SGLT2i as fourth-line therapy and risk of mortality, end-stage renal diseases and cardiovascular diseases in patients with type 2 diabetes mellitus.

AIM: Current guideline recommends insulin as fourth-line glucose-lowering medications. However, treatment effects of sodium glucose co-transporter-2 inhibitors (SGLT2i) on the risk of complications are uncertain. This study examines risks of all-cause mortality, cardiovascular diseases (CVD) and end-stage renal diseases (ESRD) in type 2 diabetes mellitus (T2DM) patients on triple oral glucose-lowering medications initiating SGLT2i, insulin or other oral medications. METHODS: A population-based retrospective cohort of patients with T2DM between 2006-2017 was extracted from Hong Kong Hospital Authority database. Patients who were initiated a fourth-line therapy with SGLT2i, insulin or other oral medications were included. Hazard ratios (HRs) for all-cause mortality, CVD and ESRD were assessed using Cox proportional hazard models. RESULTS: Over a median follow-up period of 18.5 months with 63,122 person-years, SGLT2i and insulin group had the lowest and highest incidence rate of all-cause mortality, CVD and ESRD (1.06, 0.65 and 0.61 vs 4.25, 5.58 and 4.39/100 person-years), respectively. Initiating SGLT2i as fourth-line medication had more benefits on CVD, in particular coronary heart disease and stroke. Insulin users had higher risks of CVD (HR=8.04, 95%CI=3.06-21.12) than SGLT2i users. SGLT2i was associated with insignificant reduction in ESRD (HR=4.62, 95%CI=0.73-29.09) and all-cause mortality (HR=3.06, 95%CI=0.75-12.45), and HF (HR=2.99, 95%CI=0.37-24.42) among patients without established HF. CONCLUSION: Among T2DM patients initiating fourth-line therapy, SGLT2i users had significant benefits in lowering risk of CVD, and potential benefits in lowering risks of ESRD and all-cause mortality. SGLT2i was the preferred fourth-line glucose-lowering medication least likely to be associated with complication risks.

Prediction models for the risk of cardiovascular diseases in Chinese patients with type 2 diabetes mellitus: a systematic review.

OBJECTIVES: Diabetes mellitus (DM) is a serious public health issue worldwide, and DM patients have higher risk of cardiovascular diseases (CVDs), which is the leading cause of DM-related deaths. China has the largest DM population, yet a robust model to predict CVDs in Chinese DM patients is still lacking. This systematic review is carried out to summarize existing models and identify potentially important predictors for CVDs in Chinese DM patients. STUDY DESIGN: Systematic review. METHODS: Medline and Embase were searched for data from April 1st, 2011 to May 31st, 2018. A study was eligible if it developed CVD (defined as total CVD or any major cardiovascular component) risk prediction models or explored potential predictors of CVD specifically for Chinese people with type 2 DM. Standardized forms were utilized to extract information, appraise applicability, risk of bias, and availabilities. RESULTS: Five models and 29 studies focusing on potential predictors were identified. Models for a primary care setting, or to predict total CVD, are rare. A number of common predictors (e.g. age, sex, diabetes duration, smoking status, glycated hemoglobin (HbA1c), blood pressure, lipid profile, and treatment modalities) were observed in existing models, in which urine albumin:creatinine ratio (ACR) and estimated glomerular filtration rate (eGFR) are highly recommended for the Chinese population. Variability of blood pressure (BP) and HbA1c should be included in prediction model development as novel factors. Meanwhile, interactions between age, sex, and risk factors should also be considered. CONCLUSIONS: A 10-year prediction model for CVD risk in Chinese type 2 DM patients is lacking and urgently needed. There is insufficient evidence to support the inclusion of other novel predictors in CVDs risk prediction functions for routine clinical use.

Endothelial dysfunction and vascular disease - a 30th anniversary update.

