The functional role of Higd1a in mitochondrial homeostasis and in multiple disease processes

Colorectal cancer cell dormancy: An insight into pathways

Cancer cell dormancy (CCD) in colorectal cancer (CRC) poses a significant challenge to effective treatment. In CRC, CCD contributes to tumour recurrence, drug resistance, and amplifying the disease's burden. The molecular mechanisms governing CCD and strategies for eliminating dormant cancer cells remain largely unexplored. Therefore, understanding the molecular mechanisms governing dormancy is crucial for improving patient outcomes and developing targeted therapies. This editorial highlights the complex interplay of signalling pathways and factors involved in colorectal CCD, emphasizing the roles of Hippo/YAP, pluripotent transcription factors such as NANOG, HIF-1α signalling, and Notch signalling pathways. Additionally, ERK/p38α/β/MAPK pathways, AKT signalling pathway, and Extracellular Matrix Metalloproteinase Inducer, along with some potential less explored pathways such as STAT/p53 switch and canonical and non-canonical Wnt and SMAD signalling, are also involved in promoting colorectal CCD. Highlighting their clinical significance, these findings may offer the potential for identifying key dormancy regulator pathways, improving treatment strategies, surmounting drug resistance, and advancing personalized medicine approaches. Moreover, insights into dormancy mechanisms could lead to the development of predictive biomarkers for identifying patients at risk of recurrence and the tailoring of targeted therapies based on individual dormancy profiles. It is essential to conduct further research into these pathways and their modulation to fully comprehend CRC dormancy mechanisms and enhance patient outcomes.

Telomere-related gene risk model for prognosis prediction in colorectal cancer

Background

Colorectal cancer (CRC) is the third-most prevalent cancer globally. The biological significance of telomeres in CRC carcinogenesis and progression is underscored by accumulating data. Nevertheless, not much is known about how telomere-related genes (TRGs) affect CRC prognosis. Therefore, the aim of this study was to investigate the role of TRGs in CRC prognosis.

Methods

We retrospectively obtained the expression profiles and clinical data of CRC patients from public databases. Utilizing least absolute shrinkage and selection operator (LASSO) regression analysis, we created a telomere-related risk model to predict survival outcomes, identifying ten telomere-related differentially expressed genes (TRDEGs). Based on TRDEGs, we stratified patients from The Cancer Genome Atlas (TCGA) into low- and high-risk subsets. Subsequently, we conducted comprehensive analyses, including survival assessment, immune cell infiltration, drug sensitivity, and prediction of molecular interactions using Kaplan-Meier curves, ESTIMATE, CIBERSORT, OncoPredict, and other approaches.

Results

The model showed exceptional predictive accuracy for survival. Significant differences in survival were observed between the two groups of participants grouped according to the model (P<0.001), and this difference was further confirmed in the external validation set (GSE39582) (P=0.004). Additionally, compared to the low-risk group, the high-risk group exhibited significantly advanced tumor node metastasis (TNM) stages, lower proportions of activated CD4+ T cells, effector memory CD4+ T cells, and memory B cells, but increased ratios of M2 macrophages and regulatory T cells (Tregs), elevated tumor immune dysfunction and exclusion (TIDE) scores, and diminished sensitivity to dabrafenib, lapatinib, camptothecin, docetaxel, and telomerase inhibitor IX, reflecting the signature's capacity to distinguish clinical pathological characteristics, immune environment, and drug efficacy. Finally, we validated the expression of the ten TRDEGs (ACACB, TPX2, SRPX, PPARGC1A, CD36, MMP3, NAT2, MMP10, HIGD1A, and MMP1) through quantitative real-time polymerase chain reaction (qRT-PCR) and found that compared to normal cells, the expression levels of ACACB, HIGD1A, NAT2, PPARGC1A, and TPX2 in CRC cells were elevated, whereas those of CD36, SRPX, MMP1, MMP3, and MMP10 were reduced.

Conclusions

Overall, we constructed a telomere-related biomarker capable of predicting prognosis and treatment response in CRC individuals, offering potential guidance for drug therapy selection and prognosis prediction.

HIGD1B, as a novel prognostic biomarker, is involved in regulating the tumor microenvironment and immune cell infiltration; its overexpression leads to poor prognosis in gastric cancer patients

Background

HIGD1B (HIG1 Hypoxia Inducible Domain Family Member 1B) is a protein-coding gene linked to the occurrence and progression of various illnesses. However, its precise function in gastric cancer (GC) remains unclear.

