Overburden of rare ALMS1 deleterious variants in Chinese early-onset type 2 diabetes with severe insulin resistance.

AIMS: Alström syndrome (AS) is a rare recessive disorder characterised by diabetes, obesity, insulin resistance (IR), and visual and hearing impairments. Mutations in the ALMS1 gene have been identified as the causative agents of AS. This study aimed to explore the relationship between rare ALMS1 variants and clinical features in Chinese patients with early-onset type 2 diabetes (age at diagnosis ≤40 years; EOD). MATERIALS AND METHODS: ALMS1 gene sequencing was performed in 611 Chinese individuals with EOD, 36 with postprandial hyperinsulinemia, and 47 with pre-diabetes and fasting IR. In-silico prediction algorithm and the American College of Medical Genetics Guidelines (ACMG) were used to evaluate the deleteriousness and pathogenicity of the variants. RESULTS: Sixty-two rare ALMS1 variants (frequency <0.005) were identified in 82 patients with EOD. Nineteen variants were predicted to be deleterious (pD). Patients with EOD carrying pD variants had higher fasting C-peptide, postprandial C-peptide, and HOMA2-IR levels than those without variants. The frequency of ALMS1 pD variants in the subgroup with more insulin-resistant EOD was higher than that in other EOD subgroups. Two patients with EOD, obesity, and IR who carried one heterozygous pathogenic/likely pathogenic rare variant of ALMS1 according to ACMG were identified. Moreover, rare heterozygous pD variants of ALMS1 were found in participants from cohorts of postprandial hyperinsulinemia as well as in pre-diabetes with fasting IR. CONCLUSIONS: ALMS1 rare pD variants are enriched in the populations with significant IR, which is a major hallmark of diabetes pathogenesis. Accordingly, our exploratory study provides insights and hypotheses for further studies of gene function.

SIRT1 regulates endoplasmic reticulum stress-related organ damage.

Endoplasmic reticulum (ER) stress plays a key role in the pathogenesis of several organ damages. Studies show that excessive ER stress (ERS) can destroy cellular homeostasis, causing cell damage and physiological dysfunction in various organs. In recent years, Sirtuin1 (SIRT1) has become a research hotspot on ERS. Increasing evidence suggests that SIRT1 plays a positive role in various ERS-induced organ damage via multiple mechanisms, including inhibiting cellular apoptosis and promoting autophagy. SIRT1 can also alleviate liver, heart, lung, kidney, and intestinal damage by inhibiting ERS. We discuss the possible mechanism of SIRT1, explore potential therapeutic targets of diseases, and provide a theoretical basis for treating ERS-related diseases.

Electroacupuncture pre­conditioning protects from lung injury induced by limb ischemia/reperfusion through TLR4 and NF­κB in rats.

Limb ischemia/reperfusion (I/R) can induce inflammation, causing acute lung injury. The Toll­like receptor 4 (TLR4)/NF­κB pathway plays an important role in acute and chronic inflammatory disorders. Several studies have demonstrated the efficacy of acupuncture in lung inflammatory injury. The aim of the present study was to elucidate the mechanism underlying the protective effect of electroacupuncture (EA) against lung injury induced by limb I/R. EA applied at the Zusanli and Sanyinjiao acupoints attenuated lung injury and decreased the secretion of inflammatory factors such as tumor necrosis factor­α, interleukin (IL)­1, IL­6 and myeloperoxidase. Moreover, the expression levels of TLR4 and NF­κB were suppressed by EA. Thus, the present findings suggested that EA can reduce pulmonary inflammation induced by limb I/R injury, possibly via the inhibition of the TLR4/NF­κB pathway.

PICK1 Deficiency Induces Autophagy Dysfunction via Lysosomal Impairment and Amplifies Sepsis-Induced Acute Lung Injury.

Sepsis is a systemic inflammatory reaction caused by infection. Multiple organ failure ultimately leads to high morbidity and mortality. Unfortunately, therapies against these responses have been unsuccessful due to the insufficient underlying pathophysiological evidence. Protein interacting with C-kinase 1 (PICK1) has received considerable attention because of its important physiological functions in many tissues. However, its role in sepsis-induced acute lung injury (ALI) is unclear. In this study, we used cecal ligation and puncture (CLP) to establish a septic model and found that decreased microtubule-associated protein-1light chain 3 (LC3)-II/LC3-I in PICK1-/- septic mice was caused by autophagy dysfunction. Consistently, the transmission electron microscopy (TEM) of bone marrow-derived macrophages (BMDMs) from PICK1-/- mice showed the accumulation of autophagosomes as well. However, more serious damage was caused by PICK1 deficiency indicating that the disrupted autophagic flux was harmful to sepsis-induced ALI. We also observed that it was the impaired lysosomal function that mediated autophagic flux blockade, and the autophagy progress was relevant to PI3K-Akt-mTOR pathway. These findings will aid in the potential development of PICK1 with novel evidence of autophagy in sepsis treatment and prevention.

PICK1 deficiency exacerbates sepsis-associated acute lung injury and impairs glutathione synthesis via reduction of xCT.

