Background Sustained lipolysis exacerbates subclinical ketosis(SCK)in dairy cows and is associated with inflammation and adipose tissue macrophage(ATM)infiltration.While ATM involvement in adipose homeostasis and infl...Background Sustained lipolysis exacerbates subclinical ketosis(SCK)in dairy cows and is associated with inflammation and adipose tissue macrophage(ATM)infiltration.While ATM involvement in adipose homeostasis and inflammation in early lactation is recognized,a comprehensive exploration of ATM polarization phenotypes in SCK cows is lacking.This study aimed to characterize ATM polarization and its link to lipolysis and inflammation in SCK cows.Results Subcutaneous adipose tissue samples were obtained from dairy cows to analyze protein expression and gene profiles.Compared with healthy cows,SCK cows had higher serum BHBA and NEFA,smaller adipocytes,and increased expression of lipolytic enzymes(LIPE,ATGL),indicating enhanced lipolysis.Decreased levels of FASN,PPARγ,p-SMAD3,and TGFβsuggested impaired adipogenesis.Inflammatory markers(TNF-α,IFN-γ,TLR4,Caspase1)and NFκB signaling activity were elevated.ATM infiltration was supported by increased CD9,CD68,TREM2,and CXCL1 expression.Protein abundance of M1 polarization markers(iNOS,CD86 and CCL2)in ATMs were associated with greater levels of NOS2,IL1B,CD86 and CCL2 mRNA expression in SCK cows;fluorescence intensity of NOS2 and CD86 also was elevated,alongside a higher proportion of CD68+/CD86+immunopositive cells within adipose tissue.ELISA further quantified increased concentrations of IL-1β and CCL2.Conversely,the abundance of ATM M2 polarization markers,including CD206,IL-10,KLF4,and Arg1,at both the protein and mRNA levels demonstrated a decline.Meanwhile,the proportion of CD68+/CD206+immune response cells was relatively low in SCK cows.Conclusions Overall,the present study indicated an augmented macrophage presence within adipose tissue during subclinical ketosis,with a predominance of pro-inflammatory macrophages(M1 ATM).This observation suggested a vicious cycle wherein macrophage infiltration and pro-inflammatory polarization coincide with enhanced lipolysis and an amplified inflammatory cascade.展开更多
Background Subacute ruminal acidosis(SARA)causes an increase in endotoxin,which can induce immune and inflammatory responses in the ruminal epithelium of dair y cows.In non-ruminants,epigallocatechin-3-gallate(EGCG),a...Background Subacute ruminal acidosis(SARA)causes an increase in endotoxin,which can induce immune and inflammatory responses in the ruminal epithelium of dair y cows.In non-ruminants,epigallocatechin-3-gallate(EGCG),a major bioactive ingredient of green tea,is well-known to alleviate inflammation.Whether EGCG confers protection against SARA-induced inflammation and the underlying mechanisms are unknown.Results In vivo,eight ruminally cannulated Holstein cows in mid-lactation were randomly assigned to either a low-concentrate(40%)diet(CON)or a high-concentrate(60%)diet(HC)for 3 weeks to induce SARA(n=4).Cows with SARA had greater serum coccentrations of tumor necrosis factor(TNF)-αand interleukin-6,and epitheliu m had histological signs of damage.In vitro,immortalized bovine ruminal epithelial cells(BREC)were treated with lipopolysaccharide(LPS)to imitate the inflammatory damage caused by SARA.Our data revealed that BREC treated with 10 pg/mL LPS for 6 h successfully induce a robust inflammatory response as indicated by increased phosphorylation of IKBa and nuclear factor kappa-B(NF-κB)p65.Pre-treatment of BREC with 50μmol/L EGCG for 6 h before LPS challenge promoted the degradation of NLR family pyrin domain containing 3(NLRP3)inflammasome through activation of autophagy,which further repressed activation of NF-κB pathway targeting Toll-like receptor4(TLR4).Analyses also revealed that the ECGG upregulated tight junction(TJ)protein expression upon incubation with LPS.Conclusions Subacute ruminal acidosis causes ruminal epithelium injury and systemic inflammation in dairy cows.However,the anti-in flammatory effects of EGCG help preserve the integrity of the epithelial barrier through activating autophagy when BREC are exposed to LPS.Thus,EGCG could potentially serve as an e,fifective therapeutic agent for SARA-associated inflammation.展开更多
