OBJECTIVE: To explore the inhibitory effects of Nardostachys Jatamansi DC. volatile oil (NJVO) on psychological factors substance P (SP)/cortisol (CORT)-induced hyperpigmentation. METHODS: The model of psychologically-induced hyperpigmentation of B16F10 cells was created using SP (10 nmol/L) + CORT (10 µmol/L) for 72 h. The levels of melanin content, tyrosinase (TYR) activity using NaOH lysis and L-dihydroxyphenylalanine (L-DOPA) oxidation methods were assessed, respectively. The effect of NJVO on SP/CORT-induced normal human skin tissue pigmentation was detected by Masson staining. Protein expressions of tyrosinase-related protein 1 (TRP-1), tyrosinase-relative protein 2 (DCT), and microphthalmia-associated transcription factor were determined using Western blot. The melanosome number, maturation, and melanosomal structure changes were detected through transmission electron microscopy and immunofluorescence experiments. In vivo, zebrafish pigment content was evaluated in SP/CORT-induced zebrafish hyperpigmentation model. RESULTS: NJVO significantly reduced the melanin content (P<0.01) and inhibited tyrosinase activity (P<0.01), the pigmentation of the normal skin tissue in the NJVO group was significantly lower than that in the SP/CORT group (P<0.05). And NJVO considerably downregulated expressions of melanogenesis-related proteins (TYR, TRP-1, DCT) in cells (P<0.01). In addition, the number of melanosomes was decreased and the dentrites formation of B16F10 cells was inhibited after NJVO treatment (P<0.01). In vivo, NJVO significantly reduced the pigment content in the zebrafish body (P<0.01). CONCLUSION NJVO effectively reversed SP/CORT-induced hyperpigmentation by suppressing the activity and expression of TYR and TRPs and inhibiting melanosome maturation in mouse B16F10 melanoma cells.
Animals ; Hyperpigmentation/psychology* ; Zebrafish ; Oils, Volatile/therapeutic use* ; Melanins/metabolism* ; Humans ; Monophenol Monooxygenase/metabolism* ; Mice ; Nardostachys/chemistry* ; Substance P ; Hydrocortisone ; Skin Pigmentation/drug effects* ; Cell Line, Tumor ; Melanosomes/ultrastructure* ; Microphthalmia-Associated Transcription Factor/metabolism* ; Melanoma, Experimental ; Oxidoreductases/metabolism* ; Intramolecular Oxidoreductases/metabolism*

OBJECTIVES: To investigate the subcellular localization and biological functions of transmembrane protein 240 (TMEM240). METHODS: NCBI BLAST and TMHMM bioinformatics software were used for protein sequence analysis and prediction of transmembrane domain of TMEM240. Brain tissues from male C57BL/6 mice (18-20 days old) were examined for distribution of TMEM240 using in situ hybridization, and qPCR and Western blotting were used to detect TMEM240 expression in different mouse tissues and in cortical neurons at different time points (n=3). In the in vitro experiment, HepG2 and Neuro-2a cells were transfected with plasmids for overexpression of TMEM240, and subcellular localization of TMEM240 was analyzed using cell imaging. In primary cultures of cortical neurons isolated from C57BL/6 mice, TMEM240 expression and its biological functions were investigated using qPCR, Western blotting, and immunofluorescence staining. RESULTS: Human and mouse TMEM240 proteins share a 97.69% similarity in the protein sequences, and both are transmembrane proteins with two transmembrane domains. TMEM240 mRNA and protein were highly expressed in mouse brain tissues and cortical neurons. In isolated mouse cortical neurons, TMEM240 expression reached the peak level after primary culture for 9 days and distributed in scattered spots within the cells. In HepG2 cells, TMEM240 was characterized as intracellular membrane structures and showed 80% colocalization with peroxisomes. In Neuro-2a cells, TMEM240 overexpression caused significant enhancement of the expressions of Rho GDP dissociation inhibitor β (ARHGDIB) at both the mRNA and protein levels. CONCLUSIONS TMEM240 is a novel intracellular subcellular structure specifically expressed in neurons with significant potential for targeted cellular function regulation.
Animals ; Humans ; Mice ; Peroxisomes/metabolism* ; Membrane Proteins/genetics* ; Mice, Inbred C57BL ; Neurons/metabolism* ; Male ; rho-Specific Guanine Nucleotide Dissociation Inhibitors ; Hep G2 Cells ; Brain/metabolism*

