TMC7 functions as a suppressor of Piezo2 in primary sensory neurons blunting peripheral mechanotransduction.

The transmembrane channel-like (TMC) protein family comprises eight members, with TMC1 and TMC2 being extensively studied. This study demonstrates substantial co-expression of TMC7 with the mechanosensitive channel Piezo2 in somatosensory neurons. Genetic deletion of TMC7 in primary sensory ganglia neurons in vivo enhances sensitivity in both physiological and pathological mechanosensory transduction. This deletion leads to an increase in proportion of rapidly adapting (RA) currents conducted by Piezo2 in dorsal root ganglion (DRG) neurons and accelerates RA deactivation kinetics. In HEK293 cells expressing both proteins, TMC7 significantly suppresses the current amplitudes of co-expressed Piezo2. Our findings reveal that TMC7 and Piezo2 exhibit physical interactions, and both proteins also physically interact with cytoskeletal ß-actin. We hypothesize that TMC7 functions as an inhibitory modulator of Piezo2 in DRG neurons, either through direct inhibition or by disrupting the transmission of mechanical forces from the cytoskeleton to the channel.

The transmembrane channel-like 6 (TMC6) in primary sensory neurons involving thermal sensation via modulating M channels.

Introduction: The transmembrane channel-like (TMC) protein family contains eight members, TMC1-TMC8. Among these members, only TMC1 and TMC2 have been intensively studied. They are expressed in cochlear hair cells and are crucial for auditory sensations. TMC6 and TMC8 contribute to epidermodysplasia verruciformis, and predispose individuals to human papilloma virus. However, the impact of TMC on peripheral sensation pain has not been previously investigated. Methods: RNAscope was employed to detect the distribution of TMC6 mRNA in DRG neurons. Electrophysiological recordings were conducted to investigate the effects of TMC6 on neuronal characteristics and M channel activity. Zn2+ indicators were utilized to detect the zinc concentration in DRG tissues and dissociated neurons. A series of behavioural tests were performed to assess thermal and mechanical sensation in mice under both physiological and pathological conditions. Results and Discussion: We demonstrated that TMC6 is mainly expressed in small and medium dorsal root ganglion (DRG) neurons and is involved in peripheral heat nociception. Deletion of TMC6 in DRG neurons hyperpolarizes the resting membrane potential and inhibits neuronal excitability. Additionally, the function of the M channel is enhanced in TMC6 deletion DRG neurons owing to the increased quantity of free zinc in neurons. Indeed, heat and mechanical hyperalgesia in chronic pain are alleviated in TMC6 knockout mice, particularly in the case of heat hyperalgesia. This suggests that TMC6 in the small and medium DRG neurons may be a potential target for chronic pain treatment.

Neuropathic Injury-Induced Plasticity of GABAergic System in Peripheral Sensory Ganglia.

GABA is a major inhibitory neurotransmitter in the mammalian central nervous system (CNS). Inhibitory GABAA channel circuits in the dorsal spinal cord are the gatekeepers of the nociceptive input from the periphery to the CNS. Weakening of these spinal inhibitory mechanisms is a hallmark of chronic pain. Yet, recent studies have suggested the existence of an earlier GABAergic "gate" within the peripheral sensory ganglia. In this study, we performed systematic investigation of plastic changes of the GABA-related proteins in the dorsal root ganglion (DRG) in the process of neuropathic pain development. We found that chronic constriction injury (CCI) induced general downregulation of most GABAA channel subunits and the GABA-producing enzyme, glutamate decarboxylase, consistent with the weakening of the GABAergic inhibition at the periphery. Strikingly, the α5 GABAA subunit was consistently upregulated. Knock-down of the α5 subunit in vivo moderately alleviated neuropathic hyperalgesia. Our findings suggest that while the development of neuropathic pain is generally accompanied by weakening of the peripheral GABAergic system, the α5 GABAA subunit may have a unique pro-algesic role and, hence, might represent a new therapeutic target.

[Change laws of water absorption in Chinese herbal pieces and prediction model of relative density for Chinese medicine decoction].

