Brain microvascular endothelial cell-derived exosomes transmitting circ_0000495 promote microglial M1-polarization and endothelial cell injury under hypoxia condition.

Human brain microvascular endothelial cells (HBMVECs) and microglia play critical roles in regulating cerebral homeostasis during ischemic stroke. However, the role of HBMVECs-derived exosomes in microglia polarization after stroke remains unknown. We isolated exosomes (Exos) from oxygen glucose deprivation (OGD)-exposed HBMVECs, before added them into microglia. Microglia polarization markers were tested using RT-qPCR or flow cytometry. Inflammatory cytokines were measured with ELISA. Endothelial cell damage was assessed by cell viability, apoptosis, apoptosis-related proteins, oxidative stress, and angiogenic activity using CCK-8, flow cytometry, western blot, ELISA, and endothelial tube formation assay, respectively. We also established middle cerebral artery occlusion (MCAO) mice model to examine the function of circ_0000495 on stroke in vivo. Our study found that HBMVECs-Exos reduced M2 markers (IL-10, CD163, and CD206), increased M1 markers (TNF-α, IL-1ß, and IL-12), CD86-positive cells, and inflammatory cytokines (TNF-α and IL-1ß), indicating the promotion of microglial M1-polarization. Microglial M1-polarization induced by HBMVECs-Exos reduced viability and promoted apoptosis and oxidative stress, revealing the aggravation of endothelial cell damage. However, circ_0000495 silencing inhibited HBMVECs-Exos-induced alterations. Mechanistically, circ_0000495 adsorbed miR-579-3p to upregulate toll-like receptor 4 (TLR4) in microglia; miR-579-3p suppressed HBMVECs-Exos-induced alterations via declining TLR4; furthermore, Yin Yang 1 (YY1) transcriptionally activated circ_0000495 in HBMVECs. Importantly, circ_0000495 aggravated ischemic brain injury in vivo via activating TLR4/nuclear factor-κB (NF-κB) pathway. Collectively, OGD-treated HBMVECs-Exos transmitted circ_0000495 to regulate miR-579-3p/TLR4/NF-κB axis in microglia, thereby facilitating microglial M1-polarization and endothelial cell damage.

Collectin 11 has a pivotal role in host defense against kidney and bladder infection in mice.

The urinary tract is constantly exposed to microorganisms. Host defense mechanisms in protection from microbial colonization and development of urinary tract infections require better understanding to control kidney infection. Here we report that the lectin collectin 11 (CL-11), particularly kidney produced, has a pivotal role in host defense against uropathogen infection. CL-11 was found in mouse urine under normal and pathological conditions. Mice with global gene ablation of Colec11 had increased susceptibility to and severity of kidney and to an extent, bladder infection. Mice with kidney-specific Colec11 ablation exhibited a similar disease phenotype to that observed in global Colec11 deficient mice, indicating the importance of kidney produced CL-11 for protection against kidney and bladder infection. Conversely, intravesical or systemic administration of recombinant CL-11 reduced susceptibility to and severity of kidney and bladder infection. Mechanism analysis revealed that CL-11 can mediate several key innate defense mechanisms (agglutination, anti- adhesion, opsonophagocytosis), and limit local inflammatory responses to pathogens. Furthermore, CL-11-mediated innate defense mechanisms can act on clinically relevant microorganisms including multiple antibiotic resistant strains. CL-11 was detectable in eight of 24 urine samples from patients with urinary tract infections but not detectable in urine samples from ten healthy individuals. Thus, our findings demonstrate that CL-11 is a key factor of host defense mechanisms in kidney and bladder infection with therapeutic potential for human application.

A new perspective on hippocampal synaptic plasticity and post-stroke depression.

Post-stroke depression, a common complication after stroke, severely affects the recovery and quality of life of patients with stroke. Owing to its complex mechanisms, post-stroke depression treatment remains highly challenging. Hippocampal synaptic plasticity is one of the key factors leading to post-stroke depression; however, the precise molecular mechanisms remain unclear. Numerous studies have found that neurotrophic factors, protein kinases and neurotransmitters influence depressive behaviour by modulating hippocampal synaptic plasticity. This review further elaborates on the role of hippocampal synaptic plasticity in post-stroke depression by summarizing recent research and analysing possible molecular mechanisms. Evidence for the correlation between hippocampal mechanisms and post-stroke depression helps to better understand the pathological process of post-stroke depression and improve its treatment.