Membrane-bound organelles and membraneless organelles (MLOs) coordinate various biological processes within eukaryotic cells. Among these, stress granules (SGs) are significant cytoplasmic MLOs that form in response to cellular stress, exhibiting liquid-like properties alongside stable substructures. SGs interact with diverse organelles, thereby influencing cellular pathways that are critical in both health and disease contexts. This review discusses the interplay between SGs and organelles and explores the methodologies employed to analyze interactions between SGs and other MLOs. Furthermore, it highlights the pivotal roles SGs play in regulating cellular responses and the pathogenesis of amyotrophic lateral sclerosis. Gaining insights into these interactions is essential for deciphering the mechanisms underlying both physiological processes and pathological conditions.
Humans ; Stress Granules/pathology* ; Organelles/metabolism* ; Amyotrophic Lateral Sclerosis/pathology* ; Animals ; Stress, Physiological ; Cytoplasmic Granules/metabolism*

Stress granules (SGs) are cytoplasmic ribonucleoprotein assemblies formed under stress conditions and are related to various biological processes and human diseases. Previous studies have reported the regulatory role of some proteins and linear RNAs in SG assembly. However, the relationship between circular RNAs (circRNAs) and SGs has not been discovered. Here, we screened both linear RNAs and circRNAs in SGs using improved total RNA sequencing of purified SG cores in mammalian cells and identified circular transcripts specifically localized in SGs. circRNAs with higher SG-related RNA-binding protein (RBP) binding abilities are more likely to be enriched in SGs. Furthermore, some SG-enriched circRNAs are differentially expressed in hepatocellular carcinoma (HCC) and adjacent tissues. These results suggest the regulatory role of circRNAs in SG formation and provide insights into the biological function of circRNAs and SGs in HCC.
Animals ; Humans ; RNA, Circular/metabolism* ; Carcinoma, Hepatocellular/metabolism* ; Stress Granules ; Cytoplasmic Granules/metabolism* ; Liver Neoplasms/metabolism* ; RNA/metabolism* ; Stress, Physiological/genetics* ; Mammals/genetics*

The nucleocapsid (N) protein of SARS-CoV-2 has been reported to have a high ability of liquid-liquid phase separation, which enables its incorporation into stress granules (SGs) of host cells. However, whether SG invasion by N protein occurs in the scenario of SARS-CoV-2 infection is unknow, neither do we know its consequence. Here, we used SARS-CoV-2 to infect mammalian cells and observed the incorporation of N protein into SGs, which resulted in markedly impaired self-disassembly but stimulated cell cellular clearance of SGs. NMR experiments further showed that N protein binds to the SG-related amyloid proteins via non-specific transient interactions, which not only expedites the phase transition of these proteins to aberrant amyloid aggregation in vitro, but also promotes the aggregation of FUS with ALS-associated P525L mutation in cells. In addition, we found that ACE2 is not necessary for the infection of SARS-CoV-2 to mammalian cells. Our work indicates that SARS-CoV-2 infection can impair the disassembly of host SGs and promote the aggregation of SG-related amyloid proteins, which may lead to an increased risk of neurodegeneration.
Amyloidogenic Proteins/metabolism* ; Amyotrophic Lateral Sclerosis/genetics* ; Animals ; COVID-19 ; Cytoplasmic Granules/metabolism* ; Mammals ; SARS-CoV-2 ; Stress Granules

OBJECTIVE: To estimate the detrimental effects of shortwave exposure on rat hippocampal structure and function and explore the underlying mechanisms. METHODS: One hundred Wistar rats were randomly divided into four groups (25 rats per group) and exposed to 27 MHz continuous shortwave at a power density of 5, 10, or 30 mW/cm2 for 6 min once only or underwent sham exposure for the control. The spatial learning and memory, electroencephalogram (EEG), hippocampal structure and Nissl bodies were analysed. Furthermore, the expressions of N-methyl-D-aspartate receptor (NMDAR) subunits (NR1, NR2A, and NR2B), cAMP responsive element-binding protein (CREB) and phosphorylated CREB (p-CREB) in hippocampal tissue were analysed on 1, 7, and 14 days after exposure. RESULTS: The rats in the 10 and 30 mW/cm2 groups had poor learning and memory, disrupted EEG oscillations, and injured hippocampal structures, including hippocampal neurons degeneration, mitochondria cavitation and blood capillaries swelling. The Nissl body content was also reduced in the exposure groups. Moreover, the hippocampal tissue in the 30 mW/cm2 group had increased expressions of NR2A and NR2B and decreased levels of CREB and p-CREB. CONCLUSION Shortwave exposure (27 MHz, with an average power density of 10 and 30 mW/cm2) impaired rats' spatial learning and memory and caused a series of dose-dependent pathophysiological changes. Moreover, NMDAR-related CREB pathway suppression might be involved in shortwave-induced structural and functional impairments in the rat hippocampus.
Animals ; Cyclic AMP Response Element-Binding Protein ; genetics ; metabolism ; Dose-Response Relationship, Radiation ; Electroencephalography ; radiation effects ; Hippocampus ; radiation effects ; Male ; Memory ; radiation effects ; Nissl Bodies ; physiology ; radiation effects ; Radio Waves ; adverse effects ; Random Allocation ; Rats ; Rats, Wistar ; Receptors, N-Methyl-D-Aspartate ; genetics ; metabolism ; Spatial Learning ; radiation effects

