AIM:To investigate the possible mechanism how orphan nuclear receptor 4A1(NR4A1)affects renal fibrosis in unilateral ureteral obstruction(UUO)mice.METHODS:(1)Specific pathogen-free(SPF)male C57BL/6J mice(5 to 6 weeks old)were randomly divided into sh-Con+sham group(n=6),sham+sh-NR4A1 group(n=6),sh-NR4A1+UUO group(n=6),and sh-NR4A1+UUO group(n=6).Renal NR4A1 knockdown mice were prepared by intrarenal injection of NR4A1 viral vector.(2)SPF male C57BL/6J mice(5 to 6 weeks old)were randomly assigned to in sham group,UUO group,and UUO+cytosporone-B(Csn-B)group.An animal model of renal fibrosis was prepared by UUO,and Csn-B was intervened for 14 days.HE,Masson,and Sirius red staining were used to observe renal pathological damage.Immunohistochemistry and Western blot were performed to detect the expression of NR4A1,interferon-γ(IFN-γ),α-smooth muscle actin(α-SMA)and vimentin.The purpose of this study is to observe the regulatory effect of NR4A1 on UUO-induced renal fibrosis.RESULTS:(1)The expression of NR4A1 was decreased in kidney tissues of UUO mice(P<0.05).(2)HE staining results showed that there are tubular dilation,atrophy,and massive inflammatory cell infiltra-tion in sh-Con+UUO group,and NR4A1 knockdown can aggravate UUO-induced kidney damage(P<0.05).The results of Masson and Sirius red staining showed a banded distribution of collagen deposition in the sh-Con+UUO group,and colla-gen deposition increased significantly after NR4A1 knockdown(P<0.05).Treatment with Csn-B could improve renal path-ological damage and reduce collagen deposition.(3)UUO could upregulate the expression of α-SMA and vimentin,and NR4A1 knockdown could significantly increase UUO-induced their expression(P<0.05).In addition,Csn-B could im-prove UUO-induced renal fibrosis(P<0.05).(4)The expression of IFN-γ was increased in UUO mice,and NR4A1 knockdown could upregulate UUO-induced IFN-γ expression(P<0.05).Moreover,Csn-B could down-regulate UUO-in-duced IFN-γ expression(P<0.05).CONCLUSION:NR4A1 can affect renal fibrosis by regulating IFN-γ in UUO mice.

AIM:This study aims to investigate the impact of chronic kidney disease(CKD)on the growth,development,and cognitive function of offspring rats,and to evaluate the effects of esaxerenone(ESAX)intervention.METHODS:Thirty female non-pregnant Wistar rats were randomly assigned to three groups:sham operation+pregnancy(control group),UUO+pregnancy(model group),and UUO+pregnancy+esaxerenone(treatment group),with 10 rats in each group.CKD was induced in the UUO+pregnancy and UUO+pregnancy+esaxerenone groups by performing uni-lateral ureteral obstruction(UUO),while the sham operation+pregnancy group underwent a non-ligated and non-clipped ureter procedure.Rats in the treatment group received esaxerenone at a dosage of 1 mg·kg-1·d-1.Vaginal smears were per-formed weekly from the 8th week post-UUO to monitor the estrous cycle.Female and male rats in pre-estrus or estrus were paired in a 2∶1 ratio,and the day with the first appearance of sperm in vaginal smears was recorded as the first day of preg-nancy.Offspring were delivered 21 to 22 days post-gestation,and 10 offspring from each group were selected for further experimentation:sham-offspring(sham-offspr)group,UUO-offspro group,and esaxerenone treatment offspring(ESAX-offspr)group.At 21 days of age,offspring weight and tail length were measured.Behavioral tests,including the open field test,Y maze test,and Morris water maze test,assessed learning and memory abilities.Serum levels of aldosterone,5-hydroxytryptamine(5-HT),and brain-derived neurotrophic factor(BDNF)were measured using ELISA.Serum creati-nine(SCr)and blood urea nitrogen(BUN)levels were assessed using conventional biochemical methods.Renal pathology was examined using Hematoxylin-Eosin(HE)staining.RESULTS:Offspring in the UUO-offspr group had reduced body weight and tail length compared to the sham-offspr group(P＜0.05).Behavioral tests indicated that exploration and memo-ry abilities were significantly impaired in the UUO-offspr group compared to the sham-offspr group(P＜0.05),while the ESAX-offspr group showed improved behavioral development compared to the UUO-offspr group(P＜0.05).ELISA results revealed decreased levels of serum 5-HT,BDNF,and aldosterone in the UUO-offspr group compared to the sham-offspr group(P＜0.01),with increased levels in the ESAX-offspr group(P＜0.05).Renal function tests showed elevated SCr and BUN levels in the UUO-offspr group compared to the sham-offspr group(P＜0.01),while levels in the ESAX-offspr group were reduced(P＜0.01).HE staining demonstrated mild tubular dilation and inflammatory cell infiltration in the UUO-offspr group,whereas the ESAX-offspr group had well-arranged tubules with reduced inflammation.CONCLU-SION:Chronic kidney disease adversely affects the growth,development,and cognitive function of offspring rats by 21 days of age.Esaxerenone intervention can mitigate these detrimental effects on growth,development,and cognitive abili-ties in offspring rats.