Protective role for C3aR in experimental chronic pyelonephritis.

Emerging evidence suggest that C3aR plays important roles in homeostasis, host defense and disease. Although it is known that C3aR is protective in several models of acute bacterial infections, the role for C3aR in chronic infection is largely unknown. Here we show that C3aR is protective in experimental chronic pyelonephritis. Global C3aR deficient (C3ar-/- ) mice had higher renal bacterial load, more pronounced renal histological lesions, increased renal apoptotic cell accumulation, tissue inflammation and extracellular matrix deposition following renal infection with uropathogenic E. coli (UPEC) strain IH11128, compared to WT control mice. Myeloid C3aR deficient (Lyz2-C3ar-/- ) mice exhibited a similar disease phenotype to global C3ar-/- mice. Pharmacological treatment with a C3aR agonist reduced disease severity in experimental chronic pyelonephritis. Furthermore, macrophages of C3ar-/- mice exhibited impaired ability to phagocytose UPEC. Our data clearly demonstrate a protective role for C3aR against experimental chronic pyelonephritis, macrophage C3aR plays a major role in the protection, and C3aR is necessary for phagocytosis of UPEC by macrophages. Our observation that C3aR agonist curtailed the pathology suggests a therapeutic potential for activation of C3aR in chronic infection.

Sequestration of Gßγ by deubiquitinated arrestins into the nucleus as a novel desensitization mechanism of G protein-coupled receptors.

BACKGROUND: Desensitization of G protein-coupled receptors (GPCRs) refers to a rapid attenuation of responsiveness that occurs with repeated or continuous exposure to agonists. GRK-mediated phosphorylation and subsequent binding with arrestins in the activated receptor cytoplasmic cavity in competition with G proteins has been suggested as the conventional mechanism of desensitization. Along with widely accepted conventional mechanism of desensitization, studies of various GPCRs including dopamine D2-like receptors (D2R, D3R, D4R) have suggested the existence of another desensitization mechanism. In this study, loss-of-function approaches and D2-like receptor mutants that display different desensitization properties were used to elucidate the molecular mechanisms responsible for desensitization. RESULTS: Desensitization development entailed the signaling cascade composed of Src, PDK1, and Akt, the latter of which in turn interacted with USP33, an arrestin deubiquitinase, to promote arrestin deubiquitination. The deubiquitinated arrestin subsequently formed a complex with Gßγ and translocated to the nucleus via an importin complex, wherein it sequestered Gßγ from the receptor and Gα, thereby attenuating receptor signaling. As in D2-like receptors, both USP33 and importin ß1 were involved in the desensitization of the ß2 adrenoceptor. CONCLUSIONS: In addition to the conventional mechanism of desensitization, which occurs on the plasma membrane and in the cytosol, this study provides a new insight that another desensitization pathway in which nuclear trafficking plays a critical role is operating. It is plausible that multiple, complementary desensitization measures are in place to properly induce desensitization depending on receptor characteristics or the surrounding environment. Video Abstract.

[Research Progress of High-intensity Interval Training in Cardiac Rehabilitation of Patients with Acute Coronary Syndrome].

Acute coronary syndrome (ACS),with increasing mortality year by year,has become a major public health problem in China.Exercise rehabilitation as an important part of the out-of-hospital rehabilitation for the patients with heart diseases can further reduce the mortality of patients on the basis of drug treatment.The available studies have proved that high-intensity interval training (HIIT) is more effective and efficient than moderate-intensity continuous training (MICT) such as walking and jogging on chronic cardiovascular diseases such as heart failure,stable coronary heart disease,and hypertension and has high security.According to the latest research,HIIT can reduce the platelet response,mitigate myocardial ischemia-reperfusion injury,and increase the exercise compliance of ACS patients more significantly than MICT.Moreover,it does not increase the risk of thrombotic adverse events or malignant arrhythmia.Therefore,HIIT is expected to become an important part of exercise prescription in out-of-hospital cardiac rehabilitation strategy for the patients with ACS.

The tyrosine phosphorylation of GRK2 is responsible for activated D2R-mediated insulin resistance.

