Malvidin promotes PGC-1α/Nrf2 signaling to attenuate the inflammatory response and restore mitochondrial activity in septic acute kidney injury

Canagliflozin potentially promotes renal protection against glycerol-induced acute kidney injury by activating the AMPK/SIRT1/FOXO-3a/PGC-1α and Nrf2/HO-1 pathways

The reno-protective potential of canagliflozin (Cana), an inhibitor of the sodium glucose-linked co-transporter-2 (SGLT-2), has been demonstrated in different models of kidney injury. However, its potential role in preventing glycerol (Gly)-induced acute kidney injury (AKI) remains to be divulged. Therefore, the aim of this study is to investigate the potential reno-protective effect of Cana and its underlying mechanism in a rat model of Gly-induced AKI. Rats were randomly allocated into five groups: normal, Gly, Gly pretreated with 10 mg/kg Cana, Gly pretreated with Cana 25 mg/kg, and normal pretreated with Cana 25 mg/kg for 14 consecutive days. Pretreatment with Cana improved renal structure and enhanced kidney functions manifested by reducing serum creatinine and blood urea nitrogen, as well as renal contents of neutrophil gelatinase-associated lipocalin and kidney injury molecule. Moreover, Cana signified its anti-inflammatory effect by reducing the Gly-induced elevation in renal contents of nuclear factor-κB and interleuκin-6. Additionally, Cana augmented the defense enzymatic antioxidants superoxide dismutase (SOD), manganese-SOD, and heme oxygenase-1, besides increasing the protein expression of the antioxidant transcription factor nuclear factor erythroid 2-related factor 2 to point for its ability to correct redox balance. Cana also upregulated the protein expression of the 5' adenosine monophosphate-activated protein kinase (AMPK), Sirtuin1 (SIRT1), Forkhead box protein O3 (FOXO-3a), and peroxisome proliferator-activated receptor-gamma coactivator 1α (PGC-1α), as well as the transcriptional activity of growth arrest and DNA damage-inducible protein alpha (GAAD45a). In conclusion, Cana demonstrated potentially novel reno-protective mechanisms and mitigated the consequences of AKI through its antioxidant and anti-inflammatory properties, partially by activating the AMPK/SIRT1/FOXO-3a/PGC-1α pathway.

Sepsis-induced cardiac dysfunction: mitochondria and energy metabolism

Sepsis is a life-threatening multi-organ dysfunction syndrome caused by dysregulated host response to infection, posing a significant global healthcare challenge. Sepsis-induced myocardial dysfunction (SIMD) is a common complication of sepsis, significantly increasing mortality due to its high energy demands and low compensatory reserves. The substantial mitochondrial damage rather than cell apoptosis in SIMD suggests disrupted cardiac energy metabolism as a crucial pathophysiological mechanism. Therefore, we systematically reviewed the mechanisms underlying energy metabolism dysfunction in SIMD, including alterations in myocardial cell energy metabolism substrates, excitation-contraction coupling processes, mitochondrial dysfunction, and mitochondrial autophagy and biogenesis, summarizing potential therapeutic targets within them.

PANAXADIOL SAPONIN ALLEVIATES LPS-INDUCED CARDIOMYOPATHY SIMILAR TO DEXAMETHASONE VIA IMPROVING MITOCHONDRIAL QUALITY CONTROL

ABSTRACT

Septic cardiomyopathy is linked to a dysregulation in mitochondrial integrity and elevated mortality rates, for which an efficacious treatment remains elusive. PDS is a panaxadiol saponin extracted from ginseng stem and leaf. This study identified the protective effects of PDS and DEX in LPS-induced cardiomyopathy and explored the mechanism of them treating LPS-induced cardiomyopathy from the perspectives of mitochondrial quality control. DEX and PDS enhance antioxidant defense by degrading Keap1 to activate Nrf2; activate mitochondrial occurrence protein PGC-1α and fusion protein OPA1, Mfn1, and Mfn2 expression; and inhibit phosphorylation of mitochondrial fission protein Drp1, aiming to maintain normal structure and function of mitochondrial, thereby preserving oxidative phosphorylation capacity. In summary, our findings highlighted the protective efficacy of PDS and DEX in maintaining mitochondrial in LPS-induced cardiomyopathy, and mechanism improving mitochondrial quality control at least in part by promoting Nrf2 activation.

