Curcumin relieved cisplatin-induced kidney inflammation through inhibiting Mincle-maintained M1 macrophage phenotype.

BACKGROUND: Acute kidney injury (AKI) is a common kidney disease with a high risk of death and can develop into chronic kidney disease (CKD) and renal failure eventually. Curcumin, an herbal supplement, has been reported exhibiting a renoprotective role in AKI. However, the underlying mechanism is largely unclear. PURPOSE: Recent research showed that Mincle (Macrophage-inducible C-type lectin) maintained M1 macrophage polarization, which plays a key role in kidney injury of AKI through up-regulating the expression and secretion of inflammatory cytokines. Here, we investigated the effects of Curcumin on Mincle expression and macrophage polarization in vitro using lipopolysaccharide (LPS) induced macrophage inflammatory cell model and in vivo using a cisplatin induced murine AKI (cis-AKI) model. METHODS: Cell activation, inflammatory cytokines expression and secretion, protein levels, macrophage polarization and renal pathology were analyzed. RESULTS: Our results showed that Curcumin markedly reduced the mRNA expression and secretion of IL-1ß, IL-6, TNFα and MCP-1 in LPS stimulated RAW264.7 cell and the supernatant. The same results were found in Curcumin treated cis-AKI kidney and blood. The data also demonstrated that Curcumin remarkably down-regulated mRNA expression and protein level of Mincle in cis-AKI kidney and also reduced expression of iNOS (M1 macrophage marker) as well as inhibited the activation of Syk and NF-kB. Interestingly, although Mincle deletion in RAW264.7 cell largely decreased the LPS-induced protein level of iNOS, Curcumin cannot further reduce expression of iNOS without Mincle, indicating that Curcumin inhibits M1 macrophage with a Mincle-dependent pattern. Furthermore, flow cytometry results showed that Curcumin significantly decreased the iNOS positive macrophages and increased the CD206 (M2 macrophage marker) positive macrophages in vivo and in vitro. CONCLUSION: Our findings prove that Curcumin protects kidney from cisplatin induced AKI through inhibiting Mincle maintained M1 macrophage phenotype, that may provide a specific renoprotection mechanism for Curcumin to develop it as a new therapeutic candidate for AKI.

Encapsulated Conjugated Oligomer Nanoparticles for Real-Time Photoacoustic Sentinel Lymph Node Imaging and Targeted Photothermal Therapy.

Noninvasive and nonionizing imaging of sentinel lymph nodes (SLN) is highly desirable for the detection of breast cancer metastasis through sentinel lymph node biopsy. Photoacoustic (PA) imaging is an emerging imaging technique that can serve as a suitable approach for SLN imaging. Herein, novel conjugated oligomer based nanoparticles (NPs) with strong NIR absorption, good biocompatibility, excellent PA contrast, and good photothermal conversion efficiency are reported. Real-time PA imaging of SLN reveals high resolution of the NPs via injection from the left forepaw pad. In addition, the surface functionalized NPs can target breast cancer cells and kill them efficiently and specifically through photothermal therapy upon 808 nm laser irradiation. This work shows great potential of the nanoparticle PA contrast agent to serve as a multifunctional probe for photothermal therapy at SLNs to achieve the inhibition of cancer cell metastasis in the near future.

Ginsenoside Rg1 reduces aldosterone-induced autophagy via the AMPK/mTOR pathway in NRK-52E cells.

Aldosterone is a steroid hormone secreted from the adrenal cortex, which regulates blood pressure. Higher concentrations of aldosterone can cause several diseases, including hypertension, diabetic nephropathy and chronic kidney disease. Previous reports have demonstrated that aldosterone has a pathogenic role in renal injury via reactive oxygen species (ROS), which involves the regulation of autophagy. However, whether aldosterone can induce autophagy in renal tubular cells remains to be elucidated. In the present study, elevated autophagy was observed in rat renal tubular NRK-52E cells exposed to aldosterone, which was demonstrated by the increased number of autophagosomes, conversion of LC3-I to LC3-II and the expression of Beclin-1. The enhanced autophagy was accompanied by increased production of intracellular ROS, which was reversed by N-acetylcysteine, a specific inhibitor of ROS signaling. Furthermore, treatment with ginsenoside Rg1 reduced the aldosterone-induced autophagy and production of ROS, possibly through reducing the phosphorylation of AMPK and preserving mTOR activity. These findings demonstrated that aldosterone promoted ROS generation and increased autophagy in the NRK-52E cells. Ginsenoside Rg1 effectively relieved aldosterone-induced oxidative stress and abnormal autophagy, suggesting that Rg1 may be used as a potential therapeutic drug to inhibit the renal injury, which is induced by aldosterone.

Rescue of cortical neurovascular functions during the hyperacute phase of ischemia by peripheral sensory stimulation.

To investigate the potential therapeutic effects of peripheral sensory stimulation during the hyperacute phase of stroke, the present study utilized electrophysiology and photoacoustic imaging techniques to evaluate neural and vascular responses of the rat cortex following ischemic insult. We employed a rat model of photothrombotic ischemia (PTI), which targeted the forelimb region of the primary somatosensory cortex (S1FL), due to its high reproducibility in creating localized ischemic injury. We also established a hybrid, dual-modality system, including six-channel electrocorticography (ECoG) and functional photoacoustic microscopy (fPAM), termed ECoG-fPAM, to image brain functional responses to peripheral sensory stimulation during the hyperacute phase of PTI. Our results showed that the evoked cerebral blood volume (CBV) and hemoglobin oxygen saturation (SO2) recovered to 84±7.4% and 79±6.2% of the baseline, respectively, when stimulation was delivered within 2.5 h following PTI induction. Moreover, neural activity significantly recovered, with 77±8.6%, 76±5.3% and 89±8.2% recovery for the resting-state inter-hemispheric coherence, alpha-to-delta ratio (ADR) and somatosensory evoked potential (SSEP), respectively. Additionally, we integrated the CBV or SO2 with ADR values as a recovery indicator (RI) to assess functional recovery after PTI. The RI indicated that 80±4.2% of neurovascular function was preserved when stimulation was delivered within 2.5h. Additionally, stimulation treatment within this optimal time window resulted in a minimal infarct volume in the ischemic hemisphere (4.6±2.1%). In contrast, the infarct volume comprised 13.7±1.7% of the ischemic hemisphere when no stimulation treatment was applied.

Expression of Pkd2l2 in testis is implicated in spermatogenesis.

Pkd2l2 is a novel member of the polycystic kidney disease (PKD) gene family in mammals. Prominently expressed in testis, this gene is still poorly understood. In this study, reverse transcription polymerase chain reaction (RT-PCR) results showed a time-dependent expression pattern of Pkd2l2 in postnatal mouse testis. Immunohistochemical analysis revealed that Pkd2l2 encoded a protein, polycystin-L2, which was predominantly detectable in the plasma membrane of spermatocytes and round spermatids, as well as in the head and tail of elongating spermatids within seminiferous tubules in mouse testis tissue sections of postnatal day 14 and adult mice. A green fluorescent fusion protein of Pkd2l2 resided in the plasma membrane of HEK 293 and MDCK cells, suggesting that it functions as a plasma membrane protein. Overexpression of Pkd2l2 increased the intracellular calcium concentration of MDCK cells, as detected by flow cytometry. Collectively, these data indicated that Pkd2l2 may be involved in the mid-late stage of spermatogenesis through modulation of the intracellular calcium concentration.