This study aims to explore the change laws of water absorption in Chinese herbal pieces and establish the prediction model of relative density for Chinese medicine compound decoction. Firstly, fitted equations of water absorption and decocting time was established by observing the change laws of water absorption in 36 kinds of Chinese herbal pieces in 12 groups(according to the drug-parts) with decocting time. The r value of the mineral group and other type group was 0.691 2 and 0.663 3, respectively. The r value of the remaining 10 groups was 0.802 2-0.925 4. All P values were less than 0.05(n=21). The formula of the amount of water added was optimized by combining the fitted equations with determined water absorption, and the liquid yield could be controlled in a range of 100%±10%. Secondly, it was determined that the liquid density tester could be used for the rapid determination of relative density of Chinese medicine decoction after methodological study and comparison with the pycnometer method. The linear regression equation between the corrected relative density(y) and extraction ratio(%, x) was built by measuring and analyzing the related parameters such as liquid yield, relative density and extraction ratio in 46 kinds of Chinese herbal pieces. The established equation was y=0.041 3x+1.003 7, r=0.930 9(P <0.01, n=46), with linear range of 1.94%-65.75%. Based on this, the prototype model for predicting relative density of Chinese medicine decoction was established, and the relative densities of 8 Chinese medicine decoctions were within the prediction interval of this model in verification. This study lays a foundation for database construction of Chinese medicine decoction, implementation of personalized decocting mode and rapid quality control of Chinese medicine decoction.

The mechanism of anticancer action and potential clinical use of kaempferol in the treatment of breast cancer.

In the last century, natural compounds have achieved remarkable achievements in the treatment of tumors through chemotherapy. This inspired scientists to continuously explore anticancer agents from natural compounds. Kaempferol is an ordinary natural compound, the most common flavonoid, which is widely existed in vegetables and fruits. It has been reported to have various anticancer activities, including breast cancer, prostate cancer, bladder cancer, cervical cancer, colon cancer, liver cancer, lung cancer, ovarian cancer, leukemia, etc. Meanwhile, we found that there were more reports on breast cancer among these cancers although there are limited clinical studies that have addressed the benefits of kaempferol as an anti-cancer agent for breast cancer treatment. Then we realize that although kaempferol has been reported to have anti-breast cancer effect many times, it is still far from becoming a real anti-breast cancer agent. Therefore, in this review, we talk about the options for improving the anti-breast cancer effect of kaempferol, including various techniques and methods to improve the bioavailability of kaempferol, the idea of combining other compounds to produce synergistic effects, and the possibility of developing kaempferol into a targeted drug delivery system.

Increasing effect of Tangzhiqing formula on IRS-1-dependent PI3K/AKT signaling in muscle.

BACKGROUND: Tangzhiqing fomula (TZQ-F), the mixture of Red Paeony root, Mulberry leaf, Lotus leaf, Danshen root and Hawthorn leaf, regulates the abnormal glucose and lipids in prediabetic patients. In this study, we focus on the mechanism of TZQ-F and its fractions on glucose metabolism. METHODS: After orally administration of TZQ-F for 4 weeks in KK-Ay mice, we dissected out the liver and muscle, and employed PCR and western blotting to screening the PI3K/AKT pathway. The following PI3K/AKT signaling pathway were performed in L-6 myotube and HepG2 cells. RESULTS: In the liver of KK-Ay mice, no significance was observed on PI3K, AKT and their phosphorylation between TZQ-F and controls , while, in the muscle, up-regulation of PI3K, AKT, Glycogen synthase (GYS) and their phosphorylation type, as well as GluT4, was deteced in TZQ-F. In HepG2 cells, TZQ-F increased IRS-2 by 10 folds, without interrupting AKT, IRS-1 and GluT4. In L-6 myotube cells, TZQ-F and its fractions treatment significantly increased IRS-1 and AKT at mRNA level. CONCLUSION: TZQ-F prevents pre-diabetes through increasing effect on IRS-1-dependent PI3K/AKT signaling pathway in muscle.

[Regulatory effect of leonurus extracts on hyperuricemia in rats].