PURPOSE: Obesity is a major health problem of global significance because it is clearly associated with an increased risk of health problems, such as nonalcoholic fatty liver disease (NAFLD), diabetes, cardiovascular diseases, and cancer. Lonicera caerulea (LC) originates from high mountains or wet areas and has been used as a traditional medicine in northern Russia, China, and Japan. LC contains a range of bioactive constituents, such as vitamins, minerals, and polyphenols. This study examined the anti-obesity effects of LC during differentiation in preadipocytes. METHODS: The cell viability assay was performed after the differentiation of 3T3-L1 cells for 7 days. Oil Red O staining was used to visualize the changes in lipid droplets in 3T3-L1 cells and mouse adipose-derived stem cells (MADSCs). The mRNA expression of obesity-related genes was determined by quantitative real-time PCR. RESULTS: According to the results of Oil Red O staining, the lipid levels and size of lipid droplets in the adipocytes were reduced and the LC extract (LCE, 0.25–1 mg/mL) markedly inhibited adipogenesis in a dose-dependent manner. The treatment of LCE also decreased the mRNA expression of peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer binding protein-α (C/EBPα), and sterol regulatory element binding protein 1 (SREBP1) in 3T3-L1 cells. Western blot analysis showed that the PPARγ, C/EBPα, and SREBP1 protein levels in both 3T3-L1 and MADSC were reduced in a dose-dependent manner. CONCLUSION: These results suggest that LCE can inhibit adipogenic differentiation through the regulation of adipogenesis-related markers.
3T3-L1 Cells ; Adipocytes ; Adipogenesis ; Animals ; Blotting, Western ; Cardiovascular Diseases ; Cell Survival ; China ; Japan ; Lipid Droplets ; Lonicera ; Medicine, Traditional ; Mice ; Minerals ; Miners ; Non-alcoholic Fatty Liver Disease ; Obesity ; Peroxisomes ; Polyphenols ; Real-Time Polymerase Chain Reaction ; RNA, Messenger ; Russia ; Stem Cells ; Sterol Regulatory Element Binding Protein 1 ; Vitamins

BACKGROUND/OBJECTIVES: The NAD+ precursor nicotinamide riboside (NR) is a type of vitamin B3 found in cow's milk and yeast-containing food products such as beer. Recent studies suggested that NR prevents hearing loss, high-fat diet-induced obesity, Alzheimer's disease, and mitochondrial myopathy. The objective of this study was to investigate the effects of NR on inflammation and mitochondrial biogenesis in AML12 mouse hepatocytes. MATERIALS/METHODS: A subset of hepatocytes was treated with palmitic acid (PA; 250 µM) for 48 h to induce hepatocyte steatosis. The hepatocytes were treated with NR (10 µM and 10 mM) for 24 h with and without PA. The cell viability and the levels of sirtuins, inflammatory markers, and mitochondrial markers were analyzed. RESULTS: Cytotoxicity of NR was examined by PrestoBlue assay. Exposure to NR had no effect on cell viability or morphology. Gene expression of sirtuin 1 (Sirt1) and Sirt3 was significantly upregulated by NR in PA-treated hepatocytes. However, Sirt1 activities were increased in hepatocytes treated with low-dose NR. Hepatic pro-inflammatory markers including tumor necrosis factor-alpha and interleukin-6 were decreased in NR-treated cells. NR upregulated anti-inflammatory molecule adiponectin, and, tended to down-regulate hepatokine fetuin-A in PA-treated hepatocytes, suggesting its inverse regulation on these cytokines. NR increased levels of mitochondrial markers including peroxisome proliferator-activated receptor γ coactivator-1α, carnitine palmitoyltransferase 1, uncoupling protein 2, transcription factor A, mitochondrial and mitochondrial DNA in PA-treated hepatocytes. CONCLUSIONS: These data demonstrated that NR attenuated hepatic inflammation and increased levels of mitochondrial markers in hepatocytes.
Adiponectin ; alpha-2-HS-Glycoprotein ; Alzheimer Disease ; Animals ; Beer ; Carnitine O-Palmitoyltransferase ; Cell Survival ; Cytokines ; DNA, Mitochondrial ; Fatty Liver ; Gene Expression ; Hearing Loss ; Hepatocytes ; Inflammation ; Interleukin-6 ; Mice ; Milk ; Mitochondria ; Mitochondrial Myopathies ; Niacin ; Niacinamide ; Obesity ; Organelle Biogenesis ; Palmitic Acid ; Peroxisomes ; Sirtuin 1 ; Sirtuins ; Transcription Factors ; Tumor Necrosis Factor-alpha

