Alcoholic liver disease (ALD) refers to the damages to the liver and its functions due to alcohol overconsumption. It consists of fatty liver/steatosis, alcoholic hepatitis, steatohepatitis, chronic hepatitis with liver fibrosis or cirrhosis, and hepatocellular carcinoma. However, the mechanisms behind the pathogenesis of alcoholic liver disease are extremely complicated due to the involvement of immune cells, adipose tissues, and genetic diversity. Clinically, the diagnosis of ALD is not yet well developed. Therefore, the number of patients in advanced stages has increased due to the failure of proper early detection and treatment. At present, abstinence and nutritional therapy remain the conventional therapeutic interventions for ALD. Moreover, the therapies which target the TNF receptor superfamily, hormones, antioxidant signals, and MicroRNAs are used as treatments for ALD. In particular, mesenchymal stem cells (MSCs) are gaining attention as a potential therapeutic target of ALD. Therefore, in this review, we have summarized the current understandings of the pathogenesis and diagnosis of ALD. Moreover, we also discuss the various existing treatment strategies while focusing on promising therapeutic approaches for ALD.

Is the decreased natural killer (NK) cell cytolytic activity in the peritoneal fluid (PF) of endometriosis patients due to primary cytokine activity? An increased level of interleukin-6 (IL-6) in the PF of patients with endometriosis suppresses NK cell cytolytic activity by down-regulating cytolytic granule components, such as granzyme B and perforin, through the modulation of Src homology region 2-containing protein tyrosine phosphatase-2 (SHP-2) expression. Endometriosis is known to be related to a defect in NK cell cytolytic activity. Additionally, the levels of inflammatory cytokines are elevated in the PF of women with endometriosis. The effects of PF on the differentiation and functional activity of NK cells were investigated in patients with or without endometriosis, and cytokines that reduce NK cell cytolytic activity in endometriosis patients were examined. The study included women who underwent laparoscopic examination for the diagnosis of endometriosis from August 2012 to July 2013 (33 women with, and 15 women without, endometriosis). Women of reproductive age (20–40 years old) who underwent laparoscopic examination for endometriosis were included. Cytokines present in the PF were identified by enzyme-linked immunosorbent assay. The cytolytic activity of NK cells in the PF was also analyzed using a calcein-acetoxy methyl ester (AM) release assay. PF from patients with endometriosis suppressed the differentiation and cytotoxicity of NK cells compared with PF from controls (P < 0.05). Increased levels of IL-6 were also found in the PF of patients with endometriosis (P < 0.01), and IL-6 levels were negatively correlated with the cytolytic activity of NK cells (r_s = −0.558, P = 0.03). Furthermore, IL-6 reduced the cytolytic activity of NK cells, concomitantly with the down-regulation of granzyme B and perforin (P < 0.05), by modulating SHP-2. Importantly, the addition of anti-IL-6 to the PF of endometriosis patients restored the activity of NK cells (P < 0.01), suggesting that IL-6 plays a crucial role in the reduction of NK cell activity in the PF of patients with endometriosis. PF contains various inflammatory cytokines in addition to IL-6 and so it is possible that other cytokines may affect the differentiation and activity of NK cells. Our results imply that the suppression of IL-6 using an anti-IL-6 antibody or soluble IL-6 receptor could rescue the impairment of NK cell activity in patients with endometriosis. This work was supported by the KRIBB Creative Research Program (KCS3051312); the STP project (DTM0111221) of the Ministry of Knowledge & Economy and the Basic Science Research Program (RBM0271312) of the National Research Foundation of Korea (NRF) from the Ministry of Education, Science & Technology. There are no conflicts of interest.

The c-myc proto-oncogene plays a key role in the proliferation, differentiation, apoptosis, and regulation of the cell cycle. Recently, it was demonstrated that the 5′ nontranslated region (5′ NTR) of human c-myc mRNA contains an internal ribosomal entry site (IRES). In this study, we investigated cellular proteins interacting with the IRES element of c-myc mRNA. Heterogeneous nuclear ribonucleoprotein C (hnRNP C) was identified as a cellular protein that interacts specifically with a heptameric U sequence in the c-myc IRES located between two alternative translation initiation codons CUG and AUG. Moreover, the addition of hnRNP C1 in an in vitro translation system enhanced translation of c-myc mRNA. Interestingly, hnRNP C was partially relocalized from the nucleus, where most of the hnRNP C resides at interphase, to the cytoplasm at the G₂/M phase of the cell cycle. Coincidently, translation mediated through the c-myc IRES was increased at the G₂/M phase when cap-dependent translation was partially inhibited. On the other hand, a mutant c-myc mRNA lacking the hnRNP C-binding site, showed a decreased level of translation at the G₂/M phase compared to that of the wild-type message. Taken together, these findings suggest that hnRNP C, via IRES binding, modulates translation of c-myc mRNA in a cell cycle phase-dependent manner.

Natural killer (NK) cells play important roles in immune surveillance. However, the tumor microenvironment suppresses NK cell function and allows cancer cells to evade immune detection. In this study, we investigated whether the thyroid cancer cell microenvironment has this effect on NK cells. We found that prostaglandin (PG) E2 produced by thyroid cancer cells suppressed the cytolytic activity of NK cells by inhibiting the expression of the natural cytotoxicity receptors NKp44 and NKp30 and the death receptor tumor necrosis factor-related apoptosis-inducing ligand. PGE2 and cyclooxygenase-2 were highly expressed in thyroid cancer cells; moreover, anaplastic thyroid cancer cells released higher amounts of PGE2 than the papillary subtype, which was associated with suppression of NK cell-inducing nuclear factor-κB and mitogen-activated protein kinase/extracellular signal-regulated kinase pathways via PGE2 receptor (EP) 2 and EP4 expressed on the NK cell surface. In addition, PGE2 inhibited the functional maturation of NK cells and reduced their cytotoxicity against target cells. These results indicate that PGE2 promotes thyroid cancer progression by inhibiting NK cell maturation and cytotoxicity. Thus, therapeutic strategies that target PGE2 in thyroid cancer could potentiate the immune response and improve patient prognosis.

Perforin (Prf1) and granzyme B (GzmB) are essential effector molecules for natural killer (NK)–cell cytotoxicity, but how Prf1 and GzmB expression is regulated during arming of NK cells is poorly defined. We show that human microRNA (miR)–27a* is a negative regulator of NK-cell cytotoxicity by silencing Prf1 and GzmB expression. Human miR-27a* specifically bound to the 3′ untranslated regions of Prf1 and GzmB, down-regulating expression in both resting and activated NK cells, and it functioned as a fine-tuner for homeostasis of the net amount of the effector proteins. Consistent with miR-27a* having an inhibitory role, knockdown of miR-27a* in NK cells dramatically increased cytotoxicity in vitro and decreased tumor growth in a human tumor xenograft model. Thus, NK-cell cytotoxicity is regulated, in part, by microRNA, and modulating endogenous miR-27a* levels in NK cells represents a potential immunotherapeutic strategy.