In this study, SD rats were orally administrated with oteracil potassium (300 mg . kg-1 . d-1 ) to prepare the hyperuricemia model, and divided into normal, model, Allopurinol, LE high dosage, middle dosage and low dose (200, 100, 50 mg . kg-1 . d-1) groups. The rats were orally administrated with test drugs 1 hour later after being orally administrated with Oteracil potassium. After 7 days, serum uric acid, serum creatinine, uric acid and expression of relevant transporters in kidney were tested to study the regulatory effect of leonurus extracts on serum uric acid, renal function and relevant transporters in kidney of rats with hyperuricemia. Compared with the model group, the leonurus extract group could significantly down-regulate serum uric acid and creatinine levels of rats with hyperuricemia, and increase the urine uric acid level. Meanwhile, leonurus extracts could notably down-regulate the mRNA expressions of urate transporter 1 (URAT1) and glucose transporter 9 (GLUT9), up-regulate the mRNA expressions of organic cation transportanter (OCT) and Carnitine transporter (OCTN) and promote the excretion of uric acid of kidney.

Triglyceride accumulation: inhibitory effects of tangzhiqing formula.

CONTEXT: The tangzhiqing formula (TZQ-F) is a traditional antidiabetic prescription that includes red peony root, mulberry leaf, lotus leaf, danshen root, and hawthorn leaf. The research team's previous study showed that the TZQ-F had beneficial effects on abnormal glucose and lipid metabolism. OBJECTIVE: This study was aimed at investigating TZQ-F's mechanism of lipid metabolism to evaluate its inhibitory effect on triglyceride (TG) accumulation. DESIGN: This study included both an in vivo and an in vitro component. For the in vivo study, C57BL/6 mice were used as the normal control group, and KK-A(y) mice were divided into five groups: (1) model control group, (2) positive control group (10 mg/kg/d rosiglitazone), (3) 500 mg/kg/d TZQ-F treated KK-A(y) mice, (4) 200 mg/kg/d TZQ-F treated KK-A(y) mice, and (5) 100 mg/kg/d TZQ-F treated KK-A(y) mice. For the in vitro study, 3T3-L1 cells were divided into the following: (A) red peony total saponins, (B) danshen total polyphenols, (C) lotus leaf total flavonoids, (D) lotus leaf total alkaloids, (E) mulberry leaf total flavonoids, (F) mulberry leaf total alkaloids, (G) mulberry leaf polysaccharide, and (H) hawthorn leaf total flavonoids, and (I) tangzhiqing formula, including a normal group (NG) and a model control group (CG). SETTING: This study occurred at Tianjin University of Traditional Chinese Medicine (TUTCM), Tianjin, China. INTERVENTION: TZQ-F, suspended either in a 5% acacia solution and a vehicle (5% acacia solution) were given orally to the KK-A(y) mice once/d (16:00-17:00) for 4 wk. OUTCOME MEASURES: RT-PCR and a Western blot analysis were used to detect gene and protein expression respectively. RESULTS: The in vivo study showed that TZQ-F significantly reduced body weight without changing food intake in KK-A(y) mice and significantly decreased the levels of serum glucose (GLU), triglycerides (TG), and free fatty acids (FFA). TZQ-F significantly increased expression of AMP-activated protein kinase (AMPK) and phosphorylation of AMPK in the liver and muscle tissues of the KK-A(y) mice. TZQ-F significantly decreased expression of acetyl-CoA carboxylase (ACC), fatty-acid synthase (FAS), hormone-sensitive lipase (HSL), and tumor necrosis factor-α (TNF-α) in the liver and muscles. It also significantly decreased expression of sterol regulatory element binding protein-1c (SREBP-1c) while it significantly increased expression of glucose transporter type 4 (GLUT-4). The in vitro study showed that TZQ-F significantly suppressed the accumulation of TG and FFA in mature adipocytes and similarly increased expression of AMPK and peroxisome proliferator-activated receptors-α (PPAR-α) and phosphorylation of AMPK, while it decreased expression of ACC, FAS, HSL, and SREBP-1c. CONCLUSIONS: The findings partly clarified the inhibitory effects of TZQ-F on TG accumulation related to the AMPK signaling pathway.

Rare syringyl acylated flavonol glycosides from the aerial parts of Leonurus japonicus Houtt.

