Dataset Information

A high-concentrate diet induces inflammatory injury via regulating Ca²⁺/CaMKKβ-mediated autophagy in mammary gland tissue of dairy cows.

ABSTRACT:

Introduction

Calmodulin-dependent protein kinase β (CaMKKβ) is closely related to Ca²⁺ concentration. An increase in Ca²⁺ concentration in the cytoplasm activates CaMKKβ, and activated CaMKKβ affects the activities of AMPK and mTOR and induces autophagy. A high-concentrate diet leads to Ca²⁺ disorder in mammary gland tissue.

Objectives

Therefore, this study mainly investigated the induction of mammary gland tissue autophagy by a high-concentrate diet and the specific mechanism of lipopolysaccharide (LPS)-induced autophagy in bovine mammary epithelial cells (BMECs).

Material and methods

Twelve mid-lactation Holstein dairy cows were fed with a 40% concentrate diet (LC) and a 60% concentrate diet (HC) for 3 weeks. At the end of the trial, rumen fluid, lacteal vein blood, and mammary gland tissue were collected. The results showed that the HC diet significantly decreased rumen fluid pH, with a pH lower than 5.6 for more than 3 h, indicating successfully induction of subacute rumen acidosis (SARA). The mechanism of LPS-induced autophagy in BMECs was studied in vitro. First, the cells were divided into a Ctrl group and LPS group to study the effects of LPS on the concentration of Ca²⁺ and autophagy in BMECs. Then, cells were pretreated with an AMPK inhibitor (compound C) or CaMKKβ inhibitor (STO-609) to investigate whether the CaMKKβ-AMPK signaling pathway is involved in LPS-induced BMEC autophagy.

Results

The HC diet increased the concentration of Ca²⁺ in mammary gland tissue and pro-inflammatory factors in plasma. The HC diet also significantly increased the expression of CaMKKβ, AMPK, and autophagy-related proteins, resulting in mammary gland tissue injury. In vitro cell experiments showed that LPS increased intracellular Ca²⁺ concentration and upregulated protein expression of CaMKKβ, AMPK, and autophagy-related proteins. Compound C pretreatment decreased the expression of proteins related to autophagy and inflammation. In addition, STO-609 pretreatment not only reversed LPS-induced BMECs autophagy but also inhibited the protein expression of AMPK, thereby alleviating the inflammatory response in BMECs. These results suggest that inhibition of the Ca²⁺/CaMKKβ-AMPK signaling pathway reduces LPS-induced autophagy, thereby alleviating inflammatory injury of BMECs.

Conclusion

Therefore, SARA may increase the expression of CaMKKβ by increasing Ca²⁺ levels and activate autophagy through the AMPK signaling pathway, thereby inducing inflammatory injury in mammary gland tissue of dairy cows.

SUBMITTER: Meng M

PROVIDER: S-EPMC10183583 | biostudies-literature | 2023

REPOSITORIES: biostudies-literature

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Publications

A high-concentrate diet induces inflammatory injury via regulating Ca<sup>2+</sup>/CaMKKβ-mediated autophagy in mammary gland tissue of dairy cows.

Meng Meijuan M Li Xuerui X Wang Zihan Z Huo Ran R Ma Nana N Chang Guangjun G Shen Xiangzhen X

Frontiers in immunology 20230501

<h4>Introduction</h4>Calmodulin-dependent protein kinase β (CaMKKβ) is closely related to Ca<sup>2+</sup> concentration. An increase in Ca<sup>2+</sup> concentration in the cytoplasm activates CaMKKβ, and activated CaMKKβ affects the activities of AMPK and mTOR and induces autophagy. A high-concentrate diet leads to Ca<sup>2+</sup> disorder in mammary gland tissue.<h4>Objectives</h4>Therefore, this study mainly investigated the induction of mammary gland tissue autophagy by a high-concentrate di ...[more]