BACKGROUND: Dysregulation of hepatic glucose production (HGP) contributes to the development of type 2 diabetes mellitus. Telmisartan, an angiotensin II type 1 receptor blocker (ARB), has various ancillary effects in addition to common blood pressure-lowering effects. The effects and mechanism of telmisartan on HGP have not been fully elucidated and, therefore, we investigated these phenomena in hyperglycemic HepG2 cells and high-fat diet (HFD)-fed mice.METHODS: Glucose production and glucose uptake were measured in HepG2 cells. Expression levels of phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase α (G6Pase-α), and phosphorylation levels of insulin receptor substrate-1 (IRS-1) and protein kinase C ζ (PKCζ) were assessed by western blot analysis. Animal studies were performed using HFD-fed mice.RESULTS: Telmisartan dose-dependently increased HGP, and PEPCK expression was minimally increased at a 40 μM concentration without a change in G6Pase-α expression. In contrast, telmisartan increased phosphorylation of IRS-1 at Ser302 (p-IRS-1-Ser302) and decreased p-IRS-1-Tyr632 dose-dependently. Telmisartan dose-dependently increased p-PKCζ-Thr410 which is known to reduce insulin action by inducing IRS-1 serine phosphorylation. Ectopic expression of dominant-negative PKCζ significantly attenuated telmisartan-induced HGP and p-IRS-1-Ser302 and -inhibited p-IRS-1-Tyr632. Among ARBs, including losartan and fimasartan, only telmisartan changed IRS-1 phosphorylation and pretreatment with GW9662, a specific and irreversible peroxisome proliferator-activated receptor γ (PPARγ) antagonist, did not alter this effect. Finally, in the livers from HFD-fed mice, telmisartan increased p-IRS-1-Ser302 and decreased p-IRS-1-Tyr632, which was accompanied by an increase in p-PKCζ-Thr410.CONCLUSION: These results suggest that telmisartan increases HGP by inducing p-PKCζ-Thr410 that increases p-IRS-1-Ser302 and decreases p-IRS-1-Tyr632 in a PPARγ-independent manner.
Animals ; Blotting, Western ; Diabetes Mellitus, Type 2 ; Diet, High-Fat ; Ectopic Gene Expression ; Glucose ; Glucose-6-Phosphatase ; Hep G2 Cells ; Insulin Receptor Substrate Proteins ; Insulin ; Liver ; Losartan ; Mice ; Peroxisomes ; Phosphoenolpyruvate ; Phosphorylation ; Protein Kinase C ; Protein Kinases ; Receptor, Angiotensin, Type 1 ; Receptor, Insulin ; Serine

Differentiation of preadipocyte, also named adipogenesis, leads to the phenotype of mature adipocyte that is filled with many lipid droplets. Excessive lipid accumulation in adipocytes leads to the development of obesity. In this study, we investigated the effect of 11 different natural compounds on lipid accumulation during the differentiation of 3T3-L1 preadipocytes into 3T3-L1 adipocytes. Strikingly, among the natural compounds, cryptotanshinone at 10 µM most strongly reduced triglyceride (TG) contents in 3T3-L1 cells after 8 days of the differentiation. Furthermore, cryptotanshinone at 10 µM significantly suppressed lipid accumulation in 3T3-L1 cells after 8 days of the differentiation. Cryptotanshinone at 1 to 10 µM tested did not affect the survival of 3T3-L1 cells after 8 days of the differentiation. On mechanistic levels, cryptotanshinone time-differentially decreased the expression levels of CCAAT/enhancer-binding protein-α (C/EBP-α), peroxisome proliferator-activated receptor-γ (PPAR-γ), fatty acid synthase (FAS), and perilipin A but also the phosphorylation levels of signal transducer and activator of transcription-3 (STAT-3) during the 3T3-L1 cell differentiation. Taken together, these findings demonstrate that cryptotanshinone inhibits lipid accumulation in differentiating 3T3-L1 cells, which appears to be mediated through the reduced expression and/or phosphorylation levels of C/EBP-α, PPAR-γ, FAS, Perilipin A, and STAT-3.
3T3-L1 Cells ; Adipocytes ; Adipogenesis ; Lipid Droplets ; Obesity ; Peroxisomes ; Phenotype ; Phosphorylation ; Transducers ; Triglycerides