N,N-Dimethyl-D-erythro-sphingosine inhibits store-operated Ca2+ entry in U937 monocytes

Calcium is a ubiquitous second messenger that controls a broad range of cellular functions, and store-operated calcium entry (SOCE) is the primary mechanism of regulated Ca(2+) entry in non-excitable immunocytes. In this study, we found that N,N-dimethyl-D-erythro-sphingosine (DMS) inhibited SOCE. In U937 cells, treatment with DMS for 2 h inhibited thapsigargin-induced SOCE by about 70%. DMS inhibited SOCE in a concentration-dependent manner when it was added to the cells after SOCE reached a plateau. DMS-induced SOCE inhibition was also confirmed by the Mn(2+)-quenching method, which monitors only Ca(2+) influx. Because sphingosine kinase inhibitors or protein kinase C (PKC) inhibitors could not mimic the SOCE inhibition, sphingosine kinase and PKC could be excluded as targets of DMS-induced inhibition of SOCE. Furthermore, disruption of lipid rafts with methyl-beta-cyclodextrin and bacterial sphingomyelinase did not influence DMS-induced inhibition of SOCE. DMS-induced inhibition of SOCE in U937 human monocytes is a unique observation and could serve as a basis to study modulation of intracellular Ca(2+) concentration by sphingolipids, although the precise mechanism should be elucidated in the future.     

Muscle sympathetic nerve activity in frontotemporal lobar degeneration is similar to amyotrophic lateral sclerosis

Purpose

To determine whether frontotemporal lobar degeneration (FTLD) is associated with similar cardiovascular autonomic dysfunction to that seen in amyotrophic lateral sclerosis (ALS), we compared cardiovascular parameters between ALS patients and patients with FTLD.

Methods

In ten patients with FTLD (mean age ± SD: 71.6 ± 4.6 years) and 12 patients with ALS (mean age ± SD: 71.4 ± 4.6 years), MSNA (using microneurography), heart rate (HR), and blood pressure (BP) were recorded simultaneously.

Results

MSNA was significantly higher in both groups of patients compared with the controls (p < 0.01), while there were no significant differences in MSNA between the patients with FTLD and those with ALS. During head-up tilt, changes in HR, BP, and the frequency of MSNA bursts were smaller in the patients than in controls (p < 0.05 or p < 0.01).

Conclusions

Patients with FTLD and ALS showed similar dysfunction of HR, BP, and sympathetic outflow to muscles.

     

Changes in sympathetic thermoregulatory function with aging

We recorded skin sympathetic nerve activity (SSNA), SSR, and SVR in 30 subjects. SSNA and SVR showed a slight decrease and spontaneous changes in resting SSR were significantly less frequent in older subjects compared with younger subjects (p < 0.05). There was no significant relationship between age and the reflex latency or amplitude of SSNA, SSR, and SVR in response to electrical stimulation.     

Pouch functional outcomes after restorative proctocolectomy with ileal-pouch reconstruction in patients with ulcerative colitis: Japanese multi-center nationwide cohort study

Journal of Gastroenterology - Although several complications capable of causing pouch failure may develop after restorative proctocolectomy (RPC) for ulcerative colitis (UC), the incidences and...