Objective:This study investigated the dynamic expression of lipocalin-2(LCN2)and its receptor,brain-type organic cation transporter protein(BOCT),in spinal cords of hSOD1G93A transgenic mice during disease pro-gression,providing potential targets for early anti-inflammatory therapy for ALS.Methods:Utilizing hSOD1G93A trans-genic mice and their wild-type littermates(WT)as animal models,this investigation examined the expression of LCN2 and BOCT at four distinct disease stages:pre-symptomatic stage(60 d),early-symptomatic stage(95 d),symptomatic stage(108 d),and late-symptomatic stage(122 d).Spinal cords were harvested,then RT-qPCR,Western blot,and immunofluorescence double-labeling techniques were employed to assess alteration expressions of LCN2 and BOCT.Ad-ditionally,BV2 cells transfected with the pcDNA3.1-G93A-SOD1 overexpression plasmid served as an in vitro hSOD1G93A BV2 microglial model.After stimulated with LPS for 24 hours,LCN2 mRNA and protein expression in hSOD1G93A BV2 microglial cells and its culture medium were measured by RT-qPCR and ELISA respectively,while BOCT expression was measured by Western blot.Results:Compared with WT mice littermates,increased expression of LCN2 mRNA was detected in the spinal cords of hSOD1G93A transgenic mice at 108 and 122 d.No significant differences were observed in LCN2 or BOCT protein expression in the spinal cords of hSOD1G93A transgenic mice from 60 to 122 d.Double-immunofluorescence labeling revealed co-localization of LCN2 and BOCT with the microglial marker Iba-1 in the ventral horn of lumbar spinal cord of hSOD1G93A transgenic mice from 95 to 122 d.In hSOD1G93A BV2 microglial model,LPS stimulation led to a significantly increased LCN2 mRNA expression and protein secretion.Conversely,there was no significant change in BOCT protein expression after LPS stimulation.Conclusion:Our findings suggest that during ALS progression,there is an enhanced expression and release of LCN2 from activated microglia,potentially exacerbating neuroinflammation and neuronal degeneration.

Objective:This study investigated the dynamic expression of lipocalin-2(LCN2)and its receptor,brain-type organic cation transporter protein(BOCT),in spinal cords of hSOD1G93A transgenic mice during disease pro-gression,providing potential targets for early anti-inflammatory therapy for ALS.Methods:Utilizing hSOD1G93A trans-genic mice and their wild-type littermates(WT)as animal models,this investigation examined the expression of LCN2 and BOCT at four distinct disease stages:pre-symptomatic stage(60 d),early-symptomatic stage(95 d),symptomatic stage(108 d),and late-symptomatic stage(122 d).Spinal cords were harvested,then RT-qPCR,Western blot,and immunofluorescence double-labeling techniques were employed to assess alteration expressions of LCN2 and BOCT.Ad-ditionally,BV2 cells transfected with the pcDNA3.1-G93A-SOD1 overexpression plasmid served as an in vitro hSOD1G93A BV2 microglial model.After stimulated with LPS for 24 hours,LCN2 mRNA and protein expression in hSOD1G93A BV2 microglial cells and its culture medium were measured by RT-qPCR and ELISA respectively,while BOCT expression was measured by Western blot.Results:Compared with WT mice littermates,increased expression of LCN2 mRNA was detected in the spinal cords of hSOD1G93A transgenic mice at 108 and 122 d.No significant differences were observed in LCN2 or BOCT protein expression in the spinal cords of hSOD1G93A transgenic mice from 60 to 122 d.Double-immunofluorescence labeling revealed co-localization of LCN2 and BOCT with the microglial marker Iba-1 in the ventral horn of lumbar spinal cord of hSOD1G93A transgenic mice from 95 to 122 d.In hSOD1G93A BV2 microglial model,LPS stimulation led to a significantly increased LCN2 mRNA expression and protein secretion.Conversely,there was no significant change in BOCT protein expression after LPS stimulation.Conclusion:Our findings suggest that during ALS progression,there is an enhanced expression and release of LCN2 from activated microglia,potentially exacerbating neuroinflammation and neuronal degeneration.