Weaning stress causes substantial economic loss in the swine industry. Moreover, weaning-induced intestinal barrier damage and dysfunction of the gut-liver axis are associated with reduced growth performance in piglet...Weaning stress causes substantial economic loss in the swine industry. Moreover, weaning-induced intestinal barrier damage and dysfunction of the gut-liver axis are associated with reduced growth performance in piglets. Metasilicate-based alkaline mineral water (AMW) has shown potential therapeutic effects on gastrointestinal disorders;however, the mechanisms involved and their overall effects on the gut-liver axis have not been explored. Here, sodium metasilicate (SMS) was used to prepare metasilicate-based AMW (basal water+500 mg/L SMS). A total of 240 newly weaned piglets were allocated to the Control and SMS groups (6 replicate pens per group and 20 piglets per pen) for a 15-day trial period. Histopathological evaluations were conducted using hematoxylin and eosin staining. To analyze the composition of the gut microbiota, 16S r RNA Pac Bio SMRT Gene Full-Length Sequencing was performed. Western blotting and immunofluorescence were employed to assess protein expression levels. Our results indicated that metasilicate-based AMW effectively alleviated weaning-induced colonic or liver morphological injury and inflammatory response, as well as liver cholesterol metabolism disorders. Further analysis showed that metasilicate-based AMW promoted deoxycholic acid (DCA)biosynthesis by increasing the abundance of Lactobacillus_delbrueckii in the colon (P <0.001). This consequently improved weaning-induced colon and liver injury and dysfunction through the DCAsecondary bile acid (SBA) receptors (SBAR)-nuclear factor-kappa B (NF-κB)/NOD-like receptor family pyrin domain-containing 3 (NLRP3) pathways. Growth performance parameters, including final body weight (P=0.034) and average daily gain (P <0.001), in the SMS group were significantly higher than those in the Control group. Therefore, metasilicate-based AMW maintains gut-liver axis homeostasis by regulating the microbiota-mediated SBA-SBAR pathway in piglets under weaning stress. Our research provides a new strategy for mitigating stress-induced gut-liver axis dysfunction in weaned piglets.展开更多
基金supported by grants from National Natural Science Foundation of China(32125038)National Key Research and Development Program of China(grant number 2023YFD1801100 and 2023YFD1800804)+1 种基金the Key Research and Development Program of the Xinjiang Uygur Autonomous Region(No.2024B02016)the 2115 Talent Development Program of China Agricultural University.Authors declare that no conflicts of interest exist.
文摘Background Sustained lipolysis exacerbates subclinical ketosis(SCK)in dairy cows and is associated with inflammation and adipose tissue macrophage(ATM)infiltration.While ATM involvement in adipose homeostasis and inflammation in early lactation is recognized,a comprehensive exploration of ATM polarization phenotypes in SCK cows is lacking.This study aimed to characterize ATM polarization and its link to lipolysis and inflammation in SCK cows.Results Subcutaneous adipose tissue samples were obtained from dairy cows to analyze protein expression and gene profiles.Compared with healthy cows,SCK cows had higher serum BHBA and NEFA,smaller adipocytes,and increased expression of lipolytic enzymes(LIPE,ATGL),indicating enhanced lipolysis.Decreased levels of FASN,PPARγ,p-SMAD3,and TGFβsuggested impaired adipogenesis.Inflammatory markers(TNF-α,IFN-γ,TLR4,Caspase1)and NFκB signaling activity were elevated.ATM infiltration was supported by increased CD9,CD68,TREM2,and CXCL1 expression.Protein abundance of M1 polarization markers(iNOS,CD86 and CCL2)in ATMs were associated with greater levels of NOS2,IL1B,CD86 and CCL2 mRNA expression in SCK cows;fluorescence intensity of NOS2 and CD86 also was elevated,alongside a higher proportion of CD68+/CD86+immunopositive cells within adipose tissue.ELISA further quantified increased concentrations of IL-1β and CCL2.Conversely,the abundance of ATM M2 polarization markers,including CD206,IL-10,KLF4,and Arg1,at both the protein and mRNA levels demonstrated a decline.Meanwhile,the proportion of CD68+/CD206+immune response cells was relatively low in SCK cows.Conclusions Overall,the present study indicated an augmented macrophage presence within adipose tissue during subclinical ketosis,with a predominance of pro-inflammatory macrophages(M1 ATM).This observation suggested a vicious cycle wherein macrophage infiltration and pro-inflammatory polarization coincide with enhanced lipolysis and an amplified inflammatory cascade.