Effects and mechanisms of Polygonati Rhizoma polysaccharide on potassium oxonate and hypoxanthine-induced hyperuricemia in mice

Hyperuricemia, a prevalent metabolic disturbance intricately linked to gout and chronic kidney disease (CKD), may be relieved by traditional Chinese medicine Polygonati Rhizoma. It is derived from the rhizomes of Polygonatum sibiricum, Polygonatum kingianum, and Polygonatum cyrtonema, which are rich in polysaccharides and are effective hyperuricemia alleviators. This study investigated the potential of Polygonatum sibiricum polysaccharide (PSP) in managing hyperuricemia. PSP (125, 250, and 500 mg/kg, i.g.) or allopurinol was administered to hyperuricemia mice treated with potassium oxonate and hypoxanthine for two weeks. PSP effectively decreased serum uric acid levels by inhibiting xanthine oxidase and adenosine deaminase activity and expression in the liver and modulating uric acid-related transporters (URAT1, OAT1, and OAT3) in the kidney. PSP lowered serum creatinine and blood urea nitrogen levels, alleviating hyperuricemia-induced renal tubular epithelial-mesenchymal fibrosis. In vitro, PSP promoted mitochondrial biogenesis via the PGC-1α/NRF1/TFAM pathway, suppressed reactive oxygen species production, and prevented cytochrome C and dynamin-related protein 1 dysregulation in HK-2 cells. Furthermore, PSPA (Mw 4.0 kDa) and PSPB (Mw 112.2 kDa) isolated from PSP exhibit different uric acid-lowering mechanisms. In conclusion, our findings highlight the therapeutic potential of PSP and its nephroprotective effects in hyperuricemia, thereby supporting its development as a therapeutic agent for hyperuricemia.

IRG1/itaconate alleviates acute liver injury in septic mice by suppressing NLRP3 expression and its mediated macrophage pyroptosis via regulation of the Nrf2 pathway

Sepsis, a systemic inflammatory response triggered by infection, has a considerably high mortality rate. However, effective prevention and intervention measures against sepsis remain insufficient. Therefore, this study aimed to investigate the mechanisms underlying the protective properties of immune response gene-1 (IRG1) and 4-Octyl itaconate (OI) during acute liver damage in mice with sepsis. A sepsis mouse model was established to compare wild-type and IRG1-/- groups. The impact of IRG1/Itaconate on pro- and anti-inflammatory cytokines was evaluated using J774A.1 cells. IRG1/Itaconate substantially reduced pro-inflammatory cytokines and increased the release of anti-inflammatory cytokines. It reduced pathological damage to liver tissues, preserved normal liver function, decreased the release of reactive oxygen species (ROS) and LDH, and enhanced the GSH/GSSG ratio. Moreover, IRG1 and itaconic acid activated the Nrf2 signaling pathway, regulating the expression of its downstream antioxidative stress-related proteins. Additionally, they inhibited the activity of NLRP3 inflammatory vesicles to suppress the expression of macrophage-associated pyroptosis signaling molecules. Our findings demonstrate that IRG1/OI inhibits NLRP3 inflammatory vesicle activation and macrophage pyroptosis by modulating the Nrf2 signaling pathway, thereby attenuating acute liver injury in mice with sepsis. These findings could facilitate the clinical application of IRG1/Itaconate to prevent sepsis-induced acute liver injury.

Active Components of Pueraria lobata through the MAPK/ERK Signaling Pathway Alleviate Iron Overload in Alcoholic Liver Disease

OBJECTIVE

To delve into the primary active ingredients and mechanism of Pueraria lobata for alleviating iron overload in alcoholic liver disease.

METHODS

Pueraria lobata's potential targets and signaling pathways in treating alcohol-induced iron overloads were predicted using network pharmacology analysis. Then, animal experiments were used to validate the predictions of network pharmacology. The impact of puerarin or genistein on alcohol-induced iron accumulation, liver injury, oxidative stress, and apoptosis was assessed using morphological examination, biochemical index test, and immunofluorescence. Key proteins implicated in linked pathways were identified using RT-qPCR, western blot analysis, and immunohistochemistry.

