Upregulation of RelB in the miR-122 knockout mice contributes to increased levels of proinflammatory chemokines/cytokines in the liver and macrophages

Impact of steroid therapy on pediatric acute liver failure: prognostic implication and interplay between TNF-α and miR-122

BACKGROUND

Acute liver failure (ALF) is a rare illness marked by rapid deterioration of liver function, leading to high morbidity and mortality rates, particularly in children. While steroids have been observed to correlate with improved survival, evidence supporting their efficacy in ALF children remains limited. miR-122, a liver-specific microRNA, plays a pivotal role in liver pathology, with its expression significantly altered in various liver diseases. Thus, it is considered a potential biomarker for disease progression, aids in prognosis, and identifies therapeutic targets. Our study aims to assess the expression of miR-122 in 24 children with ALF, both before and after steroid therapy, alongside its relationship with tumor necrosis factor-α (TNF-α), to better understand its potential role in treatment response and disease outcomes. miR-122 levels were determined using quantitative real-time RT-PCR (qRT-PCR), while TNF-α levels were assessed using enzyme-linked immunosorbent assay (ELISA) in patient sera.

RESULTS

In ALF children who survived after steroid treatment, miR-122 was markedly decreased compared to both pre-treatment levels (p = 0.003) and levels in deceased patients (p = 0.01). In addition, TNF-α levels significantly increased in surviving patients compared to pre-treatment levels (p = 0.008) and levels in deceased children (p = 0.028). A negative correlation was observed between TNF-α and miR-122 following steroids (r=-0.46, p = 0.04). miR-122 demonstrated 72% sensitivity and 67% specificity in distinguishing survivors and non-survivors, as indicated by its receiver-operated characteristic curve. A positive correlation was found between miR-122 before steroid therapy and both aspartate aminotransferase (AST) and alanine aminotransferase (ALT) before (r = 0.641, p = 0.002 and r = 0.512, p = 0.02, respectively) and after (r = 0.492, p = 0.03 and r = 0.652, p = 0.003, respectively) steroids treatment.

CONCLUSION

Our data implies that lower miR-122 levels in steroids-treated ALF children are associated with a better outcome. Although miR-122 is not a strong standalone marker, it could be valuable in a biomarker panel. The increased TNF-α levels and decreased miR-122 expression indicate their involvement in the disease's pathophysiology. More studies are needed to validate our results.

Sodium benzoate attenuates 2,8-dihydroxyadenine nephropathy by inhibiting monocyte/macrophage TNF-α expression

Sodium benzoate (SB), a known D-amino acid oxidase (DAO) enzyme inhibitor, has an anti-inflammatory effect, although its role in renal damage has not been explored. 2,8-dihydroxyadenine crystal induced chronic kidney disease, in which TNF-α is involved in the pathogenesis, was established by oral adenine administration in C57BL/6JJcl mice (AdCKD) with or without SB to investigate its renal protective effects. SB significantly attenuated AdCKD by decreasing serum creatinine and urea nitrogen levels, and kidney interstitial fibrosis and tubular atrophy scores. The survival of AdCKD mice improved 2.6-fold by SB administration. SB significantly decreased the number of infiltrating macrophages observed in the positive F4/80 immunohistochemistry area and reduced the expression of macrophage markers and inflammatory genes, including TNF-α, in the kidneys of AdCKD. Human THP-1 cells stimulated with either lipopolysaccharide or TNF-α showed increased expression of inflammatory genes, although this was significantly reduced by SB, confirming the anti-inflammatory effects of SB. SB exhibited renal protective effects in AdCKD in DAO enzyme deficient mice, suggesting that anti-inflammatory effect of SB was independent of DAO enzyme activity. Moreover, binding to motif DNA sequence, protein level, and mRNA level of NF-κB RelB were significantly inhibited by SB in AdCKD kidneys and lipopolysaccharide treated THP-1 cells, respectively. We report that anti-inflammatory property of SB is independent of DAO enzymatic activity and is associated with down regulated NF-κB RelB as well as its downstream inflammatory genes such as TNF-α in AdCKD.

miRNA expression profiles of the perilesional skin of atopic dermatitis and psoriasis patients are highly similar