Dopamine D2 receptor (D2R) plays a key role in the regulation of glucose homeostasis by stimulating the secretion of many glucoregulatory hormones. Insulin resistance (IR) is associated with the pathogenesis of metabolic disorders which occurs when PI3K/Akt signaling pathway is downregulated. However, the potential involvement of D2R in insulin resistance remains unclear. In the present study, we investigated the regulation of glucose transport by D2-like receptors and discovered that activation of D2R, but not D3R or D4R, suppressed insulin-induced 2-DOG uptake and Glut4 membrane translocation in a GRK2- and Src-dependent manner. Further study revealed that activation of D2R inhibits insulin-induced phosphorylation of Akt at Thr308 and Ser473, which are hallmarks of its kinase activity, by increasing the interaction of tyrosine phosphorylated GRK2 with Akt and then preventing Akt from interacting with PDK1. Thus, this study demonstrates that Src mediated GRK2 tyrosine phosphorylation is an essential physiological event that mediates the roles of D2R in insulin resistance.

Stress conditions induced circRNAs profile of extracellular vesicles in brain microvascular endothelial cells.

Cerebral ischemia causes hypoxic injury and inflammation, and brain microvascular endothelial cells (BMVECs) dysfunction is an initial stage of blood-brain barrier disruption. Endothelial cells secrete extracellular vesicles (EVs) that are involved in intercellular signal transduction. EVs contain a variety of RNAs, proteins, and metabolites. Circular RNA (circRNA) is a member of the non-coding RNA. The expression profile and potential function of circRNAs in BMVECs are unknown. Here, human BMVECs have undergone hypoxia or TNF-α induction, and the changes in circRNAs were measured by RNA sequencing. A total of 70 circRNAs showed differential expression, including 43 previously unrecorded circRNAs and 27 recorded circRNAs. Since astrocyte end-feet encircle endothelial cells, they are considered the main targets of the EVs from BMVEC. The miRNA sequence data and bioinformatics were used to predict the circRNA-miRNA-mRNA networks in astrocytes. The gene ontology (GO) analysis showed the main downstream targets of circRNAs are DNA transcription regulation and protein kinase-related signaling pathways. These results suggest that altering circRNAs may be a potential therapeutic target for cerebral ischemia induced hypoxic injury and inflammation.

Tandem Iridium Catalysis as a General Strategy for Atroposelective Construction of Axially Chiral Styrenes.

Axially chiral styrenes are of great interest since they may serve as a class of novel chiral ligands in asymmetric synthesis. However, only recently have strategies been developed for their enantioselective preparation. Thus, the development of novel and efficient methodologies is highly desirable. Herein, we reported the first tandem iridium catalysis as a general strategy for the synthesis of axially chiral styrenes enabled by Asymmetric Allylic Substitution-Isomerization (AASI) using cinnamyl carbonate analogues as electrophiles and naphthols as nucleophiles. In this approach, axially chiral styrenes were generated through two independent iridium-catalytic cycles: iridium-catalyzed asymmetric allylic substitution and in situ isomerization via stereospecific 1,3-hydride transfer catalyzed by the same iridium catalyst. Both experimental and computational studies demonstrated that the isomerization proceeded by iridium-catalyzed benzylic C-H bond oxidative addition, followed by terminal C-H reductive elimination. Amid the central-to-axial chirality transfer, the hydroxyl of naphthol plays a crucial role in ensuring the stereospecificity by coordinating with the Ir(I) center. The process accommodated broad functional group compatibility. The products were generated in excellent yields with excellent to high enantioselectivities, which could be transformed to various axially chiral molecules.

Broad and dynamic neurochemical alterations in the brain of alcoholic rats.

Ethanol is the active ingredient in alcoholic beverages. As ethanol consumption increases from zero to very high, it is still unknown which metabolites are present at different times and which are essential to normal functioning. In this article, we used an intermittent-access 20% ethanol drinking paradigm to make Wistar male rats voluntarily drink large amounts of ethanol for 10, 20, 30, and 50 days, respectively. A hydrogen-1 nuclear magnetic resonance approach was used to investigate the time-dependent neurochemical metabolites spectra in the hippocampus, striatum, nucleus accumbens and prefrontal cortex. Multivariate pattern recognition techniques were used to analyze the hydrogen-1 nuclear magnetic resonance spectra data. Metabolic profiling was obtained, differentiating the ethanol-treated and control rats. The ethanol-affected metabolites disrupted processes associated with neurotransmitters, oxidative stress, energy metabolism and amino acids. Together, our findings demonstrate broad, dynamic, and time-dependent endogenous metabolic alterations in rats treated with ethanol.

Self-reduction synthesis and luminescence properties of Eu, Dy co-doped SrMg2 (PO4 )2 phosphor.