Methods

The expression of HIGD1B is determined through the TCGA and GEO databases and verified using experiments. The association between HIGD1B and GC patients' prognosis was analyzed via the Kaplan-Meier (K-M) curve. Subsequently, the researchers utilized ROC curves to assess the diagnostic capacity of HIGD1B and employed COX analysis to investigate risk factors for GC. The differentially expressed genes (DEGs) were then subjected to functional enrichment analysis, and a nomogram was generated to forecast the survival outcome and probability of GC patients. Additionally, we evaluated the interaction between HIGD1B and the immune cell infiltration and predicted the susceptibility of GC patients to therapy.

Results

HIGD1B is markedly elevated in GC tissue and cell lines, and patients with high HIGD1B expression have a poorer outcome. In addition, HIGD1B is related to distinct grades, stages, and T stages. The survival ROC curves of HIGD1B and nomogram for five years were 0.741 and 0.735, suggesting appropriate levels of diagnostic efficacy. According to Cox regression analysis, HIGD1B represents a separate risk factor for the prognosis of gastric cancer (p<0.01). GSEA analysis demonstrated that the HIGD1B is closely related to cancer formation and advanced pathways. Moreover, patients with high HIGD1B expression exhibited a higher level of Tumor-infiltration immune cells (TIICs) and were more likely to experience immune escape and drug resistance after chemotherapy and immunotherapy.

Conclusion

This study explored the potential mechanisms and diagnostic and prognostic utility of HIGD1B in GC, as well as identified HIGD1B as a valuable biomarker and possible therapeutic target for GC.

The journey towards physiology and pathology: Tracing the path of neuregulin 4

Neuregulin 4 (Nrg4), an epidermal growth factor (EGF) family member, can bind to and activate the ErbB4 receptor tyrosine kinase. Nrg4 has five different isoforms by alternative splicing and performs a wide variety of functions. Nrg4 is involved in a spectrum of physiological processes including neurobiogenesis, lipid metabolism, glucose metabolism, thermogenesis, and angiogenesis. In pathological processes, Nrg4 inhibits inflammatory factor levels and suppresses apoptosis in inflammatory diseases. In addition, Nrg4 could ameliorate obesity, insulin resistance, and cardiovascular diseases. Furthermore, Nrg4 improves non-alcoholic fatty liver disease (NAFLD) by promoting autophagy, improving lipid metabolism, and inhibiting cell death of hepatocytes. Besides, Nrg4 is closely related to the development of cancer, hyperthyroidism, and some other diseases. Therefore, elucidation of the functional role and mechanisms of Nrg4 will provide a clearer view of the therapeutic potential and possible risks of Nrg4.

The role of Sirtuin 2 in liver - An extensive and complex biological process

Liver disease has become one of the main causes of health issue worldwide. Sirtuin (Sirt) 2 is a nicotinamide adenine dinucleotide (NAD+)-dependent deacetylase, and is expressed in multiple organs including liver, which plays important and complex roles by interacting with various substrates. Physiologically, Sirt2 can improve metabolic homeostasis. Pathologically, Sirt2 can alleviate inflammation, endoplasmic reticulum (ER) stress, promote liver regeneration, maintain iron homeostasis, aggravate fibrogenesis and regulate oxidative stress in liver. In liver diseases, Sirt2 can mitigate fatty liver disease (FLD) including non-alcoholic fatty liver disease (NAFLD) and alcoholic fatty liver disease (AFLD), but aggravate hepatitis B (HBV) and liver ischemia-reperfusion injury (LIRI). The role of Sirt2 in liver cancer and aging-related liver diseases, however, has not been fully elucidated. In this review, these biological processes regulated by Sirt2 in liver are summarized, which aims to update the function of Sirt2 in liver and to explore the potential role of Sirt2 as a therapeutic target for liver diseases.

Cdo1-Camkk2-AMPK axis confers the protective effects of exercise against NAFLD in mice

Exercise is an effective non-pharmacological strategy for ameliorating nonalcoholic fatty liver disease (NAFLD), but the underlying mechanism needs further investigation. Cysteine dioxygenase type 1 (Cdo1) is a key enzyme for cysteine catabolism that is enriched in liver, whose role in NAFLD remains poorly understood. Here, we show that exercise induces the expression of hepatic Cdo1 via the cAMP/PKA/CREB signaling pathway. Hepatocyte-specific knockout of Cdo1 (Cdo1LKO) decreases basal metabolic rate of the mice and impairs the effect of exercise against NAFLD, whereas hepatocyte-specific overexpression of Cdo1 (Cdo1LTG) increases basal metabolic rate of the mice and synergizes with exercise to ameliorate NAFLD. Mechanistically, Cdo1 tethers Camkk2 to AMPK by interacting with both of them, thereby activating AMPK signaling. This promotes fatty acid oxidation and mitochondrial biogenesis in hepatocytes to attenuate hepatosteatosis. Therefore, by promoting hepatic Camkk2-AMPK signaling pathway, Cdo1 acts as an important downstream effector of exercise to combat against NAFLD.

