/ml, was added to Aspergillus parasiticus cultures. The cultures were incubated at 28 degrees C for 3, 7 or 10 days and analyzed for mycelial dry weight, pH and accumulation of aflatoxin B1 and G1. During the first 3 days of incubation, dry weight, pH decrease and aflatoxin accumulation were suppressed by nisin, when compared with similar values for the nisin-free control. After longer incubation, differences in dry weight nd pH values decreased, whereas accumulation of aflatoxin in the nisin-containing cultures surpassed that of the control.