Comparison of short interval and low dose (SILD) with high dose of cyclophosphamide in the susceptibility to infection in SLE: a multicentrereal-world study.

OBJECTIVE: Infection is a major cause of death in patients with SLE. This study aimed to explore the infection rate in patients with SLE receiving a low dose of intravenous cyclophosphamide (IV-CYC). METHODS: Clinical parameters of 1022 patients with SLE from 24 hospitals in China were collected. Patients were divided into the short-interval and lower-dose (SILD, 400 mg every 2 weeks) IV-CYC group and the high-dose (HD, 500 mg/m2 of body surface area every month) IV-CYC group. The clinical data and infection rate between the two groups were compared. RESULTS: Compared with HD IV-CYC, the infection rate of the SILD IV-CYC group was significantly lower (13.04% vs 22.27%, p=0.001). Respiratory tract infection (10.28% vs 15.23%, p=0.046) and skin/soft tissue infection (1.78% vs 4.3%, p=0.040) were significantly decreased in the SILD IV-CYC group. Moreover, infections occurred most likely in patients with SLE with leucopenia (OR 2.266, 95% CI 1.322 to 3.887, p=0.003), pulmonary arterial hypertension (OR 2.756, 95% CI 1.249 to 6.080, p=0.012) and >15 mg/day of glucocorticoid (OR 2.220, 95% CI 1.097 to 4.489, p=0.027). CONCLUSIONS: SILD IV-CYC showed a lower frequency of infection events than high-dose IV-CYC in patients with SLE.

Cocaine increases quantal norepinephrine secretion through NET-dependent PKC activation in locus coeruleus neurons.

The norepinephrine neurons in locus coeruleus (LC-NE neurons) are essential for sleep arousal, pain sensation, and cocaine addiction. According to previous studies, cocaine increases NE overflow (the profile of extracellular NE level in response to stimulation) by blocking the NE reuptake. NE overflow is determined by NE release via exocytosis and reuptake through NE transporter (NET). However, whether cocaine directly affects vesicular NE release has not been directly tested. By recording quantal NE release from LC-NE neurons, we report that cocaine directly increases the frequency of quantal NE release through regulation of NET and downstream protein kinase C (PKC) signaling, and this facilitation of NE release modulates the activity of LC-NE neurons and cocaine-induced stimulant behavior. Thus, these findings expand the repertoire of mechanisms underlying the effects of cocaine on NE (pro-release and anti-reuptake), demonstrate NET as a release enhancer in LC-NE neurons, and provide potential sites for treatment of cocaine addiction.

Association between P-Selectin Autoantibody Positive and Response to Steroid Treatment in Newly Diagnosed Immune Thrombocytopenia Patients.

OBJECTIVE: This study aimed to detect the association between P-selectin autoantibody positive and response to steroid treatment in newly diagnosed immune thrombocytopenia (ITP) patients. METHODS: The data from 105 newly diagnosed adult ITP patients administered with first-line of steroid treatment from October 2016 to May 2021 were retrospectively analyzed. Treatment responses were evaluated within 3 months after the onset of treatment. RESULTS: Among the 105 patients, 80.00% (84/105) of patients presented with platelet glycoprotein-specific antibody positive; 44.76% (47/105) patients were anti-P-selectin positive, while 35.24% (37/105) were anti-P-selectin negative. No significant difference in overall response was observed between patients who were anti-P-selectin positive and those who were anti-P-selectin negative (74.47% vs. 89.19, χ2 = 2.910, p = 0.088). But patients who were anti-P-selectin negative had significantly higher complete response rate, compared to those who were anti-P-selectin positive (72.97% vs. 48.94%, χ2 = 4,965, p = 0.026). Logistic regression analysis revealed that anti-GP IIb/IIIa positive (OR = 3.114, p = 0.010, 95% CI: 1.313-7.388) and anti-P-selectin positive (OR = 0.309, p = 0.036, 95% CI: 0.127-0.753) were two factors that could affect patients' response. CONCLUSIONS: Our study found that ITP patients with anti-GP IIb/IIIa may have a higher response to steroid treatment, but anti-P-selectin-mediated-ITP might be less responsive to steroid treatment. In adults with ITP, the presence of anti-P-selectin autoantibodies is a predictive factor for poor response to steroid treatment.

A method for recording the two phases of dopamine release in mammalian brain striatum slices.