Five new syringyl acylated flavonol glycosides, named leonurusoides A (1), B (2), C (3), D (4), and E (5), together with one known one 6 were obtained from the aerial parts of Leonurus japonicus. Their structures were elucidated by chemical and spectroscopic methods (UV, IR, HRESI-TOF-MS, 1D and 2D NMR). Compounds 1-6 showed triglyceride (TG) accumulation inhibitory effects in free fatty acid-induced HepG2 cells.

TG accumulation inhibitory effects of Jinqi formula by AMPK signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Jinqi formula is a traditional Chinese anti-diabetic formula containing three ingredients (Coptidis rhizoma, Astragali rhadix and Lonicerae japonicae Flos). MATERIALS AND METHODS: The active fractions of Jinqi formula were purified and HPLC analyses were used for quality control. The anti-adipogenic effects of Jinqi formula were analyzed in vitro using 3T3-L1 cells and in vivo with KK-A(y) mice. RT-PCR and Western blot were used to confirm genes and proteins of interest, respectively. RESULTS: In vitro study showed that Jinqi formula suppressed the accumulation of triglyceride (TG) and free fatty acids (FFA) in mature 3T3-L1 cells by increasing the expression and tyrosine phosphorylation of 5'-AMP-activated protein kinase (AMPK), as well as decreasing the expression of Acetyl CoA Carboxylase (ACC), Fatty Acid Synthase (FAS) and Hormone Sensitive Lipase (HSL). In vivo study demonstrated that Jinqi formula reduced body weight without changing food intake in KK-A(y) mice, and decreased the levels of serum glucose, TG, FFA. In addition, consistent with the in vitro study results, Jinqi formula increased the expression and tyrosine phosphorylation of AMPK in the liver and muscular tissues of the KK-A(y) mice. Furthermore, Jingqi formula suppressed the expression of ACC and HSL and upregulated the expression of IRS-1 in the liver. Whereas in the skeletal muscles, Jingqi formula decreased the expression of ACC and increased the expression of GLUT-4 and IRS-2. CONCLUSIONS: Jingqi formula inhibits TG accumulation at least in part via the stimulation of AMPK activity in a multi-target manner.

Regulation effects of Crataegus pinnatifida leaf on glucose and lipids metabolism.

The leaf of Crataegus pinnatifida (Rosaceae) is commonly consumed either raw or cooked to improve digestion and promote blood circulation in China. To investigate the regulation effects of it on glucose and lipid metabolism, the flavonoids fraction was prepared and analyzed by HPLC and LC-MS. In vivo, at doses of 250 and 500 mg/kg, the flavonoids fraction showed inhibitory effects on TG and glucose absorption, accelerating effects on gastrointestinal transit but no effect on gastric emptying. In vitro, treatment of 3T3-L1 preadipocytes with 30 µg/mL flavonoids fraction significantly suppressed the accumulation of TG and free fatty acid. It also suppressed the gene expressions of C/EBPα, PPARγ, SREBP 1c, aP2 and adiponectin but did not affect that of leptin. C. pinnatifida leaf may be useful for type 2 diabetics and hyperlipidemics as a foodstuff.

Inhibitory effects of flavonoids from Abelmoschus manihot flowers on triglyceride accumulation in 3T3-L1 adipocytes.

The 95% EtOH extract from the flowers of Abelmoschus manihot (L.) Medic showed inhibitory activity on TG accumulation in 3T3-L1 preadipocyte. Chemical studies on the active fraction led to the isolation of 14 flavonoids (1-14). To clarify the multi-mechanism of the isolates on preadipocyte differentiation, the levels of TG and FFA and the related role transcription factors (PPARγ, CEBP/α, and ap2) expression were evaluated. At the concentration of 30 µM, compounds 1-6 and 10-14 showed inhibitory activity on TG accumulation significantly in mature 3T3-L1 cells. 1, 2, 4-7, 9, 10, 13, and 14 reduced the level of FFA. At the molecular level, the mRNA expressions of PPARγ, CEBP/α, and ap2 were down-regulated by compounds 1, 5, 9, 12, 13; 1-8, 10-14; and 1-4, 6, 8-12, 14, respectively. The structure-activity relationships of the 14 flavonoids were also discussed.