Ipragliflozin in combination with metformin for the treatment of Japanese patients with type 2 diabetes: ILLUMINATE, a randomized, double-blind, placebo-controlled study

This multicenter, double-blind, placebo-controlled study examined the efficacy and safety of ipragliflozin, a sodium-glucose co-transporter 2 inhibitor, in combination with metformin in Japanese patients with type 2 diabetes mellitus (T2DM). Patients were randomized in a 2 : 1 ratio to 50 mg ipragliflozin (n = 112) or placebo (n = 56) once daily for 24 weeks, followed by a 28-week open-label extension in which all patients received 50 or 100 mg ipragliflozin, while continuing metformin. The primary outcome was the change in glycated haemoglobin (HbA1c) from baseline to week 24. HbA1c decreased significantly in the ipragliflozin group (-0.87%; adjusted mean difference from placebo: -1.30%; p < 0.001). The overall incidence of treatment-emergent adverse events was similar in both groups, although pollakiuria and constipation were more common in the ipragliflozin group; thus, ipragliflozin significantly improved glycaemic control and reduced body weight without major safety issues in Japanese patients with T2DM.

A randomized, double-blind, placebo-controlled study on long-term efficacy and safety of ipragliflozin treatment in patients with type 2 diabetes mellitus and renal impairment: results of the long-term ASP1941 safety evaluation in patients with type 2 diabetes with renal impairment (LANTERN) study

AIMS

To assess the effects of renal impairment (RI) on the efficacy and safety of ipragliflozin in patients with type 2 diabetes mellitus (T2DM).

METHODS

A cohort of Japanese patients with T2DM and mild to moderate RI and poor glycaemic control, despite diet/exercise therapy alone or diet/exercise therapy in combination with an oral hypoglycaemic agent (an α-glucosidase inhibitor, a sulfonylurea, or pioglitazone), were randomized in a double-blind manner to 50 mg ipragliflozin or placebo once daily for 24 weeks. The patients continued open-label ipragliflozin for a 28-week extension period (total treatment duration: 52 weeks).

RESULTS

Ipragliflozin significantly decreased glycated haemoglobin (HbA1c) and fasting plasma glucose (FPG) levels and body weight from baseline to week 24 (last observation carried forward) compared with placebo in all patients with RI. The decreases in HbA1c and FPG levels were statistically significant in patients with mild RI, but not in patients with moderate RI. Ipragliflozin significantly reduced body weight in both RI groups. The improvements in glycaemic control were maintained in the 28-week extension period. Ipragliflozin was associated with no clinically significant safety concerns, and its safety profiles were not influenced by the severity of RI.

CONCLUSIONS

Ipragliflozin significantly improved glycaemic control and body weight in patients with T2DM with mild RI, but did not improve glycaemic control in patients with moderate RI. Ipragliflozin is a valid treatment option for patients with mild RI but not those with moderate RI.

Fasting-induced activation of mitogen-activated protein kinases (ERK/p38) in the mouse hypothalamus

Activity-dependent changes in neuronal plasticity depend critically on gene regulation. To understand how fasting-induced stimulation leads to gene regulation through intracellular signalling pathways, we investigated the effect of fasting on activation of the mitogen-activated protein kinase (MAPK) family, the extracellular signal-regulated kinase (ERK) and the p38 MAPK (p38) in mouse hypothalamus. In the hypothalamic arcuate nucleus, phosphorylation of ERK significantly increased during fasting, spatially coincident with phosphorylation of cAMP response element binding protein (CREB), induction of c-Fos, and expression of neuropeptide Y (NPY). In the paraventricular nucleus (PVN) of fasted mice, activation of p38 in addition to ERK was also observed. In the arcuate nucleus of ob/ob mice, phosphorylations of ERK and CREB were decreased during fasting, whereas the expression of NPY was increased. In the PVN, increased activation of p38 was observed in spite of decreased activation of ERK. These results suggest that ERK and p38 are differentially activated by fasting in distinct regions of the hypothalamus depending on the condition of energy balance.

Molecular cloning of a cDNA encoding mouse A15, a member of the transmembrane 4 superfamily, and its preferential expression in brain neurons

A15, a member of the transmembrane 4 superfamily (TM4SF), was isolated by differential screening of the cDNAs that are preferentially expressed on immature T cells. As a first step in the study of the biological function of the A15 molecule, we isolated cDNAs encoding the entire coding region of mouse A15. Nucleotide sequence analysis of the cDNAs revealed that mouse A15 shares 97% amino acid sequence identity with its human counterpart. The mouse A15 protein product has not yet been characterized, but is predicted to be 244 amino acids with four hydrophobic domains. Northern blot analysis of the RNA samples from various mouse tissues disclosed that the A15 transcripts are expressed most strongly in the brains, and are detectable in the colon, muscle, heart, kidney, and spleen. In situ hybridization of the mouse brain with ribo-probe established that the A15 transcripts are expressed primarily in neurons of the frontal cortex, olfactory bulb, dentate gyrus, caudoputamen, and CA3 region of the hypothalamus as well as in Purkinje cells in the cerebellar cortex, which strongly suggests that A15 may have a special function in the fundamental neuronal functioning of the higher nervous system.

Systematic expression of immediate early genes and intensive astrocyte activation induced by intrastriatal ferrous iron injection

The potential role(s) of transitional metals such as iron have been implicated in neurodegeneration through biochemical processes, particularly oxidative stress. We injected ferrous chloride (FeCl2) and ferric chloride (FeCl3) into the striatonigral system of Sprague-Dawley rats to investigate the biological and toxic effects of ferrous iron in the central nervous system. When FeCl2 was injected into the ventral midbrain, rats showed a characteristic behavior which indicated ipsilateral dopaminergic hyperactivity. FeCl2 injection into the striatum induced a dose-dependent damage, the activation of astrocytes and recruitment of macrophage/microglia at the injected site. Interestingly, the activation of astrocytes was also observed in the anatomically remote areas such as the ipsilateral subthalamic nucleus and pars reticulata of the substantia nigra after 1 week. Expression of immediate early genes (IEGs; c-fos and NGFI-A) was observed in the cortex, thalamic nuclei, subthalamic nucleus, pars reticulata of the substantia nigra, lateral and medial geniculate bodies on the ipsilateral side from 3 to 15 h after FeCl2 injection. Pre-treatment with dimethyl sulfoxide, a hydroxyl radical scavenger, prevented FeCl2-induced expression of IEGs in the thalamic nuclei and geniculate bodies, but not in the cerebral cortex. On the other hand, the effects of FeCl3 were faint and limited on IEGs expression and tissue damage. These results suggest that ferrous iron affects the nervous system vigorously, possibly yielding free radicals such as hydroxyl radicals, and could be one of the important candidates for neurodegenerative diseases under the state in which acclimating systems for iron toxicity are disrupted.