A series of SrMg2 (PO4 )2 :Eu2+ -Eu3+ ,Dy3+ phosphors was synthesized successfully using a high-temperature solid-state method in an air atmosphere. The structures were studied in detail using X-ray diffraction (XRD) and the luminescence properties of the samples. SrMg2 (PO4 )2 :Eu2+ -Eu3+ samples can emit adjustable blue-violet light by controlling the proportion of dopant concentration of europium and dysprosium under 340 nm excitation. Dy3+ exhibits typical blue and yellow emission under 350 nm excitation. The energy transferred from Eu3+ to Dy3+ in Dy and Eu co-doped system was determined by comparing the fluorescence spectra of single-doped system. In addition, the colour coordinates of the International Commission on lighting (CIE) indicated that SrMg2 (PO4 )2 :Eu2+ -Eu3+ ,Dy3+ could be considered as a potential blue-purple phosphor for white light-emitting diode applications.

In-air self-reduction synthesis and luminescence properties from Mg21 Ca4 Na4 (PO4 )18 :Eu2+ -Eu3+ excited using ultraviolet light.

A series of Mg21 Ca4 Na4 (PO4 )18 :Eu2+ -Eu3+ phosphors was successfully synthesized using a high-temperature solid-state method in an air atmosphere. The phase structures and luminescence properties of the samples were studied in detail. The phosphors exhibited strong visible light emission under different wavelengths of ultraviolet light excitation. By harmonizing the doping concentration of Eu3+ to adjust the relative luminescence intensity of Eu2+ and Eu3+ , a colourful emission of phosphors could be achieved. In addition, the colour coordinates of the International Commission on lighting indicated that Mg21 Ca4 Na4 (PO)18 :Eu2+ -Eu3+ could be considered as a potential blue, orange and red phosphor for white light-emitting diode applications.

Cytoplasmic recruitment of Mdm2 as a common characteristic of G protein-coupled receptors that undergo desensitization.

Desensitization of G protein-coupled receptors (GPCRs) represents a gradual attenuation of receptor responsiveness by continuous or repeated exposure to agonists. The most widely accepted molecular mechanism responsible for desensitization is that of GRK2-mediated receptor phosphorylation followed by association with ß-arrestins. However, in most cases, this mechanism cannot explain the desensitization of GPCRs. In this study, we investigated whether there exists a direct correlation between desensitization and certain cellular events that commonly observed with desensitizing receptors. Our study showed that constitutive ubiquitination of ß-arrestin, accompanied by nuclear to cytoplasmic translocation of Mdm2, was observed in cells expressing desensitizing GPCRs (dopamine D3 receptor, K149C-dopamine D2 receptor, ß2 adrenoceptor, and lysophosphatidic acid receptor 1). In contrast, Mdm2 was observed in the nucleus in cells expressing non-desensitizing GPCRs (dopamine D2 receptor, C147K-dopamine D3 receptor, and dopamine D4 receptor). Molecular manipulation to convert the characteristics of the dopamine D4 receptor from non-desensitizing to desensitizing changed the status of subcellular localization of Mdm2 from nuclear to cytoplasmic. With repeated agonist treatments of desensitizing receptors, Mdm2 translocated from cytoplasm to nucleus, resulting in the deubiquitination of ß-arrestins. This study suggests that the property of a receptor that causes a change in subcellular localization of Mdm2, from the nuclear to cytoplasmic, could be used as a biomarker to predict the desensitization of a receptor.

A novel molecular mechanism responsible for phosphorylation-independent desensitization of G protein-coupled receptors exemplified by the dopamine D3 receptor.

GRK-mediated receptor phosphorylation followed by association with ß-arrestins has been proposed to be the molecular mechanism involved in the desensitization of G protein-coupled receptors (GPCRs). However, this mechanism does not explain the desensitization of some GPCRs, such as dopamine D3 receptor (D3R), which does not undergo GRK-mediated phosphorylation. Loss-of-function approaches and mutants of dopamine D2 receptor and D3R, which exhibit different desensitization properties, were used to identify the cellular components and processes responsible for desensitization. D3R mediated the recruitment of Mdm2 to the cytosol, which resulted in the constitutive ubiquitination of ß-arrestin2 in the resting state. Under desensitization conditions, cytosolic Mdm2 returned to the nucleus, resulting in the deubiquitination of cytosolic ß-arrestins. Deubiquitinated ß-arrestins formed a tight complex with Gßγ, thereby sequestering it, causing interference in D3R signaling. In conclusion, this study shows that ß-arrestins, depending on their ubiquitination status, control the G protein cycling by regulating their interactions with Gßγ. This is a novel mechanism proposed to explain how certain GPCRs can undergo desensitization without receptor phosphorylation.