The role of oxidative stress has been well documented in the development of sepsis-induced acute lung injury (ALI). Protein interaction with C-kinase 1 (PICK1) participates in oxidative stress-related neuronal diseases. However, its function in lung infections and inflammatory diseases is not known. We therefore sought to investigate whether PICK1 is involved in sepsis-induced ALI. Cecal ligation and puncture (CLP) was performed in anesthetized wild type (WT) and PICK1 knock out (KO, PICK1-/-) mice with C57BL/6 background. At the time of CLP, mice were given fluid resuscitation. Mouse lungs were harvested at 24 and 72 h for Western blot analysis, qRT-PCR, BALF analysis, Hematoxylin and Eosin staining, TUNEL staining, maleimide staining, flow cytometry analysis, GCL, GSH, GSSG and cysteine levels measurement. A marked elevation of PICK1 mRNA and protein level were demonstrated in lung tissue, which was accompanied by increased production of reactive oxygen species (ROS) and reactive nitrogen species (RNS) and consumption of glutathione (GSH). N-acetylcysteine (NAC), buthionine sulfoximine (BSO) and GSH-monoethyl ester (GSH-MEE) were injected into mice via caudal vein to regulate glutathione (GSH) level in lung. Alterations of lung GSH content induced PICK1 level change after CLP challenge. In PICK1-/- underwent with CLP, lung injury and survival were significantly aggravated compared with wild-type mice underwent with CLP. Concomitantly, CLP-induced lung cell apoptosis was exacerbated in PICK1-/- mice. The level of xCT, other than PKCα, in lung tissue was significantly lowered in PICK1-/- but not in wild type that underwent CLP surgery. Meanwhile, Nrf2 activation, which dominating xCT expression, was inhibited in PICK1-/- but not in wild type mice that underwent CLP surgery, as well. Moreover, higher level of PICK1 was detected in PBMCs of septic patients than healthy controls. Taken together, PICK1 plays a pivotal role in sepsis-induced ALI by regulating GSH synthesis via affecting the substrate-specific subunit of lung cystine/glutamate transporter, xCT.

Effect of Huazhuojiedu medicated serum on the proliferation and activation of hepatic stellate cells and the expression of PI3K and p-Akt in rats.

To observe the effect of Huazhuojiedu medicated serum on the proliferation and activation of hepatic stellate cells, as well as the expression of PI3K and p-Akt in rats, and to explore the underlying mechanism of Huazhuojiedu prescription against hepatic fibrosis. Hepatic stellate cells harvested from rats were resuscitated and subcultured, followed by the intervention of Huazhuojiedu equivalent dose, Huazhuojiedu double dose, and positive drug (Compound Biejiaruangan Troche) medicated serum of rats. After in vitro culture, hepatic stellate cells were stimulated with 5 ng/mL transforming growth factor-ß1. At 24, 48, 72 hours, the proliferation of hepatic stellate cells was detected with MTT assay; at 48 hours, α-SMA mRNA and protein expression in hepatic stellate cells were determined with RT-PCR assay and western blot analysis, respectively, to evaluate the activation of hepatic stellate cells; in addition, PI3K and p-Akt protein expression levels were also assayed with western blot analysis at 48 hours. The results showed that, 24-hour transforming growth factor-ß1 stimulation significantly promoted the proliferation of hepatic stellate cells (P < 0.01). Each medicated serum inhibited the proliferation of hepatic stellate cells (P < 0.01). Huazhuojiedu equivalent dose had the similar inhibition effect with positive drug (P > 0.05), and Huazhuojiedu double dose achieved more apparent inhibition effect (P < 0.01). After 48 and 72 hours of transforming growth factor-ß1 stimulation, hepatic stellate cells still proliferated significantly (P < 0.01), which was inhibited by each medicated serum (P < 0.01). Huazhuojiedu equivalent dose showed a weaker inhibition effect than positive drug (P < 0.05), and Huazhuojiedu double dose exerted a strong inhibition effect (P < 0.05). After hepatic stellate cells were stimulated with transforming growth factor-ß1 for 48 hours, the expression of α-SMA mRNA and protein in hepatic stellate cells was significantly increased (P < 0.01); the medicated serums significantly down-regulated α-SMA mRNA and protein expression, and inhibited the activation of hepatic stellate cells (P < 0.01). Huazhuojiedu equivalent dose showed the similar inhibition effect with positive drug (P > 0.05), and Huazhuojiedu double dose exerted a significant inhibition effect (P < 0.05), which was stronger than Huazhuojiedu equivalent dose (P < 0.05). After hepatic stellate cells were stimulated with transforming growth factor-ß1 for 48 hours, PI3K and p-Akt protein expression levels were increased (P < 0.05); each medicated serum down-regulated the elevated expression levels of PI3K and p-Akt (P < 0.05). Huazhuojiedu equivalent dose had the similar down-regulation effect with positive drug (P > 0.05), and Huazhuojiedu double dose achieved more apparent inhibition effect on PI3K expression (P < 0.05). Huazhuojiedu double dose significantly decreased the PI3K and p-Akt protein expression compared with Huazhuojiedu equivalent dose (P < 0.05). Huazhuojiedu medicated serum inhibits the proliferation and activation of hepatic stellate cells induced by transforming growth factor-ß1 in vitro, reduces the expression of PI3K and p-Akt protein, and the mechanisms of preventing hepatic fibrosis is mediated by the intervention on PI3K/Akt pathway.