Deletion of Krüppel-like factor-4 promotes axonal regeneration in mammals.

Axonal regeneration plays an important role in functional recovery after nervous system damage. However, after axonal injury in mammals, regeneration is often poor. The deletion of Krüppel-like factor-4 (Klf4) has been shown to promote axonal regeneration in retinal ganglion cells. However, the effects of Klf4 deletion on the corticospinal tract and peripheral nervous system are unknown. In this study, using a mouse model of sciatic nerve injury, we show that the expression of Klf4 in dorsal root ganglion sensory neurons was significantly reduced after peripheral axotomy, suggesting that the regeneration of the sciatic nerve is associated with Klf4. In vitro, dorsal root ganglion sensory neurons with Klf4 knockout exhibited significantly enhanced axonal regeneration. Furthermore, the regeneration of the sciatic nerve was enhanced in vivo following Klf4 knockout. Finally, AAV-Cre virus was used to knockout the Klf4 gene in the cortex. The deletion of Klf4 enhanced regeneration of the corticospinal tract in mice with spinal cord injury. Together, our findings suggest that regulating KLF4 activity in neurons is a potential strategy for promoting axonal regeneration and functional recovery after nervous system injury. This study was approved by the Animal Ethics Committee at Soochow University, China (approval No. SUDA20200316A01).

Clinicopathological study of mixed cryoglobulinemic glomerulonephritis secondary to hepatitis B virus infection.

BACKGROUND: Cryoglobulinemic glomerulonephritis (CryoGn) caused by hepatitis B virus (HBV) infection was rarely reported. Our study aimed to investigate the clinical features, renal pathology findings, and prognosis in patients with HBV related CryoGn. METHODS: This was a retrospective study including seven Chinese patients with HBV related CryoGn in a tertiary referral hospital from April 2016 to March 2019. The clinical and pathological data were collected and analyzed. RESULTS: Age at renal biopsy was 47 ± 12 years, with female/male ratio 3/4. Urine protein was 5.6 (3.0, 6.6) g/d and five cases presented with nephrotic syndrome. The baseline eGFR was 23.5 (20.2, 46.3) ml/min per 1.73m2. The extrarenal manifestations included purpura (n = 6), arthralgia (n = 1), peripheral neuropathy (n = 1), and cardiomyopathy (n = 1). Six cases had type II cryoglobulinemia with IgMκ, the other one had type III. The median cryocrit was 4.0 (1.0, 15.0) %. Renal pathologic findings on light microscopy: endocapillary proliferative glomerulonephritis (Gn) (n = 3), membranoproliferative Gn (n = 3), and mesangial proliferative Gn (n = 1). On immunofluorescence microscopy, the predominant type of immunoglobulin deposits was IgM (n = 5). HBsAg and HBcAg deposits were found in one case. Ultrastructural studies showed granular subendothelial and mesangial electron-dense deposits in all patients and microtubules in one case. All patients received antiviral medications. They were given corticosteroid alone (n = 2) or combined with cyclophosphamide (n = 4) or mycophenolate mofetil (n = 1). Two patients received plasmapheresis. The median follow-up time was 18 (6, 37) months. Four patients got remission, two patients died of pneumonia, and one progressed to end-stage renal disease (ESRD). At endpoint of follow-up, 24hUP was 2.1 (0.8-5.2) g/d, and eGFR was 55.3 (20.7, 111.8) ml/min per 1.73m2. The median cryocrit decreased to 1.0 (0, 5.75) %. CONCLUSIONS: The etiology of mixed CryoGn should be screened for HBV infection. Endocapillary proliferative Gn and membranoproliferative Gn were the common pathologic patterns. Diagnosis and treatment in early stage benefit patients' renal outcomes. Immunosuppressive therapy should be considered for severe renal disease, based on efficient antiviral therapy.

c-Myc controls the fate of neural progenitor cells during cerebral cortex development.

