A Benzenediamine Analog FC-99 Drives M2 Macrophage Polarization and Alleviates Lipopolysaccharide- (LPS-) Induced Liver Injury.

Macrophages have variable functional phenotypes, high diversity, and plasticity and are involved in the pathogenesis of sepsis-induced liver injury. Alteration of macrophage polarization through activated (M1) macrophage to alternatively activated (M2) macrophage has emerged as a potential therapeutic strategy. This study was designed to explore the effect of a benzenediamine analog FC-99 on macrophage polarization in vitro and lipopolysaccharide- (LPS-) induced liver injury followed by the underlying mechanisms. For in vitro experiments, FC-99 inhibited M1-related macrophage factors and promoted M2-related markers induced by IL-4 in the mouse macrophage cell line RAW264.7. Moreover, FC-99-induced macrophages polarized to M2 phenotype which could be repressed by a PPAR-γ inhibitor but not STAT6 siRNA knockdown, indicating FC-99-induced M2 macrophage polarization through PPAR-γ rather than STAT6 signal. In LPS-induced septic mice, FC-99 pretreated mice displayed lower expression of M1 markers together with the increased M2 marker CD206 and improvement of liver injury. These findings illustrated that FC-99 could promote M2 macrophage polarization via PPAR-γ signaling and seemed to be a potential therapeutic candidate for inflammatory liver injury.

Oral administration of the nucleoside EFdA (4'-ethynyl-2-fluoro-2'-deoxyadenosine) provides rapid suppression of HIV viremia in humanized mice and favorable pharmacokinetic properties in mice and the rhesus macaque.

Like normal cellular nucleosides, the nucleoside reverse transcriptase (RT) inhibitor (NRTI) 4'-ethynyl-2-fluoro-2'-deoxyadenosine (EFdA) has a 3'-hydroxyl moiety, and yet EFdA is a highly potent inhibitor of human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) replication with activity against a broad range of clinically important drug-resistant HIV isolates. We evaluated the anti-HIV activity of EFdA in primary human cells and in HIV-infected humanized mice. EFdA exhibited excellent potency against HIVJR-CSF in phytohemagglutinin-stimulated peripheral blood mononuclear cells (PBMCs), with a 50% inhibitory concentration of 0.25 nM and a selectivity index of 184,000; similar antiviral potency was found against 12 different HIV clinical isolates from multiple clades (A, B, C, D, and CRF01_AE). EFdA was readily absorbed after oral dosing (5 mg/kg of body weight) in both mice and the rhesus macaque, with micromolar levels of the maximum concentration of drug in serum (Cmax) attained at 30 min and 90 min, respectively. Trough levels were at or above 90% inhibitory concentration (IC90) levels in the macaque at 24 h, suggesting once-daily dosing. EFdA showed reasonable penetration of the blood-brain barrier in the rhesus macaque, with cerebrospinal fluid levels at approximately 25% of plasma levels 8 h after single oral dosing. Rhesus PBMCs isolated 24 h following a single oral dose of 5 mg/kg EFdA were refractory to SIV infection due to sufficiently high intracellular EFdA-triphosphate levels. The intracellular half-life of EFdA-triphosphate in PBMCs was determined to be >72 h following a single exposure to EFdA. Daily oral administration of EFdA at low dosage levels (1 to 10 mg/kg/day) was highly effective in protecting humanized mice from HIV infection, and 10 mg/kg/day oral EFdA completely suppressed HIV RNA to undetectable levels within 2 weeks of treatment.

Hyperthermia and platinum complexes: time between treatments and synergy in vitro and in vivo.

To investigate the greatest therapeutic efficacy, we investigated the effect of scheduling on the cytotoxic interaction between hyperthermia and seven different platinum complexes in vitro and in vivo using the FSaII murine fibrosarcoma cells. Hyperthermia treatment (43 degrees C, 1 h) was administered at various times relative to exposure of the cells to the IC90 (at 37 degrees C, 1 h) of each platinum complex. Greater-than-additive killing of FSaII cells was obtained with cis-diamminedichloroplatinum (II) (CDDP) and hyperthermia when the drug and heat exposure were overlapping simultaneous. The same cell killing effect with carboplatin and hyperthermia resulted from heat exposure up to 5 h prior to, simultaneous with, or immediately after the drug exposure D-Tetraplatin and K2PtCl4 were synergistic with hyperthermia only if the drug and heat exposure were simultaneous. PtCl4(Nile Blue)2 and hyperthermia produced greater-than-additive cell killing if the heat and drug exposure occurred in immediate sequence, simultaneously, or with drug exposure up to 5 h prior to heat exposure. PtCl4(Rh-123)2 and hyperthermia produced greater-than-additive cell killing if the drug and heat occurred in immediate sequence, overlapping, or simultaneously. PtCl4(Fast Black)2 and hyperthermia were additive over a wide range of scheduling from heat exposure 2 h prior to 5 h after drug exposure. When animals bearing FSaIIC tumours were treated with single doses of CDDP (10 mg/kg). carboplatin/PtCl4(Nile Blue)2 (50 mg/kg), PtCl4(Rh-123)2/PtCl4(Fast Black)2 (100 mg/kg) under various combined schedules with hyperthermia treatment (43 degrees C, 30 min), similar cytotoxicity patterns were observed. To administer hyperthermia at a time when the drug concentration in the tumour tissue is at peak level, careful scheduling of systemically administered anticancer drugs with hyperthermia is needed. Modelling studies can identify the stringency/flexibility of drug/heat scheduling to achieve synergistic tumour cell killing.