LncRNA CASC2 Alleviates the Progression of Diabetic Nephropathy by Regulating the miR-144/SOCS2 Signalling Axis.

BACKGROUND: Diabetic nephropathy constitutes a large proportion of end-stage kidney failure in diabetic patients. However, the underlying molecular mechanisms remain unclear. METHODS: Db/db diabetic mouse models and high glucose (HG)-induced human renal mesangial cells (HRMCs) were used as research models in vivo and in vitro. The expression of cancer susceptibility candidate 2 (CASC2) was quantified by qRT-PCR. The regulatory role of CASC2 in cell apoptosis, inflammatory factor release, and fibrosis was verified by flow cytometry, qRT-PCR, and Western blot assay, respectively. The bioinformatics prediction software DIANA and starBase v2.0 were used to predict the putative binding sites. The interactions among CASC2, miR-144, and SOCS2 were explored by the luciferase assay and Western bolt assay. RESULTS: The expression of CASC2 in diabetic mouse models and HG-induced HRMCs was lower than that in the control (p < 0.05). Overexpression of CASC2 resulted in a decrease in the apoptosis rate, inflammatory factor release (TNF-α, IL-6, and IL-1ß), expression of cleaved caspase-3, and fibrotic proteins (fibronectin, Col-IV, and TGF-ß1) and an increase in Bcl-2 expression. Inhibition of CASC2 caused increased expression of miR-144. Furthermore, mechanistic investigations confirmed that activation of the miR-144/SOCS2 regulatory loop by overexpression of miR-144 reversed the in vitro effects of CASC2 on inhibiting cell apoptosis, inflammatory factor release, and fibrosis. In addition, simultaneous overexpression of miR-144 and SOCS2 further increased the inhibition of cell apoptosis, inflammatory factor release, and fibrosis by CASC2. CONCLUSION: CASC2 could alleviate the degree and process of apoptosis, inflammation, and fibrosis in diabetic nephropathic models by regulating the miR-144/SOCS2 axis.

[Yijing Prescription regulates the PI3K/Akt/mTOR signaling pathway and autophagy and inhibits the apoptosis of Leydig cells: An experimental study in vitro].

OBJECTIVE: To explore the mechanism of Yijing Prescription (YJP) improving sperm quality in oligozoospermia patients. METHODS: Mouse Leydig (TM3) cells were divided into five groups: normal control, acrolein-induced oxidative stress (ACR) model control, and low-, medium- and high-dose YJP. The ACR model was established in the latter four groups with 100 µmol/L acrolein, and the TM3 cells in the latter three groups were treated with the serum containing 5%, 10% and 20% YJP, respectively. After modeling, the viability of the cells and the contents of MDA, T-AOC and SOD were determined by CCK-8, and the relative expressions of PI3K/Akt/mTOR, Beclin-1, Bcl-2 and LC3-II detected by real-time PCR and Western blot. The results obtained were analyzed and compared among different groups. RESULTS: Compared with the normal control cells, the TM3 cells in the ACR model control group showed a dramatically inhibited survival rate (54%), increased content of MDA, decreased levels of T-AOC and SOD (P < 0.01), down-regulated expressions of p-PI3K/p-Akt protein (P < 0.01), and Bcl-2 protein (P < 0.05) and Bcl-2 mRNA (P < 0.01), and up-regulated mRNA and protein expressions of Beclin-1 and LC3II (P < 0.01). After administration of YJP, all the above-mentioned parameters were reversed in different degrees and improved in a dose-dependent manner. CONCLUSIONS: Yijing Prescription acts against oxidative stress, mediates the regulation of the PI3K/Akt/mTOR signaling pathway and autophagy and inhibition of the apoptosis of Leydig cells, and thus improves the sperm quality of oligozoospermia patients.

Design, synthesis, and systematic evaluation of 4-arylpiperazine- and 4-benzylpiperidine napthyl ethers as inhibitors of monoamine neurotransmitters reuptake.

