App-Controller-News.php

<?php

namespace App\Controller;
use App\Model\News;

class News {
	public function test() {
		News::doSomething();
	}
}

App-Model-News.php

<?php

namespace App\Model;

class News {
	public static function doSomething() {
		echo 'Done!';
	}
}

index.php

<?php

set_include_path('App' . PATH_SEPARATOR . get_include_path());

/**
 * Autoloader that implements the PSR-0 spec for interoperability between
 * PHP software.
 */
spl_autoload_register(
	function($className) {
		$fileParts = explode('\\', ltrim($className, '\\'));

		if (strpos(end($fileParts), '_') !== false) {
			array_splice($fileParts, -1, 1, explode('_', current($fileParts)));
		}

		$file = implode(DIRECTORY_SEPARATOR, $fileParts) . '.php';
		foreach (explode(PATH_SEPARATOR, get_include_path()) as $path) {
			if (file_exists($path = $path . DIRECTORY_SEPARATOR . $file)) {
				return require $path;
			}
		}
	}
);


use App\Controller\News;

$controller = new News();
$controller->test();