Proton Compared to X-Irradiation Induces Different Protein Profiles in Oral Cancer Cells and Their Derived Extracellular Vesicles

Extracellular vesicles (EVs) are membrane-bound particles released from cells, and their cargo can alter the function of recipient cells. EVs from X-irradiated cells have been shown to play a likely role in non-targeted effects. However, EVs derived from proton irradiated cells have not yet been studied. We aimed to investigate the proteome of EVs and their cell of origin after proton or X-irradiation. The EVs were derived from a human oral squamous cell carcinoma (OSCC) cell line exposed to 0, 4, or 8 Gy from either protons or X-rays. The EVs and irradiated OSCC cells underwent liquid chromatography-mass spectrometry for protein identification. Interestingly, we found different protein profiles both in the EVs and in the OSCC cells after proton irradiation compared to X-irradiation. In the EVs, we found that protons cause a downregulation of proteins involved in cell growth and DNA damage response compared to X-rays. In the OSCC cells, proton and X-irradiation induced dissimilar cell death pathways and distinct DNA damage repair systems. These results are of potential importance for understanding how non-targeted effects in normal tissue can be limited and for future implementation of proton therapy in the clinic.

Exercise-regulated white adipocyte differentitation: An insight into its role and mechanism

White adipocytes play a key role in the regulation of fat mass amount and energy balance. An appropriate level of white adipocyte differentiation is important for maintaining metabolic homeostasis. Exercise, an important way to improve metabolic health, can regulate white adipocyte differentiation. In this review, the effect of exercise on the differentiation of white adipocytes is summarized. Exercise could regulate adipocyte differentiation in multiple ways, such as exerkines, metabolites, microRNAs, and so on. The potential mechanism underlying the role of exercise in adipocyte differentiation is also reviewed and discussed. In-depth investigation of the role and mechanism of exercise in white adipocyte differentiation would provide new insights into exercise-mediated improvement of metabolism and facilitate the application of exercise-based strategy against obesity.

HIGD1A links SIRT1 activity to adipose browning by inhibiting the ROS/DNA damage pathway

Energy-dissipating adipocytes have the potential to improve metabolic health. Here, we identify hypoxia-induced gene domain protein-1a (HIGD1A), a mitochondrial inner membrane protein, as a positive regulator of adipose browning. HIGD1A is induced in thermogenic fats by cold exposure. Peroxisome proliferator-activated receptor gamma (PPARγ) transactivates HIGD1A expression synergistically with peroxisome proliferators-activated receptor γ coactivator α (PGC1α). HIGD1A knockdown inhibits adipocyte browning, whereas HIGD1A upregulation promotes the browning process. Mechanistically, HIGD1A deficiency impairs mitochondrial respiration to increase reactive oxygen species (ROS) level. This increases NAD⁺ consumption for DNA damage repair and curtails the NAD⁺/NADH ratio, which inhibits sirtuin1 (SIRT1) activity, thereby compromising adipocyte browning. Conversely, overexpression of HIGD1A blunts the above process to promote adaptive thermogenesis. Furthermore, mice with HIGD1A knockdown in inguinal and brown fat have impaired thermogenesis and are prone to diet-induced obesity (DIO). Overexpression of HIGD1A favors adipose tissue browning, ultimately preventing DIO and metabolic disorders. Thus, the mitochondrial protein HIGD1A links SIRT1 activity to adipocyte browning by inhibiting ROS levels.

Krüppel-like factor 10 (KLF10) as a critical signaling mediator: Versatile functions in physiological and pathophysiological processes

Krüppel-like factor 10 (KLF10), also known as TGFβ-inducible early gene-1 (TIEG1), was first found in human osteoblasts. Early studies show that KLF10 plays an important role in osteogenic differentiation. Through decades of research, KLF10 has been found to have complex functions in many different cell types, and its expression and function is regulated in multiple ways. As a downstream factor of transforming growth factor β (TGFβ)/SMAD signaling, KLF10 is involved in various biological functions, including glucose and lipid metabolism in liver and adipose tissue, the maintenance of mitochondrial structure and function of the skeletal muscle, cell proliferation and apoptosis, and plays roles in multiple disease processes, such as nonalcoholic steatohepatitis (NASH) and tumor. Besides, KLF10 shows gender-dependent difference of regulation and function in many aspects. In this review, the biological functions of KLF10 and its roles in disease states is updated and discussed, which would provide new insights into the functional roles of KLF10 and a clearer view of potential therapeutic strategies by targeting KLF10.