Two series of 4-arylpiperazine- and 4-benzylpiperidine naphthyl ethers were designed based on structure-activity relationship (SAR) and docking model of reported monoamine neurotransmitters reuptake inhibitors. The compounds were synthesized in 3-simple steps and their biological activities were evaluated. Several compounds were proven to be potent inhibitors of serotonin and norepinephrine reuptake. Computer docking was performed to study the interaction of the most potent compound 35 with human serotonin transporter. The results of the analyses suggest that 4-arylpiperazine- and 4-benzylpiperidine naphthyl ethers might be promising antidepressants worthy of further studies.

[Effectiveness of Extracorporeal Shockwave Therapy in Treating Superior Lateral Brachial Cutaneous Nerve Compression Syndrome].

Objective To evaluate the effectiveness of radial extracorporeal shockwave therapy(rESWT) for the treatment of superior lateral brachial cutaneous nerve(SLBCN) compression syndrome.Methods A total of 40 patients with SLBCN compression syndrome who were treated in our department from March 2013 to October 2015 were equally randomized into two groups according to random number table:rESWT group(treated with rESWT for 1 cycle) and control group(treated with local hormone injection for 1 cycle). Visual analogue scale(VAS) and Constant-Murley scale(CMS) were applied to evaluate the shoulder joint function before treatment and 1 month and 1 year after treatment. Results The average CMS scores were(66.7±0.9) and(65.7±1.1)scores in rESWT group and control group,respectively,before treatment(t=0.67,P=0.510) and were(86.9±1.0) and(86.4±1.1)scores one month after treatment(t=0.35,P=0.730);it increased to(89.7±0.7) scores in rESWT group one year later,which was significantly higher than that in control group[(85.3±0.8)scores](t=3.56,P=0.002). The improvement rate was 95% in rESWT group and only 75% in control group. Before treatment,the median VAS score in rESWT group and control group were 5.00(5.00,6.00) and 5.00(4.00,5.75)scores(u=1.13,P=0.29);one month after treatment,the median VAS score in these two groups were 2(1.00,2.75) and 2.00(1.00,2.00)scores(u=0.04,P=0.85);one year later,it was 1.00(0.00,1.00) scores in rESWT group,significantly lower than that in [2.00(1.00,2.00)scores] control group(u=5.09,P=0.02). Conclusion Compared with local hormone injection,rESWT can remarkably alleviate pain and restore shoulder joint function in patients with SLBCN compression syndrome after one year of treatment.

Triple reuptake inhibitors: Design, synthesis and structure-activity relationship of benzylpiperidine-tetrazoles.

Monoamine transporters are important targets in the treatment of various central nervous disorders. Several limitations of traditional reuptake inhibitors, like delayed onset of action, insomnia, and sexual dysfunction, have compelled the search for safer, more effective compounds. In this study, we have sought to identify novel monoamine reuptake inhibitors. Based upon the docking study of compounds that we had reported previously, aromatic rings (A1) were modified to generate a novel series of benzylpiperidine-tetrazoles. Thirty-one compounds were synthesized and evaluated for their triple reuptake inhibition of serotonin, norepinephrine and dopamine. Triple reuptake inhibitor, compound 2q, in particular, showed potent serotonin reuptake inhibition, validating our design approach.

Insights into water-mediated ion clustering in aqueous CaSO4 solutions: pre-nucleation cluster characteristics studied by ab initio calculations and molecular dynamics simulations.

The molecular structure of growth units building crystals is a fundamental issue in the crystallization processes from aqueous solutions. In this work, a systematic investigation of pre-nucleation clusters and their hydration characteristics in aqueous CaSO4 solutions was performed using ab initio calculations and molecular dynamics (MD) simulations. The results of ab initio calculations and MD simulations indicate that the dominant species in aqueous CaSO4 solutions are monodentate ion-associated structures. Compared with charged ion clusters, neutral clusters are more likely to be present in an aqueous CaSO4 solution. Neutral (CaSO4)m clusters are probably the growth units involved in the pre-nucleation or crystallization processes. Meanwhile, hydration behavior around ion associated species in aqueous CaSO4 solutions plays an important role in related phase/polymorphism selections. Upon ion clustering, the residence of some water molecules around Ca2+ in ion-associated species is weakened while that of some bridging waters is enhanced due to dual interaction by Ca2+ and SO42-. Some phase/polymorphism selections can be achieved in aqueous CaSO4 solutions by controlling the hydration around pre-nucleation clusters. Moreover, the association trend between calcium and sulfate is found to be relatively strong, which hints at the low solubility of calcium sulfate in water.