AIM:To investigate the possible mechanism how orphan nuclear receptor 4A1(NR4A1)affects renal fibrosis in unilateral ureteral obstruction(UUO)mice.METHODS:(1)Specific pathogen-free(SPF)male C57BL/6J mice(5 to 6 weeks old)were randomly divided into sh-Con+sham group(n=6),sham+sh-NR4A1 group(n=6),sh-NR4A1+UUO group(n=6),and sh-NR4A1+UUO group(n=6).Renal NR4A1 knockdown mice were prepared by intrarenal injection of NR4A1 viral vector.(2)SPF male C57BL/6J mice(5 to 6 weeks old)were randomly assigned to in sham group,UUO group,and UUO+cytosporone-B(Csn-B)group.An animal model of renal fibrosis was prepared by UUO,and Csn-B was intervened for 14 days.HE,Masson,and Sirius red staining were used to observe renal pathological damage.Immunohistochemistry and Western blot were performed to detect the expression of NR4A1,interferon-γ(IFN-γ),α-smooth muscle actin(α-SMA)and vimentin.The purpose of this study is to observe the regulatory effect of NR4A1 on UUO-induced renal fibrosis.RESULTS:(1)The expression of NR4A1 was decreased in kidney tissues of UUO mice(P<0.05).(2)HE staining results showed that there are tubular dilation,atrophy,and massive inflammatory cell infiltra-tion in sh-Con+UUO group,and NR4A1 knockdown can aggravate UUO-induced kidney damage(P<0.05).The results of Masson and Sirius red staining showed a banded distribution of collagen deposition in the sh-Con+UUO group,and colla-gen deposition increased significantly after NR4A1 knockdown(P<0.05).Treatment with Csn-B could improve renal path-ological damage and reduce collagen deposition.(3)UUO could upregulate the expression of α-SMA and vimentin,and NR4A1 knockdown could significantly increase UUO-induced their expression(P<0.05).In addition,Csn-B could im-prove UUO-induced renal fibrosis(P<0.05).(4)The expression of IFN-γ was increased in UUO mice,and NR4A1 knockdown could upregulate UUO-induced IFN-γ expression(P<0.05).Moreover,Csn-B could down-regulate UUO-in-duced IFN-γ expression(P<0.05).CONCLUSION:NR4A1 can affect renal fibrosis by regulating IFN-γ in UUO mice.

AIM:This study aims to investigate the impact of chronic kidney disease(CKD)on the growth,development,and cognitive function of offspring rats,and to evaluate the effects of esaxerenone(ESAX)intervention.METHODS:Thirty female non-pregnant Wistar rats were randomly assigned to three groups:sham operation+pregnancy(control group),UUO+pregnancy(model group),and UUO+pregnancy+esaxerenone(treatment group),with 10 rats in each group.CKD was induced in the UUO+pregnancy and UUO+pregnancy+esaxerenone groups by performing uni-lateral ureteral obstruction(UUO),while the sham operation+pregnancy group underwent a non-ligated and non-clipped ureter procedure.Rats in the treatment group received esaxerenone at a dosage of 1 mg·kg-1·d-1.Vaginal smears were per-formed weekly from the 8th week post-UUO to monitor the estrous cycle.Female and male rats in pre-estrus or estrus were paired in a 2∶1 ratio,and the day with the first appearance of sperm in vaginal smears was recorded as the first day of preg-nancy.Offspring were delivered 21 to 22 days post-gestation,and 10 offspring from each group were selected for further experimentation:sham-offspring(sham-offspr)group,UUO-offspro group,and esaxerenone treatment offspring(ESAX-offspr)group.At 21 days of age,offspring weight and tail length were measured.Behavioral tests,including the open field test,Y maze test,and Morris water maze test,assessed learning and memory abilities.Serum levels of aldosterone,5-hydroxytryptamine(5-HT),and brain-derived neurotrophic factor(BDNF)were measured using ELISA.Serum creati-nine(SCr)and blood urea nitrogen(BUN)levels were assessed using conventional biochemical methods.Renal pathology was examined using Hematoxylin-Eosin(HE)staining.RESULTS:Offspring in the UUO-offspr group had reduced body weight and tail length compared to the sham-offspr group(P＜0.05).Behavioral tests indicated that exploration and memo-ry abilities were significantly impaired in the UUO-offspr group compared to the sham-offspr group(P＜0.05),while the ESAX-offspr group