Atopic dermatitis (AD) and psoriasis vulgaris (PV) are chronic inflammatory skin diseases with heterogeneous molecular backgrounds. MicroRNAs (miRNAs) contribute to either development or regulation of many immune system related diseases. Only few miRNA profiling studies are available for AD and no comparisons between AD and PV skin miRNA profiles have been performed recently. We conducted a miRNA profiling analysis of skin, as well as serum, from adult AD and PV patients and control individuals. 130 miRNAs were differentially expressed in AD skin, of which 77 were common differentially expressed in AD and PV. No differentially expressed miRNAs were detected in serum. Pathway analyses revealed differentially expressed miRNAs to potentially target immune-system related pathways, including TNF-α, IL-2/STAT4 and IL-6/JAK/STAT3. Additional genetic analysis of published AD GWAS dataset detected association of several target genes of differentially expressed miRNAs in skin. Moreover, miR-28-5p, miR-31-5p, miR-378a-3p and miR-203a were validated as upregulated in the skin of AD and PV patients. All validated miRNAs were reliable predictive markers for AD or PV. In conclusion, miRNA expression pattern in the skin of adult AD patients is highly similar to that of PV with multiple differentially expressed miRNAs potentially involved in the regulation of immune responses in AD and PV.

Regulatory Networks, Management Approaches, and Emerging Treatments of Nonalcoholic Fatty Liver Disease

The pathogenesis of NAFLD is complex and diverse, involving multiple signaling pathways and cytokines from various organs. Hepatokines, stellakines, adipokines, and myokines secreted by hepatocytes, hepatic stellate cells, adipose tissue, and myocytes play an important role in the occurrence and development of nonalcoholic fatty liver disease (NAFLD). The nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) contributes to the progression of NAFLD by mediating liver inflammation, immune response, hepatocyte death, and later compensatory proliferation. In this review, we first discuss the crosstalk and interaction between hepatokines, stellakines, adipokines, and myokines and NF-κB in NAFLD. The characterization of the crosstalk of NF-κB with these factors will provide a better understanding of the molecular mechanisms involved in the progression of NAFLD. In addition, we examine new expert management opinions for NAFLD and explore the therapeutic potential of silymarin in NAFLD/NASH.

Triptolide increases resistance to bile duct ligation-induced liver injury and fibrosis in mice by inhibiting RELB

Cholestasis is a common, chronic liver disease that may cause fibrosis and cirrhosis. Tripterygium wilfordii Hook.f (TWHF) is a species in the Euonymus family that is commonly used as a source of medicine and food in Eastern and Southern China. Triptolide (TP) is an epoxy diterpene lactone of TWHF, as well as the main active ingredient in TWHF. Here, we used a mouse model of common bile duct ligation (BDL) cholestasis, along with cultured human intrahepatic biliary epithelial cells, to explore whether TP can relieve cholestasis. Compared with the control treatment, TP at a dose of 70 or 140 μg/kg reduced the serum levels of the liver enzymes alanine transaminase, aspartate aminotransferase, and alkaline phosphatase in mice; hematoxylin and eosin staining also showed that TP reduced necrosis in tissues. Both in vitro and in vivo analyses revealed that TP inhibited cholangiocyte proliferation by reducing the expression of RelB. Immunohistochemical staining of CK19 and Ki67, as well as measurement of Ck19 mRNA levels in hepatic tissue, revealed that TP inhibited the BDL-induced ductular reaction. Masson 3 and Sirius Red staining for hepatic hydroxyproline showed that TP alleviated BDL-induced hepatic fibrosis. Additionally, TP substantially inhibited BDL-induced hepatic inflammation. In summary, TP inhibited the BDL-induced ductular reaction by reducing the expression of RelB in cholangiocytes, thereby alleviating liver injury, fibrosis, and inflammation.

MicroRNAs in non-alcoholic fatty liver disease: Progress and perspectives

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a spectrum of disease ranging from simple hepatic steatosis (NAFL) to non-alcoholic steatohepatitis (NASH) which may progress to cirrhosis and liver cancer. NAFLD is rapidly becoming a global health challenge, and there is a need for improved diagnostic- and prognostic tools and for effective pharmacotherapies to treat NASH. The molecular mechanisms of NAFLD development and progression remain incompletely understood, though ample evidence supports a role of microRNAs (miRNAs) - small non-coding RNAs regulating gene expression - in the progression of metabolic liver disease.

SCOPE OF REVIEW

In this review, we summarise the currently available liver miRNA profiling studies in people with various stages of NAFLD. We further describe the mechanistic role of three of the most extensively studied miRNA species, miR-34a, miR-122 and miR-21, and highlight selected findings on novel NAFLD-linked miRNAs. We also examine the literature on exosomal microRNAs (exomiRs) as inter-hepatocellular or -organ messengers in NAFLD. Furthermore, we address the status for utilizing circulating NAFLD-associated miRNAs as minimally invasive tools for disease diagnosis, staging and prognosis as well as their potential use as NASH pharmacotherapeutic targets. Finally, we reflect on future directions for research in the miRNA field.