RESULTS

Network pharmacological predictions combined with animal experiments suggest that the model group compared to the control group, exhibited activation of the MAPK/ERK signaling pathway, suppression of hepcidin expression, and aggravated iron overload, liver damage, oxidative stress, and hepatocyte death. Puerarin and genistein, the active compounds in Pueraria lobata, effectively mitigated the aforementioned alcohol-induced effects. No statistically significant disparities were seen in the effects above between the two groups receiving drug therapy.

CONCLUSION

This study preliminarily demonstrated that puerarin and genistein in Pueraria lobata may increase hepcidin production to alleviate alcohol-induced iron overload by inhibiting the MAPK/ERK signaling pathway.

Grape/Blueberry Anthocyanins and Their Gut-Derived Metabolites Attenuate LPS/Nigericin-Induced Inflammasome Activation by Inhibiting ASC Speck Formation in THP-1 Monocytes

Inflammasomes are multi-protein complexes, which are formed in response to tissue injury, infections, and metabolic stress. However, aberrant inflammasome activation has been linked to several inflammatory diseases. Anthocyanins have been reported to attenuate NLR family pyrin domain-containing 3 (NLRP3) inflammasome activation, but the influence of grape/blueberry anthocyanins and especially their gut-derived metabolites on NLRP3 inflammasome activation in human monocytes remains unclear. Therefore, human leukemic monocytes (THP-1 cells, Tohoku Hospital Pediatrics-1 cells) were preincubated with different concentrations of grape/blueberry anthocyanins, homovanillyl alcohol, or 2,4,6-trihydroxybenzaldehyde (THBA) before the NLRP3 inflammasome was activated by lipopolysaccharide and/or nigericin. Apoptosis-associated speck-like protein containing a CARD (ASC) speck formation, as well as ASC and NLRP3 protein expression, were determined using flow cytometry. Caspase-1 activity was measured in cultured cells, and pro-inflammatory cytokine secretion was determined using enzyme-linked immunosorbent assays. Anthocyanins and their metabolites had no effect on ASC or NLRP3 protein expression. However, THBA significantly inhibited ASC speck formation in primed and unprimed THP-1 monocytes, while caspase-1 activity was significantly declined by grape/blueberry anthocyanins. Furthermore, reduced inflammasome activation resulted in lower pro-inflammatory cytokine secretion. In conclusion, our results show for the first time that grape/blueberry anthocyanins and their gut-derived metabolites exert anti-inflammatory effects by attenuating NLRP3 inflammasome activation in THP-1 monocytes.

The Interplay between Ferroptosis and Neuroinflammation in Central Neurological Disorders

Central neurological disorders are significant contributors to morbidity, mortality, and long-term disability globally in modern society. These encompass neurodegenerative diseases, ischemic brain diseases, traumatic brain injury, epilepsy, depression, and more. The involved pathogenesis is notably intricate and diverse. Ferroptosis and neuroinflammation play pivotal roles in elucidating the causes of cognitive impairment stemming from these diseases. Given the concurrent occurrence of ferroptosis and neuroinflammation due to metabolic shifts such as iron and ROS, as well as their critical roles in central nervous disorders, the investigation into the co-regulatory mechanism of ferroptosis and neuroinflammation has emerged as a prominent area of research. This paper delves into the mechanisms of ferroptosis and neuroinflammation in central nervous disorders, along with their interrelationship. It specifically emphasizes the core molecules within the shared pathways governing ferroptosis and neuroinflammation, including SIRT1, Nrf2, NF-κB, Cox-2, iNOS/NO·, and how different immune cells and structures contribute to cognitive dysfunction through these mechanisms. Researchers' findings suggest that ferroptosis and neuroinflammation mutually promote each other and may represent key factors in the progression of central neurological disorders. A deeper comprehension of the common pathway between cellular ferroptosis and neuroinflammation holds promise for improving symptoms and prognosis related to central neurological disorders.