The endothelium can evoke relaxations of the underlying vascular smooth muscle, by releasing vasodilator substances. The best-characterized endothelium-derived relaxing factor (EDRF) is nitric oxide (NO) which activates soluble guanylyl cyclase in the vascular smooth muscle cells, with the production of cyclic guanosine monophosphate (cGMP) initiating relaxation. The endothelial cells also evoke hyperpolarization of the cell membrane of vascular smooth muscle (endothelium-dependent hyperpolarizations, EDH-mediated responses). As regards the latter, hydrogen peroxide (H2 O2 ) now appears to play a dominant role. Endothelium-dependent relaxations involve both pertussis toxin-sensitive Gi (e.g. responses to α2 -adrenergic agonists, serotonin, and thrombin) and pertussis toxin-insensitive Gq (e.g. adenosine diphosphate and bradykinin) coupling proteins. New stimulators (e.g. insulin, adiponectin) of the release of EDRFs have emerged. In recent years, evidence has also accumulated, confirming that the release of NO by the endothelial cell can chronically be upregulated (e.g. by oestrogens, exercise and dietary factors) and downregulated (e.g. oxidative stress, smoking, pollution and oxidized low-density lipoproteins) and that it is reduced with ageing and in the course of vascular disease (e.g. diabetes and hypertension). Arteries covered with regenerated endothelium (e.g. following angioplasty) selectively lose the pertussis toxin-sensitive pathway for NO release which favours vasospasm, thrombosis, penetration of macrophages, cellular growth and the inflammatory reaction leading to atherosclerosis. In addition to the release of NO (and EDH, in particular those due to H2 O2 ), endothelial cells also can evoke contraction of the underlying vascular smooth muscle cells by releasing endothelium-derived contracting factors. Recent evidence confirms that most endothelium-dependent acute increases in contractile force are due to the formation of vasoconstrictor prostanoids (endoperoxides and prostacyclin) which activate TP receptors of the vascular smooth muscle cells and that prostacyclin plays a key role in such responses. Endothelium-dependent contractions are exacerbated when the production of nitric oxide is impaired (e.g. by oxidative stress, ageing, spontaneous hypertension and diabetes). They contribute to the blunting of endothelium-dependent vasodilatations in aged subjects and essential hypertensive and diabetic patients. In addition, recent data confirm that the release of endothelin-1 can contribute to endothelial dysfunction and that the peptide appears to be an important contributor to vascular dysfunction. Finally, it has become clear that nitric oxide itself, under certain conditions (e.g. hypoxia), can cause biased activation of soluble guanylyl cyclase leading to the production of cyclic inosine monophosphate (cIMP) rather than cGMP and hence causes contraction rather than relaxation of the underlying vascular smooth muscle.

Endothelial dysfunction and vascular disease.

The endothelium can evoke relaxations (dilatations) of the underlying vascular smooth muscle, by releasing vasodilator substances. The best characterized endothelium-derived relaxing factor (EDRF) is nitric oxide (NO). The endothelial cells also evoke hyperpolarization of the cell membrane of vascular smooth muscle (endothelium-dependent hyperpolarizations, EDHF-mediated responses). Endothelium-dependent relaxations involve both pertussis toxin-sensitive G(i) (e.g. responses to serotonin and thrombin) and pertussis toxin-insensitive G(q) (e.g. adenosine diphosphate and bradykinin) coupling proteins. The release of NO by the endothelial cell can be up-regulated (e.g. by oestrogens, exercise and dietary factors) and down-regulated (e.g. oxidative stress, smoking and oxidized low-density lipoproteins). It is reduced in the course of vascular disease (e.g. diabetes and hypertension). Arteries covered with regenerated endothelium (e.g. following angioplasty) selectively loose the pertussis toxin-sensitive pathway for NO release which favours vasospasm, thrombosis, penetration of macrophages, cellular growth and the inflammatory reaction leading to atherosclerosis. In addition to the release of NO (and causing endothelium-dependent hyperpolarizations), endothelial cells also can evoke contraction (constriction) of the underlying vascular smooth muscle cells by releasing endothelium-derived contracting factor (EDCF). Most endothelium-dependent acute increases in contractile force are due to the formation of vasoconstrictor prostanoids (endoperoxides and prostacyclin) which activate TP receptors of the vascular smooth muscle cells. EDCF-mediated responses are exacerbated when the production of NO is impaired (e.g. by oxidative stress, ageing, spontaneous hypertension and diabetes). They contribute to the blunting of endothelium-dependent vasodilatations in aged subjects and essential hypertensive patients.

Calcium and reactive oxygen species increase in endothelial cells in response to releasers of endothelium-derived contracting factor.