Interaction of platinum(II) tetrachlorodianion (Fast Black)2 with superhelical DNA and with radiation in vitro and in vivo.

A new complex of tetrachloroplatinum(II) and the azoic diazo dye, Fast Black K, Pt(Fast Black)2, was made in an attempt to produce an uncharged molecule which could readily gain access into cells and could bring a high concentration of tetrachloroplatinum into the vicinity of the DNA. Even the lowest concentration of Pt(Fast Black)2 tested in the superhelical pBR322 plasmid DNA assay in vitro completely converted the superhelical DNA to the circular and linear forms by 24 h. When the cytotoxicity of the Pt(Fast Black)2 and Fast Black were tested in exponentially growing EMT6 cells. Pt(Fast Black)2 was slightly more toxic to normally oxygenated than to hypoxic cells at pH 7.40, but was far more toxic to cells at pH 6.45 with no difference based on cellular oxygenation. Fast Black was much less toxic than Pt(Fast Black)2 and its cytotoxicity was unaffected by pH. Pt(Fast Black)2 had a small radiosensitizing effect on hypoxic EMT6 cells with a dose-modifying factor of 1.3, but exposure to the drug entirely removed the shoulder region on the radiation survival curves for both the oxygenated and hypoxic cells. In contrast, Fast Black reduced the shoulder in hypoxic but not in oxygenated cells. When Pt(Fast Black)2 (500 mg/kg), Fast Black (300 mg/kg) (the maximally tolerated dose), or misonidazole (1 g/kg) were given intraperitoneally 15 min prior to irradiation of FSaIIC tumors with 0, 10, 20, or 30 Gy, Pt(Fast Black)2 alone caused a tumor growth delay of 6 days versus 3 days for Fast Black. With radiation, Pt(Fast Black)2 produced the greatest enhancement in tumor growth delay of the drugs tested, especially at the lowest (10 Gy) radiation dose (i.e., in the in vivo "shoulder region"). These results indicate that Pt(Fast Black)2 may be suitable for clinical development because it causes both significant direct cytotoxicity and enhancement of radiation killing. The fact that its cytotoxicity is markedly increased at an acidic pH and its radiation enhancing effects are greatest in combination with relatively low single-fraction radiation doses make it especially interesting. The cytotoxicity of Pt(Fast Black)2 may be influenced by the tumor environment, and the radiosensitizing properties appear well suited for use with radiation fraction sizes that are employed in the clinic.

[Cytogenetic characteristics of the leukemia L1210 strain in the development of drug resistance]. / Tsitogeneticheskaia kharakteristika shtamma leikoza L1210 pri razvitii lekarstvennoi ustoichivosti.

The dose and schedule dependent resistance occurred at the 17th (L1210/D1) and 27th (L1210/D2) generations during leukemia L1210 transplantation by the cells treated with suboptimal diazane doses. With growth of the resistance to diazane the selection of modal cell class with 39 chromosomes took place while in the parent leukemia line the modal cell class consists of the cells with 40 chromosomes. No reliable differences were observed in G-banded karyotypes between the resistant subline L1210/D1 and the parent line L1210. When the resistant sublines were transplanted without supporting the diazane doses no restoration of the leukemic cells sensitivity to the drug was observed (the time of observation for L1210/D1 was 92 transplantation generations and for L1210/D2-48 generations). The changed number chromosome characteristics remained the same in this case.

[Changes in the proliferative activity of human breast cancer cells cultivated in vivo in diffusion chambers in response to antineoplastic agents]. / Izmenenie proliferativnoi aktivnosti kletok raka molochnoi zhelezy cheloveka, kul'tiviruemykh v diffuzionnykh kamerakh in vivo, pod deistviem protivoopukholevykh preparatov.

A study was made of the effect of nitrosomethylurea (NMU), thiophosphamide and diazane on proliferative activity of human breast cancer cells cultured in diffusion chambers in vivo. NMU highly suppressed the proliferation of human breast cancer cells throughout the experiment. The maximum effect of diazane and thiophosphamide became apparent after 24 hours, while almost complete renewal of the proliferation was observed by the 72nd hour of culture. Diazane and NMU hold promise for clinical trials in human breast cancer.

[Diazane resistance of leukemia L1210 strain: obtaining and kinetic characteristics of growth]. / Rezistentnyi diazanu shtamm leikemii L1210. Poluchenie i kineticheskaia kharakteristika rosta.

The diazane (1-2-bis diazoacetylene) resistant strain was obtained by consecutive transplantation of leukemia L 1210 cell from mice, treated by subtherapeutic doses of the drug. The kinetic pattern of development of the primary and resistant strain were analogous. The resistant strain differed from the primary one by a less rate of the growth and more persistant course. Death of mice in both strains occurred under gaining similar thershold number of cells. In both strains a linear dependence was noted between the survival of mice and the logarithm of the transplanted cells number. The time of doubling of the total number of leukemic cells in the organism of mice in the resistant strain was twice as that in the primary one.