ABSTRACT
Objective:To prepare the anti-programmed death-ligand 1 (PD-L1) nanoantibody P3C8-C3Fab by ligating with C3Fab and to investigate its role in plasma half-life.Methods:The C3Fab peptide derived from protein G was molecularly fused with the nanobody P3C8 by DNA recombination technology. The nanoantibody P3C8-C3Fab was inducibly expressed and purified in the E. coli BL21 strain, and the binding of it to PD-L1 protein, mouse IgG, and PD-L1-expressing tumor cells was detected by enzyme-linked immunosorbent assay (ELISA). The residual P3C8-C3Fab was detected in mouse serum at different times using double-antibody sandwich ELISA to assess the prolongation of the plasma half-life of PD-L1 nanobodies by C3Fab. Results:The nanoantibody P3C8-C3Fab was successfully constructed, and it could efficiently express itself in soluble form in BL21. The purified NbP3C8-C3Fab protein was obtained with a mass fraction of about 90% at a yield of 7.18 mg/L. The affinity of P3C8-C3Fab for PD-L1 protein and mouse IgG gradually increased with increasing mass concentration and showed a concentration correlation. The binding of P3C8-C3Fab to lung cancer A549 cells showed a concentration correlation. The concentration standard curve of P3C8-C3Fab in mouse serum showed a typical S-shape with a concentration correlation. The plasma half-life of P3C8 was only 0.44 h, while the plasma half-life of P3C8-C3Fab was 21.27-fold higher, up to 9.36 h.Conclusions:The linkage of C3Fab to the nanobodies of P3C8 can significantly prolong the plasma half-life of P3C8, which is valuable for the improvement of in vivo nanobody effects.
ABSTRACT
<p><b>OBJECTIVE</b>To examine the neuroprotective effects of a novel manganese porphyrin, manganese (III) meso-tetrakis (N,N'-diethylimidazolium-2-yl) porphyrin (MnTDM), in the mouse model of Parkinson's disease (PD) induced by paraquat (PQ).</p><p><b>METHODS</b>Male C57BL/6 mice were subcutaneously injected with either saline or PQ at 2-day intervals for a total of 10 doses, MnTDM was subcutaneously injected with the PQ 2 h before treatment. Performance on the pole and swim test were measured 7 days after the last injection and animals were sacrificed one day later. Levels of dopamine (DA) and its metabolites in the striatum were measured by high-performance liquid chromatography with an electrochemical detector (HPLC-ECD). Thiobarbituric acid (TBA) method was used to assay the lipid peroxidation product, malondialdehyde (MDA), and the number of tyrosine hydroxylase (TH) positive neurons was estimated using immunohistochemistry.</p><p><b>RESULTS</b>Pretreatment with MnTDM significantly attenuated PQ-impaired behavioral performance, depleted dopamine content in striata, increased MDA, and dopaminergic neuron loss in the substantia nigra.</p><p><b>CONCLUSIONS</b>Oxidative stress plays an important role in PQ-induced neurotoxicity which can be potentially prevented by manganese porphyrin. These findings also propose a possible therapeutical strategy for neurodegenerative disorders associated with oxidative stress such as PD.</p>
Subject(s)
Animals , Male , Mice , Antioxidants , Therapeutic Uses , Antiparkinson Agents , Therapeutic Uses , Behavior, Animal , Catalysis , Corpus Striatum , Metabolism , Dopamine , Metabolism , Malondialdehyde , Metabolism , Metalloporphyrins , Therapeutic Uses , Mice, Inbred C57BL , Neuroprotective Agents , Therapeutic Uses , Paraquat , Parkinson Disease , Drug Therapy , Metabolism , Substantia Nigra , Tyrosine 3-Monooxygenase , MetabolismABSTRACT
Objective: To observe the effects of manganese( Ⅲ ) meso-tetrakis (N, N'-diethylimidazolium-2-yl) porphyrin (MnTDM) in treatment of early Parkinson's disease(PD) mouse model induced by subcutaneous injection of 1-methyl-4-phenyl1, 2, 3, 6-tetrahydropyridine(MPTP) and to discuss its possible mechanism. Methods:Forty male C57BL/6 mice were evenly randomized into 4 groups: MPTP model group(subcutaneous injection of 25 mg/kg MPTP for 3 days), MnTDM+ MPTP group (15 mg/kg MnTDM was subcutaneously injected 1 h before MPTP injection), MnTDM control group, and normal saline group. Performance of animals in the pole and swimming test was observed 3 days after the last injection. Levels of dopamine (DA) and its metabolites(3,4-dihydroxyphenylacetic acid [DOPAC] and homovanillic acid [HVA]) in the striatum of animals were measured by high-performance liquid chromatography with an electrochemical detector(HPLC-ECD). Thiobarbituric acid (TBA) method was used to examine the levels of malondialdehyde(MDA). Results: Acute injection of MPTP could be used for establishment of PD model. The striatal levels of DA, DOPAC and HVA in MPTP group were significantly lower(P＜0.01)and the striatal level of MDA was significantly higher(P＜0.05) than those of the control group. MPTP had no obvious effect on the behavioral performance of the animals in a short term. MnTDM could partly inhibit the above effects of MPTP. Compared with MPTP group, MnTDM+ MPTP group had significantly higher DA, DOPAC, and HVA levels and significantly lower MDA level(all P＜0.05). There was no significant difference in the behavioral indices of animals between the 4 groups. Conclusion:MnTDM can inhibit lipid peroxidation and promote DA production; it has preventive and therapeutic effects on MPTP induced PD.
ABSTRACT
Objective: To observe the effects of manganese( Ⅲ ) meso-tetrakis (N, N'-diethylimidazolium-2-yl) porphyrin (MnTDM) in treatment of early Parkinson's disease(PD) mouse model induced by subcutaneous injection of 1-methyl-4-phenyl1, 2, 3, 6-tetrahydropyridine(MPTP) and to discuss its possible mechanism. Methods:Forty male C57BL/6 mice were evenly randomized into 4 groups: MPTP model group(subcutaneous injection of 25 mg/kg MPTP for 3 days), MnTDM+ MPTP group (15 mg/kg MnTDM was subcutaneously injected 1 h before MPTP injection), MnTDM control group, and normal saline group. Performance of animals in the pole and swimming test was observed 3 days after the last injection. Levels of dopamine (DA) and its metabolites(3,4-dihydroxyphenylacetic acid [DOPAC] and homovanillic acid [HVA]) in the striatum of animals were measured by high-performance liquid chromatography with an electrochemical detector(HPLC-ECD). Thiobarbituric acid (TBA) method was used to examine the levels of malondialdehyde(MDA). Results: Acute injection of MPTP could be used for establishment of PD model. The striatal levels of DA, DOPAC and HVA in MPTP group were significantly lower(P＜0.01)and the striatal level of MDA was significantly higher(P＜0.05) than those of the control group. MPTP had no obvious effect on the behavioral performance of the animals in a short term. MnTDM could partly inhibit the above effects of MPTP. Compared with MPTP group, MnTDM+ MPTP group had significantly higher DA, DOPAC, and HVA levels and significantly lower MDA level(all P＜0.05). There was no significant difference in the behavioral indices of animals between the 4 groups. Conclusion:MnTDM can inhibit lipid peroxidation and promote DA production; it has preventive and therapeutic effects on MPTP induced PD.