BACKGROUND AND PURPOSE: Experiments were designed to assess whether or not the intracellular concentration of calcium and reactive oxygen species (ROS) increase in endothelial cells of the rat thoracic aorta in response to releasers of endothelium-derived contracting factor (EDCF) and if so, whether or not a difference exists between spontaneously hypertensive (SHR) and normotensive (WKY) rats. EXPERIMENTAL APPROACH: Calcium and ROS were measured by confocal microscopy, using Fura-red in combination with Fluo-4 and dichlorodihydrofluorescein diacetate, respectively. KEY RESULTS: Acetylcholine caused a rapid increase in cytosolic calcium concentration in endothelial cells of both SHR and WKY, which was significantly more pronounced in aortae of the former strain. This rise of calcium was not affected by indomethacin (an inhibitor of cyclooxygenase) or Tiron plus diethyldithiocarbamate acid (DETCA) (membrane permeable antioxidants). In the presence of a nitric oxide synthase blocker, acetylcholine also caused a rapid increase in ROS in endothelial cells of SHR but not in those of WKY. The burst of ROS was prevented by indomethacin or Tiron plus DETCA. CONCLUSIONS AND IMPLICATIONS: These experiments show that endothelial cells of SHR are more prone to calcium and ROS overload upon stimulation with acetylcholine. The abnormal accumulation of calcium is a prerequisite to initiate the release of EDCF and can be mimicked using the calcium ionophore A23187. The sequence of events occurring during endothelium-dependent contractions firstly requires the accumulation of calcium, which then activates cyclooxygenase and produces ROS along with EDCF that in turn stimulates TP-receptors, resulting in EDCF-mediated contractions.

Curcumin protects PC12 cells against 1-methyl-4-phenylpyridinium ion-induced apoptosis by bcl-2-mitochondria-ROS-iNOS pathway.

The aim of present study is to explore the cytoprotection of curcumin against 1-methyl-4-phenylpridinium ions (MPP(+))-induced apoptosis and the molecular mechanisms underlying in PC12 cells. Our findings indicated that MPP(+) significantly reduced the cell viability and induced apoptosis of PC12 cells. Curcumin protected PC12 cells against MPP(+)-induced cytotoxicity and apoptosis not only by inducing overexpression of Bcl-2, but also reducing the loss of mitochondrial membrane potential (MMP), an increase in intracellular reactive oxygen species (ROS) and overexpression of inducible nitric oxide synthase (iNOS). The selective iNOS inhibitor AG partly blocked MPP(+)-induced apoptosis of PC12 cells. The results of present study suggested that the cytoprotective effects of curcumin might be mediated, at least in part, by the Bcl-2-mitochondria-ROS-iNOS pathway. Because of its non-toxic property, curcumin could be further developed to treat the neurodegenerative diseases which are associated with oxidative stress, such as Parkinson's disease (PD).

Role of the JAK-STAT pathway in protection of hydrogen peroxide preconditioning against apoptosis induced by oxidative stress in PC12 cells.

The aim of this study was to investigate the role of JAK-STAT pathway in the cytoprotection afforded by preconditioning with H(2)O(2). It was shown that (1) Preconditioning with 100 micromol/L H(2)O(2) can markedly protect PC12 cells against apoptosis and cytotoxicity induced by 300 micromol/L H(2)O(2); (2) The expression and tyrosine phosphorylation of JAK2, not JAK1 were rapidly increased at 5 min after H(2)O(2) preconditioning; (3) The expression of STAT1 and STAT3 were significantly increased at 15 min after H(2)O(2) preconditioning, and the pTyr-STAT1 and pTyr-STAT3 were markedly increased at 60 min after H(2)O(2) preconditioning; (4) Pretreatment with the JAK inhibitor AG-490 (10 micromol/L) 20 min before H(2)O(2) preconditioning blocked not only the activation of JAK2, STAT1 and STAT3, but also the cytoprotection of H(2)O(2) preconditioning against apoptosis and cytotoxicity induced by oxidative stress. These findings suggested that preconditioning with H(2)O(2) activated the JAK-STAT pathway that played an important role in the cytoprotection induced by H(2)O(2) preconditioning.

Actinic keratosis. Current treatment options.