The anatomical structure of the mammalian cerebral cortex is the essential foundation for its complex neural activity. This structure is developed by proliferation, differentiation, and migration of neural progenitor cells (NPCs), the fate of which is spatially and temporally regulated by the proper gene. This study was used in utero electroporation and found that the well-known oncogene c-Myc mainly promoted NPCs' proliferation and their transformation into intermediate precursor cells. Furthermore, the obtained results also showed that c-Myc blocked the differentiation of NPCs to postmitotic neurons, and the expression of telomere reverse transcriptase was controlled by c-Myc in the neocortex. These findings indicated c-Myc as a key regulator of the fate of NPCs during the development of the cerebral cortex.

Regulation of adult mammalian intrinsic axonal regeneration by NF-κB/STAT3 signaling cascade.

The inflammatory response is a critical regulator for the regeneration of axon following nervous system injury. Nuclear factor-kappa B (NF-κB) is characteristically known for its ubiquitous role in the inflammatory response. However, its functional role in adult mammalian axon growth remains elusive. Here, we found that the NF-κB signaling pathway is activated in adult sensory neurons through peripheral axotomy. Furthermore, inhibition of NF-κB in peripheral sensory neurons attenuated their axon growth in vitro and in vivo. Our results also showed that NF-κB modulated axon growth by repressing the phosphorylation of STAT3. Furthermore, activation of STAT3 significantly promoted adult optic nerve regeneration. Taken together, the findings of our study indicated that NF-κB/STAT3 cascade is a critical regulator of intrinsic axon growth capability in the adult nervous system.

Calcium/calmodulin-dependent protein kinase II regulates mammalian axon growth by affecting F-actin length in growth cone.

While axon regeneration is a key determinant of functional recovery of the nervous system after injury, it is often poor in the mature nervous system. Influx of extracellular calcium (Ca2+ ) is one of the first phenomena that occur following axonal injury, and calcium/calmodulin-dependent protein kinase II (CaMKII), a target substrate for calcium ions, regulates the status of cytoskeletal proteins such as F-actin. Herein, we found that peripheral axotomy activates CaMKII in dorsal root ganglion (DRG) sensory neurons, and inhibition of CaMKII impairs axon outgrowth in both the peripheral and central nervous systems (PNS and CNS, respectively). Most importantly, we also found that the activation of CaMKII promotes PNS and CNS axon growth, and regulatory effects of CaMKII on axon growth occur via affecting the length of the F-actin. Thus, we believe our findings provide clear evidence that CaMKII is a critical modulator of mammalian axon regeneration.

High prevalence of coexisting prehypertension and prediabetes among healthy adults in northern and northeastern China.

BACKGROUND: Prehypertension and prediabetes are major risk factors of cardiovascular disease, and their combined presence may result in more serious cardiovascular outcomes than expected with either prehypertension or prediabetes alone. The aim of the present study was to evaluate the prevalence of coexisting prehypertension and prediabetes, and the associated risk profiles in a Chinese population. METHODS: A cross-sectional survey in a representative sample of 3,595 men and 4,593 women aged 18 years and older was performed between 2008 and 2010. Prehypertension and prediabetes were diagnosed using the guidelines from the Seventh Report of the Joint National Committee on prevention, detection, and treatment of high blood pressure and American Diabetes Association, respectively. Prehypertension was defined as a systolic blood pressure of 120-139 mmHg and/or diastolic blood pressure of 80-89 mmHg, and prediabetes was defined as a fasting blood glucose of 5.6-6.9 mmol/L. RESULTS: The prevalence of coexisting prehypertension and prediabetes was 11.0%. Men had a higher prevalence of coexisting prehypertension and prediabetes than women (14.2% vs. 8.4%; P < 0.0001). This prevalence increased with age and body mass index, and was the lowest among Mongolian-Chinese (5.1%). A multivariate analysis showed that γ-glutamyltransferase and uric acid were significantly and positively correlated with body mass index, waist circumference, blood pressure, triglycerides, and total cholesterol, and negatively correlated with high density lipoprotein cholesterol in subjects with prehypertension and prediabetes. CONCLUSIONS: There is a large proportion of Chinese adults with coexisting prehypertension and prediabetes. Thus, there is a need for more efforts that implement public health programs that target the earlier stages of hypertension and diabetes.