基金supported by the National Natural Science Foundation of China(Beijing,China,grant nos.32125038)。
文摘Background Subacute ruminal acidosis(SARA)causes an increase in endotoxin,which can induce immune and inflammatory responses in the ruminal epithelium of dair y cows.In non-ruminants,epigallocatechin-3-gallate(EGCG),a major bioactive ingredient of green tea,is well-known to alleviate inflammation.Whether EGCG confers protection against SARA-induced inflammation and the underlying mechanisms are unknown.Results In vivo,eight ruminally cannulated Holstein cows in mid-lactation were randomly assigned to either a low-concentrate(40%)diet(CON)or a high-concentrate(60%)diet(HC)for 3 weeks to induce SARA(n=4).Cows with SARA had greater serum coccentrations of tumor necrosis factor(TNF)-αand interleukin-6,and epitheliu m had histological signs of damage.In vitro,immortalized bovine ruminal epithelial cells(BREC)were treated with lipopolysaccharide(LPS)to imitate the inflammatory damage caused by SARA.Our data revealed that BREC treated with 10 pg/mL LPS for 6 h successfully induce a robust inflammatory response as indicated by increased phosphorylation of IKBa and nuclear factor kappa-B(NF-κB)p65.Pre-treatment of BREC with 50μmol/L EGCG for 6 h before LPS challenge promoted the degradation of NLR family pyrin domain containing 3(NLRP3)inflammasome through activation of autophagy,which further repressed activation of NF-κB pathway targeting Toll-like receptor4(TLR4).Analyses also revealed that the ECGG upregulated tight junction(TJ)protein expression upon incubation with LPS.Conclusions Subacute ruminal acidosis causes ruminal epithelium injury and systemic inflammation in dairy cows.However,the anti-in flammatory effects of EGCG help preserve the integrity of the epithelial barrier through activating autophagy when BREC are exposed to LPS.Thus,EGCG could potentially serve as an e,fifective therapeutic agent for SARA-associated inflammation.
基金National Natural Science Foundation of China (No. 32402972 and No. W2433075)Postdoctoral Fellowship Program of CPSF (No. GZB20240133) and China Agriculture Research System of MOF and MARA (No. CARS-35)
文摘Weaning stress causes substantial economic loss in the swine industry. Moreover, weaning-induced intestinal barrier damage and dysfunction of the gut-liver axis are associated with reduced growth performance in piglets. Metasilicate-based alkaline mineral water (AMW) has shown potential therapeutic effects on gastrointestinal disorders;however, the mechanisms involved and their overall effects on the gut-liver axis have not been explored. Here, sodium metasilicate (SMS) was used to prepare metasilicate-based AMW (basal water+500 mg/L SMS). A total of 240 newly weaned piglets were allocated to the Control and SMS groups (6 replicate pens per group and 20 piglets per pen) for a 15-day trial period. Histopathological evaluations were conducted using hematoxylin and eosin staining. To analyze the composition of the gut microbiota, 16S r RNA Pac Bio SMRT Gene Full-Length Sequencing was performed. Western blotting and immunofluorescence were employed to assess protein expression levels. Our results indicated that metasilicate-based AMW effectively alleviated weaning-induced colonic or liver morphological injury and inflammatory response, as well as liver cholesterol metabolism disorders. Further analysis showed that metasilicate-based AMW promoted deoxycholic acid (DCA)biosynthesis by increasing the abundance of Lactobacillus_delbrueckii in the colon (P <0.001). This consequently improved weaning-induced colon and liver injury and dysfunction through the DCAsecondary bile acid (SBA) receptors (SBAR)-nuclear factor-kappa B (NF-κB)/NOD-like receptor family pyrin domain-containing 3 (NLRP3) pathways. Growth performance parameters, including final body weight (P=0.034) and average daily gain (P <0.001), in the SMS group were significantly higher than those in the Control group. Therefore, metasilicate-based AMW maintains gut-liver axis homeostasis by regulating the microbiota-mediated SBA-SBAR pathway in piglets under weaning stress. Our research provides a new strategy for mitigating stress-induced gut-liver axis dysfunction in weaned piglets.