PMID: 37197665

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Project description:This study investigated the effects of rumen bypass dandelion extract on the lactation performance, immune index, and mammary oxidative stress of lactating dairy cows fed a high-concentrate diet. This study used a complete randomized block design, and initial milk production, somatic cell counts, and parities were set as block factors. Sixty Holstein cows with similar health conditions and lactating periods (70 ± 15 d) were divided into three groups with 20 replicates per group. The treatments included the LCD group (low-concentrate diet, concentrate-forage = 4:6), HCD group (high-concentrate group, concentrate-forage = 6:4), and DAE group (dandelion aqueous extract group, HCD group with 0.5% DAE). The experimental period was 35 d, and cows were fed three times in the morning, afternoon, and night with free access to water. The results showed the following: (1) Milk production in the HCD and DAE groups was significantly higher (p < 0.05) than that in the LCD group from WK4, and the milk quality differed during the experimental period. (2) The HCD group's pH values significantly differed (p < 0.01) from those of the LCD and DAE groups. (3) In WK2 and WK4 of the experimental period, the somatic cell counts of dairy cows in the HCD group were significantly higher (p < 0.05) than those in the DAE group. (4) The serum concentrations of 8-hydroxy-2'-deoxyguanosine (8-OHdG) and protein carbonyl (PC) in the HCD group were significantly higher (p < 0.05) than those in the LCD group. The activity of catalase (CAT) in the LCD and DAE groups was stronger (p < 0.01) than that in the HCD group. (5) The correlation analysis revealed significantly positive correlations between the plasma LPS concentration and serum concentrations of 8-OHdG (p < 0.01), PC (p < 0.01), and malondialdehyde (MDA, p < 0.05) and significantly negative correlations (p < 0.01) between the plasma LPS concentration and activities of CAT and superoxide dismutase. (6) Compared with that in the HCD and DAE groups, the mRNA expression of α, β, and κ casein and acetyl CoA carboxylase in bovine mammary epithelial cells was significantly higher (p < 0.05) in the LCD group, and the mRNA expression of fatty acid synthetase and stearoyl CoA desaturase in the LCD group was significantly higher (p < 0.01) than that in the HCD group. (7) Compared with that in the LCD and HCD groups, the mRNA expression of Nrf2 was significantly higher (p < 0.01) in the DAE group, and the mRNA expression of cystine/glutamate transporter and NAD (P) H quinone oxidoreductase 1 in the DAE group was significantly higher (p < 0.05) than that in the HCD group. Overall, feeding a high-concentrate diet could increase the milk yield of dairy cows, but the milk quality, rumen homeostasis, and antioxidative capability were adversely affected. The supplementation of DAE in a high-concentrate diet enhanced antioxidative capability by activating the Nrf2 regulatory factor and improved rumen homeostasis and production performance.

Project description:BACKGROUND:Lactation is extremely important for dairy cows; however, the understanding of the underlying metabolic mechanisms is very limited. This study was conducted to investigate the inherent metabolic patterns during lactation using the overall biofluid metabolomics and the metabolic differences from non-lactation periods, as determined using partial tissue-metabolomics. We analyzed the metabolomic profiles of four biofluids (rumen fluid, serum, milk and urine) and their relationships in six mid-lactation Holstein cows and compared their mammary gland (MG) metabolomic profiles with those of six non-lactating cows by using gas chromatography-time of flight/mass spectrometry. RESULTS:In total, 33 metabolites were shared among the four biofluids, and 274 metabolites were identified in the MG tissues. The sub-clusters of the hierarchical clustering analysis revealed that the rumen fluid and serum metabolomics profiles were grouped together and highly correlated but were separate from those for milk. Urine had the most different profile compared to the other three biofluids. Creatine was identified as the most different metabolite among the four biofluids (VIP = 1.537). Five metabolic pathways, including gluconeogenesis, pyruvate metabolism, the tricarboxylic acid cycle (TCA cycle), glycerolipid metabolism, and aspartate metabolism, showed the most functional enrichment among the four biofluids (false discovery rate < 0.05, fold enrichment >2). Clear discriminations were observed in the MG metabolomics profiles between the lactating and non-lactating cows, with 54 metabolites having a significantly higher abundance (P < 0.05, VIP > 1) in the lactation group. Lactobionic acid, citric acid, orotic acid and oxamide were extracted by the S-plot as potential biomarkers of the metabolic difference between lactation and non-lactation. The TCA cycle, glyoxylate and dicarboxylate metabolism, glutamate metabolism and glycine metabolism were determined to be pathways that were significantly impacted (P < 0.01, impact value >0.1) in the lactation group. Among them, the TCA cycle was the most up-regulated pathway (P < 0.0001), with 7 of the 10 related metabolites increased in the MG tissues of the lactating cows. CONCLUSIONS:The overall biofluid and MG tissue metabolic mechanisms in the lactating cows were interpreted in this study. Our findings are the first to provide an integrated insight and a better understanding of the metabolic mechanism of lactation, which is beneficial for developing regulated strategies to improve the metabolic status of lactating dairy cows.

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Dataset Information

A high-concentrate diet induces inflammatory injury via regulating Ca²⁺/CaMKKβ-mediated autophagy in mammary gland tissue of dairy cows.

Introduction

Objectives

Material and methods

Results

Conclusion

Publications

A high-concentrate diet induces inflammatory injury via regulating Ca<sup>2+</sup>/CaMKKβ-mediated autophagy in mammary gland tissue of dairy cows.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets

Dataset Information

A high-concentrate diet induces inflammatory injury via regulating Ca2+/CaMKKβ-mediated autophagy in mammary gland tissue of dairy cows.

Introduction

Objectives

Material and methods

Results

Conclusion

Publications

A high-concentrate diet induces inflammatory injury via regulating Ca<sup>2+</sup>/CaMKKβ-mediated autophagy in mammary gland tissue of dairy cows.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets

A high-concentrate diet induces inflammatory injury via regulating Ca²⁺/CaMKKβ-mediated autophagy in mammary gland tissue of dairy cows.