Effect of recombinant erythropoietin on ischemia–reperfusion-induced apoptosis in rat liver

Ischemia–reperfusion (I/R) cannot be avoided in liver transplantation procedures, and apoptosis is a central mechanism of cell death after liver reperfusion. Protective effect of recombinant erythropoietin (rhEPO) on liver apoptosis has not been clearly investigated. This work investigated intraportal (IP) rhEPO-protective effect in a rat model of hepatic I/R-induced apoptosis and its appropriated time and dose of administration. Eight groups were included (n = 10/group): sham-operated, I/R (45 min ischemia and 2 h reperfusion), preconditioned rhEPO I/R (24 h or 30 min before ischemia), and postconditioned rhEPO I/R (before reperfusion) using two different rhEPO doses (1,000 and 5,000 IU/kg). When compared with the sham-operated group, the I/R group showed significant increase of serum levels of aspartate and alanine aminotransferases (AST, ALT), hepatic caspase-9 activity(894.99 ± 176.90 relative fluorescence units (RFU)/mg/min versus 458.48 ± 82.96 RFU/mg/min), and Fas ligand (FasL) expression, histopathological damages, and significant decrease in the antiapoptotic Bcl-xL/apoptotic Bax ratio(0.38 ± 0.21 versus 3.35 ± 0.77) rhEPO-improved ALT and AST but failed to reduce FasL expression in all groups compared with the I/R group. Thirty minutes and 24 h preconditioning with rhEPO (1,000 IU/kg) increased Bcl-xL/Bax ratio and reduced caspase-9 activity, and the same effect was observed when higher dose was given 24 h before ischemia. Preconditioning was more effective than postconditioning in improving caspase-9 activity, and no dose-dependent effect was observed. In conclusion, single IP rhEPO injection 30 min before ischemia has an advantage over rhEPO postconditioning in improving post-hepatic I/R-induced apoptosis with no additional time- and dose-dependent effects which may provide potentially useful guide in liver transplantation procedures.     

Human apolipoprotein B: identification of cDNA clones and characterization of mRNA.

Apolipoprotein B (apoB) is a major protein component of low density and very low density lipoproteins. Because of its large size and heterogeneity, molecular studies of apoB have been difficult, and its structure and regulation remain poorly understood. We now report the identification of human apoB cDNA clones by antibody screening of hepatoma libraries in the expression vector lambda gt11. Both oligo(dT) primed and random primed libraries were constructed and screened with polyclonal antibodies to intact apoB, as well as with antibodies raised against a synthetic peptide based on the limited amino acid sequence available for apoB. The identity of the clones was unambiguously established by comparisons of the cloned cDNA sequences with apoB amino acid sequences. The clones hybridize to an exceptionally large 20 kb mRNA that is present in liver and intestine but not other tissues examined, consistent with the distribution expected from protein biosynthetic studies. The properties of the mRNA have implications for the biogenesis of the multiple apoB molecular weight forms secreted by liver and intestine.     

Neosetophomone B induces apoptosis in multiple myeloma cells via targeting of AKT/SKP2 signaling pathway

Multiple myeloma (MM) is a hematologic malignancy associated with malignant plasma cell proliferation in the bone marrow. Despite the available treatments, drug resistance and adverse side effects pose significant challenges, underscoring the need for alternative therapeutic strategies. Natural products, like the fungal metabolite neosetophomone B (NSP-B), have emerged as potential therapeutic agents due to their bioactive properties. Our study investigated NSP-B's antitumor effects on MM cell lines (U266 and RPMI8226) and the involved molecular mechanisms. NSP-B demonstrated significant growth inhibition and apoptotic induction, triggered by reduced AKT activation and downregulation of the inhibitors of apoptotic proteins and S-phase kinase protein. This was accompanied by an upregulation of p21Kip1 and p27Cip1 and an elevated Bax/BCL2 ratio, culminating in caspase-dependent apoptosis. Interestingly, NSP-B also enhanced the cytotoxicity of bortezomib (BTZ), an existing MM treatment. Overall, our findings demonstrated that NSP-B induces caspase-dependent apoptosis, increases cell damage, and suppresses MM cell proliferation while improving the cytotoxic impact of BTZ. These findings suggest that NSP-B can be used alone or in combination with other medicines to treat MM, highlighting its importance as a promising phytoconstituent in cancer therapy.     

Recombinant DNA in Medicine

Studies in bacteria and bacterial viruses have led to methods to manipulate and recombine DNA in unique and reproducible ways and to amplify these recombined molecules millions of times. Once properly identified, the recombinant DNA molecules can be used in various ways useful in medicine and human biology. There are many applications for recombinant DNA technology. Cloned complementary DNA has been used to produce various human proteins in microorganisms. Insulin and growth hormone have been extensively and successfully tested in humans and insulin has been licensed for sale. Mass production of bacterial and viral antigens with recombinant DNA technology is likely to provide safe and effective vaccines for some disorders for which there is no prevention. The cloned probes for the human α- and β-globin loci, for specific disease genes, such as the Z allele of α-antitrypsin, and for random genomic sequences are proving useful for prenatally diagnosing human genetic disorders and preventing their clinical consequences.     