showed improved behavioral development compared to the UUO-offspr group(P＜0.05).ELISA results revealed decreased levels of serum 5-HT,BDNF,and aldosterone in the UUO-offspr group compared to the sham-offspr group(P＜0.01),with increased levels in the ESAX-offspr group(P＜0.05).Renal function tests showed elevated SCr and BUN levels in the UUO-offspr group compared to the sham-offspr group(P＜0.01),while levels in the ESAX-offspr group were reduced(P＜0.01).HE staining demonstrated mild tubular dilation and inflammatory cell infiltration in the UUO-offspr group,whereas the ESAX-offspr group had well-arranged tubules with reduced inflammation.CONCLU-SION:Chronic kidney disease adversely affects the growth,development,and cognitive function of offspring rats by 21 days of age.Esaxerenone intervention can mitigate these detrimental effects on growth,development,and cognitive abili-ties in offspring rats.

AIM:To explore the mechanisms behind the inhibition of lymphangiogenesis in pregnant rats with obstructive nephropathy and assess the protective effects on kidney function.METHODS:Forty nulliparous female Wi-star rats were randomly assigned to four groups:sham operation,sham operation+pregnancy,model,and Esaxerenone groups,with 10 rats in each group.Renal injury was induced in the model and Esaxerenone groups via unilateral ureteral obstruction(UUO).The other two groups underwent ureteral dissociation without ligation.Nine weeks post-UUO,female rats in the sham operation+pregnancy,model,and Esaxerenone groups were mated with male rats(2:1 ratio)to establish a rat model of obstructive nephropathy during pregnancy.Starting the day after UUO,rats in the Esaxerenone group re-ceived Esaxerenone at 1 mg·kg-1·d-1.On the 18th day of pregnancy,24-hour urine was collected using metabolic cages.The following day,the rats were sacrificed,serum samples collected,and the contralateral kidney removed.Blood urea ni-trogen(BUN)was measured using standard biochemical methods,and endogenous creatinine clearance rate(Ccr)was calculated.Kidney tissue pathology was assessed using HE,Masson,and Sirius red staining.Serum aldosterone levels were determined via ELISA.Immunohistochemistry,real-time PCR,and Western blot were employed to assess mineralo-corticoid receptor(MR)activation,lymphangiogenesis,signaling pathways,and fibrosis-related markers.RESULTS:Renal function tests revealed increased BUN levels and decreased Ccr in the model group(P<0.01).Pathological exami-nation showed dilated renal tubules,significant collagen deposition,and inflammatory cell infiltration in the model group.ELISA results indicated a significant increase in serum aldosterone levels in the model group(P<0.01).Immunohisto-chemistry showed enhanced nuclear translocation of MR in the kidneys of the model group post-activation.Western blot and real-time PCR demonstrated a marked increase in neutrophil gelatinase-associated lipocalin(NGAL)expression in the model group(P<0.01).Additionally,the expression of vascular endothelial growth factor C(VEGF-C)and its receptor VEGFR3 was significantly elevated in the renal tubulointerstitium of the model group,as shown by both immunohistochem-istry and real-time PCR(P<0.01).The PI3K/Akt signaling pathway was activated in the model group,with significantly increased phosphorylation levels observed primarily in renal tubular epithelial and interstitial cells(P<0.01).Collagen type III(Col III)expression,primarily in the renal tubulointerstitium,was also significantly upregulated in the model group,consistent with real-time PCR results(P<0.01).Esaxerenone treatment improved renal function,reduced patho-logical damage,inhibited aldosterone secretion,and downregulated the expression of MR,NGAL,VEGF-C,VEGFR3,phosphorylated PI3K,phosphorylated Akt,and Col III(P<0.01).CONCLUSION:Esaxerenone mitigates aldosterone-induced MR activation,modulates the PI3K/Akt signaling pathway,reduces lymphangiogenesis in the contralateral kidney of pregnant rats with obstructive nephropathy,decreases collagen deposition,and delays the progression of renal intersti-tial fibrosis.