thymosin-beta(4) and Necrosis

Exposure of tissues to sulfur mustard (SM) results in the formation of protein and nucleotide adducts that disrupt cellular metabolism and cause cell death. Subsequent pathologies involve a significant proinflammatory response, disrupted healing, and long-term defects in tissue architecture. Following ocular exposure, acute corneal sequelae include epithelial erosions, necrosis, and corneal inflammation. Longer term, a progressive injury becomes distributed throughout the anterior chamber, which ultimately causes a profound remodeling of corneal tissues. In many cases, debilitating and vision-threatening injuries reoccur months to years after the initial exposure. Preliminary data in humans suffering from chronic epithelial lesions suggest that thymosin beta4 (Tbeta4) may be a viable candidate to mitigate acute or long-term ocular SM injury. To evaluate therapeutic candidates, we have developed a rabbit ocular exposure model system. In this paper, we report molecular, histological, ultrastructural, and clinical consequences of rabbit ocular SM injury, which can be used to assess Tbeta4 efficacy, including timepoints at which Tbeta4 will be assessed for therapeutic utility.

Topics: Animals; Cornea; Eye; Eye Injuries; Humans; Male; Mice; Mustard Gas; Necrosis; Physiological Phenomena; Rabbits; Thymosin; Wound Healing

To study the effects of exogenous thymosinβ4 (Tβ4) treatment in acetaminophen (APAP)-induced hepatotoxicity.. Liver injury was induced in mice by a single intraperitoneal injection of APAP (500 mg/kg). Exogenous Tβ4 was intraperitoneally administrated at 0 h, 2 h and 4 h after APAP injection. Chloroquine (CQ) (60 mg/kg) was intraperitoneally injected 2 h before APAP administration to inhibit autophagy. Six hours after APAP injection liver injury was evaluated by histological examinations, biochemical measurements and enzyme linked immunosorbent assay (ELISAs). Western blots were performed to detect proteins expression.. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities were significantly increased 6 h after APAP administration, but were significantly reduced by co-administration of Tβ4. Histological examinations demonstrated that Tβ4 reduced necrosis and inflammation induced by APAP. Immunofluorescence showed that Tβ4 suppressed APAP-induced translocation of high mobility group box-1 protein (HMGB1) from the nucleus to cytosol and intercellular space. Hepatic glutathione (GSH) depletion, malondialdehyde (MDA) formation and decreased superoxide dismutase (SOD) activities induced by APAP were all attenuated by Tβ4. APAP-induced increases in hepatic nuclear factor-κB (NF-κB) p65 protein expression and inflammatory cytokines production including interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) were reduced by Tβ4 treatment. Increased LC3 and p62 proteins in the liver tissues of APAP-treated mice were decreased by Tβ4 treatment, which indicated the enhancement of autophagy flux by Tβ4. Furthermore, inhibiting autophagy by CQ abrogated the protective effects of Tβ4 against APAP hepatotoxicity.. Exogenous Tβ4 treatment exerts protective effects against APAP-induced hepatotoxicity in mice. The underneath molecular mechanisms may involve autophagy enhancement and inhibition of oxidative stress by Tβ4.

Topics: Acetaminophen; Alanine Transaminase; Animals; Antioxidants; Aspartate Aminotransferases; Autophagy; Chemical and Drug Induced Liver Injury; Disease Models, Animal; HMGB1 Protein; Humans; Interleukin-1beta; Liver; Male; Mice; Mice, Inbred BALB C; Necrosis; Thymosin; Tumor Necrosis Factor-alpha

Zinc exhibits inhibitory effects on apoptosis, and a deficiency in this metal generally causes this type of cell death to occur. In the present study, we found that exposure to zinc results in necrosis of prostate carcinoma cells. When zinc acetate was added to LNCaP or PC-3 cells in monolayer culture, they began to detach from the culture dishes, and viability was lost after 4-8 h. Most of the cell death was found to be due to necrosis as determined by double staining with fluorescein-isothiocyanate-labeled annexin V and ethidium bromide, and by detection of hypodiploid cells. Associated with the induction of necrosis was an increase in low molecular-mass proteins, identified by HPLC analysis to be thymosin beta10, parathymosin and GAGE in LNCaP cells, and thymosin beta4, parathymosin and metallothionein in PC-3. The time course of the increase of thymosin beta10 in LNCaP cells and thymosin beta4 in PC-3 cells was consistent with that of appearance of cell detachment and dead cells. These results indicate that zinc can induce necrosis and suggest that production of proteins including beta-thymosins is involved in induction of processes leading to cell detachment.

Topics: Adenocarcinoma; Annexin A5; Apoptosis; Cell Adhesion; Cell Division; Cell Survival; Copper; DNA, Neoplasm; Humans; Male; Metallothionein; Necrosis; Neoplasm Proteins; Prostatic Neoplasms; Thymosin; Tumor Cells, Cultured; Zinc

We have shown the in vivo usefulness of a novel chimera tumor necrosis factor (TNF), called rTNF-STH, which was constituted with human thymosin beta 4 and recombinant human TNF-SAM1. Tumor necrosis was induced by intravenous injection of a smaller amount of rTNF-STH (1 x 10(3) U/mouse, 0.67 microgram/mouse) than rTNF-alpha or rTNF-S (1 x 10(4) U/mouse, 2.5-5 micrograms/mouse). Significant antitumor effects of rTNF-STH to Meth A fibrosarcoma, B16 melanoma, MH134 hepatoma, or Lewis lung carcinoma (3LL) were observed by systemic injection of rTNF-STH at the maximum tolerable dose of 1 x 10(4) U/mouse (6.7 micrograms/mouse); this dose did not cause regression of tumors by conventional rTNF-alpha. rTNF-STH showed a significant prolongation of its half-life in serum. The average calculated half-life of the chimera protein is about 110 min, which is 15 times longer than that of original TNF-SAM1 (7.5 min). On the basis of this prolongation of half-life of rTNF-STH and its efficient hemorrhagic necrotic activity, the antitumor effect of rTNF-STH--as compared with that of the known TNF species--is discussed. Findings indicate that use of the chimera protein to alter the N-terminal region of TNF may be a promising approach to obtain molecules that more favorably attack tumors and other diseases than conventional rTNFs.

Topics: Animals; Fibrosarcoma; Half-Life; Liver Neoplasms, Experimental; Lung Neoplasms; Melanoma, Experimental; Mice; Mice, Inbred BALB C; Mice, Inbred C3H; Mice, Inbred C57BL; Necrosis; Neoplasm Transplantation; Neoplasms, Experimental; Recombinant Fusion Proteins; Recombinant Proteins; Thymosin; Tumor Necrosis Factor-alpha