Effect of <Emphasis Type="Italic">Streptomyces</Emphasis> 23-2B metabolites on hepatic lipid peroxidation and some antioxidant parameters in Wister rats

Streptomyces 23-2B is one of actinomycetes associated with marine clam Donax trunculus and has potential source of bioactive metabolites, which possesses a broad spectrum antibiotic and anticancer activities. This study aims to evaluate the effect of Streptomyces 23-2B metabolites on hepatic lipid peroxidation (LPO), reduced glutathione (GSH) levels, as well as serum uric acid, total cholesterol (TC), triglyceride (TG), nitric oxide (NO) and tumor necrosis factor-alpha (TNF-α) levels of rat. Animals were divided into four groups: the control group, which received 0.1 ml of 10% Tween-80 by intraperitoneally injection, and the other three experimental groups, which received 10% Tween 80 solution of Streptomyces 23-2B metabolites in doses of 0.5, 5 and 50 mg/kg body weight at an interval 2 days for 2 weeks. LPO levels showed significant decrease with the lowest doses. The effect at a dose of 50 mg/kg of Streptomyces 23-2B metabolites on TG was more pronounced than the other two doses (0.5 and 5 mg/kg body weight). Hypocholesterolemia was recorded in the treated rats with 0.5 and 5 mg/kg of Streptomyces 23-2B. However, the highest dose enhanced the elevation of serum TNF-α and NO levels. Thus, the present study reveals that Streptomyces 23-2B metabolite is a newly discovered biomaterial from microorganisms. The novel substance showed inhibitory activity against LPO in rat liver homogenate and improving the immune response by releasing TNF-α and NO in serum.     

Synthesis,X-ray diffraction analysis,quantum chemical studies and α-amylase inhibition of probenecid derived S-alkylphthalimide-oxadiazole-benzenesulfonamide hybrids

Sulphonamide and 1,3,4-oxadiazole moieties are present as integral structural parts of many drugs and pharmaceuticals. Taking into account the significance of these moieties, we herein present the synthesis, single-crystal X-ray analysis, DFT studies, and α-amylase inhibition of probenecid derived two S-alkylphthalimide-oxadiazole-benzenesulfonamide hybrids. The synthesis has been accomplished in high yields. The final structures of both hybrids have been established completely with the help of different spectro-analytical techniques, including NMR, FTIR, HR-MS, and single-crystal X-ray diffraction analyses. In an effort to confirm the experimental findings, versatile quantum mechanical calculations and Hirshfeld Surface analysis have been performed. α-Amylase inhibition assay has been executed to investigate the enzyme inhibitory potential of both hybrids. The low IC₅₀ value (76.92 ± 0.19 μg/mL) of hybrid 2 shows the good α-amylase inhibition potential of the respective compound. Ultimately, the binding affinities and features of the two hybrids are elucidated utilising a molecular docking technique against the α-amylase enzyme.     

Chloroquine inhibits glutamate-induced death of a neuronal cell line by reducing reactive oxygen species through sigma-1 receptor

Chloroquine, a widely used anti-malarial and anti-rheumatoid agent, has been reported to induce apoptotic and non-apoptotic cell death. Accumulating evidence now suggests that chloroquine can sensitize cancer cells to cell death and augment chemotherapy-induced apoptosis by inhibiting autophagy. However, chloroquine is reported to induce GM1 ganglioside accumulation in cultured cells at low μM concentrations and prevent damage to the blood brain barrier in mice. It remains unknown whether chloroquine has neuroprotective properties at concentrations below its reported ability to inhibit lysosomal enzymes and autophagy. In the present study, we demonstrated that chloroquine protected mouse hippocampal HT22 cells from glutamate-induced oxidative stress by attenuating production of excess reactive oxygen species. The concentration of chloroquine required to rescue HT22 cells from oxidative stress was much lower than that sufficient enough to induce cell death and inhibit autophagy. Chloroquine increased GM1 level in HT22 cells at low μM concentrations but glutamate-induced cell death occurred before GM1 accumulation, suggesting that GM1 induction is not related to the protective effect of chloroquine against glutamate-induced cell death. Interestingly, BD1047 and NE-100, sigma-1 receptor antagonists, abrogated the protective effect of chloroquine against glutamate-induced cell death and reactive oxygen species production. In addition, cutamesine (SA4503), a sigma-1 receptor agonist, prevented both glutamate-induced cell death and reactive oxygen species production. These findings indicate that chloroquine at concentrations below its ability to inhibit autophagy and induce cell death is able to rescue HT22 cells from glutamate-induced cell death by reducing excessive production of reactive oxygen species through sigma-1 receptors. These results suggest potential use of chloroquine, an established anti-malarial agent, as a neuroprotectant against oxidative stress, which occurs in a variety of neurodegenerative diseases.