Actinic keratoses are hyperkeratotic skin lesions that represent focal abnormal proliferation of epidermal keratinocytes. Some actinic keratoses evolve into squamous cell carcinoma of the skin, while others resolve spontaneously. The conversion rate of actinic keratosis to squamous cell carcinoma is not accurately known, but appears to be in the range of 0.25 to 1% per year. Although there is a low rate of conversion of actinic keratoses to squamous cell carcinoma, 60% of squamous cell carcinomas of the skin probably arise from actinic keratoses. The main cause of actinic keratoses in otherwise healthy Caucasians appears to be the sun. Therapy for actinic keratoses begins with prevention which starts with sun avoidance and physical protection. Sunprotection with sunscreens actually slows the return of actinic keratoses in patients already getting actinic keratoses. Interestingly, a few studies are available that demonstrate that a high fat diet is associated with the production of more actinic keratoses than is a low fat diet. One of the mainstays of therapy has been local destruction of the actinic keratoses with cryotherapy, and curettage and electrodesiccation. A new addition to this group of therapies to treat individual actinic keratoses is photodynamic therapy with topical aminolevulinic acid and light. In patients who have numerous actinic keratoses in an area of severely sun damaged skin, therapies which are applied to the whole actinic keratosis area are used. The goal of treating such an area of skin is to treat all of the early as well as the numerous clinically evident actinic keratoses at the same time. The classical approaches for treating areas of photodamaged skin without treating actinic keratoses individually include: the use of topically applied fluorouracil cream, dermabrasion, and cutaneous peels with various agents like trichloroacetic acid. Both topically as well as orally administered retinoids have been used to treat actinic keratoses but retinoids alone are probably not an optimal monotherapy. Photodynamic therapy with topical aminolevulinic acid and light is a new therapy for actinic keratoses. Aminolevulinic acid is a precursor of protoporphyrin IX (PpIX) which is synthesized in the actinic keratosis when it is treated with aminolevulinic acid, and the PpIX photosensitizes the actinic keratosis so that light exposure can lead to its destruction. Photodynamic therapy with topical aminolevulinic acid is approved in the US to treat multiple individual actinic keratoses on the face and scalp and has similar cure rates to those reported for cryotherapy and fluorouracil therapy.

Post-transcriptional regulation of UV induced TNF-alpha expression.

Ultraviolet (UV) irradiation exerts multiple effects on skin cells, including the induction of several cytokines involved in immunomodulation. Specifically, UV irradiation has been shown to upregulate the level of tumor necrosis factor-alpha (TNF-alpha) mRNA in keratinocytes. To determine whether the induction of TNF-alpha mRNA is regulated by transcriptional or post-transcriptional mechanisms, we examined cells of keratinocytic lineage (SCC12F) for steady state level, transcription rate, and stability of TNF-alpha mRNA after UV irradiation. Within 4 h there was a 20-40-fold induction of TNF-alpha mRNA that persisted at lower levels through 48 h. Consistently, TNF-alpha protein secretion increased at 24 and 48 h after UV irradiation. UV irradiation increased the half-life of TNF-alpha mRNA from approximately 35 min to approximately 10 h. Conversely, the transcription rate of the TNF-alpha gene increased < 2-fold at the time of peak mRNA steady state levels. Thus, post-transcriptional mechanisms play a major role in UV induced TNF-alpha transcript level.

[The role of G protein in Leu-enkephalin induced Ca2+ release from intracellular pool in myocytes].

The mechanism underlying Leu-enkephalin (LEK) induced increase of the intracellular concentration of free calcium ([Ca2+]i) in rat ventricular myocytes was investigated by using fura-2 AM as a calcium indicator. The results were as follows: LEK (60 mumol/L) elevated [Ca2+]i in ventricular myocytes no matter whether extracellular calcium was removed or not. However, the effect was no longer observed when the calcium in the intracellular pool was depleted by caffeine (5 mmol/L). The LEK effect could also be blocked by naloxone (100 mumol/L), pretreatment of the cells with PTX (200 ng/L) 8-10 h or procain (2 mmol/L). The results suggest that the LEK effect is mediated by coupling of G-protein with delta-receptor that induced Ca2+ release from the intracellular pool in myocytes.

Preliminary studies on antigenic variation of poliovirus using neutralizing monoclonal antibodies.

Cross-neutralization assays were done using 85 strains of poliovirus type 1 with five groups of monoclonal antibodies. These strains were classified into 10 subgroups which had marked differences in antigenicity. Subgroups P1-2 (28%) and P1-5 (43%) were dominant and have been epidemic in China in recent years. These two subgroups were antigenically different from the Sabin-1 strain, but according to their responses to one group of monoclonal antibodies they had antigenic epitopes in common with the Mahoney and Brunhilde strains. Similarly, 91 strains of type 3 poliovirus were classified into six subgroups with another five groups of monoclonal antibodies. The results showed that strain P3/Yunnan/2/84, which was isolated from cases of poliomyelitis in a local epidemic in the Yunnan province of China in 1984, and strain P3/Finland/23127/84, which was isolated in Finland in 1984, were both antigenically different from the Sabin-3 strain and the reference virulent strain.