MAJOR CONCLUSIONS

NAFLD is associated with changes in hepatic miRNA expression patterns at early, intermediate and late stages, and specific miRNA species appear to be involved in steatosis development and NAFL progression to NASH and cirrhosis. These miRNAs act either within or between hepatocytes and other liver cell types such as hepatic stellate cells and Kupffer cells or as circulating inter-organ messengers carrying signals between the liver and extra-hepatic metabolic tissues, including the adipose tissues and the cardiovascular system. Among circulating miRNAs linked to NAFLD, miR-34a, miR-122 and miR-192 are the best candidates as biomarkers for NAFLD diagnosis and staging. To date, no miRNA-targeting pharmacotherapy has been approved for the treatment of NASH, and no such therapy is currently under clinical development. Further research should be conducted to translate the contribution of miRNAs in NAFLD into innovative therapeutic strategies.

Unveiling the anti-senescence effects and senescence-associated secretory phenotype (SASP) inhibitory mechanisms of Scutellaria baicalensis Georgi in low glucose-induced astrocytes based on boolean network

BACKGROUND

Astrocytes senescence has been demonstrated in the aging brain and Alzheimer's disease (AD). Moreover, lower glucose metabolism has been confirmed in the early stage of AD. However, whether low glucose could induce astrocytes senescence remain ambiguous. Studies have shown that the ethanol extracts of Scutellaria baicalensis Georgi (SGE) exert neuroprotective and anti-aging effects, while whether SGE could delay astrocytes senescence was unclear.

PURPOSE

This study investigated the anti-senescence effect of SGE in low glucose-induced T98G cells and primary astrocytes, and explored the possible mechanisms based on boolean network.

METHODS

The neuroprotective effects of SGE in low glucose-induced T98G cells were evaluated by measurement of cell viability, LDH, ROS and ATP. The anti-senescence effects of SGE were investigated by detection of senescence-associated β-galactosidase (SA-β-Gal), senescence-associated secretory phenotype (SASP), cell cycle and senescence-related markers. The possible mechanisms of SGE in delaying astrocytes senescence were discovered through integrating transcriptomics with boolean network, and validation experiments were further performed.

RESULTS

Our results revealed that low glucose could induce astrocytes senescence, and SGE could delay astrocytes senescence by decreasing the staining rate of SA-β-gal, reducing secretions of SASP factors (IL-6, CXCL1, MMP-1), alleviating cell cycle arrest in G0/G1 phase, decreasing the formation of punctate DNA foci and down-regulating the expression of p16INK4A, p21 and γH2A.X. Transcriptomics and further verification results showed that SGE could markedly inhibit the mRNA expression levels of SASP factors (CXCL10, CXCL2, CCL2, IL-6, CXCR4, CCR7). Moreover, C-X-C motif chemokine 10 (CXCL10) was predicted to be the key SASP factor affecting the network stability by using boolean network. Further experiments validated that SGE could markedly reduce CXCL10 level, decrease the secretion of IL-6 and inhibit cell migration in CXCL10 induced primary astrocytes.

CONCLUSION

In summary, our research unmasks that the anti-senescence effects of SGE were highly correlated with the suppression of SASP secretions, and CXCL10 mediated the SASP inhibition effect of SGE in low glucose-induced astrocytes. Our study highlights that the delay of astrocytes senescence and the inhibition of SASP might be a new mechanism of SGE for alleviating neurodegenerative diseases such as AD.

Macro- and microtranscriptomic evidence of the monocyte recruitment to regenerating liver after partial hepatectomy in mouse model

Macrophages are important regulators of liver repair. Participation of migratory monocytes/macrophages in regeneration of hepatic tissues after resection remains disputable. In mouse the resection promotes migration of Ly6C+CD11b+ monocytes/macrophages to the remnant liver accompanied by a reduction in its CD206 + macrophage content. Macrophage proliferation within the liver reaches maximum on day 3 after the surgery. Corresponding macro- and microtranscriptomic profiles of macrophages in regeneration liver cannot be unambiguously defined as pro- or anti-inflammatory. Their typical features include elevated expression of leukocyte chemoattractant factors, and many of the differentially expressed sequences are related to the control of cell growth and metabolic processes in the liver. These findings revealed essential roles of immigration of monocytes/macrophages and macrophages proliferation in maintenance of macrophage populations in the mouse liver during its recovery from a massive resection.