Striatal dopamine (DA) release plays an essential role in many physiological functions including motor and non-motor behaviors (such as reward, motivation, and cognition). We have previously reported that, following a single electrical field stimulation, the amperometric recording of DA release from presynaptic terminals in striatal slices (both ventral and dorsal) contains two temporally separated phases. The first phase (direct DA transmission, direct DT) arises from DA terminal release following autologous action potentials (APs), while the second phase (cholinergic transmission-induced DA transmission, CTDT) arises from delayed DA release triggered by the activation of cholinergic interneurons to DA terminals (axon-axon transmission). The millisecond time-resolution of amperometry permits separation of an ∼7 ms latency difference from the single synapse (axon-axon) within the two-phase DA-release (2pDA) signal, and thus the 2pDA signal provides a novel method to study either direct DT, or CTDT, or both. Here, we describe the 2pDA method, including signal recording, processing, analysis, and troubleshooting (anti-artifact). Compared with other DA assays using different stimuli, recording methods, and preparations (such as high performance liquid chromatography or fast scan cyclic voltammetry), 2pDA recording is a novel and powerful physiological recording method for the study of DA transmissions in situ.

Synaptotagmin-11 is a critical mediator of parkin-linked neurotoxicity and Parkinson's disease-like pathology.

Loss-of-function mutations in Parkin are the most common causes of autosomal recessive Parkinson's disease (PD). Many putative substrates of parkin have been reported; their pathogenic roles, however, remain obscure due to poor characterization, particularly in vivo. Here, we show that synaptotagmin-11, encoded by a PD-risk gene SYT11, is a physiological substrate of parkin and plays critical roles in mediating parkin-linked neurotoxicity. Unilateral overexpression of full-length, but not C2B-truncated, synaptotagmin-11 in the substantia nigra pars compacta (SNpc) impairs ipsilateral striatal dopamine release, causes late-onset degeneration of dopaminergic neurons, and induces progressive contralateral motor abnormalities. Mechanistically, synaptotagmin-11 impairs vesicle pool replenishment and thus dopamine release by inhibiting endocytosis. Furthermore, parkin deficiency induces synaptotagmin-11 accumulation and PD-like neurotoxicity in mouse models, which is reversed by SYT11 knockdown in the SNpc or knockout of SYT11 restricted to dopaminergic neurons. Thus, PD-like neurotoxicity induced by parkin dysfunction requires synaptotagmin-11 accumulation in SNpc dopaminergic neurons.

Temporal components of cholinergic terminal to dopaminergic terminal transmission in dorsal striatum slices of mice.

Striatal dopamine (DA) is critically involved in major brain functions such as motor control and deficits such as Parkinson's disease. DA is released following stimulation by two pathways: the nigrostriatal pathway and the cholinergic interneuron (ChI) pathway. The timing of synaptic transmission is critical in striatal circuits, because millisecond latency changes can reverse synaptic plasticity from long-term potentiation to long-term depression in a DA-dependent manner. Here, we determined the temporal components of ChI-driven DA release in striatal slices from optogenetic ChAT-ChR2-EYFP mice. After a light stimulus at room temperature, ChIs fired an action potential with a delay of 2.8 ms. The subsequent DA release mediated by nicotinic acetylcholine (ACh) receptors had a total latency of 17.8 ms, comprising 7.0 ms for cholinergic transmission and 10.8 ms for the downstream terminal DA release. Similar latencies of DA release were also found in striatal slices from wild-type mice. The latency of ChI-driven DA release was regulated by inhibiting the presynaptic vesicular ACh release. Moreover, we describe the time course of recovery of DA release via the two pathways and that of vesicle replenishment in DA terminals. Our work provides an example of unravelling the temporal building blocks during fundamental synaptic terminal-terminal transmission in motor regulation.

Modulation of dopamine release in the striatum by physiologically relevant levels of nicotine.

Striatal dopamine (DA) release can be independently triggered not only by action potentials (APs) in dopaminergic axons but also APs in cholinergic interneurons (ChIs). Nicotine causes addiction by modulating DA release, but with paradoxical findings. Here, we investigate how physiologically relevant levels of nicotine modulate striatal DA release. The optogenetic stimulation of ChIs elicits DA release, which is potently inhibited by nicotine with an IC50 of 28 nM in the dorsal striatum slice. This ChI-driven DA release is predominantly mediated by α6ß2* nAChRs. Local electrical stimulus (Estim) activates both dopaminergic axons and ChIs. Nicotine does not affect the AP(DA)-dependent DA release (AP(DA), AP of dopaminergic axon). During burst Estim, nicotine permits the facilitation of DA release by prevention of DA depletion. Our work indicates that cholinergic stimulation-induced DA release is profoundly modulated by physiologically relevant levels of nicotine and resolves the paradoxical observation of nicotine's effects on striatal DA release.